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Brian Paul	bb21846	2003-03-22 18:35:53 +0000	[diff] [blame]	1	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
				2	<html>
				3	<head>
				4	<title>Mini GLX Specification</title>
				5	</head>
				6	<body>
				7	<span style="font-style: italic;"></span><span
				8	style="font-weight: bold;"></span>
				9	<h1>
				10	<center>Mesa Subset Specification</center>
				11	</h1>
				12	<h2>
				13	<center>
				14	<h3>Tungsten Graphics, Inc.</h3>
				15	<h3>February 26, 2003<br>
				16	</h3>
				17	</center>
				18	</h2>
				19	<p> Copyright © 2002-2003 by <a
				20	href="http://www.tungstengraphics.com/">Tungsten Graphics, Inc.</a>,
				21	Cedar Park, Texas. All Rights Reserved. <br>
				22	<br>
				23	Permission is granted to make and distribute verbatim copies of this
				24	document provided the copyright notice and this permission notice are
				25	preserved on all copies.<br>
				26	</p>
				27	<p> OpenGL is a trademark of <a href="http://www.sgi.com">Silicon
				28	Graphics, Inc.</a>.</p>
				29	<h1>1. Introduction</h1>
				30	This document describes a subset of the Mesa implemented by Tungsten
				31	Graphics, Inc. for embedded devices.  Prior to reading this
				32	document the reader should be familiar with the OpenGL 1.2.1
				33	specification dated April 1, 1999 (available from <a
				34	href="http://www.opengl.org/developers/documentation/specs.html">http://www.opengl.org/developers/documentation/specs.html</a>.)
				35	Experience with OpenGL programming is highly advisable.<a
				36	href="http://www.opengl.org/developers/documentation/specs.html"><br>
				37	</a><br>
				38	Tungsten Graphics, Inc. is working with industry standards
				39	organizations +in an attempt to standardize this Mesa subset and any
				40	other possible subsets +as a result of this work. <br>
				41	<br>
				42	Appendix A contains a list of issues of which some may not be resolved.<br>
				43	<br>
				44	To summarize, the following major features of Mesa are omitted from the
				45	subset:<br>
				46	<ul>
				47	<li>Vertex arrays</li>
				48	<li>Texture coordinate generation</li>
				49	<li>Lighting</li>
				50	<li>Point size</li>
				51	<li>Polygon stipple</li>
				52	<li>DrawPixels, CopyPixels, PixelZoom</li>
				53	<li>1-D and 3-D textures</li>
				54	<li>CopyTex[Sub]Image</li>
				55	<li>Fog</li>
				56	<li>Depth test</li>
				57	<li>Color Index mode</li>
				58	<li>Accumulation buffer</li>
				59	<li>Feedback mode</li>
				60	<li>Evaluators</li>
				61	<li>Push/Pop attributes</li>
				62	<li>Display lists<br>
				63	</li>
				64	</ul>
				65	<p>Further reductions are made at a lower level of detail.<br>
				66	</p>
				67	<p>Mesa function names are printed in <span style="font-weight: bold;">bold
				68	face</span>.  Function parameters are printed in <span
				69	style="font-style: italic;">italics</span>.<br>
				70	</p>
				71	<p>The Tungsten Graphics, Inc. Mesa subset library is hereafter
				72	referred to as <span style="font-style: italic;">the subset.</span><br>
				73	<br>
				74	</p>
				75	<h1>2. Primitive Specification</h1>
				76	<h2>2.1 glBegin, glEnd and glVertex Commands</h2>
				77	The basic rendering primitives are points, lines and triangles.
				78	Quadrilaterals and polygons are composed of triangles.
				79	Primitives are drawn with the <span style="font-weight: bold;">glBegin</span>
				80	and <span style="font-weight: bold;">glEnd</span> commands and a subset
				81	of the <span style="font-weight: bold;">glVertex</span> commands:<br>
				82	<br>
				83	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glBegin</span>(GLenum<span
				84	style="font-style: italic;">mode</span>)<br>
				85	void <span style="font-weight: bold;">glEnd</span>(void)<br>
				86	<br>
				87	void <span style="font-weight: bold;">glVertex2f</span>(GLfloat <span
				88	style="font-style: italic;">x</span>, GLfloat <span
				89	style="font-style: italic;">y</span>)<br>
				90	void <span style="font-weight: bold;">glVertex2fv</span>(const GLfloat
				91	*<span style="font-style: italic;">v</span>)<br>
				92	void <span style="font-weight: bold;">glVertex3f</span>(GLfloat <span
				93	style="font-style: italic;">x</span>, GLfloat <span
				94	style="font-style: italic;">y</span>, GLfloat <span
				95	style="font-style: italic;">z</span>)<br>
				96	void <span style="font-weight: bold;">glVertex3fv</span>(const GLfloat
				97	*<span style="font-style: italic;">v</span>)<br>
				98	</div>
				99	<br>
				100	The <span style="font-style: italic;">mode</span> parameter to <span
				101	style="font-weight: bold;">glBegin</span> may be one of the following<br>
				102	<br>
				103	<div style="margin-left: 40px;">GL_POINTS - a series of individual
				104	points<br>
				105	GL_LINES - a series of disjoint line segments<br>
				106	GL_LINE_STRIP - series of connected line segments<br>
				107	GL_LINE_LOOP - a closed loop of line segments<br>
				108	GL_TRIANGLES - a series of individual triangles<br>
				109	GL_TRIANGLE_STRIP - a connected strip of triangles<br>
				110	GL_TRIANGLE_FAN - a sequence of triangles all sharing a common vertex<br>
				111	GL_QUADS - a sequence of individual quadrilaterals<br>
				112	GL_QUAD_STRIP - a connected strip of quadrilaterals<br>
				113	GL_POLYGON - a closed, convex polygon<br>
				114	<br>
				115	</div>
				116	<br>
				117	The <span style="font-weight: bold;">glVertex</span> commands take two
				118	or three floating point coordinates, or a pointer to an array of two or
				119	three floating point coordinates.  Vertices are actually 4-element
				120	homogeneous coordinates.  The fourth component, unspecified by the
				121	subset's <span style="font-weight: bold;">glVertex</span> commands, is
				122	one.<br>
				123	<br>
				124	<span style="font-weight: bold;"></span>
				125	<h2>2.2 Other Per-vertex Commands<br>
				126	</h2>
				127	The <span style="font-weight: bold;">glColor</span> and <span
				128	style="font-weight: bold;">glTexCoord</span> commands may be used to
				129	specify colors and texture coordinates for each vertex:<br>
				130	<br>
				131	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glColor3f</span>(GLfloat<span
				132	style="font-style: italic;">red</span>, GLfloat <span
				133	style="font-style: italic;">green</span>, GLfloat <span
				134	style="font-style: italic;">blue</span>)<br>
				135	void <span style="font-weight: bold;">glColor3fv</span>(const GLfloat *<span
				136	style="font-style: italic;">rgb</span>)<br>
				137	void <span style="font-weight: bold;">glColor4f</span>(GLfloat <span
				138	style="font-style: italic;">red,</span> GLfloat <span
				139	style="font-style: italic;">green,</span> GLfloat <span
				140	style="font-style: italic;">blue,</span> GLfloat <span
				141	style="font-style: italic;">alpha</span>)<br>
				142	void <span style="font-weight: bold;">glColor4fv</span>(const GLfloat *<span
				143	style="font-style: italic;">rgba</span>)<br>
				144	void <span style="font-weight: bold;">glTexCoord2f</span>(GLfloat <span
				145	style="font-style: italic;">s</span>, GLfloat<span
				146	style="font-style: italic;"> t</span>)<br>
				147	void <span style="font-weight: bold;">glTexCoord2fv</span>(const
				148	GLfloat *<span style="font-style: italic;">c</span>)<br>
				149	<br>
				150	</div>
				151	The <span style="font-weight: bold;">glColor</span> commands specify
				152	the color and optionally, the alpha value, for subsequent vertices.
				153	For the <span style="font-weight: bold;">glColor3</span> commands,
				154	alpha is set to one.<br>
				155	<br>
				156	The <span style="font-weight: bold;">glTexCoord2</span> commands
				157	specify the texture coordinate for subsequent vertices.  Texture
				158	coordinates are actually four-component coordinates: (s, t, r, q).
				159	The <span style="font-weight: bold;">glTexCoord2</span> commands
				160	set s and t explicitly.  The r and q components are zero and one,
				161	respectively.<br>
				162	<br>
				163	<span style="font-weight: bold;"></span>Only <span
				164	style="font-weight: bold;">glVertex, glColor</span> and <span
				165	style="font-weight: bold;">glTexCoord</span> commands are allowed
				166	between <span style="font-weight: bold;">glBegin</span> and <span
				167	style="font-weight: bold;">glEnd.</span>  Calling any other
				168	command between <span style="font-weight: bold;">glBegin</span> and <span
				169	style="font-weight: bold;">glEnd</span> will result in the error
				170	GL_INVALID_OPERATION.<br>
				171	<br>
				172	<h2>2.3 Unsupported Commands</h2>
				173	None of the following commands related to primitive specification are
				174	supported by the subset:<br>
				175	<br>
				176	<div style="margin-left: 40px;">Per-Vertex commands:<br>
				177	</div>
				178	<div style="margin-left: 40px;">
				179	<div style="margin-left: 40px;"><span style="font-weight: bold;">glVertex2d,
				180	glVertex2i, glVertex2s, glVertex3d, glVertex3i, glVertex3s, glVertex4d,
				181	glVertex4i, glVertex4s, glVertex2dv, glVertex2iv, glVertex2sv,
				182	glVertex3dv, glVertex3iv, glVertex3sv, glVertex4dv, glVertex4iv,
				183	glVertex4sv,<br>
				184	glNormal3b, glNormal3d, glNormal3f, glNormal3i, glNormal3s, </span><span
				185	style="font-weight: bold;">glNormal3bv, glNormal3dv, glNormal3fv,
				186	glNormal3iv, glNormal3sv,<br>
				187	glIndexd, glIndexf, glIndexi, glIndexs, glIndexub, glIndexdv,
				188	glIndexfv, glIndexiv, glIndexsv, glIndexubv,<br>
				189	glColor3b, glColor3d, glColor3i, glColor3s, glColor3ub, glColor3ui,
				190	glColor3us, </span><span style="font-weight: bold;">glColor3bv,
				191	glColor3dv, glColor3iv, glColor3sv, glColor3ubv, glColor3uiv,
				192	glColor3usv,</span><span style="font-weight: bold;"> lColor4b,
				193	glColor4d, glColor4i, glColor4s, glColor4ub, glColor4ui, glColor4us, </span><span
				194	style="font-weight: bold;">glColor4bv, glColor4dv, glColor4iv,
				195	glColor4sv, glColor4ubv, glColor4uiv, glColor4usv,<br>
				196	</span><span style="font-weight: bold;">glTexCoord1d, glTexCoord1f,
				197	glTexCoord1i, glTexCoord1s, glTexCoord2d, glTexCoord2i, glTexCoord2s,
				198	glTexCoord3d, glTexCoord3f, glTexCoord3i, glTexCoord3s, glTexCoord4d,
				199	glTexCoord4f, glTexCoord4i, glTexCoord4s, glTexCoord1dv, glTexCoord1fv,
				200	glTexCoord1iv, glTexCoord1sv, glTexCoord2dv, glTexCoord2iv,
				201	glTexCoord2sv, glTexCoord3dv, glTexCoord3fv, glTexCoord3iv,
				202	glTexCoord3sv, glTexCoord4dv, glTexCoord4fv, glTexCoord4iv,
				203	glTexCoord4sv,<br>
				204	glEdgeFlag, glEdgeFlagv</span><br style="font-weight: bold;">
				205	<br>
				206	</div>
				207	Vertex array commands:<br>
				208	<div style="margin-left: 40px;"><span style="font-weight: bold;">glVertexPointer,
				209	glColorPointer, glIndexPointer, glTexCoordPointer, glEdgeFlagPointer,
				210	glNormalPointer, glInterleavedArrays, glArrayElement, glDrawArrays,
				211	glDrawElements, glDrawRangeElements, glEnableClientState,
				212	glDisableClientState</span><br>
				213	</div>
				214	</div>
				215	<div style="margin-left: 40px;"><br>
				216	Rectangle commands:<br>
				217	<div style="margin-left: 40px;"><span style="font-weight: bold;">glRects,
				218	glRecti, glRectf, glRectd, glRectsv, glRectiv, glRectfv, glRectdv,<br>
				219	<br>
				220	</span></div>
				221	</div>
				222	<div style="margin-left: 40px;">Lighting commands:<br>
				223	</div>
				224	<div style="margin-left: 80px;"><span style="font-weight: bold;">glMaterialf,
				225	glMateriali, glMaterialfv, glMaterialiv<br>
				226	</span><br>
				227	</div>
				228	<div style="margin-left: 40px;"> Evaluator commands:<br>
				229	<div style="margin-left: 40px;"><span style="font-weight: bold;">glEvalCoord1d,
				230	glEvalCoord1f, glEvalCoord1dv, glEvalCoord1fv, </span><span
				231	style="font-weight: bold;">glEvalCoord2d, glEvalCoord2f,
				232	glEvalCoord2dv, glEvalCoord2fv,<br>
				233	</span><span style="font-weight: bold;">glEvalPoint1, glEvalPoint2</span><br>
				234	<br>
				235	</div>
				236	</div>
				237	<h1>3. Coordinate Transformation</h1>
				238	<h2>3.1 Vertex Transformation</h2>
				239	Vertex coordinates are transformed by the current modelview and
				240	projection matrices then mapped to window coordinates as specified by
				241	the viewport.  The following coordinate transformation commands are
				242	supported by the subset<br>
				243	<br>
				244	<div style="margin-left: 40px; font-weight: bold;">glMatrixMode<span
				245	style="font-weight: normal;">(GLenum <span style="font-style: italic;">mode</span>)</span><br>
				246	glLoadIdentity<span style="font-weight: normal;">(void)</span><br>
				247	glPushMatrix<span style="font-weight: normal;">(void)</span><br>
				248	glPopMatrix<span style="font-weight: normal;">(void)</span><br>
				249	glLoadMatrixf<span style="font-weight: normal;">(const GLfloat *<span
				250	style="font-style: italic;">m</span>)</span><br>
				251	glMultMatrixf<span style="font-weight: normal;">(const GLfloat *<span
				252	style="font-style: italic;">m</span>)</span><br>
				253	glRotatef<span style="font-weight: normal;">(GLfloat <span
				254	style="font-style: italic;">angle</span>, GLfloat <span
				255	style="font-style: italic;">x</span>, GLfloat <span
				256	style="font-style: italic;">y</span>, GLfloat <span
				257	style="font-style: italic;">z</span>)</span><br>
				258	glTranslatef<span style="font-weight: normal;">(GLfloat <span
				259	style="font-style: italic;">x</span>, GLfloat <span
				260	style="font-style: italic;">y</span>, GLfloat <span
				261	style="font-style: italic;">z</span>)</span><br>
				262	glScalef<span style="font-weight: normal;">(GLfloat <span
				263	style="font-style: italic;">x</span>, GLfloat <span
				264	style="font-style: italic;">y</span>, GLfloat <span
				265	style="font-style: italic;">z</span>)<br>
				266	<span style="font-weight: bold;">glFrustum(</span>GLdouble <span
				267	style="font-style: italic;">left,</span> GLdouble <span
				268	style="font-style: italic;">right,</span> GLdouble <span
				269	style="font-style: italic;">bottom,</span> GLdouble <span
				270	style="font-style: italic;">top,</span> GLdouble <span
				271	style="font-style: italic;">near,</span> GLdouble <span
				272	style="font-style: italic;">far</span>)</span><br>
				273	<span style="font-weight: normal;"><span style="font-weight: bold;">glOrtho(</span>GLdouble<span
				274	style="font-style: italic;"> left,</span> GLdouble <span
				275	style="font-style: italic;">right,</span> GLdouble <span
				276	style="font-style: italic;">bottom,</span> GLdouble <span
				277	style="font-style: italic;">top,</span> GLdouble <span
				278	style="font-style: italic;">near,</span> GLdouble <span
				279	style="font-style: italic;">far</span>)</span><br>
				280	glViewport<span style="font-weight: normal;">(GLint <span
				281	style="font-style: italic;">x</span>, GLint <span
				282	style="font-style: italic;">y</span>, GLsize <span
				283	style="font-style: italic;">width,</span> GLsizei <span
				284	style="font-style: italic;">height</span>)</span><br>
				285	</div>
				286	<br>
				287	The <span style="font-weight: bold;">glMatrixMode</span> command
				288	specifies the <span style="font-style: italic;">current matrix.</span>
				289	The mode parameter may be GL_MODELVIEW or GL_PROJECTION to specify
				290	the modelview matrix or projection matrix.  Subsequent matrix
				291	commands will effect the current matrix.  Also associated with the
				292	modelview and projection matrices are a modelview matrix stack and
				293	projection matrix stack.<br>
				294	<br>
				295	The <span style="font-weight: bold;">glLoadIdentity</span> command
				296	replaces the current matrix with the identity matrix.  The matrix
				297	elements are specified in column-major order.<br>
				298	<br>
				299	The <span style="font-weight: bold;">glPushMatrix</span> command pushes
				300	a copy of the current matrix onto either the modelview matrix stack or
				301	the projection matrix stack.  The <span style="font-weight: bold;">glPopMatrix</span>
				302	command replaces the current matrix with a copy of the top matrix off
				303	the modelview matrix stack or projection matrix stack, the pops the
				304	stack.  Matrix stacks are useful for traversing and rendering
				305	hierarchical models.<br>
				306	<br>
				307	The <span style="font-weight: bold;">glMultMatrixf</span> command
				308	post-multiplies the current matrix by the specified matrix.  The
				309	matrix elements are specified in column-major order.<br>
				310	<br>
				311	The <span style="font-weight: bold;">glRotatef</span> command
				312	post-multiplies the current matrix by a rotation matrix defined by the
				313	angle and rotation axis defined by x, y and z.<br>
				314	<br>
				315	The <span style="font-weight: bold;">glTranslatef</span> command
				316	post-multiplies the current matrix by a translation matrix defined by
				317	the <span style="font-style: italic;">x</span>, <span
				318	style="font-style: italic;">y</span> and <span
				319	style="font-style: italic;">z</span> translation parameters.<br>
				320	<span style="font-weight: bold;"></span><br>
				321	The <span style="font-weight: bold;">glScalef</span> command
				322	post-multiplies the current matrix by a scaling matrix defined by the <span
				323	style="font-style: italic;">x</span>, <span
				324	style="font-style: italic;">y</span> and <span
				325	style="font-style: italic;">z</span> scale factors.<br>
				326	<span style="font-weight: bold;"></span><br>
				327	The <span style="font-weight: bold;">glFrustum</span> command
				328	post-multiplies the current matrix by a perspective projection matrix.
				329	The <span style="font-style: italic;">near</span> and <span
				330	style="font-style: italic;">far</span> values specify the position of
				331	the hither and yon Z-axis clipping planes.  The <span
				332	style="font-style: italic;">left, right, bottom</span> and <span
				333	style="font-style: italic;">top</span> parameters are the X and Y
				334	extents at the near clipping plane.  <span
				335	style="font-weight: bold;">glFrustum</span> is normally used to modify
				336	the projection matrix.<br>
				337	<br>
				338	The <span style="font-weight: bold;">glOrtho</span> command
				339	post-multiplies the current matrix by an orthographic projection matrix.
				340	The <span style="font-style: italic;">near</span> and <span
				341	style="font-style: italic;">far</span> values specify the position of
				342	the hither and yon Z-axis clipping planes.  The <span
				343	style="font-style: italic;">left, right, bottom</span> and <span
				344	style="font-style: italic;">top</span> parameters specify the X and
				345	Y-axis clipping planes.  <span style="font-weight: bold;">glOrtho</span>
				346	is normally used to modify the projection matrix.<br>
				347	<br>
				348	The <span style="font-weight: bold;">glViewport</span> command
				349	specifies the mapping of coordinates from normalized device coordinates
				350	to window coordinates.  The <span style="font-style: italic;">x</span>
				351	and <span style="font-style: italic;">y</span> parameters specify the
				352	viewport's lower-left corner in the window and the <span
				353	style="font-style: italic;">width</span> and <span
				354	style="font-style: italic;">height</span> parameters specify the size
				355	of the viewport.  <span style="font-weight: bold;">glViewport</span>
				356	does not effect the current matrix.<br>
				357	<br>
				358	A coordinate transformed to window coordinates is hereafter known as (x<sub>w</sub>,
				359	y<sub>w</sub>, z<sub>w</sub>).<br>
				360	<br>
				361	<h2>3.2 Clipping</h2>
				362	View-volume clipping automatically discards or trims primitives which
				363	lie completely or partially outside of the view volume specified by <span
				364	style="font-weight: bold;">glFrustum</span> and <span
				365	style="font-weight: bold;">glOrtho</span>.  Note that the <span
				366	style="font-weight: bold;">glViewport</span> command does not define a
				367	clipping region.<br>
				368	<br>
				369	Clipping occurs in <span style="font-style: italic;">clip coordinate
				370	space - </span>the coordinates produced after applying the projection
				371	matrix.<br>
				372	<br>
				373	<h2>3.3 Current Raster Position</h2>
				374	The current raster position specifies the location for drawing images
				375	with <span style="font-weight: bold;">glBitmap.</span>  The current
				376	raster position is set with the commands:<br>
				377	<br>
				378	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glRasterPos2f</span>(GLfloat<span
				379	style="font-style: italic;">x</span>, GLfloat <span
				380	style="font-style: italic;">y</span>)<br>
				381	void <span style="font-weight: bold;">glRasterPos2fv</span>(const
				382	GLfloat *<span style="font-style: italic;">v</span>)<br>
				383	void <span style="font-weight: bold;">glRasterPos2i</span>(GLint <span
				384	style="font-style: italic;">x</span>, GLint <span
				385	style="font-style: italic;">y</span>)<br>
				386	void <span style="font-weight: bold;">glRasterPos2iv</span>(const
				387	GLint *<span style="font-style: italic;">v</span>)<br>
				388	</div>
				389	<br>
				390	<span style="font-weight: bold;">glRasterPos</span> specifies a
				391	4-component coordinate (x, y, 0, 1).  The coordinate is processed
				392	like a vertex; it is transformed by the modelview matrix, the projection
				393	matrix and mapped to the viewport.  The resulting window coordinate
				394	is stored as the current raster position.  The coordinate is
				395	clipped-tested against the frustum like a vertex.  If the
				396	coordinate is clipped, then the current raster position becomes invalid
				397	and subsequent <span style="font-weight: bold;">glBitmap</span> commands
				398	have no effect.<br>
				399	<br>
				400	<span style="font-weight: bold;">glRasterPos</span> also updates the
				401	current raster color and current raster texture coordinates.  The
				402	current raster color is updated (copied) from the current color (as
				403	specified by <span style="font-weight: bold;">glColor</span>).
				404	The current raster texture coordinate is updated (copied) from the
				405	current texture coordinate (as specified by <span
				406	style="font-weight: bold;">glTexCoord</span>).<br>
				407	<br>
				408	<h2>3.4 Unsupported Commands</h2>
				409	The following commands related to vertex transformation are not
				410	supported by the subset:<br>
				411	<br>
				412	<div style="margin-left: 40px;">User-defined clip plane commands:<br>
				413	<div style="margin-left: 40px;"><span style="font-weight: bold;">glClipPlane</span><br>
				414	</div>
				415	<span style="font-weight: bold;"></span></div>
				416	<br>
				417	<div style="margin-left: 40px;">Lighting and material commands:</div>
				418	<div style="margin-left: 80px;"><span style="font-weight: bold;">glLightModeli,
				419	glLightModelf, </span><span style="font-weight: bold;">glLightModeliv,
				420	glLightModelfv,</span><span style="font-weight: bold;"> glLightf,
				421	glLighti, glLightfv, glLightiv, glColorMaterial</span><br>
				422	</div>
				423	<br>
				424	<div style="margin-left: 40px;">Automatic texture coordinate generation
				425	commands:<br>
				426	</div>
				427	<div style="margin-left: 40px;">
				428	<div style="margin-left: 40px;"><span style="font-weight: bold;">glTexGend,
				429	glTexGenf, glTexGeni, </span><span style="font-weight: bold;">glTexGendv,
				430	glTexGenfv, glTexGeniv, </span><br>
				431	<br style="font-weight: bold;">
				432	</div>
				433	Double-valued commands:<br>
				434	<div style="margin-left: 40px;"><span style="font-weight: bold;">glLoadMatrixd,
				435	glMultMatrixd, glRotated, glTranslated, glScaled</span><br
				436	style="font-weight: bold;">
				437	</div>
				438	<br>
				439	Depth Range command:<br>
				440	<div style="margin-left: 40px;"><span style="font-weight: bold;">glDepthRange</span>
				441	(the near value is always 0.0 and the far value is always 1.0)<br>
				442	</div>
				443	<br>
				444	Extra RasterPos commands:<br>
				445	<div style="margin-left: 40px;"><span style="font-weight: bold;">glRasterPos2d,
				446	glRasterPos2s, glRasterPos3d, glRasterPos3f, glRasterPos3i,
				447	glRasterPos3s, glRasterPos4d, glRasterPos4f, glRasterPos4i,
				448	glRasterPos4s, glRasterPos2dv, glRasterPos2sv, glRasterPos3dv,
				449	glRasterPos3fv, glRasterPos3iv, glRasterPos3sv, glRasterPos4dv,
				450	glRasterPos4fv, glRasterPos4iv, glRasterPos4sv</span><br>
				451	</div>
				452	<br>
				453	<br>
				454	</div>
				455	<h1>4. Rasterization</h1>
				456	This section describes the commands and options for drawing points,
				457	lines, triangles and bitmaps.  <span style="font-style: italic;">Rasterization</span>
				458	is the term for the process which produces fragments from the geometric
				459	description of a primitive (a point, line, polygon or bitmap).  For
				460	example, given the two coordinates for the end-points of a line segment,
				461	rasterization determines which pixels in the frame buffer are modified
				462	to <span style="font-style: italic;">draw</span> the line.  A
				463	fragment is a tuple which consists of a window coordinate, colors and
				464	texture coordinates.  The fragments produced by rasterization are
				465	subsequently processed by the per-fragment operations described later.<br>
				466	<br>
				467	<h2>4.1 Point Rasterization</h2>
				468	Points are rendered with the command sequence <span
				469	style="font-weight: bold;">glBegin</span>(GL_POINTS), <span
				470	style="font-weight: bold;">glVertex</span>, ... <span
				471	style="font-weight: bold;">glEnd</span>.  The window coordinate (x<sub>w</sub>,
				472	y<sub>w</sub>, z<sub>w</sub>) is truncated to rasterize the point.
				473	The truncated coordinate with its associated color and texture
				474	coordinate is sent as a single fragment to the per-fragment processing
				475	stages.<br>
				476	<br>
				477	The <span style="font-weight: bold;">glPointSize</span> command is not
				478	supported; only 1-pixel points are supported.<br>
				479	<br>
				480	Point smoothing (antialiasing) is also not supported.<br>
				481	<br>
				482	<h2>4.2 Line Rasterization</h2>
				483	Lines are rendered with the command sequence <span
				484	style="font-weight: bold;">glBegin</span>(<span
				485	style="font-style: italic;">mode</span>), <span
				486	style="font-weight: bold;">glVertex</span>, <span
				487	style="font-weight: bold;">glVertex</span>, ... <span
				488	style="font-weight: bold;">glEnd</span> where <span
				489	style="font-style: italic;">mode</span> is one of GL_LINES,
				490	GL_LINE_STRIP or GL_LINE_LOOP.  Lines are rasterized as described
				491	in the OpenGL specification.  Note that OpenGL specifies the <span
				492	style="font-style: italic;">half-open</span> convention for drawing
				493	lines: the last fragment in a line segment is omitted so that endpoint
				494	pixels shared by two line segments will only be drawn once instead of
				495	twice.<br>
				496	<br>
				497	<h3>4.2.1 Line Width</h3>
				498	The width of lines can be controlled by<br>
				499	<br>
				500	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glLineWidth</span>(GLfloat<span
				501	style="font-style: italic;">width</span>)<br>
				502	</div>
				503	<br>
				504	where <span style="font-style: italic;">width</span> is the line width
				505	in pixels.  The width defaults to 1.0.  Attempting to set the
				506	width to a value less than or equal to zero will raise the error
				507	GL_INVALID_VALUE.<br>
				508	<br>
				509	<h3>4.2.2 Line Stipple<br>
				510	</h3>
				511	Lines may be stippled (i.e. dashed) with the command<br>
				512	<br>
				513	<div style="margin-left: 40px;"><span style="font-weight: bold;">glLineStipple</span>(GLint<span
				514	style="font-style: italic;">factor</span>, GLushort <span
				515	style="font-style: italic;">pattern</span>)<br>
				516	</div>
				517	<br>
				518	<span style="font-style: italic;">pattern</span> describes an on/off
				519	pattern for the fragments produced by rasterization and <span
				520	style="font-style: italic;">factor</span> specifies how many subsequent
				521	fragments are kept or culled for each pattern bit.  Line stippling
				522	can be enabled or disabled by the commands <span
				523	style="font-weight: bold;">glEnable</span>(GL_LINE_STIPPLE) and <span
				524	style="font-weight: bold;">glDisable</span>(GL_LINE_STIPPLE).<br>
				525	<br>
				526	<h3>4.2.3 Line Antialiasing</h3>
				527	Lines may be antialiased.  For antialiased lines, each fragment
				528	produced by rasterization is assigned a <span
				529	style="font-style: italic;">coverage value</span> which describes how
				530	much of the fragment's area is considered to be <span
				531	style="font-style: italic;">inside</span> the line.  Later, the
				532	alpha value of each fragment is multiplied by the coverage value.
				533	By blending the fragments into the frame buffer, the edges of
				534	lines appear smoothed.<br>
				535	<br>
				536	Line antialiasing can be enabled or disabled with the commands <span
				537	style="font-weight: bold;">glEnable</span>(GL_LINE_SMOOTH) and <span
				538	style="font-weight: bold;">glDisable</span>(GL_LINE_SMOOTH).<br>
				539	<br>
				540	<h2>4.3 Polygon Rasterization</h2>
				541	Polygons, quadrilaterals and triangles share the same polygon
				542	rasterization options. <br>
				543	<br>
				544	Triangles are rendered by the command sequence <span
				545	style="font-weight: bold;">glBegin</span><span
				546	style="font-style: italic;"><span style="font-style: italic;">(mode</span></span>),<span
				547	style="font-weight: bold;">glVertex</span>, <span
				548	style="font-weight: bold;">glVertex</span>, ... <span
				549	style="font-weight: bold;">glEnd</span> where <span
				550	style="font-style: italic;">mode</span> may be one of GL_TRIANGLES,
				551	GL_TRIANGLE_STRIP or GL_TRIANGLE_FAN.<span style="font-weight: bold;"></span>
				552	For GL_TRIANGLES mode, the number of vertices should be a multiple
				553	of three - extra vertices will be ignored.  For GL_TRIANGLE_STRIP
				554	and GL_TRIANGLE_FAN, at least three vertices should be specified.
				555	If less than three are specified, nothing is drawn.  <br>
				556	<br>
				557	Quadrilaterals are <span style="font-weight: bold;"></span>rendered by
				558	the command sequence <span style="font-weight: bold;">glBegin</span>(<span
				559	style="font-style: italic;"><span style="font-style: italic;">mode</span></span>),<span
				560	style="font-weight: bold;">glVertex</span>, <span
				561	style="font-weight: bold;">glVertex</span>, ... <span
				562	style="font-weight: bold;">glEnd</span> where <span
				563	style="font-style: italic;">mode</span> may be one of GL_QUADS or
				564	GL_QUAD_STRIP.<span style="font-weight: bold;"></span>   For
				565	GL_QUADS, the number of vertices should be a multiple of four - extra
				566	vertices will be ignored.  For GL_QUAD_STRIP, the number of
				567	vertices should be even and at least four.  Extra vertices (one)
				568	will be ignored.<br>
				569	<br>
				570	Convex polygons are <span style="font-weight: bold;"></span>rendered
				571	by the command sequence <span style="font-weight: bold;">glBegin</span><span
				572	style="font-style: italic;"><span style="font-style: italic;"></span></span>(GL_POLYGON),<span
				573	style="font-weight: bold;">glVertex</span>, <span
				574	style="font-weight: bold;">glVertex</span>, ... <span
				575	style="font-weight: bold;">glEnd</span>.<span
				576	style="font-style: italic;"></span><span style="font-weight: bold;"></span>
				577	If less than three vertices are specified, nothing is drawn.<br>
				578	<br>
				579	<h3>4.3.1 Polygon Orientation</h3>
				580	The <span style="font-style: italic;">winding order</span> of vertices
				581	(clockwise or counter-clockwise) is significant.  It is used to
				582	determine the <span style="font-style: italic;">front-facing</span> or <span
				583	style="font-style: italic;">back-facing</span> orientation of polygons.
				584	By default, a front-facing polygon's vertices are in
				585	counter-clockwise order (in window coordinates).  Figures 2.4 and
				586	2.5 of the OpenGL 1.2.1 specification illustrate the winding order for
				587	front-facing triangles and quadrilaterals, respectively.<br>
				588	<br>
				589	The command<br>
				590	<br>
				591	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glFrontFace</span>(GLenum<span
				592	style="font-style: italic;"> mode</span>)<br>
				593	</div>
				594	<br>
				595	specifies whether clockwise or counter-clockwise winding indicates a
				596	front-facing polygon.  If <span style="font-style: italic;">mode</span>
				597	is GL_CW then polygons with clockwise winding are front-facing.  If <span
				598	style="font-style: italic;">mode</span> is GL_CCW then polygons with
				599	counter-clockwise winding are front-facing.  The default value is
				600	GL_CCW.  If <span style="font-style: italic;">mode</span> is not
				601	GL_CCW or GL_CW then the error GL_INVALID_ENUM will be raised.<span
				602	style="font-style: italic;"></span><span style="font-style: italic;"></span><br>
				603	<br>
				604	<h3>4.3.2 Polygon Culling</h3>
				605	Polygons may be culled (discarded) depending on whether they are
				606	front-facing or back-facing.  The command<br>
				607	<br>
				608	<div style="margin-left: 40px;">void<span style="font-weight: bold;">
				609	glCullFace</span>(GLenum <span style="font-style: italic;">mode</span>)<br>
				610	</div>
				611	<br>
				612	specifies whether front-facing, back-facing or all polygons should be
				613	culled.  If <span style="font-style: italic;">mode</span> is
				614	GL_FRONT then front-facing polygons will be culled.  If <span
				615	style="font-style: italic;">mode</span> is GL_BACK then back-facing
				616	polygons will be culled. Otherwise, if <span style="font-style: italic;">mode</span>
				617	is GL_FRONT_AND_BACK then all polygons will be culled.  Any other
				618	value for <span style="font-style: italic;">mode</span> will raise the
				619	error GL_INVALID_ENUM.<br>
				620	<br>
				621	Polygon culling is enabled and disabled with the commands <span
				622	style="font-weight: bold;">glEnable</span>(GL_CULL_FACE) and <span
				623	style="font-weight: bold;">glDisable</span>(GL_CULL_FACE),
				624	respectively.<br>
				625	<br>
				626	<h3>4.3.3 Polygon Antialiasing</h3>
				627	Polygons may be antialiased in order to smooth their edges.
				628	Polygon antialiasing is enabled and disabled with the commands <span
				629	style="font-weight: bold;">glEnable</span>(GL_POLYGON_SMOOTH) and <span
				630	style="font-weight: bold;">glDisable</span>(GL_POLYGON_SMOOTH).<br>
				631	<br>
				632	When polygon antialiasing is enabled each fragment produced by polygon,
				633	triangle and quadrilateral rasterization will be given a <span
				634	style="font-style: italic;">coverage</span> value which indicates how
				635	much of the fragment is covered by the polygon.  Fragments
				636	completely inside the polygon have coverage 1.0.  Fragments
				637	completely outside the polygon have zero coverage (in theory).
				638	Fragments which intersect the polygon's edge have a coverage value
				639	in the range (0, 1).<br>
				640	<br>
				641	The fragment's alpha value is multiplied by the coverage value.
				642	By enabling the appropriate blending mode, polygon edges will
				643	appear smoothed.<br>
				644	<br>
				645	<h2>4.4 Shading</h2>
				646	The command<br>
				647	<br>
				648	<div style="margin-left: 40px;"> void <span style="font-weight: bold;">glShadeModel</span>(GLenum<span
				649	style="font-style: italic;">mode</span>)<br>
				650	</div>
				651	<br>
				652	determines whether colors are interpolated between vertices during
				653	rasterization.  If <span style="font-style: italic;">mode</span> is
				654	GL_FLAT then vertex colors are not interpolated.  The color used
				655	for drawing lines, triangles and quadrilaterals is that of the last
				656	vertex used to specify each primitive.  For polygons, the color of
				657	the first vertex specifies the color for the entire polygon.  If <span
				658	style="font-style: italic;">mode</span> is GL_SMOOTH then vertex colors
				659	are linearly interpolated to produce the fragment colors.<br>
				660	<br>
				661	<h2>4.5 Bitmap Rasterization</h2>
				662	A bitmap is a monochromatic, binary image in which each image element
				663	(or pixel) is represented by one bit.  Fragments are only generated
				664	for the bits (pixels) which are set.  Bitmaps are commonly used to
				665	draw text (glyphs) and markers.<br>
				666	<br>
				667	A bitmap is drawn with the command<br>
				668	<br>
				669	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glBitmap</span>(GLsizei<span
				670	style="font-style: italic;">width</span>, GLsizei <span
				671	style="font-style: italic;">height</span>, GLfloat <span
				672	style="font-style: italic;">xOrig</span>, GLfloat <span
				673	style="font-style: italic;">yOrig</span>, GLfloat <span
				674	style="font-style: italic;">xMove</span>, GLfloat <span
				675	style="font-style: italic;">yMove</span>, const  GLubyte *<span
				676	style="font-style: italic;">image</span>)<br>
				677	</div>
				678	<br>
				679	<span style="font-style: italic;">width </span>and <span
				680	style="font-style: italic;">height</span> specify the image size in
				681	pixels.  <span style="font-style: italic;">xOrig</span> and <span
				682	style="font-style: italic;">yOrig</span> specify the bitmap origin.
				683	<span style="font-style: italic;">xMove</span> and <span
				684	style="font-style: italic;">yMove</span> are added to the current
				685	raster position after the bitmap is rasterized.  <span
				686	style="font-style: italic;">image</span> is a pointer to the bitmap
				687	data.<br>
				688	<br>
				689	If the current raster position is not valid, <span
				690	style="font-weight: bold;">glBitmap</span> has no effect.<br>
				691	<br>
				692	<h3>4.5.1 Bitmap Unpacking</h3>
				693	The first step in bitmap rendering is <span style="font-style: italic;">unpacking.
				694	</span>Unpacking is the process of extracting image data from
				695	client memory subject to byte swapping, non-default row strides, etc.
				696	The unpacking parameters are specified with the command<br>
				697	<br>
				698	<div style="margin-left: 40px;">void<span style="font-weight: bold;">
				699	glPixelStorei</span>(GLenum pname, GLint value)<br>
				700	</div>
				701	<span style="font-style: italic;"></span><br>
				702	The following unpacking parameters may be set:<br>
				703	<br>
				704	<table cellpadding="2" cellspacing="2" border="1"
				705	style="text-align: left; width: 90%; margin-left: auto; margin-right: auto;">
				706	<tbody>
				707	<tr>
				708	<td style="vertical-align: top;">Parameter (<span
				709	style="font-style: italic;">pname</span>)<br>
				710	</td>
				711	<td style="vertical-align: top;">Value (<span
				712	style="font-style: italic;">value</span>)<br>
				713	</td>
				714	<td style="vertical-align: top;">Default<br>
				715	</td>
				716	</tr>
				717	<tr>
				718	<td style="vertical-align: top;">GL_UNPACK_ROW_LENGTH<br>
				719	</td>
				720	<td style="vertical-align: top;">Width of the image in memory, in
				721	pixels.<br>
				722	</td>
				723	<td style="vertical-align: top;">0<br>
				724	</td>
				725	</tr>
				726	<tr>
				727	<td style="vertical-align: top;">GL_UNPACK_LSB_FIRST<br>
				728	</td>
				729	<td style="vertical-align: top;">GL_FALSE indicates that the most
				730	significant bit is unpacked first from each byte.  GL_TRUE
				731	indicates that the least significant bit is unpacked first from each
				732	byte. <br>
				733	</td>
				734	<td style="vertical-align: top;">GL_FALSE<br>
				735	</td>
				736	</tr>
				737	</tbody>
				738	</table>
				739	<br>
				740	<br>
				741	The GL_UNPACK_ROW_LENGTH specifies the stride (in pixels) for advancing
				742	from one row of the image to the next.  If it's zero, the <span
				743	style="font-style: italic;">width</span> parameter to <span
				744	style="font-weight: bold;">glBitmap</span> specifies the width of the
				745	image in memory.<br>
				746	<br>
				747	GL_UNPACK_LSB_FIRST determines whether the least significant or most
				748	significant bit in each byte is unpacked first.  Unpacking occurs
				749	in left to right order (in image space).<br>
				750	<br>
				751	The value of bit (i, j) of the image (where i is the image row and j is
				752	the image column) is found as follows:<br>
				753	<br>
				754	<div style="margin-left: 40px;">rowLength = (GL_UNPACK_ROW_LENGTH != 0)
				755	? GL_UNPACK_ROW_LENGTH : <span style="font-style: italic;">width</span>;<br>
				756	<br>
				757	byte = <span style="font-style: italic;">image</span>[((rowLength + 7)
				758	/ 8) * i + j / 8];<br>
				759	<br>
				760	if (GL_UNPACK_LSB_FIRST != 0)<br>
				761	bitMask = 1 << (j % 8);<br>
				762	else<br>
				763	bitMask = 128 >> (j % 8);<br>
				764	<br>
				765	if (byte & bitMask)<br>
				766	bit = 1;<br>
				767	else<br>
				768	bit = 0;<br>
				769	<br>
				770	</div>
				771	<span style="font-style: italic;"><span style="font-style: italic;"></span></span>
				772	<h3>4.5.2 Rasterization</h3>
				773	If the current raster position is (x<sub>rp</sub>, y<sub>rp</sub>, z<sub>rp</sub>,
				774	w<sub>rp</sub>), then the bitmap is rasterized according to the
				775	following algorithm:<br>
				776	<br>
				777	for (j = 0; j < <span style="font-style: italic;">height</span>;
				778	j++) {<br>
				779	for (i = 0; i < <span style="font-style: italic;">width</span>;
				780	i++) {<br>
				781	if (bit(i,j)) {<br>
				782	fragment.x =
				783	floor(x<sub>rp</sub> - <span style="font-style: italic;">xOrig</span>)
				784	+ i;<br>
				785	fragment.y =
				786	floor(y<sub>rp</sub> - <span style="font-style: italic;">yOrig</span>)
				787	+ j;<br>
				788	fragment.color
				789	= GL_CURRENT_RASTER_COLOR;<br>
				790
				791	fragment.texture = GL_CURRENT_RASTER_TEXTURE_COORDS;<br>
				792
				793	ProcessFragment(fragment)<br>
				794	}<br>
				795	}<br>
				796	}<br>
				797	<br>
				798	After the bitmap has been rendered the current raster position is
				799	updated as follows:<br>
				800	<br>
				801	<div style="margin-left: 40px;">x<sub>rp</sub> = x<sub>rp</sub> + <span
				802	style="font-style: italic;">xMove</span><br>
				803	y<sub>rp</sub> = y<sub>rp</sub> + <span style="font-style: italic;">yMove</span><br>
				804	</div>
				805	<br>
				806	<h3>4.5.3 Per-fragment Operations</h3>
				807	XXX supported?  See issue in appendix A.<br>
				808	<br>
				809	<h2>4.6 Unsupported Commands</h2>
				810	The following commands related to rasterization are not supported by
				811	the subset.<br>
				812	<br>
				813	<div style="margin-left: 40px;">Point commands:<br>
				814	<div style="margin-left: 40px;"><span style="font-weight: bold;">glPointSize</span><br>
				815	</div>
				816	<br>
				817	Polygon commands:<br>
				818	<div style="margin-left: 40px; font-weight: bold;">glPolygonStipple<br>
				819	glPolygonOffset<br>
				820	glPolygonMode<br>
				821	<br>
				822	</div>
				823	</div>
				824	<div style="margin-left: 40px;">Pixel storage commands:<br>
				825	</div>
				826	<div style="font-weight: bold; margin-left: 80px;">glPixelStoref<br>
				827	</div>
				828	<br>
				829	<br>
				830	<h1>5. Texture Mapping<br>
				831	</h1>
				832	There are four elements to texture mapping: texture coordinate
				833	specification, texture image specification, texture sampling and texture
				834	application.<br>
				835	<br>
				836	Texture mapping is enabled and disabled with the commands <span
				837	style="font-weight: bold;">glEnable</span>(GL_TEXTURE_2D) and <span
				838	style="font-weight: bold;">glDisable</span>(GL_TEXTURE_2D).<br>
				839	<br>
				840	<h2>5.1 Texture Image Specification</h2>
				841	A texture image is specified with the command:<br>
				842	<br>
				843	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glTexImage2D</span>(GLenum<span
				844	style="font-style: italic;"> target</span>, GLint <span
				845	style="font-style: italic;">level</span>, GLint <span
				846	style="font-style: italic;">internalFormat,</span> GLsizei <span
				847	style="font-style: italic;">width,</span> GLsizei <span
				848	style="font-style: italic;">height,</span> GLint <span
				849	style="font-style: italic;">border,</span> GLenum <span
				850	style="font-style: italic;">format,</span> GLenum <span
				851	style="font-style: italic;">type,</span> const GLvoid *<span
				852	style="font-style: italic;">pixels</span> )<br>
				853	</div>
				854	<br>
				855	<span style="font-style: italic;">target</span> must be GL_TEXTURE_2D.
				856	<span style="font-style: italic;">level </span>indicates the
				857	mipmap level for mipmap textures.  <span style="font-style: italic;">internalFormat</span>
				858	is a hint to indicate the preferred internal storage format for the
				859	texture.  <span style="font-style: italic;">width</span> and <span
				860	style="font-style: italic;">height </span>indicate the image size in
				861	pixels (or texels).  <span style="font-style: italic;">border </span>must
				862	be zero.  <span style="font-style: italic;">format</span> and <span
				863	style="font-style: italic;">type</span> describe the pixel format and
				864	data type for the incoming image.  <span style="font-style: italic;">pixels</span>
				865	points to the incoming texture image.  These parameters are
				866	described in more detail below.<br>
				867	<br>
				868	<h3>5.1.1 Texture Image Size and Mipmaps</h3>
				869	<h3><span style="font-style: italic;"></span></h3>
				870	Texture images must have dimensions (width and height) that are powers
				871	of two. For example: 256 x 256, 32 x 1024, 1 x 8, etc.  That is, it
				872	must be the case that <span style="font-style: italic;">width </span>=
				873	2<sup>n</sup> and <span style="font-style: italic;">height</span> = 2<sup>m</sup>
				874	for some positive integers n and m.<br>
				875	<br>
				876	Mipmapping is a method of antialiasing or filtering textures to improve
				877	their appearance.  A mipmap is a set of images consisting of a base
				878	image and a set of filtered, reduced-resolution images.  If the
				879	base image (<span style="font-style: italic;">level</span>=0) is of
				880	width 2<sup>n</sup> and height 2<sup>m</sup> then the level 1 image must
				881	be of width 2<sup>n-1</sup> and height 2<sup>m-1</sup>.  Each mipmap
				882	level is half the width and height of the previous level, or at least
				883	one.  The last mipmap level has a width and height of one.<br>
				884	<br>
				885	The following is an example of a mipmap's image levels:<br>
				886	<br>
				887	<table cellpadding="2" cellspacing="2" border="1"
				888	style="text-align: left; width: 50%; margin-left: auto; margin-right: auto;">
				889	<tbody>
				890	<tr>
				891	<td style="vertical-align: top;">mipmap level<br>
				892	</td>
				893	<td style="vertical-align: top;">width<br>
				894	</td>
				895	<td style="vertical-align: top;">height<br>
				896	</td>
				897	</tr>
				898	<tr>
				899	<td style="vertical-align: top;">0<br>
				900	</td>
				901	<td style="vertical-align: top;">256<br>
				902	</td>
				903	<td style="vertical-align: top;">64<br>
				904	</td>
				905	</tr>
				906	<tr>
				907	<td style="vertical-align: top;">1<br>
				908	</td>
				909	<td style="vertical-align: top;">128<br>
				910	</td>
				911	<td style="vertical-align: top;">32<br>
				912	</td>
				913	</tr>
				914	<tr>
				915	<td style="vertical-align: top;">2<br>
				916	</td>
				917	<td style="vertical-align: top;">64<br>
				918	</td>
				919	<td style="vertical-align: top;">16<br>
				920	</td>
				921	</tr>
				922	<tr>
				923	<td style="vertical-align: top;">3<br>
				924	</td>
				925	<td style="vertical-align: top;">32<br>
				926	</td>
				927	<td style="vertical-align: top;">8<br>
				928	</td>
				929	</tr>
				930	<tr>
				931	<td style="vertical-align: top;">4<br>
				932	</td>
				933	<td style="vertical-align: top;">16<br>
				934	</td>
				935	<td style="vertical-align: top;">4<br>
				936	</td>
				937	</tr>
				938	<tr>
				939	<td style="vertical-align: top;">5<br>
				940	</td>
				941	<td style="vertical-align: top;">8<br>
				942	</td>
				943	<td style="vertical-align: top;">2<br>
				944	</td>
				945	</tr>
				946	<tr>
				947	<td style="vertical-align: top;">6<br>
				948	</td>
				949	<td style="vertical-align: top;">4<br>
				950	</td>
				951	<td style="vertical-align: top;">1<br>
				952	</td>
				953	</tr>
				954	<tr>
				955	<td style="vertical-align: top;">7<br>
				956	</td>
				957	<td style="vertical-align: top;">2<br>
				958	</td>
				959	<td style="vertical-align: top;">1<br>
				960	</td>
				961	</tr>
				962	<tr>
				963	<td style="vertical-align: top;">8<br>
				964	</td>
				965	<td style="vertical-align: top;">1<br>
				966	</td>
				967	<td style="vertical-align: top;">1<br>
				968	</td>
				969	</tr>
				970	</tbody>
				971	</table>
				972	<br>
				973	If the <span style="font-style: italic;">width</span> or <span
				974	style="font-style: italic;">height</span> parameters are not powers of
				975	two, the error GL_INVALID_VALUE is raised.  If the image levels in
				976	a mipmap do not satisfy the restrictions listed above the texture is
				977	considered to be <span style="font-style: italic;">inconsistent</span>
				978	and the system will behave as if the texturing is disabled.<br>
				979	<br>
				980	<h3>5.1.2 Texture Image Formats and Unpacking</h3>
				981	The <span style="font-weight: bold;">glTexImage2D</span> command's <span
				982	style="font-style: italic;"><span style="font-weight: bold;"></span></span><span
				983	style="font-style: italic;">format</span> and <span
				984	style="font-style: italic;">type</span> parameters describe the format
				985	of the incoming texture image.  Accepted values for <span
				986	style="font-style: italic;">format</span> are GL_INTENSITY, GL_RGB and
				987	GL_RGBA.  The <span style="font-style: italic;">type</span>
				988	parameter must be GL_UNSIGNED_BYTE.  Pixel component values are
				989	thus in the range 0 through 255.<br>
				990	<br>
				991	If <span style="font-style: italic;">format</span> is GL_INTENSITY then
				992	the image has one byte per pixel which specifies the pixel's red, green,
				993	blue and alpha values.<span style="font-style: italic;"></span><br>
				994	<br>
				995	If <span style="font-style: italic;">format</span> is GL_RGB then the
				996	image has three bytes per pixel which specify the pixel's red, green and
				997	blue values (in that order).  The alpha value defaults to 255.<br>
				998	<br>
				999	If <span style="font-style: italic;">format</span> is GL_RGBA then the
				1000	image has four bytes per pixel which specify the pixel's red, green,
				1001	blue and alpha values (in that order).<br>
				1002	<br>
				1003	The command<br>
				1004	<br>
				1005	<div style="margin-left: 40px;">void<span style="font-weight: bold;">
				1006	glPixelStorei</span>(GLenum <span style="font-style: italic;">pname</span>,
				1007	GLint <span style="font-style: italic;">value</span>)<br>
				1008	</div>
				1009	<br>
				1010	controls the unpacking of texture image data from client memory.  <span
				1011	style="font-style: italic;">pname</span> may be GL_UNPACK_ROW_LENGTH to
				1012	indicate the stride, in pixels, between subsequent rows of the image in
				1013	client memory.  If GL_UNPACK_ROW_LENGTH is zero (the default) then
				1014	the <span style="font-style: italic;">width</span> parameter to <span
				1015	style="font-weight: bold;">glTexImage2D </span>determines the stride.<span
				1016	style="font-style: italic;"></span><br>
				1017	<br>
				1018	<h3>5.1.3 Internal Texture Format</h3>
				1019	<span style="font-weight: bold;">glTexImage2D<span
				1020	style="font-style: italic;"> </span></span>converts the incoming
				1021	texture image to one of the supported internal texture formats.<br>
				1022	<br>
				1023	The <span style="font-style: italic;">internalFormat</span> parameter
				1024	indicates the desired internal format for the texture and may be either
				1025	GL_INTENSITY8, GL_RGB5 or GL_RGBA8.<br>
				1026	<br>
				1027	If <span style="font-style: italic;">internalFormat</span> is
				1028	GL_INTENSITY8 then the texture has one byte per texel (texture element)
				1029	which indicates the texel's intensity (or brightness).  The
				1030	intensity is obtained from the incoming image's red channel.<br>
				1031	<br>
				1032	If <span style="font-style: italic;">internalFormat</span> is GL_RGB5
				1033	then the texture is stored with two bytes per texel:  5 bits per
				1034	red value, 5 bits per green value and 5 bits per blue value.<br>
				1035	<br>
				1036	If <span style="font-style: italic;">internalFormat </span>is
				1037	GL_RGBA8 then the texture is stored with four bytes per texel:  8
				1038	bits for each of the red, green,  blue and alpha values.<br>
				1039	<br>
				1040	The internal format is also significant to texture application (see
				1041	section 5.4).<br>
				1042	<br>
				1043	<h2>5.2 Texture Coordinates</h2>
				1044	Texture coordinates control the mapping from local polygon space to
				1045	texture image space.  Texture coordinates are set for each vertex
				1046	with the <span style="font-weight: bold;">glTexCoord</span> commands.
				1047	During line and polygon rasterization the vertex's texture
				1048	coordinates are interpolated across the primitive to produce a texture
				1049	coordinate for each fragment.  The fragment texture coordinates are
				1050	used to sample the current texture image.<br>
				1051	<br>
				1052	Texture coordinates are normally in the range [0, 1].  Values
				1053	outside that range are processed according to the <span
				1054	style="font-style: italic;">texture wrap mode</span>.  The
				1055	texture wrap mode is set with the command<br>
				1056	<br>
				1057	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glTexParameteri</span>(GLenum<span
				1058	style="font-style: italic;"> target</span>, GLenum <span
				1059	style="font-style: italic;">pname</span>, GLint <span
				1060	style="font-style: italic;">value</span>)<br>
				1061	<br>
				1062	</div>
				1063	<span style="font-style: italic;">target</span> must be GL_TEXTURE_2D.
				1064	If <span style="font-style: italic;">pname</span> is
				1065	GL_TEXTURE_WRAP_S or GL_TEXTURE_WRAP_T then <span
				1066	style="font-style: italic;">value</span> must be either
				1067	GL_CLAMP_TO_EDGE or GL_REPEAT.<br>
				1068	<br>
				1069	For GL_CLAMP_TO_EDGE, texture coordinates are effectively clamped to
				1070	the interval [0, 1].<br>
				1071	<br>
				1072	For GL_REPEAT, the integer part of texture coordinates is ignored; only
				1073	the fractional part of the texture coordinates is used.  This
				1074	allows texture images to repeated or tiled across an object.<br>
				1075	<br>
				1076	<h2>5.3 Texture Sampling</h2>
				1077	Texture sampling is the process of using texture coordinates to extract
				1078	a color from the texture image.  Multiple, weighted samples may be
				1079	taken from the texture and combined during the filtering step.<br>
				1080	<br>
				1081	During texture coordinate interpolation a <span
				1082	style="font-style: italic;">level of detail</span> value (lambda) is
				1083	computed for each fragment.  For a mipmapped texture, lambda
				1084	determines which level (or levels) of the mipmap will be sampled to
				1085	obtain the texture color.<br>
				1086	<br>
				1087	If lambda indicates that multiple texels map to a single screen pixel,
				1088	then the texture <span style="font-style: italic;">minification</span>
				1089	filter will be used.  Otherwise, if lambda indicates that a single
				1090	texel maps to multiple screen pixels, then the texture <span
				1091	style="font-style: italic;">magnification</span> filter will be used.<br>
				1092	<span style="font-weight: bold;"></span><span
				1093	style="font-style: italic;"></span><br>
				1094	<h3>5.3.1 Texture Minification</h3>
				1095	The texture minification filter is set with the <span
				1096	style="font-weight: bold;">glTexParameteri </span><span
				1097	style="font-style: italic;"></span><span style="font-weight: bold;"></span><span
				1098	style="font-style: italic;"></span> command by setting <span
				1099	style="font-style: italic;">target</span> to GL_TEXTURE_2D, setting <span
				1100	style="font-style: italic;">pname</span> to GL_TEXTURE_MIN_FILTER and
				1101	setting <span style="font-style: italic;">value</span> to GL_NEAREST,
				1102	GL_LINEAR, GL_NEAREST_MIPMAP_NEAREST,
				1103	GL_NEAREST_MIPMAP_LINEAR,   GL_LINEAR_MIPMAP_NEAREST or
				1104	GL_LINEAR_MIPMAP_LINEAR.<br>
				1105	<br>
				1106	GL_NEAREST samples the texel nearest the texture coordinate in the
				1107	level 0 texture image.<br>
				1108	<br>
				1109	GL_LINEAR samples the four texels around the texture coordinate in the
				1110	level 0 texture image.  The four texels are linearly weighted to
				1111	compute the final texel value.<br>
				1112	<br>
				1113	GL_NEAREST_MIPMAP_NEAREST samples the texel nearest the texture
				1114	coordinate in the level N texture image.  N is the level of detail
				1115	and is computed by the partial derivatives of the texture coordinates
				1116	with respect to the window coordinates.<br>
				1117	<br>
				1118	GL_NEAREST_MIPMAP_LINEAR samples two texels nearest the texture
				1119	coordinates in the level N and N+1 texture images.  The two texels
				1120	are linearly weighted to compute the final texel value.  N is the
				1121	level of detail and is computed by the partial derivatives of the
				1122	texture coordinates with respect to the window coordinates.<br>
				1123	<br>
				1124	GL_LINEAR_MIPMAP_NEAREST samples four texels around the texture
				1125	coordinate in the level N texture image.  The four texels are
				1126	linearly weighted to compute the final texel value.  N is the level
				1127	of detail and is computed by the partial derivatives of the texture
				1128	coordinates with respect to the window coordinates.<br>
				1129	<br>
				1130	GL_LINEAR_MIPMAP_LINEAR samples four texels around the texture
				1131	coordinate in the level N texture image and four texels around the
				1132	texture coordinate in the level N+1 texture image.  The eight
				1133	texels are linearly weighted to compute the final texel value.  N
				1134	is the level of detail and is computed by the partial derivatives of the
				1135	texture coordinates with respect to the window coordinates.<br>
				1136	<br>
				1137	Filter modes other than GL_LINEAR and GL_NEAREST requires that the
				1138	texture have a complete set of mipmaps.  If the mipmap is
				1139	incomplete, it is as if texturing is disabled.<br>
				1140	<br>
				1141	<h3>5.3.2 Texture Magnification</h3>
				1142	The texture magnification filter is set with the <span
				1143	style="font-weight: bold;">glTexParameteri </span><span
				1144	style="font-style: italic;"></span><span style="font-weight: bold;"></span>command
				1145	by setting <span style="font-style: italic;">target</span> to
				1146	GL_TEXTURE_2D, setting <span style="font-style: italic;">pname</span> to
				1147	GL_TEXTURE_MAG_FILTER and setting <span style="font-style: italic;">value</span>
				1148	to GL_NEAREST or GL_LINEAR.<br>
				1149	<br>
				1150	GL_NEAREST samples the texel nearest the texture coordinate in the
				1151	level 0 texture image.<br>
				1152	<br>
				1153	GL_LINEAR samples the four texels around the texture coordinate in the
				1154	level 0 texture image.  The four texels are linearly weighted to
				1155	compute the final texel value.<br>
				1156	<br>
				1157	<h2>5.4 Texture Application</h2>
				1158	The sampled texture value is combined with the incoming fragment color
				1159	to produce a new fragment color.  The fragment and texture colors
				1160	are combined according to the texture environment mode and the current
				1161	texture's base internal format.  The texture environment mode is
				1162	set with the command<br>
				1163	<br>
				1164	<div style="margin-left: 40px;">void<span style="font-weight: bold;">
				1165	glTexEnvi</span>(GLenum <span style="font-style: italic;">target</span>,
				1166	GLenum <span style="font-style: italic;">pname</span>, GLint <span
				1167	style="font-style: italic;">value</span>)<br>
				1168	</div>
				1169	<br>
				1170	<span style="font-style: italic;">target</span> must be GL_TEXTURE_ENV.
				1171	If <span style="font-style: italic;">pname</span> is
				1172	GL_TEXTURE_ENV_MODE then <span style="font-style: italic;">value</span>
				1173	must be one of GL_REPLACE, GL_MODULATE, GL_DECAL, or GL_BLEND.<br>
				1174	<br>
				1175	There is also a <span style="font-style: italic;">texture environment
				1176	color</span> that can factor into texture application.  The texture
				1177	environment color can be set with the command<br>
				1178	<br>
				1179	<div style="margin-left: 40px;">void<span style="font-weight: bold;">
				1180	glTexEnvfv</span>(GLenum <span style="font-style: italic;">target</span>,
				1181	GLenum <span style="font-style: italic;">pname</span>, const GLfloat *<span
				1182	style="font-style: italic;">value</span>)<br>
				1183	</div>
				1184	<span style="font-style: italic;"></span><br>
				1185	<span style="font-style: italic;">target</span> must be GL_TEXTURE_ENV.
				1186	If <span style="font-style: italic;">pname</span> is
				1187	GL_TEXTURE_ENV_COLOR then <span style="font-style: italic;">value </span>must
				1188	point to an array of four values which specify the red, green, blue,
				1189	and alpha values of the texture environment color.  The values are
				1190	clamped to the range [0, 1].  The default color is (0, 0, 0, 0).<br>
				1191	<span style="font-style: italic;"></span><br>
				1192	The following table describes the arithmetic used for each combination
				1193	of environment mode and base internal format.  (Rf, Gf, Bf, Af) is
				1194	the incoming fragment color.  (Rt, Gt, Bt, At) is the sampled
				1195	texture color.  Lt is the sampled texture luminance.  <span
				1196	style="font-style: italic;"></span>'It' is the sampled texture
				1197	intensity.  (Rc, Gc, Bc, Ac) is the texture environment color.
				1198	(Rv, Gv, Bv, Av) is the resulting value.<br>
				1199	<br>
				1200	<br>
				1201	<table cellpadding="2" cellspacing="2" border="1"
				1202	style="text-align: left; width: 90%; margin-left: auto; margin-right: auto;">
				1203	<tbody>
				1204	<tr>
				1205	<td style="vertical-align: top;">Base Internal Format<br>
				1206	</td>
				1207	<td style="vertical-align: top;">GL_REPLACE<br>
				1208	</td>
				1209	<td style="vertical-align: top;">GL_MODULATE<br>
				1210	</td>
				1211	<td style="vertical-align: top;">GL_DECAL<br>
				1212	</td>
				1213	<td style="vertical-align: top;">GL_BLEND<br>
				1214	</td>
				1215	</tr>
				1216	<tr>
				1217	<td style="vertical-align: top;">GL_INTENSITY<br>
				1218	</td>
				1219	<td style="vertical-align: top;">Rv = It<br>
				1220	Gv = It<br>
				1221	Bv = It<br>
				1222	Bf = It<br>
				1223	</td>
				1224	<td style="vertical-align: top;">Rv = Rf * It<br>
				1225	Gv = Gf * It<br>
				1226	Bv = Bf * It<br>
				1227	Av = Af * It</td>
				1228	<td style="vertical-align: top;">undefined<br>
				1229	</td>
				1230	<td style="vertical-align: top;">Rv = Rf(1-It) + RcIt<br>
				1231	Gv = Gf(1-It) + GcIt<br>
				1232	Bv = Bf(1-It) + BcIt<br>
				1233	Av = Af(1-It) + AcIt</td>
				1234	</tr>
				1235	<tr>
				1236	<td style="vertical-align: top;">GL_RGB<br>
				1237	</td>
				1238	<td style="vertical-align: top;">Rv = Rt<br>
				1239	Gv = Gt<br>
				1240	Bv = Bt<br>
				1241	Av = Af<br>
				1242	</td>
				1243	<td style="vertical-align: top;">Rv = Rf * Rt<br>
				1244	Gv = Gf * Gt<br>
				1245	Bv = Bf * Bt<br>
				1246	Av = Af<br>
				1247	</td>
				1248	<td style="vertical-align: top;">Rv = Rt<br>
				1249	Gv = Gt<br>
				1250	Bv = Bt<br>
				1251	Av = Af</td>
				1252	<td style="vertical-align: top;">Rv = Rf(1-Rt) + RcRt<br>
				1253	Gv = Gf(1-Gt) + GcGt<br>
				1254	Bv = Bf(1-Bt) + BcBt<br>
				1255	Av = Af</td>
				1256	</tr>
				1257	<tr>
				1258	<td style="vertical-align: top;">GL_RGBA<br>
				1259	</td>
				1260	<td style="vertical-align: top;">Rv = Rt<br>
				1261	Gv = Gt<br>
				1262	Bv = Bt<br>
				1263	Av = At<br>
				1264	</td>
				1265	<td style="vertical-align: top;">Rv = Rf * Rt<br>
				1266	Gv = Gf * Gt<br>
				1267	Bv = Bf * Bt<br>
				1268	Av = Af * At</td>
				1269	<td style="vertical-align: top;">Rv = Rf(1-At) + RtAt<br>
				1270	Gv = Gf(1-At) + GtAt<br>
				1271	Bv = Bf(1-At) + BtAt<br>
				1272	Av = Af<br>
				1273	</td>
				1274	<td style="vertical-align: top;">Rv = Rf(1-Rt) + RcRt<br>
				1275	Gv = Gf(1-Gt) + GcGt<br>
				1276	Bv = Bf(1-Bt) + BcBt<br>
				1277	Av = Af*At</td>
				1278	</tr>
				1279	</tbody>
				1280	</table>
				1281	<br>
				1282	<br>
				1283	<br>
				1284	<h2>5.5 Texture Objects</h2>
				1285	Texture objects encapsulate a set of texture images (mipmap) and
				1286	related state into a named object.  This facilitates use of
				1287	multiple textures in an application.  Texture objects are named
				1288	with GLuints (unsigned integers).  There is a default texture
				1289	object with the name/identifier zero which can never be deleted.<br>
				1290	<br>
				1291	<h3>5.5.1 Creating Texture Objects</h3>
				1292	A texture object is created by binding a new GLuint identifier to the
				1293	GL_TEXTURE_2D target with the command:<br>
				1294	<br>
				1295	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glBindTexture</span>(GLenum<span
				1296	style="font-style: italic;"> target</span>, GLuint <span
				1297	style="font-style: italic;">textureID</span>)<br>
				1298	</div>
				1299	<br>
				1300	<span style="font-style: italic;">target</span> must be GL_TEXTURE_2D.
				1301	<span style="font-style: italic;">textureID</span> may be any
				1302	unsigned integer.  If <span style="font-style: italic;">textureID</span>
				1303	does not name an existing texture object, a new texture object with that
				1304	ID will be created, initialized to the default state.  Whether the
				1305	ID is new or existed previously, that named texture object is bound as
				1306	the <span style="font-style: italic;">current texture object</span>.
				1307	Subsequent <span style="font-weight: bold;">glTexParameter </span>and<span
				1308	style="font-weight: bold;">glTexImage2D<span
				1309	style="font-style: italic;"> </span></span>calls will effect the
				1310	current texture object.<br>
				1311	<span style="font-style: italic;"></span><span
				1312	style="font-weight: bold;"><span style="font-style: italic;"> </span></span><br>
				1313	<h3>5.5.2 Deleting Texture Objects</h3>
				1314	One or more texture objects may be deleted with the command:<br>
				1315	<br>
				1316	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glDeleteTextures</span>(GLsizei<span
				1317	style="font-style: italic;">n</span>, const GLuint *<span
				1318	style="font-style: italic;">textureIDs</span>)<br>
				1319	</div>
				1320	<br>
				1321	<span style="font-style: italic;">textureIDs</span> is an array of <span
				1322	style="font-style: italic;">n</span> texture IDs.  The named
				1323	texture objects will be deleted.  If the current texture object is
				1324	deleted the default texture object (number 0) will be bound as the
				1325	current texture object.<br>
				1326	<br>
				1327	<h3>5.5.3 Allocating Texture Object Identifiers</h3>
				1328	A list of new, unused texture IDs can be obtained by calling the command<br>
				1329	<br>
				1330	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glGenTextures</span>(GLsizei<span
				1331	style="font-style: italic;"> n</span>, GLuint *<span
				1332	style="font-style: italic;">textureIDs</span>)<br>
				1333	</div>
				1334	<br>
				1335	An array of <span style="font-style: italic;">n</span> unused texture
				1336	IDs will be returned in the <span style="font-style: italic;">textureIDs</span>
				1337	array.<br>
				1338	<br>
				1339	<br>
				1340	<h1>6. Per-fragment Operations</h1>
				1341	The fragments produced by rasterization are subjected to a number of
				1342	operations which either modify the fragment or test the fragment
				1343	(discarding the fragment if the test fails.)  This chapter
				1344	describes the per-fragment operations.  They are presented in the
				1345	order in which they're performed.  If a fragment fails a test it is
				1346	discarded and not subjected to subsequent tests or modifications.<br>
				1347	<br>
				1348	<h2>6.1 Scissor Test</h2>
				1349	The scissor test limits rendering to a 2-D rectangular region of the
				1350	framebuffer.  The command<br>
				1351	<br>
				1352	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glScissor</span>(GLint<span
				1353	style="font-style: italic;">x</span>, GLint <span
				1354	style="font-style: italic;">y</span>, GLsizei <span
				1355	style="font-style: italic;">width</span>, GLsizei<span
				1356	style="font-style: italic;"> height</span>)<br>
				1357	</div>
				1358	<br>
				1359	defines a clipping region with the lower-left corner at (<span
				1360	style="font-style: italic;">x, y</span>) and the given <span
				1361	style="font-style: italic;">width</span> and <span
				1362	style="font-style: italic;">height</span>.  The scissor test is
				1363	enabled and disabled with the command <span style="font-weight: bold;">glEnable</span>(GL_SCISSOR_TEST)
				1364	and <span style="font-weight: bold;">glDisable</span>(GL_SCISSOR_TEST).<br>
				1365	<br>
				1366	If the incoming fragment's position is (x<sub>f</sub>, y<sub>f</sub>)
				1367	then the fragment will pass the test if <span
				1368	style="font-style: italic;">x</span> <= x<sub>f</sub> < <span
				1369	style="font-style: italic;">x</span> + <span
				1370	style="font-style: italic;">width</span> and <span
				1371	style="font-style: italic;">y</span> <= y<sub>f</sub> < <span
				1372	style="font-style: italic;">y</span> + <span
				1373	style="font-style: italic;">height.  </span>Otherwise, the
				1374	fragment is discarded.<br>
				1375	<br>
				1376	If <span style="font-style: italic;">width</span> or <span
				1377	style="font-style: italic;">height</span> is less than zero the error
				1378	GL_INVALID_VALUE is raised.  The default scissor rectangle bounds
				1379	are (0, 0, w, h) where w is the initial window width and h is the
				1380	initial window height.  The scissor test is disabled by default.<br>
				1381	<br>
				1382	<h2>6.2 Alpha Test</h2>
				1383	The alpha test compares the fragment's alpha value against a reference
				1384	value and discards the fragment if the comparison fails.  The test
				1385	is specified by the command<br>
				1386	<br>
				1387	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glAlphaFunc</span>(GLenum<span
				1388	style="font-style: italic;">mode</span>, GLclampf <span
				1389	style="font-style: italic;">reference</span>)<br>
				1390	</div>
				1391	<br>
				1392	<span style="font-style: italic;">mode</span> specifies an inequality
				1393	and <span style="font-style: italic;">reference</span> specifies a value
				1394	to compare against.  The following table lists all possible
				1395	modes <span style="font-style: italic;"></span>and the
				1396	corresponding test:<br>
				1397	<br>
				1398	<table cellpadding="2" cellspacing="2" border="1"
				1399	style="text-align: left; width: 50%; margin-left: auto; margin-right: auto;">
				1400	<tbody>
				1401	<tr>
				1402	<td style="vertical-align: top;">Comparison mode<br>
				1403	</td>
				1404	<td style="vertical-align: top;">The test passes if<br>
				1405	</td>
				1406	</tr>
				1407	<tr>
				1408	<td style="vertical-align: top;">GL_LESS<br>
				1409	</td>
				1410	<td style="vertical-align: top;">alpha < <span
				1411	style="font-style: italic;">reference</span><br>
				1412	</td>
				1413	</tr>
				1414	<tr>
				1415	<td style="vertical-align: top;">GL_LEQUAL<br>
				1416	</td>
				1417	<td style="vertical-align: top;">alpha <= <span
				1418	style="font-style: italic;">reference</span></td>
				1419	</tr>
				1420	<tr>
				1421	<td style="vertical-align: top;">GL_GREATER<br>
				1422	</td>
				1423	<td style="vertical-align: top;">alpha > <span
				1424	style="font-style: italic;">reference</span></td>
				1425	</tr>
				1426	<tr>
				1427	<td style="vertical-align: top;">GL_GEQUAL<br>
				1428	</td>
				1429	<td style="vertical-align: top;">alpha >= <span
				1430	style="font-style: italic;">reference</span></td>
				1431	</tr>
				1432	<tr>
				1433	<td style="vertical-align: top;">GL_EQUAL<br>
				1434	</td>
				1435	<td style="vertical-align: top;">alpha == <span
				1436	style="font-style: italic;">reference</span></td>
				1437	</tr>
				1438	<tr>
				1439	<td style="vertical-align: top;">GL_NOTEQUAL<br>
				1440	</td>
				1441	<td style="vertical-align: top;">alpha != <span
				1442	style="font-style: italic;">reference</span></td>
				1443	</tr>
				1444	<tr>
				1445	<td style="vertical-align: top;">GL_NEVER<br>
				1446	</td>
				1447	<td style="vertical-align: top;">never pass<br>
				1448	</td>
				1449	</tr>
				1450	<tr>
				1451	<td style="vertical-align: top;">GL_ALWAYS<br>
				1452	</td>
				1453	<td style="vertical-align: top;">always passes<br>
				1454	</td>
				1455	</tr>
				1456	</tbody>
				1457	</table>
				1458	<br>
				1459	The <span style="font-style: italic;">reference</span> parameter is
				1460	clamped to the range [0, 1].<br>
				1461	<br>
				1462	The alpha test is enabled and disabled with the commands <span
				1463	style="font-weight: bold;">glEnable</span>(GL_ALPHA_TEST) and <span
				1464	style="font-weight: bold;">glDisable</span>(GL_ALPHA_TEST).<br>
				1465	<br>
				1466	The default mode is GL_ALWAYS and the default reference value is 0.<br>
				1467	<br>
				1468	<h2>6.3 Stencil Test</h2>
				1469	The stencil buffer stores an N-bit integer value for each pixel in the
				1470	frame buffer.  The stencil test compares the stencil buffer value
				1471	at the fragment's position to a reference value and possibly discards
				1472	the fragment based on the outcome.  Furthermore, the stencil buffer
				1473	value may be updated or modified depending on the outcome.  If
				1474	there is no stencil buffer the stencil test is bypassed.<br>
				1475	<br>
				1476	Stenciling is controlled by the commands<br>
				1477	<br>
				1478	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glStencilFunc</span>(GLenum<span
				1479	style="font-style: italic;">func</span>, GLint <span
				1480	style="font-style: italic;">ref</span>, GLuint <span
				1481	style="font-style: italic;">mask</span>)<br>
				1482	void <span style="font-weight: bold;">glStencilOp</span>(GLenum <span
				1483	style="font-style: italic;">stencilFail</span>, GLenum <span
				1484	style="font-style: italic;">depthTestFail</span>, GLenum <span
				1485	style="font-style: italic;">depthTestPass</span>)<br>
				1486	</div>
				1487	<br>
				1488	The <span style="font-weight: bold;">glStencilFunc<span
				1489	style="font-style: italic;"> </span></span>command controls the
				1490	stencil test while <span style="font-weight: bold;">glStencilOp</span>
				1491	command controls the how the stencil buffer is updated/modified after
				1492	the test.<br>
				1493	<br>
				1494	<span style="font-style: italic;">ref</span> is clamped to the range [0,
				1495	2<sup>N</sup>-1] where N is the number of bits per stencil value in the
				1496	stencil buffer.<span style="font-style: italic;"></span><br>
				1497	<br>
				1498	The following table lists all possible values for the <span
				1499	style="font-style: italic;">func</span> parameter and when the stencil
				1500	test will pass.  Both the stencil buffer value and the stencil
				1501	reference value are bit-wise ANDed with the <span
				1502	style="font-style: italic;">mask</span> parameter before the test.<br>
				1503	<br>
				1504	<span style="font-style: italic;"></span><span
				1505	style="font-style: italic;"></span><span style="font-style: italic;"></span>
				1506	<table
				1507	style="text-align: left; margin-left: auto; margin-right: auto; width: 70%;"
				1508	border="1" cellspacing="2" cellpadding="2">
				1509	<tbody>
				1510	<tr>
				1511	<td style="vertical-align: top;">Stencil <span
				1512	style="font-style: italic;">func</span> value<br>
				1513	</td>
				1514	<td style="vertical-align: top;">Stencil test passes if<br>
				1515	</td>
				1516	</tr>
				1517	<tr>
				1518	<td style="vertical-align: top;">GL_LESS<br>
				1519	</td>
				1520	<td style="vertical-align: top;"><span style="font-style: italic;">(ref</span>&<span
				1521	style="font-style: italic;">mask)</span> < (stencil buffer value
				1522	& <span style="font-style: italic;">mask)</span><br>
				1523	</td>
				1524	</tr>
				1525	<tr>
				1526	<td style="vertical-align: top;">GL_LEQUAL<br>
				1527	</td>
				1528	<td style="vertical-align: top;"><span style="font-style: italic;">(ref</span>
				1529	& <span style="font-style: italic;">mask) </span><= (stencil
				1530	buffer value & <span style="font-style: italic;">mask)</span></td>
				1531	</tr>
				1532	<tr>
				1533	<td style="vertical-align: top;">GL_GREATER<br>
				1534	</td>
				1535	<td style="vertical-align: top;"><span style="font-style: italic;">(ref</span>
				1536	& <span style="font-style: italic;">mask) </span>> (stencil
				1537	buffer value & <span style="font-style: italic;">mask)</span></td>
				1538	</tr>
				1539	<tr>
				1540	<td style="vertical-align: top;">GL_GEQUAL<br>
				1541	</td>
				1542	<td style="vertical-align: top;"><span style="font-style: italic;">(ref</span>
				1543	& <span style="font-style: italic;">mask) </span>>= (stencil
				1544	buffer value & <span style="font-style: italic;">mask)</span></td>
				1545	</tr>
				1546	<tr>
				1547	<td style="vertical-align: top;">GL_EQUAL<br>
				1548	</td>
				1549	<td style="vertical-align: top;"><span style="font-style: italic;">(ref</span>
				1550	& <span style="font-style: italic;">mask) </span>== (stencil
				1551	buffer value & <span style="font-style: italic;">mask)</span></td>
				1552	</tr>
				1553	<tr>
				1554	<td style="vertical-align: top;">GL_NOTEQUAL<br>
				1555	</td>
				1556	<td style="vertical-align: top;"><span style="font-style: italic;">(ref</span>
				1557	& <span style="font-style: italic;">mask) </span>!= (stencil
				1558	buffer value & <span style="font-style: italic;">mask)</span></td>
				1559	</tr>
				1560	<tr>
				1561	<td style="vertical-align: top;">GL_NEVER<br>
				1562	</td>
				1563	<td style="vertical-align: top;">never passes<br>
				1564	</td>
				1565	</tr>
				1566	<tr>
				1567	<td style="vertical-align: top;">GL_ALWAYS<br>
				1568	</td>
				1569	<td style="vertical-align: top;">always passes<br>
				1570	</td>
				1571	</tr>
				1572	</tbody>
				1573	</table>
				1574	<br>
				1575	<span style="font-style: italic;"></span><br>
				1576	If the stencil test passes, the fragment is passed to the next
				1577	per-fragment operation.  Otherwise, if the stencil test fails, the
				1578	value in the stencil buffer is updated according to the value of the <span
				1579	style="font-style: italic;">stencilFail</span> parameter to <span
				1580	style="font-weight: bold;">glStencilOp</span>.<br>
				1581	<br>
				1582	<table cellpadding="2" cellspacing="2" border="1"
				1583	style="text-align: left; width: 70%; margin-left: auto; margin-right: auto;">
				1584	<tbody>
				1585	<tr>
				1586	<td style="vertical-align: top;"><span style="font-style: italic;">stencilFail</span>
				1587	value<br>
				1588	</td>
				1589	<td style="vertical-align: top;">New stencil buffer value<br>
				1590	</td>
				1591	</tr>
				1592	<tr>
				1593	<td style="vertical-align: top;">GL_KEEP<br>
				1594	</td>
				1595	<td style="vertical-align: top;">originalValue<br>
				1596	</td>
				1597	</tr>
				1598	<tr>
				1599	<td style="vertical-align: top;">GL_ZERO<br>
				1600	</td>
				1601	<td style="vertical-align: top;">0<br>
				1602	</td>
				1603	</tr>
				1604	<tr>
				1605	<td style="vertical-align: top;">GL_INVERT<br>
				1606	</td>
				1607	<td style="vertical-align: top;">BitWiseInvert(originalValue)
				1608	i.e. ~originalValue<br>
				1609	</td>
				1610	</tr>
				1611	<tr>
				1612	<td style="vertical-align: top;">GL_REPLACE<br>
				1613	</td>
				1614	<td style="vertical-align: top;"><span style="font-style: italic;">ref</span><br>
				1615	</td>
				1616	</tr>
				1617	<tr>
				1618	<td style="vertical-align: top;">GL_INCR<br>
				1619	</td>
				1620	<td style="vertical-align: top;">originalValue + 1, clamped to
				1621	[0, 2<sup>N</sup>-1]</td>
				1622	</tr>
				1623	<tr>
				1624	<td style="vertical-align: top;">GL_DECR<br>
				1625	</td>
				1626	<td style="vertical-align: top;">originalValue - 1, clamped to
				1627	[0, 2<sup>N</sup>-1]</td>
				1628	</tr>
				1629	</tbody>
				1630	</table>
				1631	<span style="font-style: italic;"></span><span
				1632	style="font-style: italic;"></span><br>
				1633	<br>
				1634	The <span style="font-style: italic;">depthTestFail</span> and <span
				1635	style="font-style: italic;">depthTestPass</span> parameters to <span
				1636	style="font-weight: bold;">glStencilOp</span> are ignored.  Values
				1637	for <span style="font-style: italic;">func</span> and <span
				1638	style="font-style: italic;">stencilFail</span> other than those listed
				1639	in the table will cause the error GL_INVALID_ENUM to be raised.<br>
				1640	<br>
				1641	The stencil test is enabled and disabled with the commands <span
				1642	style="font-weight: bold;">glEnable</span>(GL_STENCIL_TEST) and <span
				1643	style="font-weight: bold;">glDisable</span>(GL_STENCIL_TEST).<br>
				1644	<br>
				1645	The default stencil function is GL_ALWAYS.  The default stencil
				1646	reference value is 0.  The default stencil mask is ~0.  The
				1647	default stencil fail operation is GL_KEEP.<br>
				1648	<br>
				1649	Values written into the stencil buffer are masked with the command<br>
				1650	<br>
				1651	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glStencilMask</span>(GLuint<span
				1652	style="font-style: italic;">mask</span>)<br>
				1653	</div>
				1654	<br>
				1655	Only the bits which are set in <span style="font-style: italic;">mask</span>
				1656	will be modified in the stencil buffer when written to.  If each
				1657	stencil buffer value has N bits, only the least significant N bits of <span
				1658	style="font-style: italic;">mask</span> are relevant.  The default
				1659	stencil mask is ~0.<br>
				1660	<br>
				1661	<h2>6.4 Blending and Logicop</h2>
				1662	Blending or a logic operation combines the incoming fragment color with
				1663	the destination frame buffer color according to a blending equation or
				1664	bit-wise Boolean logical operation.<br>
				1665	<br>
				1666	Blending is enabled and disabled with the commands <span
				1667	style="font-weight: bold;">glEnable</span>(GL_BLEND) and <span
				1668	style="font-weight: bold;">glDisable</span>(GL_BLEND).<br>
				1669	<br>
				1670	The logic operation is enabled and disabled with the commands <span
				1671	style="font-weight: bold;">glEnable</span>(GL_LOGIC_OP) and <span
				1672	style="font-weight: bold;">glDisable</span>(GL_LOGIC_OP).<br>
				1673	<br>
				1674	If both blending and the logic operation are enabled, the logic
				1675	operation has higher priority; blending is bypassed.<br>
				1676	<br>
				1677	<h3>6.4.1 Logic Op</h3>
				1678	The command<br>
				1679	<br>
				1680	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glLogicop</span>(GLenum<span
				1681	style="font-style: italic;">mode</span>)<br>
				1682	<br>
				1683	</div>
				1684	Specifies the Boolean logic operation for combining the incoming
				1685	fragment color with the destination frame buffer color.  Both the
				1686	incoming fragment color and destination frame buffer colors are
				1687	interpreted as four-tuples of unsigned integer color components in the
				1688	range [0, 2<sup>N</sup>-1] where N is the number of bits per color
				1689	channel.  N may not be the same for all color channels.<br>
				1690	<br>
				1691	The following table lists all values for <span
				1692	style="font-style: italic;">mode</span> and the boolean arithmetic used
				1693	to combine the incoming fragment color value (src)<span
				1694	style="font-style: italic;"></span><span style="font-style: italic;"></span><span
				1695	style="font-style: italic;"></span><span style="font-style: italic;"></span><span
				1696	style="font-style: italic;"></span> with the destination framebuffer
				1697	color value (dst).  Standard ANSI C operators used.<br>
				1698	<br>
				1699	<table cellpadding="2" cellspacing="2" border="1"
				1700	style="text-align: left; width: 50%; margin-left: auto; margin-right: auto;">
				1701	<tbody>
				1702	<tr>
				1703	<td style="vertical-align: top;">LogicOp <span
				1704	style="font-style: italic;">mode</span><br>
				1705	</td>
				1706	<td style="vertical-align: top;">Resulting channel value<br>
				1707	</td>
				1708	</tr>
				1709	<tr>
				1710	<td style="vertical-align: top;">GL_CLEAR<br>
				1711	</td>
				1712	<td style="vertical-align: top;">0<br>
				1713	</td>
				1714	</tr>
				1715	<tr>
				1716	<td style="vertical-align: top;">GL_SET<br>
				1717	</td>
				1718	<td style="vertical-align: top;">~0<br>
				1719	</td>
				1720	</tr>
				1721	<tr>
				1722	<td style="vertical-align: top;">GL_COPY<br>
				1723	</td>
				1724	<td style="vertical-align: top;">src<br>
				1725	</td>
				1726	</tr>
				1727	<tr>
				1728	<td style="vertical-align: top;">GL_COPY_INVERTED<br>
				1729	</td>
				1730	<td style="vertical-align: top;">~s<br>
				1731	</td>
				1732	</tr>
				1733	<tr>
				1734	<td style="vertical-align: top;">GL_NOOP<br>
				1735	</td>
				1736	<td style="vertical-align: top;">dst<br>
				1737	</td>
				1738	</tr>
				1739	<tr>
				1740	<td style="vertical-align: top;">GL_INVERT<br>
				1741	</td>
				1742	<td style="vertical-align: top;">~dst<br>
				1743	</td>
				1744	</tr>
				1745	<tr>
				1746	<td style="vertical-align: top;">GL_AND<br>
				1747	</td>
				1748	<td style="vertical-align: top;">src & dst<br>
				1749	</td>
				1750	</tr>
				1751	<tr>
				1752	<td style="vertical-align: top;">GL_NAND<br>
				1753	</td>
				1754	<td style="vertical-align: top;">~(src & dst)<br>
				1755	</td>
				1756	</tr>
				1757	<tr>
				1758	<td style="vertical-align: top;">GL_AND_REVERSE<br>
				1759	</td>
				1760	<td style="vertical-align: top;">src & ~dst<br>
				1761	</td>
				1762	</tr>
				1763	<tr>
				1764	<td style="vertical-align: top;">GL_AND_INVERTED<br>
				1765	</td>
				1766	<td style="vertical-align: top;">~src & dst<br>
				1767	</td>
				1768	</tr>
				1769	<tr>
				1770	<td style="vertical-align: top;">GL_OR<br>
				1771	</td>
				1772	<td style="vertical-align: top;">src \| dst<br>
				1773	</td>
				1774	</tr>
				1775	<tr>
				1776	<td style="vertical-align: top;">GL_NOR<br>
				1777	</td>
				1778	<td style="vertical-align: top;">~(src \| dst)<br>
				1779	</td>
				1780	</tr>
				1781	<tr>
				1782	<td style="vertical-align: top;">GL_OR_REVERSE<br>
				1783	</td>
				1784	<td style="vertical-align: top;">src \| ~dst<br>
				1785	</td>
				1786	</tr>
				1787	<tr>
				1788	<td style="vertical-align: top;">GL_OR_INVERTED<br>
				1789	</td>
				1790	<td style="vertical-align: top;">~src \| dst<br>
				1791	</td>
				1792	</tr>
				1793	<tr>
				1794	<td style="vertical-align: top;">GL_XOR<br>
				1795	</td>
				1796	<td style="vertical-align: top;">src ^ dst<br>
				1797	</td>
				1798	</tr>
				1799	<tr>
				1800	<td style="vertical-align: top;">GL_EQUIV<br>
				1801	</td>
				1802	<td style="vertical-align: top;">~(src ^ dst)<br>
				1803	</td>
				1804	</tr>
				1805	</tbody>
				1806	</table>
				1807	<br>
				1808	The fragment's color is replaced by the result of the logic operation.<br>
				1809	<br>
				1810	Specifying any value for <span style="font-style: italic;">mode</span>
				1811	other than those listed in the above table will cause the error
				1812	GL_INVALID_ENUM to be raised.<br>
				1813	<br>
				1814	The default value for <span style="font-style: italic;">mode</span> is
				1815	GL_COPY.  The logic operation is disabled by default.<br>
				1816	<br>
				1817	<h3>6.4.2 Blending</h3>
				1818	The command<br>
				1819	<br>
				1820	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glBlendFunc</span>(GLenum<span
				1821	style="font-style: italic;">srcTerm</span>, GLenum <span
				1822	style="font-style: italic;">dstTerm</span>)<br>
				1823	</div>
				1824	<br>
				1825	specifies the terms of the blending equation.  If Cf = (Rf, Gf,
				1826	Bf, Af) is the incoming fragment color and Cb = (Rb, Gb, Bb, Ab) is the
				1827	frame buffer color, then the resulting color Cv = (Rv, Gv, Bv, Av) is
				1828	computed by:<br>
				1829	<br>
				1830	<div style="margin-left: 40px;">Cv = Cf * <span
				1831	style="font-style: italic;">srcTerm</span> + Cb * <span
				1832	style="font-style: italic;">dstTerm</span><br>
				1833	<span style="font-style: italic;"></span></div>
				1834	<span style="font-style: italic;"> </span><br>
				1835	All possible values for <span style="font-style: italic;">srcTerm</span>
				1836	and the corresponding arithmetic term are listed in the following table:<br>
				1837	<br>
				1838	<table cellpadding="2" cellspacing="2" border="1"
				1839	style="text-align: left; width: 70%; margin-left: auto; margin-right: auto;">
				1840	<tbody>
				1841	<tr>
				1842	<td style="vertical-align: top;"><span style="font-style: italic;">srcTerm</span><br>
				1843	</td>
				1844	<td style="vertical-align: top;"><span style="font-style: italic;">srcTerm</span>Arithmetic<br>
				1845	</td>
				1846	</tr>
				1847	<tr>
				1848	<td style="vertical-align: top;">GL_ZERO<br>
				1849	</td>
				1850	<td style="vertical-align: top;">(0, 0, 0, 0)<br>
				1851	</td>
				1852	</tr>
				1853	<tr>
				1854	<td style="vertical-align: top;">GL_ONE<br>
				1855	</td>
				1856	<td style="vertical-align: top;">(1, 1, 1, 1)<br>
				1857	</td>
				1858	</tr>
				1859	<tr>
				1860	<td style="vertical-align: top;">GL_DST_COLOR<br>
				1861	</td>
				1862	<td style="vertical-align: top;">(Rb, Gb, Bb, Ab)<br>
				1863	</td>
				1864	</tr>
				1865	<tr>
				1866	<td style="vertical-align: top;">GL_ONE_MINUS_DST_COLOR<br>
				1867	</td>
				1868	<td style="vertical-align: top;">(1-Rb, 1-Gb, 1-Bb, 1-Ab)<br>
				1869	</td>
				1870	</tr>
				1871	<tr>
				1872	<td style="vertical-align: top;">GL_SRC_ALPHA<br>
				1873	</td>
				1874	<td style="vertical-align: top;">(Af, Af, Af, AF)<br>
				1875	</td>
				1876	</tr>
				1877	<tr>
				1878	<td style="vertical-align: top;">GL_ONE_MINUS_SRC_ALPHA<br>
				1879	</td>
				1880	<td style="vertical-align: top;">(1-Af, 1-Af, 1-Af, 1-Af)<br>
				1881	</td>
				1882	</tr>
				1883	<tr>
				1884	<td style="vertical-align: top;">GL_DST_ALPHA<br>
				1885	</td>
				1886	<td style="vertical-align: top;">(Ab, Ab, Ab, Ab)<br>
				1887	</td>
				1888	</tr>
				1889	<tr>
				1890	<td style="vertical-align: top;">GL_ONE_MINUS_DST_ALPHA<br>
				1891	</td>
				1892	<td style="vertical-align: top;">(1-Ab, 1-Ab, 1-Ab, 1-Ab)<br>
				1893	</td>
				1894	</tr>
				1895	<tr>
				1896	<td style="vertical-align: top;">GL_SRC_ALPHA_SATURATE<br>
				1897	</td>
				1898	<td style="vertical-align: top;">(m, m, m, 1) where m = MIN(Af,
				1899	1-Ab)<br>
				1900	</td>
				1901	</tr>
				1902	</tbody>
				1903	</table>
				1904	<br>
				1905	All possible values for <span style="font-style: italic;">srcTerm</span>
				1906	and the corresponding arithmetic term are listed in the following table:<br>
				1907	<br>
				1908	<table cellpadding="2" cellspacing="2" border="1"
				1909	style="text-align: left; width: 70%; margin-left: auto; margin-right: auto;">
				1910	<tbody>
				1911	<tr>
				1912	<td style="vertical-align: top;"><span style="font-style: italic;">dstTerm</span><br>
				1913	</td>
				1914	<td style="vertical-align: top;"><span style="font-style: italic;">dstTerm</span>Arithmetic<br>
				1915	</td>
				1916	</tr>
				1917	<tr>
				1918	<td style="vertical-align: top;">GL_ZERO<br>
				1919	</td>
				1920	<td style="vertical-align: top;">(0, 0, 0, 0)<br>
				1921	</td>
				1922	</tr>
				1923	<tr>
				1924	<td style="vertical-align: top;">GL_ONE<br>
				1925	</td>
				1926	<td style="vertical-align: top;">(1, 1, 1, 1)<br>
				1927	</td>
				1928	</tr>
				1929	<tr>
				1930	<td style="vertical-align: top;">GL_SRC_COLOR<br>
				1931	</td>
				1932	<td style="vertical-align: top;">(Rf, Gf, Bf, Af)<br>
				1933	</td>
				1934	</tr>
				1935	<tr>
				1936	<td style="vertical-align: top;">GL_ONE_MINUS_SRC_COLOR<br>
				1937	</td>
				1938	<td style="vertical-align: top;">(1-Rf, 1-Gf, 1-Bf, 1-Af)<br>
				1939	</td>
				1940	</tr>
				1941	<tr>
				1942	<td style="vertical-align: top;">GL_SRC_ALPHA<br>
				1943	</td>
				1944	<td style="vertical-align: top;">(Af, Af, Af, AF)<br>
				1945	</td>
				1946	</tr>
				1947	<tr>
				1948	<td style="vertical-align: top;">GL_ONE_MINUS_SRC_ALPHA<br>
				1949	</td>
				1950	<td style="vertical-align: top;">(1-Af, 1-Af, 1-Af, 1-Af)<br>
				1951	</td>
				1952	</tr>
				1953	<tr>
				1954	<td style="vertical-align: top;">GL_DST_ALPHA<br>
				1955	</td>
				1956	<td style="vertical-align: top;">(Ab, Ab, Ab, Ab)<br>
				1957	</td>
				1958	</tr>
				1959	<tr>
				1960	<td style="vertical-align: top;">GL_ONE_MINUS_DST_ALPHA<br>
				1961	</td>
				1962	<td style="vertical-align: top;">(1-Ab, 1-Ab, 1-Ab, 1-Ab)<br>
				1963	</td>
				1964	</tr>
				1965	</tbody>
				1966	</table>
				1967	<br>
				1968	The fragment's color is replaced by the result of the blending equation.<br>
				1969	<br>
				1970	Values for <span style="font-style: italic;">srcTerm</span> and <span
				1971	style="font-style: italic;">dstTerm</span> other than those listed in
				1972	the table will cause the error GL_INVALID_ENUM to be raised.<br>
				1973	<br>
				1974	The default value for <span style="font-style: italic;">srcTerm</span>
				1975	is GL_ONE.  The default value for <span style="font-style: italic;">dstTerm</span>
				1976	is GL_ZERO.  Blending is disabled by default.<br>
				1977	<br>
				1978	<h2>6.5 Color Mask</h2>
				1979	The final fragment color is written into the current color buffer at
				1980	the end of the per-fragment operations.  Normally, all color
				1981	channels in the frame buffer are replaced with the final fragment color.
				1982	However, the command<br>
				1983	<br>
				1984	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glColorMask</span>(GLboolean<span
				1985	style="font-style: italic;">redMask</span>, GLboolean <span
				1986	style="font-style: italic;">greenMask</span>, GLboolean <span
				1987	style="font-style: italic;">blueMask</span>, GLboolean <span
				1988	style="font-style: italic;">alphaMask</span>)<br>
				1989	</div>
				1990	<br>
				1991	allows selective writing to individual color channels.  If <span
				1992	style="font-style: italic;">redMask</span> is GL_TRUE then writing to
				1993	the red color channel is enabled, otherwise it's disabled.
				1994	Similarly, the green, blue and alpha channels can also be masked.<br>
				1995	<br>
				1996	Initially all four mask values are GL_TRUE.<br>
				1997	<br>
				1998	Color masking is not enabled/disabled with the <span
				1999	style="font-weight: bold;">glEnable</span>/<span
				2000	style="font-weight: bold;">glDisable</span> commands.<br>
				2001	<br>
				2002	<h1>7. Frame Buffer Operations</h1>
				2003	The frame buffer is considered to be a two-dimensional array of pixels.
				2004	The frame buffer is also organized into layers or logical buffers.
				2005	There may be a front color buffer, back color buffer and stencil
				2006	buffer.  A double-buffered frame buffer has both a front color
				2007	buffer and back color buffer.  A single-buffered framebuffer only
				2008	has a front color buffer.  Each pixel in a color buffer has a red,
				2009	green and blue value and an optional alpha value.<br>
				2010	<br>
				2011	<h2>7.1 Clearing Buffers</h2>
				2012	Buffers are cleared (set to uniform values) with the command<br>
				2013	<br>
				2014	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glClear</span>(GLbitfield<span
				2015	style="font-style: italic;">buffers</span>)<br>
				2016	</div>
				2017	<br>
				2018	<span style="font-style: italic;">buffers</span> is a bitmask for which
				2019	the value may be the bitwise-OR of the values GL_COLOR_BUFFER_BIT and
				2020	GL_STENCIL_BUFFER_BIT.  If the GL_COLOR_BUFFER_BIT bit is
				2021	specified, the current color buffer will be cleared.  If the
				2022	GL_STENCIL_BUFFER_BIT bit is specified, the stencil buffer will be
				2023	cleared.<br>
				2024	<br>
				2025	The current color buffer is specified with the command<br>
				2026	<br>
				2027	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glDrawBuffer</span>(GLenum<span
				2028	style="font-style: italic;"> buffer</span>)<br>
				2029	</div>
				2030	<br>
				2031	<span style="font-style: italic;">buffer</span> may be either GL_FRONT,
				2032	GL_BACK or GL_NONE.  GL_FRONT indicates that the front color buffer
				2033	will be modified by <span style="font-weight: bold;">glClear</span> and
				2034	any drawing command.  GL_BACK indicates that the back color buffer
				2035	will be modified by <span style="font-weight: bold;">glClear</span> and
				2036	any drawing command.  GL_NONE indicates that neither color buffer
				2037	will be modified by <span style="font-weight: bold;">glClear</span> or
				2038	any drawing command.  GL_BACK is only valid for double-buffered
				2039	frame buffers.<br>
				2040	<br>
				2041	The current scissor rectangle, set by the <span
				2042	style="font-weight: bold;">glScissor</span> command, effects <span
				2043	style="font-weight: bold;">glClear</span><span
				2044	style="font-style: italic;">,</span><span style="font-style: italic;"> </span>limiting
				2045	the clear to the scissor rectangle, if it's enabled.  Furthermore, <span
				2046	style="font-weight: bold;"></span>only the color channels enabled by <span
				2047	style="font-weight: bold;">glColorMask</span> will be effected by <span
				2048	style="font-weight: bold;">glClear</span>(GL_COLOR_BUFFER_BIT).
				2049	Likewise, only the stencil bits enabled by <span
				2050	style="font-weight: bold;">glStencilMask</span> will be effected by <span
				2051	style="font-weight: bold;">glClear</span>(GL_STENCIL_BUFFER_BIT).<br>
				2052	<br>
				2053	The current clear color is set with the command<br>
				2054	<br>
				2055	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glClearColor</span>(GLclampf<span
				2056	style="font-style: italic;">red</span>, GLclampf <span
				2057	style="font-style: italic;">green</span>, GLclampf <span
				2058	style="font-style: italic;">blue</span>, GLclampf <span
				2059	style="font-style: italic;">alpha</span>)<br>
				2060	</div>
				2061	<br>
				2062	Subsequent calls to <span style="font-weight: bold;">glClear</span>
				2063	will use the color (<span style="font-style: italic;">red, green, blue,
				2064	alpha</span>) to clear the front or back color buffers.<br>
				2065	<span style="font-style: italic;"></span><br>
				2066	The current stencil clear value is set with the command<br>
				2067	<br>
				2068	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glClearStencil</span>(GLint<span
				2069	style="font-style: italic;">clearValue</span>)<br>
				2070	</div>
				2071	<br>
				2072	If the stencil buffer is N bits deep, the least significant N bits of <span
				2073	style="font-style: italic;">clearValue</span> will be used to clear the
				2074	stencil buffer.<br>
				2075	<br>
				2076	<br>
				2077	<h1>8. Other Features</h1>
				2078	<h2>8.1 Frame Buffer Readback</h2>
				2079	A rectangular region of pixels can be read from the frame buffer and
				2080	placed in client memory with the command<br>
				2081	<br>
				2082	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glReadPixels</span>(GLint<span
				2083	style="font-style: italic;">x</span>, GLint <span
				2084	style="font-style: italic;">y</span>, GLsizei <span
				2085	style="font-style: italic;">width</span>, GLsizei <span
				2086	style="font-style: italic;">height</span>, GLenum <span
				2087	style="font-style: italic;">format</span>, GLenum <span
				2088	style="font-style: italic;">type</span>, GLvoid *<span
				2089	style="font-style: italic;">data</span>)<br>
				2090	</div>
				2091	<br>
				2092	<span style="font-style: italic;">x</span> and <span
				2093	style="font-style: italic;">y</span> specify the coordinate of the
				2094	lower-left corner of the region to read and <span
				2095	style="font-style: italic;">width</span> and <span
				2096	style="font-style: italic;">height</span> specify the size of the
				2097	rectangular region to read.  <span style="font-style: italic;">format</span>
				2098	specifies the format of image data and must be either GL_RGB or
				2099	GL_RGBA.  <span style="font-style: italic;">type</span> specify the
				2100	data type of the image data and must be either GL_UNSIGNED_BYTE or
				2101	GL_FLOAT.  Other values for <span style="font-style: italic;">format</span>
				2102	or <span style="font-style: italic;">type</span> will cause the error
				2103	GL_INVALID_ENUM to be raised.<br>
				2104	<br>
				2105	The framebuffer may contain 3-component colors (red, green, blue) or
				2106	4-component colors (red, green, blue, alpha).  If an alpha channel
				2107	is not present, alpha values default to 1.0.<br>
				2108	<br>
				2109	The frame buffer color components (red, green, blue, alpha) are either
				2110	converted to 8-bit unsigned integers in the range[0, 255] if <span
				2111	style="font-style: italic;">type </span>is GL_UNSIGNED_BYTE or
				2112	converted to floating point values in the range [0, 1] if <span
				2113	style="font-style: italic;">type</span> is GL_FLOAT.  The (red,
				2114	green, blue, alpha) tuples are then stored as GL_RGB triplets (by
				2115	dropping the alpha component) or GL_RGBA quadruples in client memory.<br>
				2116	<br>
				2117	Image data is <span style="font-style: italic;">packed</span> into
				2118	client memory according to the pixel packing parameters which are set by
				2119	the command<br>
				2120	<br>
				2121	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glPixelStorei</span>(GLenum<span
				2122	style="font-style: italic;"> pname</span>, GLint <span
				2123	style="font-style: italic;">value</span>)<br>
				2124	</div>
				2125	<br>
				2126	<span style="font-style: italic;">pname</span> must be
				2127	GL_PACK_ROW_LENGTH.  <span style="font-style: italic;">value</span>
				2128	indicates the stride (in pixels) between subsequent rows in the
				2129	destination image.  If GL_PACK_ROW_LENGTH is zero (the default)
				2130	then the <span style="font-style: italic;">width</span> parameter to <span
				2131	style="font-weight: bold;">glReadPixels</span> indicates the row stride.<br>
				2132	<br>
				2133	Pixel readback takes place as follows:<br>
				2134	<br>
				2135	<div style="margin-left: 40px;">if (GL_PACK_ROW_LENGTH == 0)<br>
				2136	rowLength = <span style="font-style: italic;">width</span>;<br>
				2137	else<br>
				2138	rowLength = GL_PACK_ROW_LENGTH<br>
				2139	<br>
				2140	if (<span style="font-style: italic;">format</span> == GL_RGB) {<br>
				2141	for (i = 0; i < <span style="font-style: italic;">height</span>;
				2142	i++) {<br>
				2143	for (j = 0; j < <span
				2144	style="font-style: italic;">width</span>; j++) {<br>
				2145	k = (i *
				2146	rowLength + j) * 3;<br>
				2147	<span
				2148	style="font-style: italic;">data</span>[k+0] = FrameBuffer(<span
				2149	style="font-style: italic;">x</span> + j, <span
				2150	style="font-style: italic;">y</span> + i).red;<br>
				2151	<span
				2152	style="font-style: italic;">data</span>[k+1] = FrameBuffer(<span
				2153	style="font-style: italic;">x</span> + j, <span
				2154	style="font-style: italic;">y</span> + i).green;<br>
				2155	<span
				2156	style="font-style: italic;">data</span>[k+2] = FrameBuffer(<span
				2157	style="font-style: italic;">x</span> + j, <span
				2158	style="font-style: italic;">y</span> + i).blue;<span
				2159	style="font-style: italic;"></span><br>
				2160	}<br>
				2161	}<br>
				2162	}<br>
				2163	else {<br>
				2164	for (i = 0; i < <span style="font-style: italic;">height</span>;
				2165	i++) {<br>
				2166	for (j = 0; j < <span
				2167	style="font-style: italic;">width</span>; j++) {<br>
				2168	k = (i *
				2169	rowLength + j) * 4;<br>
				2170	<span
				2171	style="font-style: italic;">data</span>[k+0] = FrameBuffer(<span
				2172	style="font-style: italic;">x</span> + j, <span
				2173	style="font-style: italic;">y</span> + i).red;<br>
				2174	<span
				2175	style="font-style: italic;">data</span>[k+1] = FrameBuffer(<span
				2176	style="font-style: italic;">x</span> + j, <span
				2177	style="font-style: italic;">y</span> + i).green;<br>
				2178	<span
				2179	style="font-style: italic;">data</span>[k+2] = FrameBuffer(<span
				2180	style="font-style: italic;">x</span> + j, <span
				2181	style="font-style: italic;">y</span> + i).blue;<span
				2182	style="font-style: italic;"></span><br>
				2183	<span
				2184	style="font-style: italic;">data</span>[k+3] = FrameBuffer(<span
				2185	style="font-style: italic;">x</span> + j, <span
				2186	style="font-style: italic;">y</span> + i).alpha;<span
				2187	style="font-style: italic;"></span><br>
				2188	}<br>
				2189	}<br>
				2190	}<br>
				2191	</div>
				2192	<br>
				2193	The function FrameBuffer(<span style="font-style: italic;">c, r</span>)
				2194	returns the pixel in the frame buffer at column <span
				2195	style="font-style: italic;">c</span> of row <span
				2196	style="font-style: italic;">r.  </span><span
				2197	style="font-style: italic;">data</span> is considered to be either a
				2198	GLubyte pointer or a GLfloat pointer, depending on the <span
				2199	style="font-style: italic;">type</span> parameter.  Similarly, the
				2200	FrameBuffer function returns either GLubyte values in the range [0, 255]
				2201	or GLfloat values in the range [0,1], depending on the <span
				2202	style="font-style: italic;">type</span> parameter.<br>
				2203	<br>
				2204	Pixels may be read from either the front or back color buffer.
				2205	The command<br>
				2206	<br>
				2207	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glReadBuffer</span>(GLenum<span
				2208	style="font-style: italic;">buffer</span>)<br>
				2209	</div>
				2210	<br>
				2211	specifies the source for reading images with <span
				2212	style="font-weight: bold;">glReadPixels</span>.  If <span
				2213	style="font-style: italic;">buffer</span> is GL_FRONT then front color
				2214	buffer is the source.  If <span style="font-style: italic;">buffer</span>
				2215	is GL_BACK then the back color buffer is the source.  It is illegal
				2216	to specify GL_BACK when the color buffer is not double buffered.
				2217	Any invalid value for <span style="font-style: italic;">buffer</span>
				2218	will raise the error GL_INVALID_ENUM.<br>
				2219	<br>
				2220	The default read source is GL_BACK if the frame buffer is double
				2221	buffered.  Otherwise, the default read source is GL_FRONT.<br>
				2222	<br>
				2223	<h2>8.2 Selection Mode</h2>
				2224	Selection mode is typically used to implement <span
				2225	style="font-style: italic;">picking</span>: determining which
				2226	primitive(s) are present at particular window positions.  The
				2227	command<br>
				2228	<br>
				2229	<div style="margin-left: 40px;">GLint <span style="font-weight: bold;">glRenderMode</span>(GLenum<span
				2230	style="font-style: italic;">mode</span>)<br>
				2231	</div>
				2232	<br>
				2233	is used to enable selection mode.  If <span
				2234	style="font-style: italic;">mode</span> is GL_SELECTION the graphics
				2235	library is put into selection mode.  If <span
				2236	style="font-style: italic;">mode</span> is GL_RENDER the graphic
				2237	library is put into normal rendering mode.  Any other value for <span
				2238	style="font-style: italic;">mode</span> will raise the error
				2239	GL_INVALID_ENUM.<br>
				2240	<br>
				2241	When in selection mode rendering commands will not effect the
				2242	framebuffer.  Instead, a record of the primitives that would have
				2243	been drawn is placed in the <span style="font-style: italic;">selection</span> <span
				2244	style="font-style: italic;">buffer</span>.  The selection buffer
				2245	is specified with the command<br>
				2246	<br>
				2247	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glSelectionBuffer</span>(GLsizei<span
				2248	style="font-style: italic;">n</span>, GLuint *<span
				2249	style="font-style: italic;">buffer</span>)<br>
				2250	</div>
				2251	<span style="font-style: italic;"></span><span
				2252	style="font-style: italic;"><br>
				2253	buffer</span> is an array of <span style="font-style: italic;">n</span>
				2254	unsigned integers.  No more than <span style="font-style: italic;">n</span>
				2255	values will be placed in the buffer.<br>
				2256	<br>
				2257	The <span style="font-style: italic;">name stack</span> is a stack
				2258	(LIFO) of unsigned integer names.  The following commands
				2259	manipulate the name stack:<br>
				2260	<br>
				2261	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glInitNames</span>(void)<br>
				2262	void <span style="font-weight: bold;">glPushName</span>(GLuint <span
				2263	style="font-style: italic;">name</span>)<br>
				2264	void <span style="font-weight: bold;">glPopName</span>(void)<br>
				2265	void <span style="font-weight: bold;">glLoadName</span>(GLuint <span
				2266	style="font-style: italic;">name</span>)<br>
				2267	</div>
				2268	<br>
				2269	<span style="font-weight: bold;">glInitNames</span> resets the name
				2270	stack to an empty state.  <span style="font-weight: bold;">glPushName<span
				2271	style="font-style: italic;"> </span></span>pushes the given <span
				2272	style="font-style: italic;">name</span> value onto the stack.  <span
				2273	style="font-weight: bold;">glPopName</span> pops the top name from the
				2274	stack.  <span style="font-weight: bold;">glLoadName<span
				2275	style="font-style: italic;"> </span></span>replaces the top value on
				2276	the stack with the specified <span style="font-style: italic;">name</span>.
				2277	Stack underflow and overflow conditions cause the errors
				2278	GL_STACK_OVERFLOW and GL_STACK_UNDERFLOW to be raised.<br>
				2279	<br>
				2280	While in selection mode, primitives (points, lines, polygons) are
				2281	transformed and clip-tested normally.  Primitives which aren't
				2282	discarded by clipping cause the <span style="font-style: italic;">hit</span> <span
				2283	style="font-style: italic;">data</span> to be updated.  The hit
				2284	data consists of three pieces of information: a hit flag, a minimum Z
				2285	value and a maximum Z value.  First, the hit flag is set.
				2286	Then, for each of the primitive's vertices, the vertex Z value is
				2287	compared to the minimum and maximum Z values.  The minimum Z value
				2288	is updated if the vertex's Z value is less than the minimum Z value.
				2289	The maximum Z value is updated if the vertex's Z value is greater
				2290	than the maximum Z value.<br>
				2291	<br>
				2292	When any of <span style="font-weight: bold;">glInitNames</span><span
				2293	style="font-style: italic;"><span style="font-style: italic;">, </span></span><span
				2294	style="font-weight: bold;">glPushName</span>, <span
				2295	style="font-weight: bold;">glPopName</span>, <span
				2296	style="font-weight: bold;">glLoadName</span> or <span
				2297	style="font-weight: bold;">glRenderMode</span> are called and the hit
				2298	flag is set, a <span style="font-style: italic;">hit record</span> is
				2299	written to the selection buffer.<br>
				2300	<br>
				2301	A hit record consists of a sequence of unsigned integers.  The
				2302	first value is the size of the name stack.  The second value is the
				2303	minimum Z value multiplied by 2<sup>32</sup>-1.  The third value is
				2304	the maximum Z value multiplied by 2<sup>32</sup>-1.  The remaining
				2305	values are the values in the name stack, in bottom to top order.
				2306	The hit flag is cleared after a hit record is written to the
				2307	selection buffer.  Hit records are places sequentially into the
				2308	selection buffer until it is full or selection mode is terminated.<br>
				2309	<br>
				2310	Selection mode is terminated by calling <span
				2311	style="font-weight: bold;">glRenderMode</span>(GL_RENDER).   The
				2312	return value of <span style="font-weight: bold;">glRenderMode</span>
				2313	will be -1 if the selection buffer overflowed.  Otherwise, the
				2314	return value will indicate the number of values written into the
				2315	selection buffer.<br>
				2316	<br>
				2317	<h2>8.3 Synchronization</h2>
				2318	The command<br>
				2319	<br>
				2320	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glFlush</span>(void)<br>
				2321	</div>
				2322	<br>
				2323	makes the graphics library to flush all pending graphics commands.
				2324	The command<br>
				2325	<div style="margin-left: 40px;"><br>
				2326	void <span style="font-weight: bold;">glFinish</span>(void)<br>
				2327	</div>
				2328	<br>
				2329	makes the graphics library flush the command queue and wait until those
				2330	commands are completed.  <span style="font-weight: bold;">glFlush</span>
				2331	will not return until all previous graphics commands have been fully
				2332	completed.<br>
				2333	<br>
				2334	These commands are typically used to force completion of rendering to
				2335	the front color buffer.  Otherwise, rendering to the front color
				2336	buffer may not appear.  The <span style="font-style: italic;">swapbuffers</span>
				2337	command (part of the window system binding library) does an implicit
				2338	flush before swapping the front and back color buffers.  The <span
				2339	style="font-weight: bold;">glReadPixels</span> command also does an
				2340	implicit flush before reading pixel data from the frame buffer.<br>
				2341	<br>
				2342	<h1>9. State Queries</h1>
				2343	The current value of nearly all library state variables can be queried.
				2344	This chapter describes the commands used for querying the value of
				2345	state variables.<br>
				2346	<br>
				2347	<h2>9.1 General State Queries</h2>
				2348	The command<br>
				2349	<br>
				2350	<div style="margin-left: 40px;">void <span style="font-weight: bold;">glGetFloatv</span>(GLenum<span
				2351	style="font-style: italic;">pname</span>, GLfloat *<span
				2352	style="font-style: italic;">values</span>)<br>
				2353	</div>
				2354	<br>
				2355	returns the value(s) of the state variable specified by <span
				2356	style="font-style: italic;">pname</span>.  The following table
				2357	lists all accepted values for <span style="font-style: italic;">pname</span>
				2358	and a description of the value(s).  Specifying any other value for <span
				2359	style="font-style: italic;">pname</span> causes the error
				2360	GL_INVALID_ENUM to be raised.<br>
				2361	<br>
				2362	<table cellpadding="2" cellspacing="2" border="1"
				2363	style="text-align: left; width: 90%; margin-left: auto; margin-right: auto;">
				2364	<tbody>
				2365	<tr>
				2366	<td style="vertical-align: top;">Variable (<span
				2367	style="font-style: italic;">pname)</span><br>
				2368	</td>
				2369	<td style="vertical-align: top;">Number of values<br>
				2370	</td>
				2371	<td style="vertical-align: top;">Value(s) Description<br>
				2372	</td>
				2373	</tr>
				2374	<tr>
				2375	<td style="vertical-align: top;">GL_ALPHA_BITS<br>
				2376	</td>
				2377	<td style="vertical-align: top;">1<br>
				2378	</td>
				2379	<td style="vertical-align: top;">Number of bits per alpha value
				2380	in the frame buffer.<br>
				2381	</td>
				2382	</tr>
				2383	<tr>
				2384	<td style="vertical-align: top;">GL_ALPHA_TEST<br>
				2385	</td>
				2386	<td style="vertical-align: top;">1<br>
				2387	</td>
				2388	<td style="vertical-align: top;">Zero if the alpha test is
				2389	disabled.<br>
				2390	One if the alpha test is enabled.<br>
				2391	</td>
				2392	</tr>
				2393	<tr>
				2394	<td style="vertical-align: top;">GL_ALPHA_TEST_FUNC<br>
				2395	</td>
				2396	<td style="vertical-align: top;">1<br>
				2397	</td>
				2398	<td style="vertical-align: top;">The alpha test function.<br>
				2399	</td>
				2400	</tr>
				2401	<tr>
				2402	<td style="vertical-align: top;">GL_BLEND<br>
				2403	</td>
				2404	<td style="vertical-align: top;">1<br>
				2405	</td>
				2406	<td style="vertical-align: top;">Zero if blending is disabled.<br>
				2407	One if blending is enabled.<br>
				2408	</td>
				2409	</tr>
				2410	<tr>
				2411	<td style="vertical-align: top;">GL_BLEND_DST<br>
				2412	</td>
				2413	<td style="vertical-align: top;">1<br>
				2414	</td>
				2415	<td style="vertical-align: top;">Blend destination function/term.<br>
				2416	</td>
				2417	</tr>
				2418	<tr>
				2419	<td style="vertical-align: top;">GL_BLEND_SRC<br>
				2420	</td>
				2421	<td style="vertical-align: top;">1<br>
				2422	</td>
				2423	<td style="vertical-align: top;">Blend source function/term.<br>
				2424	</td>
				2425	</tr>
				2426	<tr>
				2427	<td style="vertical-align: top;">GL_BLUE_BITS<br>
				2428	</td>
				2429	<td style="vertical-align: top;">1<br>
				2430	</td>
				2431	<td style="vertical-align: top;">Number of bits per blue value in
				2432	the frame buffer.<br>
				2433	</td>
				2434	</tr>
				2435	<tr>
				2436	<td style="vertical-align: top;">GL_COLOR_CLEAR_VALUE<br>
				2437	</td>
				2438	<td style="vertical-align: top;">4<br>
				2439	</td>
				2440	<td style="vertical-align: top;">Clear color (red, green, blue,
				2441	alpha).<br>
				2442	</td>
				2443	</tr>
				2444	<tr>
				2445	<td style="vertical-align: top;">GL_COLOR_WRITE_MASK<br>
				2446	</td>
				2447	<td style="vertical-align: top;">4<br>
				2448	</td>
				2449	<td style="vertical-align: top;">Color buffer writemask (red,
				2450	green, blue, alpha).<br>
				2451	Zero if writing is disabled.<br>
				2452	One if writing is enabled.<br>
				2453	</td>
				2454	</tr>
				2455	<tr>
				2456	<td style="vertical-align: top;">GL_CULL_FACE<br>
				2457	</td>
				2458	<td style="vertical-align: top;">1<br>
				2459	</td>
				2460	<td style="vertical-align: top;">Zero if polygon culling is
				2461	disabled.<br>
				2462	One if polygon culling is enabled.<br>
				2463	</td>
				2464	</tr>
				2465	<tr>
				2466	<td style="vertical-align: top;">GL_CULL_FACE_MODE<br>
				2467	</td>
				2468	<td style="vertical-align: top;">1<br>
				2469	</td>
				2470	<td style="vertical-align: top;">Polygon cull mode: GL_FRONT,
				2471	GL_BACK or GL_FRONT_AND_BACK.<br>
				2472	</td>
				2473	</tr>
				2474	<tr>
				2475	<td style="vertical-align: top;">GL_CURRENT_COLOR<br>
				2476	</td>
				2477	<td style="vertical-align: top;">4<br>
				2478	</td>
				2479	<td style="vertical-align: top;">Current color (red, green, blue,
				2480	alpha).<br>
				2481	</td>
				2482	</tr>
				2483	<tr>
				2484	<td style="vertical-align: top;">GL_CURRENT_RASTER_COLOR<br>
				2485	</td>
				2486	<td style="vertical-align: top;">4<br>
				2487	</td>
				2488	<td style="vertical-align: top;">Current raster position color
				2489	(red, green, blue, alpha).<br>
				2490	</td>
				2491	</tr>
				2492	<tr>
				2493	<td style="vertical-align: top;">GL_CURRENT_RASTER_TEXTURE_COORDS<br>
				2494	</td>
				2495	<td style="vertical-align: top;">4<br>
				2496	</td>
				2497	<td style="vertical-align: top;">Current raster position texture
				2498	coordinates (s, t, r, q).<br>
				2499	</td>
				2500	</tr>
				2501	<tr>
				2502	<td style="vertical-align: top;">GL_CURRENT_RASTER_POSITION<br>
				2503	</td>
				2504	<td style="vertical-align: top;">4<br>
				2505	</td>
				2506	<td style="vertical-align: top;">Current raster position (x, y,
				2507	z, w).<br>
				2508	</td>
				2509	</tr>
				2510	<tr>
				2511	<td style="vertical-align: top;">GL_CURRENT_POSITION_VALID<br>
				2512	</td>
				2513	<td style="vertical-align: top;">1<br>
				2514	</td>
				2515	<td style="vertical-align: top;">Zero if current raster position
				2516	is invalid.<br>
				2517	One if current raster position is valid.<br>
				2518	</td>
				2519	</tr>
				2520	<tr>
				2521	<td style="vertical-align: top;">GL_CURRENT_TEXTURE_COORDS<br>
				2522	</td>
				2523	<td style="vertical-align: top;">4<br>
				2524	</td>
				2525	<td style="vertical-align: top;">Current texture coordinates (s,
				2526	t, r, q)<br>
				2527	</td>
				2528	</tr>
				2529	<tr>
				2530	<td style="vertical-align: top;">GL_DOUBLEBUFFER<br>
				2531	</td>
				2532	<td style="vertical-align: top;">1<br>
				2533	</td>
				2534	<td style="vertical-align: top;">Zero if color buffer is
				2535	single-buffered.<br>
				2536	One if color buffer is double-buffered.<br>
				2537	</td>
				2538	</tr>
				2539	<tr>
				2540	<td style="vertical-align: top;">GL_DRAW_BUFFER<br>
				2541	</td>
				2542	<td style="vertical-align: top;">1<br>
				2543	</td>
				2544	<td style="vertical-align: top;">Current color draw buffer:
				2545	GL_FRONT or GL_BACK.<br>
				2546	</td>
				2547	</tr>
				2548	<tr>
				2549	<td style="vertical-align: top;">GL_FRONT_FACE</td>
				2550	<td style="vertical-align: top;">1<br>
				2551	</td>
				2552	<td style="vertical-align: top;">Polygon front-face winding:
				2553	GL_CW or GL_CCW.<br>
				2554	</td>
				2555	</tr>
				2556	<tr>
				2557	<td style="vertical-align: top;">GL_GREEN_BITS<br>
				2558	</td>
				2559	<td style="vertical-align: top;">1<br>
				2560	</td>
				2561	<td style="vertical-align: top;">Number of bits per green value
				2562	in the frame buffer.<br>
				2563	</td>
				2564	</tr>
				2565	<tr>
				2566	<td style="vertical-align: top;">GL_LINE_SMOOTH<br>
				2567	</td>
				2568	<td style="vertical-align: top;">1<br>
				2569	</td>
				2570	<td style="vertical-align: top;">Zero if line smoothing is
				2571	disabled.<br>
				2572	One if line smoothing is enabled.<br>
				2573	</td>
				2574	</tr>
				2575	<tr>
				2576	<td style="vertical-align: top;">GL_LINE_STIPPLE<br>
				2577	</td>
				2578	<td style="vertical-align: top;">1<br>
				2579	</td>
				2580	<td style="vertical-align: top;">Zero if line stippling is
				2581	disabled.<br>
				2582	One if line stippling is enabled.<br>
				2583	</td>
				2584	</tr>
				2585	<tr>
				2586	<td style="vertical-align: top;">GL_LINE_STIPPLE_PATTERN<br>
				2587	</td>
				2588	<td style="vertical-align: top;">1<br>
				2589	</td>
				2590	<td style="vertical-align: top;">Line stipple pattern.<br>
				2591	</td>
				2592	</tr>
				2593	<tr>
				2594	<td style="vertical-align: top;">GL_LINE_STIPPLE_REPEAT<br>
				2595	</td>
				2596	<td style="vertical-align: top;">1<br>
				2597	</td>
				2598	<td style="vertical-align: top;">Line stipple repeat factor.<br>
				2599	</td>
				2600	</tr>
				2601	<tr>
				2602	<td style="vertical-align: top;">GL_LINE_WIDTH<br>
				2603	</td>
				2604	<td style="vertical-align: top;">1<br>
				2605	</td>
				2606	<td style="vertical-align: top;">Line width in pixels.<br>
				2607	</td>
				2608	</tr>
				2609	<tr>
				2610	<td style="vertical-align: top;">GL_LINE_WIDTH_GRANULARITY<br>
				2611	</td>
				2612	<td style="vertical-align: top;">1<br>
				2613	</td>
				2614	<td style="vertical-align: top;">Aliased line width granularity.<br>
				2615	</td>
				2616	</tr>
				2617	<tr>
				2618	<td style="vertical-align: top;">GL_LINE_WIDTH_RANGE<br>
				2619	</td>
				2620	<td style="vertical-align: top;">2<br>
				2621	</td>
				2622	<td style="vertical-align: top;">Minimum and maximum aliased line
				2623	widths.<br>
				2624	</td>
				2625	</tr>
				2626	<tr>
				2627	<td style="vertical-align: top;">GL_ALIASED_LINE_WIDTH_RANGE<br>
				2628	</td>
				2629	<td style="vertical-align: top;">2<br>
				2630	</td>
				2631	<td style="vertical-align: top;">Minimum and maximum antialiased
				2632	line widths.</td>
				2633	</tr>
				2634	<tr>
				2635	<td style="vertical-align: top;">GL_COLOR_LOGIC_OP<br>
				2636	</td>
				2637	<td style="vertical-align: top;">1<br>
				2638	</td>
				2639	<td style="vertical-align: top;">Zero if logicop is disabled.<br>
				2640	One if logicop is enabled.<br>
				2641	</td>
				2642	</tr>
				2643	<tr>
				2644	<td style="vertical-align: top;">GL_LOGIC_OP_MODE<br>
				2645	</td>
				2646	<td style="vertical-align: top;">1<br>
				2647	</td>
				2648	<td style="vertical-align: top;">Logicop function.<br>
				2649	</td>
				2650	</tr>
				2651	<tr>
				2652	<td style="vertical-align: top;">GL_MATRIX_MODE<br>
				2653	</td>
				2654	<td style="vertical-align: top;">1<br>
				2655	</td>
				2656	<td style="vertical-align: top;">Matrix mode: GL_MODELVIEW or
				2657	GL_PROJECTION.<br>
				2658	</td>
				2659	</tr>
				2660	<tr>
				2661	<td style="vertical-align: top;">GL_MAX_MODELVIEW_STACK_DEPTH<br>
				2662	</td>
				2663	<td style="vertical-align: top;">1<br>
				2664	</td>
				2665	<td style="vertical-align: top;">Maximum size of the modelview
				2666	matrix stack.<br>
				2667	</td>
				2668	</tr>
				2669	<tr>
				2670	<td style="vertical-align: top;">GL_MAX_NAME_STACK_DEPTH<br>
				2671	</td>
				2672	<td style="vertical-align: top;">1<br>
				2673	</td>
				2674	<td style="vertical-align: top;">Maximum size of the selection
				2675	name stack.<br>
				2676	</td>
				2677	</tr>
				2678	<tr>
				2679	<td style="vertical-align: top;">GL_MAX_PROJECTION_STACK_DEPTH<br>
				2680	</td>
				2681	<td style="vertical-align: top;">1<br>
				2682	</td>
				2683	<td style="vertical-align: top;">Maximum size of the projection
				2684	matrix stack.<br>
				2685	</td>
				2686	</tr>
				2687	<tr>
				2688	<td style="vertical-align: top;">GL_MAX_TEXTURE_SIZE<br>
				2689	</td>
				2690	<td style="vertical-align: top;">1<br>
				2691	</td>
				2692	<td style="vertical-align: top;">Maximum 2D texture image width
				2693	and height.<br>
				2694	</td>
				2695	</tr>
				2696	<tr>
				2697	<td style="vertical-align: top;">GL_MAX_VIEWPORT_DIMS<br>
				2698	</td>
				2699	<td style="vertical-align: top;">2</td>
				2700	<td style="vertical-align: top;">Maximum viewport width and
				2701	height in pixels.<br>
				2702	</td>
				2703	</tr>
				2704	<tr>
				2705	<td style="vertical-align: top;">GL_MODELVIEW_MATRIX<br>
				2706	</td>
				2707	<td style="vertical-align: top;">16<br>
				2708	</td>
				2709	<td style="vertical-align: top;">Current/top modelview matrix
				2710	values.<br>
				2711	</td>
				2712	</tr>
				2713	<tr>
				2714	<td style="vertical-align: top;">GL_MODELVIEW_MATRIX_STACK_DEPTH<br>
				2715	</td>
				2716	<td style="vertical-align: top;">1<br>
				2717	</td>
				2718	<td style="vertical-align: top;">Current size of the modelview
				2719	matrix stack.<br>
				2720	</td>
				2721	</tr>
				2722	<tr>
				2723	<td style="vertical-align: top;">GL_NAME_STACK_DEPTH<br>
				2724	</td>
				2725	<td style="vertical-align: top;">1<br>
				2726	</td>
				2727	<td style="vertical-align: top;">Current size of the selection
				2728	name stack.<br>
				2729	</td>
				2730	</tr>
				2731	<tr>
				2732	<td style="vertical-align: top;">GL_PACK_ROW_LENGTH<br>
				2733	</td>
				2734	<td style="vertical-align: top;">1<br>
				2735	</td>
				2736	<td style="vertical-align: top;">Pixel packing row length.<br>
				2737	</td>
				2738	</tr>
				2739	<tr>
				2740	<td style="vertical-align: top;">GL_POLYGON_SMOOTH<br>
				2741	</td>
				2742	<td style="vertical-align: top;">1<br>
				2743	</td>
				2744	<td style="vertical-align: top;">Zero if polygon smoothing is
				2745	disabled.<br>
				2746	One if polygon smoothing is enabled.<br>
				2747	</td>
				2748	</tr>
				2749	<tr>
				2750	<td style="vertical-align: top;">GL_PROJECTION_MATRIX<br>
				2751	</td>
				2752	<td style="vertical-align: top;">16<br>
				2753	</td>
				2754	<td style="vertical-align: top;">Current/top projection matrix
				2755	values.<br>
				2756	</td>
				2757	</tr>
				2758	<tr>
				2759	<td style="vertical-align: top;">GL_PROJECTION_STACK_DEPTH<br>
				2760	</td>
				2761	<td style="vertical-align: top;">1<br>
				2762	</td>
				2763	<td style="vertical-align: top;">Current size of projection
				2764	matrix stack.<br>
				2765	</td>
				2766	</tr>
				2767	<tr>
				2768	<td style="vertical-align: top;">GL_READ_BUFFER<br>
				2769	</td>
				2770	<td style="vertical-align: top;">1<br>
				2771	</td>
				2772	<td style="vertical-align: top;">Current read buffer: GL_FRONT or
				2773	GL_BACK.<br>
				2774	</td>
				2775	</tr>
				2776	<tr>
				2777	<td style="vertical-align: top;">GL_RED_BITS<br>
				2778	</td>
				2779	<td style="vertical-align: top;">1<br>
				2780	</td>
				2781	<td style="vertical-align: top;">Number of bits per red value in
				2782	the frame buffer.<br>
				2783	</td>
				2784	</tr>
				2785	<tr>
				2786	<td style="vertical-align: top;">GL_RENDER_MODE<br>
				2787	</td>
				2788	<td style="vertical-align: top;">1<br>
				2789	</td>
				2790	<td style="vertical-align: top;">Current rendering mode:
				2791	GL_RENDER or GL_SELECTION.<br>
				2792	</td>
				2793	</tr>
				2794	<tr>
				2795	<td style="vertical-align: top;">GL_RGBA_MODE<br>
				2796	</td>
				2797	<td style="vertical-align: top;">1<br>
				2798	</td>
				2799	<td style="vertical-align: top;">Always one.<br>
				2800	</td>
				2801	</tr>
				2802	<tr>
				2803	<td style="vertical-align: top;">GL_SCISSOR_BOX<br>
				2804	</td>
				2805	<td style="vertical-align: top;">4<br>
				2806	</td>
				2807	<td style="vertical-align: top;">Scissor box (x, y, width,
				2808	height).<br>
				2809	</td>
				2810	</tr>
				2811	<tr>
				2812	<td style="vertical-align: top;">GL_SCISSOR_TEST<br>
				2813	</td>
				2814	<td style="vertical-align: top;">1<br>
				2815	</td>
				2816	<td style="vertical-align: top;">Zero if scissor test is disabled.<br>
				2817	One if scissor test is enabled.<br>
				2818	</td>
				2819	</tr>
				2820	<tr>
				2821	<td style="vertical-align: top;">GL_SELECTION_BUFFER_SIZE<br>
				2822	</td>
				2823	<td style="vertical-align: top;">1<br>
				2824	</td>
				2825	<td style="vertical-align: top;">Size of selection buffer.<br>
				2826	</td>
				2827	</tr>
				2828	<tr>
				2829	<td style="vertical-align: top;">GL_SHADE_MODEL<br>
				2830	</td>
				2831	<td style="vertical-align: top;">1<br>
				2832	</td>
				2833	<td style="vertical-align: top;">Shade model: GL_FLAT or
				2834	GL_SMOOTH.<br>
				2835	</td>
				2836	</tr>
				2837	<tr>
				2838	<td style="vertical-align: top;">GL_STENCIL_BITS<br>
				2839	</td>
				2840	<td style="vertical-align: top;">1<br>
				2841	</td>
				2842	<td style="vertical-align: top;">Number of bits per stencil value
				2843	in the frame buffer.<br>
				2844	</td>
				2845	</tr>
				2846	<tr>
				2847	<td style="vertical-align: top;">GL_STENCIL_CLEAR_VALUE<br>
				2848	</td>
				2849	<td style="vertical-align: top;">1<br>
				2850	</td>
				2851	<td style="vertical-align: top;">Stencil buffer clear value.<br>
				2852	</td>
				2853	</tr>
				2854	<tr>
				2855	<td style="vertical-align: top;">GL_STENCIL_FAIL<br>
				2856	</td>
				2857	<td style="vertical-align: top;">1<br>
				2858	</td>
				2859	<td style="vertical-align: top;">Stencil fail operation.<br>
				2860	</td>
				2861	</tr>
				2862	<tr>
				2863	<td style="vertical-align: top;">GL_STENCIL_FUNC<br>
				2864	</td>
				2865	<td style="vertical-align: top;">1<br>
				2866	</td>
				2867	<td style="vertical-align: top;">Stencil function.<br>
				2868	</td>
				2869	</tr>
				2870	<tr>
				2871	<td style="vertical-align: top;">GL_STENCIL_REF<br>
				2872	</td>
				2873	<td style="vertical-align: top;">1<br>
				2874	</td>
				2875	<td style="vertical-align: top;">Stencil reference value.<br>
				2876	</td>
				2877	</tr>
				2878	<tr>
				2879	<td style="vertical-align: top;">GL_STENCIL_TEST<br>
				2880	</td>
				2881	<td style="vertical-align: top;">1<br>
				2882	</td>
				2883	<td style="vertical-align: top;">Zero if stencil test is disabled.<br>
				2884	One if stencil test is enabled.<br>
				2885	</td>
				2886	</tr>
				2887	<tr>
				2888	<td style="vertical-align: top;">GL_STENCIL_VALUE_MASK<br>
				2889	</td>
				2890	<td style="vertical-align: top;">1<br>
				2891	</td>
				2892	<td style="vertical-align: top;">Stencil mask value.<br>
				2893	</td>
				2894	</tr>
				2895	<tr>
				2896	<td style="vertical-align: top;">GL_STENCIL_WRITE_MASK<br>
				2897	</td>
				2898	<td style="vertical-align: top;">1<br>
				2899	</td>
				2900	<td style="vertical-align: top;">Stencil buffer write mask.<br>
				2901	</td>
				2902	</tr>
				2903	<tr>
				2904	<td style="vertical-align: top;">GL_TEXTURE_2D<br>
				2905	</td>
				2906	<td style="vertical-align: top;">1<br>
				2907	</td>
				2908	<td style="vertical-align: top;">Zero if 2D texture mapping is
				2909	disabled.<br>
				2910	One if 2D texture mapping is enabled.<br>
				2911	</td>
				2912	</tr>
				2913	<tr>
				2914	<td style="vertical-align: top;">GL_TEXTURE_BINDING_2D</td>
				2915	<td style="vertical-align: top;">1<br>
				2916	</td>
				2917	<td style="vertical-align: top;">Name of currently bound 2D
				2918	texture object.<br>
				2919	</td>
				2920	</tr>
				2921	<tr>
				2922	<td style="vertical-align: top;">GL_TEXTURE_ENV_COLOR<br>
				2923	</td>
				2924	<td style="vertical-align: top;">4<br>
				2925	</td>
				2926	<td style="vertical-align: top;">Texture environment color (red,
				2927	green, blue, alpha).<br>
				2928	</td>
				2929	</tr>
				2930	<tr>
				2931	<td style="vertical-align: top;">GL_TEXTURE_ENV_MODE<br>
				2932	</td>
				2933	<td style="vertical-align: top;">1<br>
				2934	</td>
				2935	<td style="vertical-align: top;">Texture environment mode.<br>
				2936	</td>
				2937	</tr>
				2938	<tr>
				2939	<td style="vertical-align: top;">GL_UNPACK_ROW_LENGTH<br>
				2940	</td>
				2941	<td style="vertical-align: top;">1<br>
				2942	</td>
				2943	<td style="vertical-align: top;">Pixel unpacking row length.<br>
				2944	</td>
				2945	</tr>
				2946	<tr>
				2947	<td style="vertical-align: top;">GL_UNPACK_LSB_FIRST<br>
				2948	</td>
				2949	<td style="vertical-align: top;">1<br>
				2950	</td>
				2951	<td style="vertical-align: top;">Zero if most significant bit is
				2952	unpacked first for bitmaps.<br>
				2953	One if least significant bit is unpacked first for bitmaps.<br>
				2954	</td>
				2955	</tr>
				2956	<tr>
				2957	<td style="vertical-align: top;">GL_VIEWPORT<br>
				2958	</td>
				2959	<td style="vertical-align: top;">4<br>
				2960	</td>
				2961	<td style="vertical-align: top;">Current viewport (x, y, width,
				2962	height).<br>
				2963	</td>
				2964	</tr>
				2965	</tbody>
				2966	</table>
				2967	<br>
				2968	<br>
				2969	<h2>9.2 String Queries</h2>
				2970	The command<br>
				2971	<br>
				2972	<div style="margin-left: 40px;">const GLubyte *<span
				2973	style="font-weight: bold;">glGetString</span>(GLenum <span
				2974	style="font-style: italic;">name</span>)<br>
				2975	</div>
				2976	<br>
				2977	is used to query string-valued values.  The legal values for <span
				2978	style="font-style: italic;">name</span> are described in the following
				2979	table:<br>
				2980	<br>
				2981	<table cellpadding="2" cellspacing="2" border="1"
				2982	style="text-align: left; width: 80%; margin-left: auto; margin-right: auto;">
				2983	<tbody>
				2984	<tr>
				2985	<td style="vertical-align: top;"><span style="font-style: italic;">name</span><br>
				2986	</td>
				2987	<td style="vertical-align: top;">Return value<br>
				2988	</td>
				2989	</tr>
				2990	<tr>
				2991	<td style="vertical-align: top;">GL_VERSION<br>
				2992	</td>
				2993	<td style="vertical-align: top;">The library version, such as
				2994	"1.2".<br>
				2995	</td>
				2996	</tr>
				2997	<tr>
				2998	<td style="vertical-align: top;">GL_RENDERER<br>
				2999	</td>
				3000	<td style="vertical-align: top;">The renderer, such as "Mesa DRI
				3001	Radeon".<br>
				3002	</td>
				3003	</tr>
				3004	<tr>
				3005	<td style="vertical-align: top;">GL_VENDOR<br>
				3006	</td>
				3007	<td style="vertical-align: top;">The vendor of this
				3008	implementation, such as "Tungsten Graphics, Inc."<br>
				3009	</td>
				3010	</tr>
				3011	<tr>
				3012	<td style="vertical-align: top;">GL_EXTENSIONS<br>
				3013	</td>
				3014	<td style="vertical-align: top;">A white-space separated list of
				3015	the supported extensions. </td>
				3016	</tr>
				3017	</tbody>
				3018	</table>
				3019	<br>
				3020	<h2>9.3 Error Queries</h2>
				3021	The command<br>
				3022	<br>
				3023	<div style="margin-left: 40px;">GLenum <span style="font-weight: bold;">glGetError</span>(void)<br>
				3024	</div>
				3025	<br>
				3026	returns the current error code.  The current error code will be
				3027	set by a GL command when an error condition has been detected.  If
				3028	the current error code is already set, subsequent errors will not be
				3029	recorded.  The error code is reset/cleared to GL_NO_ERROR when <span
				3030	style="font-weight: bold;">glGetError</span> returns.  The
				3031	following error codes are possible:<br>
				3032	<br>
				3033	<table cellpadding="2" cellspacing="2" border="1"
				3034	style="text-align: left; width: 80%; margin-left: auto; margin-right: auto;">
				3035	<tbody>
				3036	<tr>
				3037	<td style="vertical-align: top;">Error code<br>
				3038	</td>
				3039	<td style="vertical-align: top;">Meaning<br>
				3040	</td>
				3041	</tr>
				3042	<tr>
				3043	<td style="vertical-align: top;">GL_NO_ERROR<br>
				3044	</td>
				3045	<td style="vertical-align: top;">No error has been recorded.<br>
				3046	</td>
				3047	</tr>
				3048	<tr>
				3049	<td style="vertical-align: top;">GL_INVALID_ENUM<br>
				3050	</td>
				3051	<td style="vertical-align: top;">An enum parameter had an invalid
				3052	value.<br>
				3053	</td>
				3054	</tr>
				3055	<tr>
				3056	<td style="vertical-align: top;">GL_INVALID_VALUE<br>
				3057	</td>
				3058	<td style="vertical-align: top;">A numeric parameter had an
				3059	invalid value.<br>
				3060	</td>
				3061	</tr>
				3062	<tr>
				3063	<td style="vertical-align: top;">GL_INVALID_OPERATION<br>
				3064	</td>
				3065	<td style="vertical-align: top;">A function was called when not
				3066	legal to do so.<br>
				3067	</td>
				3068	</tr>
				3069	<tr>
				3070	<td style="vertical-align: top;">GL_STACK_OVERFLOW<br>
				3071	</td>
				3072	<td style="vertical-align: top;">The current transformation
				3073	matrix stack is full.<br>
				3074	</td>
				3075	</tr>
				3076	<tr>
				3077	<td style="vertical-align: top;">GL_STACK_UNDERFLOW<br>
				3078	</td>
				3079	<td style="vertical-align: top;">The current transformation
				3080	matrix stack is empty.<br>
				3081	</td>
				3082	</tr>
				3083	<tr>
				3084	<td style="vertical-align: top;">GL_OUT_OF_MEMORY<br>
				3085	</td>
				3086	<td style="vertical-align: top;">The system ran out of dynamic
				3087	memory.<br>
				3088	</td>
				3089	</tr>
				3090	</tbody>
				3091	</table>
				3092	<br>
				3093	<br>
				3094	<h1>10. Unsupported Features</h1>
				3095	This section lists other features and functions which are not supported
				3096	and not previously discussed.<br>
				3097	<br>
				3098	<h2>10.1 Feedback Mode</h2>
				3099	Feedback mode and the following related functions are not supported.<br>
				3100	<br>
				3101	<div style="margin-left: 40px;"><span style="font-weight: bold;">glFeedbackBuffer</span><br>
				3102	<span style="font-weight: bold;">glPassThrough</span><br>
				3103	</div>
				3104	<br>
				3105	<h2>10.2 1D and 3D Textures<br>
				3106	</h2>
				3107	Only 2D texture images are supported.  The following functions
				3108	used to specify 1D and 3D texture images are not supported:<br>
				3109	<br>
				3110	<div style="margin-left: 40px;"><span style="font-weight: bold;">glTexImage1D</span><br
				3111	style="font-weight: bold;">
				3112	<span style="font-weight: bold;">glTexImage3D</span><br
				3113	style="font-weight: bold;">
				3114	<span style="font-weight: bold;">glTexSubImage1D</span><br
				3115	style="font-weight: bold;">
				3116	<span style="font-weight: bold;"> glTexSubImage3D</span><br
				3117	style="font-weight: bold;">
				3118	<span style="font-weight: bold;">glCopyTexImage1D</span><br
				3119	style="font-weight: bold;">
				3120	<span style="font-weight: bold;"> glCopyTexSubImage1D</span><br
				3121	style="font-weight: bold;">
				3122	<span style="font-weight: bold;"> glCopyTexSubImage3D</span><br>
				3123	</div>
				3124	<br>
				3125	<h2>10.3 Alternate Texture Image Commands<br>
				3126	</h2>
				3127	Texture images may only be specified with <span
				3128	style="font-weight: bold;">glTexImage2D</span>.  The following
				3129	alternate texture image commands are not supported:<br>
				3130	<br>
				3131	<div style="margin-left: 40px; font-weight: bold;">glTexSubImage2D<br>
				3132	glCopyTexImage2D<br>
				3133	glCopyTexSubImage2D<br>
				3134	</div>
				3135	<br>
				3136	<h2>10.4 Proxy Textures</h2>
				3137	Proxy textures are not supported and the GL_PROXY_TEXTURE_2D token is
				3138	not supported by any function.<br>
				3139	<br>
				3140	<br>
				3141	<h2>10.5 Other Texture Commands</h2>
				3142	The following commands related to texture mapping are not supported by
				3143	the subset:<br>
				3144	<br>
				3145	<div style="margin-left: 40px; font-weight: bold;"> glPrioritizeTextures<br>
				3146	glAreTexturesResident<br>
				3147	glIsTexture<br>
				3148	glTexEnviv<br>
				3149	glTexEnvf<br>
				3150	glTexParameterf<br>
				3151	glTexParameteriv<br>
				3152	glTexParameterfv<br>
				3153	</div>
				3154	<br>
				3155	<br>
				3156	<h2>10.6 Copy and Draw Pixels<br>
				3157	</h2>
				3158	The following commands are not supported:<br>
				3159	<br>
				3160	<div style="margin-left: 40px;"><span style="font-weight: bold;">glDrawPixels<br>
				3161	glCopyPixels<br>
				3162	glPixelZoom<br>
				3163	<br>
				3164	</span></div>
				3165	<h2>10.7 Color Index Mode<br>
				3166	</h2>
				3167	Color index mode and the following related commands are not supported:<br>
				3168	<br>
				3169	<span style="font-weight: bold;"></span>
				3170	<div style="margin-left: 40px;"><span style="font-weight: bold;">glIndexub<br>
				3171	</span><span style="font-weight: bold;">glIndexi</span><br>
				3172	<span style="font-weight: bold;">glIndexs<br>
				3173	glIndexf<br>
				3174	glIndexd<br>
				3175	</span><span style="font-weight: bold;">glIndexubv<br>
				3176	</span><span style="font-weight: bold;">glIndexiv</span><br>
				3177	<span style="font-weight: bold;">glIndexsv<br>
				3178	glIndexfv<br>
				3179	glIndexdv</span><span style="font-weight: bold;"><br>
				3180	glIndexMask<br>
				3181	</span><span style="font-weight: bold;">glClearIndex<br>
				3182	glIndexPointer</span><br style="font-weight: bold;">
				3183	<br>
				3184	</div>
				3185	<h2>10.8 Pixel Transfer Operations</h2>
				3186	The pixel transfer operations (scale, bias, look-up table, etc) are not
				3187	supported and the following commands are omitted:<br>
				3188	<br style="font-weight: bold;">
				3189	<div style="margin-left: 40px;"><span style="font-weight: bold;">glPixelTransferf</span><br
				3190	style="font-weight: bold;">
				3191	<span style="font-weight: bold;">glPixelTransferi</span><br
				3192	style="font-weight: bold;">
				3193	<span style="font-weight: bold;">glPixelMapfv</span><br
				3194	style="font-weight: bold;">
				3195	<span style="font-weight: bold;">glPixelMapuiv</span><br
				3196	style="font-weight: bold;">
				3197	<span style="font-weight: bold;">glPixelMapusv</span><br
				3198	style="font-weight: bold;">
				3199	<span style="font-weight: bold;">glGetPixelMapfv</span><br
				3200	style="font-weight: bold;">
				3201	<span style="font-weight: bold;">glGetPixelMapuiv</span><br
				3202	style="font-weight: bold;">
				3203	<span style="font-weight: bold;">glGetPixelMapusv</span><br>
				3204	</div>
				3205	<br>
				3206	<h2>10.9 Hints</h2>
				3207	Hints and the following related command is not supported:<br>
				3208	<br>
				3209	<div style="margin-left: 40px;"><span style="font-weight: bold;">glHint<br>
				3210	</span><br>
				3211	</div>
				3212	<h2>10.10 State Query Commands<br>
				3213	</h2>
				3214	The following state query commands are not supported:<br>
				3215	<br>
				3216	<div style="margin-left: 40px; font-weight: bold;">glGetBooleanv<br>
				3217	glGetIntegerv<br>
				3218	glGetDoublev<br>
				3219	glGetPointerv<br>
				3220	glGetTexEnvi<br>
				3221	glGetTexEnvf<br>
				3222	glGetTexParameteriv<br>
				3223	glGetTexParameterfv<br>
				3224	glGetTexLevelParameteriv<br>
				3225	glGetTexLevelParameterfv<br>
				3226	glGetTexImage<br>
				3227	glGetClipPlane<br>
				3228	</div>
				3229	<br>
				3230	<h2>10.11 Attribute Stacks</h2>
				3231	State attribute stacks and the following related commands are not
				3232	supported:<br>
				3233	<br>
				3234	<div style="margin-left: 40px;"><span style="font-weight: bold;">glPushAttrib</span><br
				3235	style="font-weight: bold;">
				3236	<span style="font-weight: bold;">glPopAtttrib</span><br>
				3237	<br style="font-weight: bold;">
				3238	</div>
				3239	<h2>10.12 Double-Valued Functions</h2>
				3240	All functions which take double-precision floating point values, but
				3241	for which there is an equivalent single-precision valued function, are
				3242	omitted.  This includes, but is not limited to:<br>
				3243	<br>
				3244	<div style="margin-left: 40px;"><span style="font-weight: bold;">glVertex2d</span><br
				3245	style="font-weight: bold;">
				3246	<span style="font-weight: bold;">glVertex2dv</span><br
				3247	style="font-weight: bold;">
				3248	<span style="font-weight: bold;">glVertex3d</span><br
				3249	style="font-weight: bold;">
				3250	<span style="font-weight: bold;"> glVertex3dv</span><br
				3251	style="font-weight: bold;">
				3252	<span style="font-weight: bold;">glVertex4d</span><br
				3253	style="font-weight: bold;">
				3254	<span style="font-weight: bold;"> glVertex4dv</span><br
				3255	style="font-weight: bold;">
				3256	<span style="font-weight: bold;">glColor3d</span><br
				3257	style="font-weight: bold;">
				3258	<span style="font-weight: bold;">glColor3d</span><span
				3259	style="font-weight: bold;">v</span><br style="font-weight: bold;">
				3260	<span style="font-weight: bold;">glColor4d</span><br
				3261	style="font-weight: bold;">
				3262	<span style="font-weight: bold;"> glColor4dv</span><br
				3263	style="font-weight: bold;">
				3264	<span style="font-weight: bold;">glTexCoord1d</span><br
				3265	style="font-weight: bold;">
				3266	<span style="font-weight: bold;">glTexCoord1d</span><span
				3267	style="font-weight: bold;">v</span><br style="font-weight: bold;">
				3268	<span style="font-weight: bold;">glTexCoord2d</span><br
				3269	style="font-weight: bold;">
				3270	<span style="font-weight: bold;"> glTexCoord2dv</span><br
				3271	style="font-weight: bold;">
				3272	<span style="font-weight: bold;">glTexCoord3d</span><br
				3273	style="font-weight: bold;">
				3274	<span style="font-weight: bold;"> glTexCoord3dv</span><br
				3275	style="font-weight: bold;">
				3276	<span style="font-weight: bold;">glTexCoord4d</span><br
				3277	style="font-weight: bold;">
				3278	<span style="font-weight: bold;"> glTexCoord4dv</span><br
				3279	style="font-weight: bold;">
				3280	<span style="font-weight: bold;">glRasterPos2d</span><br
				3281	style="font-weight: bold;">
				3282	<span style="font-weight: bold;"> glRasterPos2dv</span><br
				3283	style="font-weight: bold;">
				3284	<span style="font-weight: bold;">glRasterPos3d</span><br
				3285	style="font-weight: bold;">
				3286	<span style="font-weight: bold;"> glRasterPos3dv</span><br
				3287	style="font-weight: bold;">
				3288	<span style="font-weight: bold;">glRasterPos4d</span><br
				3289	style="font-weight: bold;">
				3290	<span style="font-weight: bold;"> glRasterPos4dv</span><br
				3291	style="font-weight: bold;">
				3292	<span style="font-weight: bold;">glLoadMatrixd</span><br
				3293	style="font-weight: bold;">
				3294	<span style="font-weight: bold;">glMultMatrixd</span><br
				3295	style="font-weight: bold;">
				3296	<span style="font-weight: bold;">glScaled</span><br
				3297	style="font-weight: bold;">
				3298	<span style="font-weight: bold;">glRotated</span><br
				3299	style="font-weight: bold;">
				3300	<span style="font-weight: bold;">glTranslated<br>
				3301	glRectd<br>
				3302	glRectdv<br>
				3303	</span> <span style="font-weight: bold;"><br>
				3304	</span> </div>
				3305	<h2>10.13 Evaluators</h2>
				3306	Evaluators and the following related commands are not supported:<br>
				3307	<br>
				3308	<div style="margin-left: 40px;"><span style="font-weight: bold;">glMap1f</span><br
				3309	style="font-weight: bold;">
				3310	<span style="font-weight: bold;">glMap2d</span><br
				3311	style="font-weight: bold;">
				3312	<span style="font-weight: bold;">glMap2f</span><br
				3313	style="font-weight: bold;">
				3314	<span style="font-weight: bold;">glGetMapdv</span><br
				3315	style="font-weight: bold;">
				3316	<span style="font-weight: bold;">glGetMapfv</span><br
				3317	style="font-weight: bold;">
				3318	<span style="font-weight: bold;">glGetMapiv</span><br
				3319	style="font-weight: bold;">
				3320	<span style="font-weight: bold;">glEvalCoord1d</span><br
				3321	style="font-weight: bold;">
				3322	<span style="font-weight: bold;">glEvalCoord1f</span><br
				3323	style="font-weight: bold;">
				3324	<span style="font-weight: bold;">glEvalCoord1dv</span><br
				3325	style="font-weight: bold;">
				3326	<span style="font-weight: bold;">glEvalCoord1fv</span><br
				3327	style="font-weight: bold;">
				3328	<span style="font-weight: bold;">glEvalCoord2d</span><br
				3329	style="font-weight: bold;">
				3330	<span style="font-weight: bold;">glEvalCoord2f</span><br
				3331	style="font-weight: bold;">
				3332	<span style="font-weight: bold;">glEvalCoord2dv</span><br
				3333	style="font-weight: bold;">
				3334	<span style="font-weight: bold;">glEvalCoord2fv</span><br
				3335	style="font-weight: bold;">
				3336	<span style="font-weight: bold;">glMapGrid1d</span><br
				3337	style="font-weight: bold;">
				3338	<span style="font-weight: bold;">glMapGrid1f</span><br
				3339	style="font-weight: bold;">
				3340	<span style="font-weight: bold;">glMapGrid2d</span><br
				3341	style="font-weight: bold;">
				3342	<span style="font-weight: bold;">glMapGrid2f</span><br
				3343	style="font-weight: bold;">
				3344	<span style="font-weight: bold;">glEvalPoint1</span><br
				3345	style="font-weight: bold;">
				3346	<span style="font-weight: bold;">glEvalPoint2</span><br
				3347	style="font-weight: bold;">
				3348	<span style="font-weight: bold;">glEvalMesh1</span><br
				3349	style="font-weight: bold;">
				3350	<span style="font-weight: bold;">glEvalMesh2</span><br
				3351	style="font-weight: bold;">
				3352	</div>
				3353	<br>
				3354	<h2>10.14 Display Lists</h2>
				3355	Display lists and the following related commands are not supported:<br>
				3356	<br>
				3357	<div style="margin-left: 40px; font-weight: bold;">glIsList<br>
				3358	glDeleteLists<br>
				3359	glGenLists<br>
				3360	glNewList<br>
				3361	glEndList<br>
				3362	glCallList<br>
				3363	glCallLists<br>
				3364	glListBase<br>
				3365	</div>
				3366	<br>
				3367	<h2>10.15 Accumulation Buffer</h2>
				3368	The accumulation buffer and the following related commands are not
				3369	supported:<br>
				3370	<br style="font-weight: bold;">
				3371	<div style="margin-left: 40px;"><span style="font-weight: bold;">glAccum</span><br
				3372	style="font-weight: bold;">
				3373	<span style="font-weight: bold;">glClearAccum</span><br>
				3374	</div>
				3375	<br>
				3376	<h2>10.16 Fog</h2>
				3377	Fog and the following related commands are not supported:<br>
				3378	<br>
				3379	<div style="margin-left: 40px; font-weight: bold;"> glFogi<br>
				3380	glFogf<br>
				3381	glFogiv<br>
				3382	glFogfv<br>
				3383	</div>
				3384	<br>
				3385	<h2>10.17 Depth Test</h2>
				3386	Depth testing and the following related commands are not supported:<br>
				3387	<br>
				3388	<div style="margin-left: 40px;"><span style="font-weight: bold;">glDepthFunc</span><br
				3389	style="font-weight: bold;">
				3390	<span style="font-weight: bold;">glDepthMask</span><br
				3391	style="font-weight: bold;">
				3392	<span style="font-weight: bold;">glDepthRange</span><br
				3393	style="font-weight: bold;">
				3394	<span style="font-weight: bold;">glClearDepth</span><br>
				3395	</div>
				3396	<br>
				3397	<h2>10.18 Imaging Subset</h2>
				3398	The OpenGL imaging subset (which implements features such as
				3399	convolution, histogram, min/max recording, color matrix and color
				3400	tables) is not supported.<br>
				3401	<br>
				3402	<br>
				3403	<h1>Appendix A: Issues</h1>
				3404	This appendix lists documentation and subset issues with their current
				3405	status.  For items which are still open, the documentation (above)
				3406	follows the recommended solution.<br>
				3407	<br>
				3408	<h2>A.1 Vertex Arrays</h2>
				3409	Should vertex arrays be supported?  Is there a performance
				3410	advantage?<br>
				3411	<br>
				3412	RESOLUTION: No, there isn't enough of a performance advantage to
				3413	justify them.<br>
				3414	<br>
				3415	<h2>A.2 Polygon Antialiasing and Edge Flags</h2>
				3416	Should edge flags be supported for antialiasing?<br>
				3417	<br>
				3418	Edge flags don't effect antialiasing, at least not normally.  A
				3419	number of approaches to antialiasing have been summarized in email.<br>
				3420	<br>
				3421	RECOMMENDATION: don't support edge flags.  They don't effect
				3422	polygon antialiasing.<br>
				3423	<br>
				3424	RESOLUTION: closed, as of 26 Feb 2003.<br>
				3425	<br>
				3426	<h2>A.3 glRasterPos vs. glWindowPos</h2>
				3427	Should glRasterPos and/or glWindowPos commands be supported?<br>
				3428	<br>
				3429	RESOLUTION: Closed: implement glRasterPos commands, but not glWindowPos
				3430	commands.<br>
				3431	<br>
				3432	<h2>A.4 GL_IBM_rasterpos_clip extension</h2>
				3433	Should the GL_IBM_rasterpos_clip extension be implemented?<br>
				3434	<br>
				3435	RESOLUTION:  No.  It's not required.<br>
				3436	<br>
				3437	<h2>A.5 Image Formats and Types</h2>
				3438	Which image formats and types should be supported for <span
				3439	style="font-weight: bold;">glTexImage2D</span> and <span
				3440	style="font-weight: bold;">glReadPixels</span>?<br>
				3441	<br>
				3442	OpenGL specifies a <span style="font-weight: bold;">large</span>
				3443	variety of image formats and data types.  Only a few are commonly
				3444	used.<br>
				3445	<br>
				3446	RECOMMENDATION:  we propose a subset:<br>
				3447	<br>
				3448	For <span style="font-weight: bold;">glTexImage2D</span> only allow <span
				3449	style="font-style: italic;">type</span>=GL_UNSIGNED_BYTE and <span
				3450	style="font-style: italic;">format</span>=GL_RGBA, GL_RGB,
				3451	GL_INTENSITY.   Only allow <span style="font-style: italic;">internalFormat</span>
				3452	to be GL_RGBA, GL_RGB or GL_INTENSITY as well.  Basically, only
				3453	support image formats/types that are directly supported by the Radeon
				3454	hardware.  This will allow <span style="font-weight: bold;">glTexImage2D</span>
				3455	to basically just use <span style="font-weight: bold;">memcpy</span> to
				3456	copy texture images.<br>
				3457	<br>
				3458	For <span style="font-weight: bold;">glReadPixels</span>, only allow <span
				3459	style="font-style: italic;">type</span> = GL_UNSIGNED_BYTE or GL_FLOAT.
				3460	Only allow <span style="font-style: italic;">format</span> =
				3461	GL_RGB or GL_RGBA.  This is just enough to support the OpenGL
				3462	conformance tests.<br>
				3463	<br>
				3464	RESOLUTION: open<br>
				3465	<br>
				3466	<h2>A.6 Texture Environment Modes</h2>
				3467	Which texture environment modes should be supported?  OpenGL 1.2
				3468	has GL_REPLACE, GL_MODULATE, GL_DECAL and GL_BLEND.  GL_DECAL isn't
				3469	defined for all base internal texture formats.  GL_ADD is another
				3470	useful mode.  Perhaps drop GL_DECAL mode and add GL_ADD mode.<br>
				3471	<br>
				3472	RECOMMENDATION: implement the standard modes GL_REPLACE, GL_MODULATE,
				3473	GL_DECAL and GL_BLEND.<br>
				3474	<br>
				3475	RESOLUTION: open<br>
				3476	<br>
				3477	<h2>A.7 Truncated Mipmaps and LOD Control</h2>
				3478	Should we support the GL_TEXTURE_BASE_LEVEL, GL_TEXTURE_MAX_LEVEL,
				3479	GL_TEXTURE_MIN_LOD and GL_TEXTURE_MAX_LOD texture parameters?<br>
				3480	<br>
				3481	RECOMMENDATION:  We propose omitting these features at this time,
				3482	in the interest of simplifying the driver.<br>
				3483	<br>
				3484	RESOLUTION: open<br>
				3485	<br>
				3486	<h2>A.8 Texture Priorities and Residency</h2>
				3487	Should the subset support texture priorities via <span
				3488	style="font-weight: bold;">glPrioritizeTextures</span> and the <span
				3489	style="font-weight: bold;">glAreTexturesResident</span> command?<br>
				3490	<br>
				3491	RECOMMENDATION:  Few applications use these features and
				3492	functions.  We propose omitting them to simplify the driver.<br>
				3493	<br>
				3494	RESOLUTION: open<br>
				3495	<br>
				3496	<h2>A.9 Pixel Pack/Unpack Alignment Control</h2>
				3497	Should we support the GL_PACK_ALIGNMENT and GL_UNPACK_ALIGNMENT options?<br>
				3498	<br>
				3499	These are used to align pixel data addresses to 1, 2 and 4-byte
				3500	multiples for <span style="font-weight: bold;">glBitmap, glTexImage2D</span>
				3501	and <span style="font-weight: bold;">glReadPixels</span>.  These
				3502	aren't strictly needed since the user can provide a 1, 2 or 4-byte
				3503	aligned address and appropriate GL_PACK_ROW_LENGTH or
				3504	GL_UNPACK_ROW_LENGTH values instead.<br>
				3505	<br>
				3506	RECOMMENDATION:  We recommend omitting them to simplify the driver.<br>
				3507	<br>
				3508	RESOLUTION: open<br>
				3509	<br>
				3510	<h2>A.10 Pixel Pack/Unpack Skip Rows/Pixels Control</h2>
				3511	Should we support the GL_UNPACK_SKIP_PIXELS, GL_UNPACK_SKIP_ROWS,
				3512	GL_PACK_SKIP_PIXELS and GL_PACK_SKIP_ROWS options for pixel
				3513	unpacking/packing?<br>
				3514	<br>
				3515	These options aren't really needed since the user can adjust the start
				3516	address and GL_PACK/UNPACK_ROW_LENGTH parameters to achieve the same
				3517	effect.<br>
				3518	<br>
				3519	RECOMMENDATION:  omit these parameters.<br>
				3520	<br>
				3521	RESOLUTION: open<br>
				3522	<br>
				3523	<h2>A.11 Texture State Queries</h2>
				3524	Should we support the command <span style="font-weight: bold;">glGetTexEnvi/fv,
				3525	glGetTexParameteri/fv</span> and <span style="font-weight: bold;">glGetTexLevelParameteri/fv</span>?<br>
				3526	<br>
				3527	RECOMMENDATION:  No. They're seldom needed and their
				3528	implementation is several hundred lines of code in length.<br>
				3529	<br>
				3530	RESOLUTION:  open<br>
				3531	<br>
				3532	<h2>A.12 glGetIntegerv, glGetBooleanv and glGetDoublev</h2>
				3533	Should we support the commands <span style="font-weight: bold;">glGetIntegerv,
				3534	glGetBooleanv </span>and <span style="font-weight: bold;">glGetDoublev</span>
				3535	in addition to <span style="font-weight: bold;">glGetFloatv</span>?<br>
				3536	<br>
				3537	RECOMMENDATION:  Omit the boolean, integer and double-valued
				3538	functions. All state values which can be queried by these commands can
				3539	be expressed as floating point values and queried with <span
				3540	style="font-weight: bold;">glGetFloatv</span>.  The
				3541	implementation of the other three commands involves many lines of code.<br>
				3542	<br>
				3543	RESOLUTION:  open<br>
				3544	<br>
				3545	<h2>A.13 glBitmap and Per-Fragment Operations</h2>
				3546	Should bitmaps rendered with <span style="font-weight: bold;">glBitmap</span>
				3547	be subjected to the per-fragment operations?<br>
				3548	<br>
				3549	If bitmaps are implemented with points it will be easy to implement the
				3550	per-fragment operations.  Otherwise, it could be difficult.<br>
				3551	<br>
				3552	RECOMMENDATION:  Implement glBitmap by drawing points/pixels with
				3553	the hardware.  This will make supporting the per-fragments
				3554	trivially easy.  Also, it makes portrait-mode display relatively
				3555	easy.<br>
				3556	<br>
				3557	RESOLUTION:  open<br>
				3558	<br>
				3559	<h2>A.14 Reduced gl.h Header File</h2>
				3560	Should we produce a reduced gl.h header file which only defines the
				3561	tokens and functions which are implemented by the subset?<br>
				3562	<br>
				3563	RECOMMENDATION: yes.  It would be a useful reference to
				3564	programmers to quickly determine which functions and tokens are
				3565	supported.<br>
				3566	<br>
				3567	RESOLUTION: open<br>
				3568	<br>
				3569	<h2>A.15 glPolygonMode</h2>
				3570	Is <span style="font-weight: bold;">glPolygonMode</span> needed?<br>
				3571	<br>
				3572	RECOMMENDATION: No.  Omit it.<br>
				3573	<br>
				3574	RESOLUTION: closed, as of 26 Feb 2003<br>
				3575	<br>
				3576	<br>
				3577	<p> </p>
				3578	</body>
				3579	</html>