Ian Romanick | 5f6691f | 2004-05-11 19:57:58 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright IBM Corporation 2004 |
| 3 | * All Rights Reserved. |
| 4 | * |
| 5 | * Permission is hereby granted, free of charge, to any person obtaining a |
| 6 | * copy of this software and associated documentation files (the "Software"), |
| 7 | * to deal in the Software without restriction, including without limitation |
| 8 | * on the rights to use, copy, modify, merge, publish, distribute, sub |
| 9 | * license, and/or sell copies of the Software, and to permit persons to whom |
| 10 | * the Software is furnished to do so, subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice (including the next |
| 13 | * paragraph) shall be included in all copies or substantial portions of the |
| 14 | * Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
| 19 | * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, |
| 20 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
| 21 | * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
| 22 | * USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 23 | */ |
| 24 | |
| 25 | /** |
| 26 | * \file blendminmax.c |
| 27 | * |
| 28 | * Simple test of GL_EXT_blend_minmax functionality. Four squares are drawn |
| 29 | * with different blending modes, but all should be rendered with the same |
| 30 | * final color. |
| 31 | * |
| 32 | * \author Ian Romanick <idr@us.ibm.com> |
| 33 | */ |
| 34 | |
| 35 | #include <stdio.h> |
| 36 | #include <stdlib.h> |
Keith Whitwell | a58065d | 2009-03-10 13:11:23 +0000 | [diff] [blame] | 37 | #include <GL/glew.h> |
Ian Romanick | 5f6691f | 2004-05-11 19:57:58 +0000 | [diff] [blame] | 38 | #include <GL/glut.h> |
| 39 | |
| 40 | static int Width = 400; |
| 41 | static int Height = 200; |
| 42 | static const GLfloat Near = 5.0, Far = 25.0; |
| 43 | |
| 44 | |
| 45 | static void Display( void ) |
| 46 | { |
| 47 | glClearColor(0.2, 0.2, 0.8, 0); |
| 48 | glClear( GL_COLOR_BUFFER_BIT ); |
| 49 | |
| 50 | glPushMatrix(); |
| 51 | |
| 52 | /* This is the "reference" square. |
| 53 | */ |
| 54 | |
| 55 | glTranslatef(-4.5, 0, 0); |
| 56 | glBlendEquation( GL_FUNC_ADD ); |
| 57 | glBlendFunc( GL_ONE, GL_ZERO ); |
| 58 | glBegin(GL_QUADS); |
| 59 | glColor3f( 0.5, 0.5, 0.5 ); |
| 60 | glVertex2f(-1, -1); |
| 61 | glVertex2f( 1, -1); |
| 62 | glVertex2f( 1, 1); |
| 63 | glVertex2f(-1, 1); |
| 64 | glEnd(); |
| 65 | |
| 66 | |
| 67 | /* GL_MIN and GL_MAX are supposed to ignore the blend function setting. |
| 68 | * To test that, we set the blend function to GL_ZERO for both color and |
| 69 | * alpha each time GL_MIN or GL_MAX is used. |
| 70 | * |
| 71 | * Apple ships an extension called GL_ATI_blend_weighted_minmax (supported |
| 72 | * on Mac OS X 10.2 and later). I believe the difference with that |
| 73 | * extension is that it uses the blend function. However, I have no idea |
| 74 | * what the enums are for it. The extension is listed at Apple's developer |
| 75 | * site, but there is no documentation. |
| 76 | * |
| 77 | * http://developer.apple.com/opengl/extensions.html |
| 78 | */ |
| 79 | |
| 80 | glTranslatef(3.0, 0, 0); |
| 81 | glBlendEquation( GL_FUNC_ADD ); |
| 82 | glBlendFunc( GL_ONE, GL_ZERO ); |
| 83 | glBegin(GL_QUADS); |
| 84 | glColor3f( 0.5, 0.5, 0.5 ); |
| 85 | glVertex2f(-1, -1); |
| 86 | glVertex2f( 1, -1); |
| 87 | glVertex2f( 1, 1); |
| 88 | glVertex2f(-1, 1); |
| 89 | glEnd(); |
| 90 | |
| 91 | glBlendEquation( GL_MAX ); |
| 92 | glBlendFunc( GL_ZERO, GL_ZERO ); |
| 93 | glBegin(GL_QUADS); |
| 94 | glColor3f( 0.2, 0.2, 0.2 ); |
| 95 | glVertex2f(-1, -1); |
| 96 | glVertex2f( 1, -1); |
| 97 | glVertex2f( 1, 1); |
| 98 | glVertex2f(-1, 1); |
| 99 | glEnd(); |
| 100 | |
| 101 | |
| 102 | glTranslatef(3.0, 0, 0); |
| 103 | glBlendEquation( GL_FUNC_ADD ); |
| 104 | glBlendFunc( GL_ONE, GL_ZERO ); |
| 105 | glBegin(GL_QUADS); |
| 106 | glColor3f( 0.5, 0.5, 0.5 ); |
| 107 | glVertex2f(-1, -1); |
| 108 | glVertex2f( 1, -1); |
| 109 | glVertex2f( 1, 1); |
| 110 | glVertex2f(-1, 1); |
| 111 | glEnd(); |
| 112 | |
| 113 | glBlendEquation( GL_MIN ); |
| 114 | glBlendFunc( GL_ZERO, GL_ZERO ); |
| 115 | glBegin(GL_QUADS); |
| 116 | glColor3f( 0.8, 0.8, 0.8 ); |
| 117 | glVertex2f(-1, -1); |
| 118 | glVertex2f( 1, -1); |
| 119 | glVertex2f( 1, 1); |
| 120 | glVertex2f(-1, 1); |
| 121 | glEnd(); |
| 122 | |
| 123 | |
| 124 | glTranslatef(3.0, 0, 0); |
| 125 | glBlendEquation( GL_FUNC_ADD ); |
| 126 | glBlendFunc( GL_ONE, GL_ZERO ); |
| 127 | glBegin(GL_QUADS); |
| 128 | glColor3f( 0.8, 0.8, 0.8 ); |
| 129 | glVertex2f(-1, -1); |
| 130 | glVertex2f( 1, -1); |
| 131 | glVertex2f( 1, 1); |
| 132 | glVertex2f(-1, 1); |
| 133 | glEnd(); |
| 134 | |
| 135 | glBlendEquation( GL_MIN ); |
| 136 | glBlendFunc( GL_ZERO, GL_ZERO ); |
| 137 | glBegin(GL_QUADS); |
| 138 | glColor3f( 0.5, 0.5, 0.5 ); |
| 139 | glVertex2f(-1, -1); |
| 140 | glVertex2f( 1, -1); |
| 141 | glVertex2f( 1, 1); |
| 142 | glVertex2f(-1, 1); |
| 143 | glEnd(); |
| 144 | |
| 145 | glPopMatrix(); |
| 146 | |
| 147 | glutSwapBuffers(); |
| 148 | } |
| 149 | |
| 150 | |
| 151 | static void Reshape( int width, int height ) |
| 152 | { |
| 153 | GLfloat ar = (float) width / (float) height; |
| 154 | Width = width; |
| 155 | Height = height; |
| 156 | glViewport( 0, 0, width, height ); |
| 157 | glMatrixMode( GL_PROJECTION ); |
| 158 | glLoadIdentity(); |
| 159 | glFrustum( -ar, ar, -1.0, 1.0, Near, Far ); |
| 160 | glMatrixMode( GL_MODELVIEW ); |
| 161 | glLoadIdentity(); |
| 162 | glTranslatef( 0.0, 0.0, -15.0 ); |
| 163 | } |
| 164 | |
| 165 | |
| 166 | static void Key( unsigned char key, int x, int y ) |
| 167 | { |
| 168 | (void) x; |
| 169 | (void) y; |
| 170 | switch (key) { |
| 171 | case 27: |
| 172 | exit(0); |
| 173 | break; |
| 174 | } |
| 175 | glutPostRedisplay(); |
| 176 | } |
| 177 | |
| 178 | |
| 179 | static void Init( void ) |
| 180 | { |
| 181 | const char * const ver_string = (const char * const) |
| 182 | glGetString( GL_VERSION ); |
| 183 | |
| 184 | printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); |
| 185 | printf("GL_VERSION = %s\n", ver_string); |
| 186 | |
| 187 | if ( !glutExtensionSupported("GL_ARB_imaging") && !glutExtensionSupported("GL_EXT_blend_minmax")) { |
| 188 | printf("Sorry, this program requires either GL_ARB_imaging or GL_EXT_blend_minmax.\n"); |
| 189 | exit(1); |
| 190 | } |
| 191 | |
| 192 | printf("\nAll 4 squares should be the same color.\n"); |
| 193 | glEnable( GL_BLEND ); |
| 194 | } |
| 195 | |
| 196 | |
| 197 | int main( int argc, char *argv[] ) |
| 198 | { |
| 199 | glutInit( &argc, argv ); |
| 200 | glutInitWindowPosition( 0, 0 ); |
| 201 | glutInitWindowSize( Width, Height ); |
| 202 | glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE ); |
| 203 | glutCreateWindow( "GL_EXT_blend_minmax test" ); |
Keith Whitwell | a58065d | 2009-03-10 13:11:23 +0000 | [diff] [blame] | 204 | glewInit(); |
Ian Romanick | 5f6691f | 2004-05-11 19:57:58 +0000 | [diff] [blame] | 205 | glutReshapeFunc( Reshape ); |
| 206 | glutKeyboardFunc( Key ); |
| 207 | glutDisplayFunc( Display ); |
| 208 | Init(); |
| 209 | glutMainLoop(); |
| 210 | return 0; |
| 211 | } |