progs/glsl/multitex.c - fp2-dev/platform/external/mesa3d - Gitiles

 /**
  * Test multi-texturing with GL shading language.
  *
  * Copyright (C) 2008  Brian Paul   All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included
  * in all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */


 #include <assert.h>
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <GL/glew.h>
 #include "GL/glut.h"
 #include "readtex.h"
 #include "shaderutil.h"

 static const char *Demo = "multitex";

 static const char *VertFile = "multitex.vert";
 static const char *FragFile = "multitex.frag";

 static const char *TexFiles[2] =
    {
       "../images/tile.rgb",
       "../images/tree2.rgba"
    };


 static GLuint Program;

 static GLfloat Xrot = 0.0, Yrot = .0, Zrot = 0.0;
 static GLfloat EyeDist = 10;
 static GLboolean Anim = GL_TRUE;
 static GLboolean UseArrays = GL_TRUE;
 static GLboolean UseVBO = GL_TRUE;
 static GLuint VBO = 0;

 static GLint VertCoord_attr = -1, TexCoord0_attr = -1, TexCoord1_attr = -1;


 /* value[0] = tex unit */
 static struct uniform_info Uniforms[] = {
    { "tex1",  1, GL_SAMPLER_2D, { 0, 0, 0, 0 }, -1 },
    { "tex2",  1, GL_SAMPLER_2D, { 1, 0, 0, 0 }, -1 },
    END_OF_UNIFORMS
 };


 static const GLfloat Tex0Coords[4][2] = {
    { 0.0, 0.0 }, { 2.0, 0.0 }, { 2.0, 2.0 }, { 0.0, 2.0 }
 };

 static const GLfloat Tex1Coords[4][2] = {
    { 0.0, 0.0 }, { 1.0, 0.0 }, { 1.0, 1.0 }, { 0.0, 1.0 }
 };

 static const GLfloat VertCoords[4][2] = {
    { -3.0, -3.0 }, { 3.0, -3.0 }, { 3.0, 3.0 }, { -3.0, 3.0 }
 };


 static void
 SetupVertexBuffer(void)
 {
    glGenBuffersARB(1, &VBO);
    glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);

    glBufferDataARB(GL_ARRAY_BUFFER_ARB,
                         sizeof(VertCoords) +
                         sizeof(Tex0Coords) +
                         sizeof(Tex1Coords),
                         NULL,
                         GL_STATIC_DRAW_ARB);

    /* non-interleaved vertex arrays */

    glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
                            0,                   /* offset */
                            sizeof(VertCoords),  /* size */
                            VertCoords);         /* data */

    glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
                            sizeof(VertCoords),  /* offset */
                            sizeof(Tex0Coords),  /* size */
                            Tex0Coords);         /* data */

    glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
                            sizeof(VertCoords) +
                            sizeof(Tex0Coords),  /* offset */
                            sizeof(Tex1Coords),  /* size */
                            Tex1Coords);         /* data */

    glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
 }


 static void
 DrawPolygonArray(void)
 {
    void *vertPtr, *tex0Ptr, *tex1Ptr;

    if (UseVBO) {
       glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
       vertPtr = (void *) 0;
       tex0Ptr = (void *) sizeof(VertCoords);
       tex1Ptr = (void *) (sizeof(VertCoords) + sizeof(Tex0Coords));
    }
    else {
       glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
       vertPtr = VertCoords;
       tex0Ptr = Tex0Coords;
       tex1Ptr = Tex1Coords;
    }

    if (VertCoord_attr >= 0) {
       glVertexAttribPointer(VertCoord_attr, 2, GL_FLOAT, GL_FALSE,
                                  0, vertPtr);
       glEnableVertexAttribArray(VertCoord_attr);
    }
    else {
       glVertexPointer(2, GL_FLOAT, 0, vertPtr);
       glEnableClientState(GL_VERTEX_ARRAY);
    }

    glVertexAttribPointer(TexCoord0_attr, 2, GL_FLOAT, GL_FALSE,
                               0, tex0Ptr);
    glEnableVertexAttribArray(TexCoord0_attr);

    glVertexAttribPointer(TexCoord1_attr, 2, GL_FLOAT, GL_FALSE,
                               0, tex1Ptr);
    glEnableVertexAttribArray(TexCoord1_attr);

    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

    glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
 }


 static void
 DrawPolygonVert(void)
 {
    GLuint i;

    glBegin(GL_TRIANGLE_FAN);

    for (i = 0; i < 4; i++) {
       glVertexAttrib2fv(TexCoord0_attr, Tex0Coords[i]);
       glVertexAttrib2fv(TexCoord1_attr, Tex1Coords[i]);

       if (VertCoord_attr >= 0)
          glVertexAttrib2fv(VertCoord_attr, VertCoords[i]);
       else
          glVertex2fv(VertCoords[i]);
    }

    glEnd();
 }


 static void
 draw(void)
 {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix(); /* modelview matrix */
       glTranslatef(0.0, 0.0, -EyeDist);
       glRotatef(Zrot, 0, 0, 1);
       glRotatef(Yrot, 0, 1, 0);
       glRotatef(Xrot, 1, 0, 0);

       if (UseArrays)
          DrawPolygonArray();
       else
          DrawPolygonVert();

    glPopMatrix();

    glutSwapBuffers();
 }


 static void
 idle(void)
 {
    GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
    Yrot = t;
    glutPostRedisplay();
 }


 static void
 key(unsigned char k, int x, int y)
 {
    (void) x;
    (void) y;
    switch (k) {
    case 'a':
       UseArrays = !UseArrays;
       printf("Arrays: %d\n", UseArrays);
       break;
    case 'v':
       UseVBO = !UseVBO;
       printf("Use VBO: %d\n", UseVBO);
       break;
    case ' ':
       Anim = !Anim;
       if (Anim)
          glutIdleFunc(idle);
       else
          glutIdleFunc(NULL);
       break;
    case 'z':
       EyeDist -= 0.5;
       if (EyeDist < 3.0)
          EyeDist = 3.0;
       break;
    case 'Z':
       EyeDist += 0.5;
       if (EyeDist > 90.0)
          EyeDist = 90;
       break;
    case 27:
       exit(0);
    }
    glutPostRedisplay();
 }


 static void
 specialkey(int key, int x, int y)
 {
    GLfloat step = 2.0;
    (void) x;
    (void) y;
    switch (key) {
    case GLUT_KEY_UP:
       Xrot += step;
       break;
    case GLUT_KEY_DOWN:
       Xrot -= step;
       break;
    case GLUT_KEY_LEFT:
       Yrot -= step;
       break;
    case GLUT_KEY_RIGHT:
       Yrot += step;
       break;
    }
    glutPostRedisplay();
 }


 /* new window size or exposure */
 static void
 Reshape(int width, int height)
 {
    GLfloat ar = (float) width / (float) height;
    glViewport(0, 0, (GLint)width, (GLint)height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(-2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
 }


 static void
 InitTextures(void)
 {
    GLenum filter = GL_LINEAR;
    int i;

    for (i = 0; i < 2; i++) {
       GLint imgWidth, imgHeight;
       GLenum imgFormat;
       GLubyte *image = NULL;

       image = LoadRGBImage(TexFiles[i], &imgWidth, &imgHeight, &imgFormat);
       if (!image) {
          printf("Couldn't read %s\n", TexFiles[i]);
          exit(0);
       }

       glActiveTexture(GL_TEXTURE0 + i);
       glBindTexture(GL_TEXTURE_2D, 42 + i);
       gluBuild2DMipmaps(GL_TEXTURE_2D, 4, imgWidth, imgHeight,
                         imgFormat, GL_UNSIGNED_BYTE, image);
       free(image);

       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
    }
 }


 static GLuint
 CreateProgram(const char *vertProgFile, const char *fragProgFile,
               struct uniform_info *uniforms)
 {
    GLuint fragShader, vertShader, program;

    vertShader = CompileShaderFile(GL_VERTEX_SHADER, vertProgFile);
    fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, fragProgFile);
    assert(vertShader);
    program = LinkShaders(vertShader, fragShader);

    glUseProgram(program);

    SetUniformValues(program, uniforms);
    PrintUniforms(Uniforms);

    assert(ValidateShaderProgram(program));

    VertCoord_attr = glGetAttribLocation(program, "VertCoord");
    if (VertCoord_attr > 0) {
       /* We want the VertCoord attrib to have position zero so that
        * the call to glVertexAttrib(0, xyz) triggers vertex processing.
        * Otherwise, if TexCoord0 or TexCoord1 gets position 0 we'd have
        * to set that attribute last (which is a PITA to manage).
        */
       glBindAttribLocation(program, 0, "VertCoord");
       /* re-link */
       glLinkProgram(program);
       /* VertCoord_attr should be zero now */
       VertCoord_attr = glGetAttribLocation(program, "VertCoord");
       assert(VertCoord_attr == 0);
    }

    TexCoord0_attr = glGetAttribLocation(program, "TexCoord0");
    TexCoord1_attr = glGetAttribLocation(program, "TexCoord1");

    printf("TexCoord0_attr = %d\n", TexCoord0_attr);
    printf("TexCoord1_attr = %d\n", TexCoord1_attr);
    printf("VertCoord_attr = %d\n", VertCoord_attr);

    return program;
 }


 static void
 InitPrograms(void)
 {
    Program = CreateProgram(VertFile, FragFile, Uniforms);
 }


 static void
 InitGL(void)
 {
    if (!ShadersSupported())
       exit(1);

    printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
    printf("Usage:\n");
    printf("  a     - toggle arrays vs. immediate mode rendering\n");
    printf("  v     - toggle VBO usage for array rendering\n");
    printf("  z/Z   - change viewing distance\n");
    printf("  SPACE - toggle animation\n");
    printf("  Esc   - exit\n");

    InitTextures();
    InitPrograms();

    SetupVertexBuffer();

    glEnable(GL_DEPTH_TEST);

    glClearColor(.6, .6, .9, 0);
    glColor3f(1.0, 1.0, 1.0);
 }


 int
 main(int argc, char *argv[])
 {
    glutInit(&argc, argv);
    glutInitWindowSize(500, 400);
    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
    glutCreateWindow(Demo);
    glewInit();
    glutReshapeFunc(Reshape);
    glutKeyboardFunc(key);
    glutSpecialFunc(specialkey);
    glutDisplayFunc(draw);
    if (Anim)
       glutIdleFunc(idle);
    InitGL();
    glutMainLoop();
    return 0;
 }
	/**
	* Test multi-texturing with GL shading language.
	*
	* Copyright (C) 2008 Brian Paul All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included
	* in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
	* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/



	#include <assert.h>
	#include <math.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <GL/glew.h>
	#include "GL/glut.h"
	#include "readtex.h"
	#include "shaderutil.h"

	static const char *Demo = "multitex";

	static const char *VertFile = "multitex.vert";
	static const char *FragFile = "multitex.frag";

	static const char *TexFiles[2] =
	{
	"../images/tile.rgb",
	"../images/tree2.rgba"
	};


	static GLuint Program;

	static GLfloat Xrot = 0.0, Yrot = .0, Zrot = 0.0;
	static GLfloat EyeDist = 10;
	static GLboolean Anim = GL_TRUE;
	static GLboolean UseArrays = GL_TRUE;
	static GLboolean UseVBO = GL_TRUE;
	static GLuint VBO = 0;

	static GLint VertCoord_attr = -1, TexCoord0_attr = -1, TexCoord1_attr = -1;


	/* value[0] = tex unit */
	static struct uniform_info Uniforms[] = {
	{ "tex1", 1, GL_SAMPLER_2D, { 0, 0, 0, 0 }, -1 },
	{ "tex2", 1, GL_SAMPLER_2D, { 1, 0, 0, 0 }, -1 },
	END_OF_UNIFORMS
	};


	static const GLfloat Tex0Coords[4][2] = {
	{ 0.0, 0.0 }, { 2.0, 0.0 }, { 2.0, 2.0 }, { 0.0, 2.0 }
	};

	static const GLfloat Tex1Coords[4][2] = {
	{ 0.0, 0.0 }, { 1.0, 0.0 }, { 1.0, 1.0 }, { 0.0, 1.0 }
	};

	static const GLfloat VertCoords[4][2] = {
	{ -3.0, -3.0 }, { 3.0, -3.0 }, { 3.0, 3.0 }, { -3.0, 3.0 }
	};



	static void
	SetupVertexBuffer(void)
	{
	glGenBuffersARB(1, &VBO);
	glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);

	glBufferDataARB(GL_ARRAY_BUFFER_ARB,
	sizeof(VertCoords) +
	sizeof(Tex0Coords) +
	sizeof(Tex1Coords),
	NULL,
	GL_STATIC_DRAW_ARB);

	/* non-interleaved vertex arrays */

	glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
	0, /* offset */
	sizeof(VertCoords), /* size */
	VertCoords); /* data */

	glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
	sizeof(VertCoords), /* offset */
	sizeof(Tex0Coords), /* size */
	Tex0Coords); /* data */

	glBufferSubDataARB(GL_ARRAY_BUFFER_ARB,
	sizeof(VertCoords) +
	sizeof(Tex0Coords), /* offset */
	sizeof(Tex1Coords), /* size */
	Tex1Coords); /* data */

	glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
	}


	static void
	DrawPolygonArray(void)
	{
	void vertPtr, tex0Ptr, *tex1Ptr;

	if (UseVBO) {
	glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
	vertPtr = (void *) 0;
	tex0Ptr = (void *) sizeof(VertCoords);
	tex1Ptr = (void *) (sizeof(VertCoords) + sizeof(Tex0Coords));
	}
	else {
	glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
	vertPtr = VertCoords;
	tex0Ptr = Tex0Coords;
	tex1Ptr = Tex1Coords;
	}

	if (VertCoord_attr >= 0) {
	glVertexAttribPointer(VertCoord_attr, 2, GL_FLOAT, GL_FALSE,
	0, vertPtr);
	glEnableVertexAttribArray(VertCoord_attr);
	}
	else {
	glVertexPointer(2, GL_FLOAT, 0, vertPtr);
	glEnableClientState(GL_VERTEX_ARRAY);
	}

	glVertexAttribPointer(TexCoord0_attr, 2, GL_FLOAT, GL_FALSE,
	0, tex0Ptr);
	glEnableVertexAttribArray(TexCoord0_attr);

	glVertexAttribPointer(TexCoord1_attr, 2, GL_FLOAT, GL_FALSE,
	0, tex1Ptr);
	glEnableVertexAttribArray(TexCoord1_attr);

	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

	glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
	}


	static void
	DrawPolygonVert(void)
	{
	GLuint i;

	glBegin(GL_TRIANGLE_FAN);

	for (i = 0; i < 4; i++) {
	glVertexAttrib2fv(TexCoord0_attr, Tex0Coords[i]);
	glVertexAttrib2fv(TexCoord1_attr, Tex1Coords[i]);

	if (VertCoord_attr >= 0)
	glVertexAttrib2fv(VertCoord_attr, VertCoords[i]);
	else
	glVertex2fv(VertCoords[i]);
	}

	glEnd();
	}


	static void
	draw(void)
	{
	glClear(GL_COLOR_BUFFER_BIT \| GL_DEPTH_BUFFER_BIT);

	glPushMatrix(); /* modelview matrix */
	glTranslatef(0.0, 0.0, -EyeDist);
	glRotatef(Zrot, 0, 0, 1);
	glRotatef(Yrot, 0, 1, 0);
	glRotatef(Xrot, 1, 0, 0);

	if (UseArrays)
	DrawPolygonArray();
	else
	DrawPolygonVert();

	glPopMatrix();

	glutSwapBuffers();
	}


	static void
	idle(void)
	{
	GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
	Yrot = t;
	glutPostRedisplay();
	}


	static void
	key(unsigned char k, int x, int y)
	{
	(void) x;
	(void) y;
	switch (k) {
	case 'a':
	UseArrays = !UseArrays;
	printf("Arrays: %d\n", UseArrays);
	break;
	case 'v':
	UseVBO = !UseVBO;
	printf("Use VBO: %d\n", UseVBO);
	break;
	case ' ':
	Anim = !Anim;
	if (Anim)
	glutIdleFunc(idle);
	else
	glutIdleFunc(NULL);
	break;
	case 'z':
	EyeDist -= 0.5;
	if (EyeDist < 3.0)
	EyeDist = 3.0;
	break;
	case 'Z':
	EyeDist += 0.5;
	if (EyeDist > 90.0)
	EyeDist = 90;
	break;
	case 27:
	exit(0);
	}
	glutPostRedisplay();
	}


	static void
	specialkey(int key, int x, int y)
	{
	GLfloat step = 2.0;
	(void) x;
	(void) y;
	switch (key) {
	case GLUT_KEY_UP:
	Xrot += step;
	break;
	case GLUT_KEY_DOWN:
	Xrot -= step;
	break;
	case GLUT_KEY_LEFT:
	Yrot -= step;
	break;
	case GLUT_KEY_RIGHT:
	Yrot += step;
	break;
	}
	glutPostRedisplay();
	}


	/* new window size or exposure */
	static void
	Reshape(int width, int height)
	{
	GLfloat ar = (float) width / (float) height;
	glViewport(0, 0, (GLint)width, (GLint)height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glFrustum(-2.0ar, 2.0ar, -2.0, 2.0, 4.0, 100.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	}


	static void
	InitTextures(void)
	{
	GLenum filter = GL_LINEAR;
	int i;

	for (i = 0; i < 2; i++) {
	GLint imgWidth, imgHeight;
	GLenum imgFormat;
	GLubyte *image = NULL;

	image = LoadRGBImage(TexFiles[i], &imgWidth, &imgHeight, &imgFormat);
	if (!image) {
	printf("Couldn't read %s\n", TexFiles[i]);
	exit(0);
	}

	glActiveTexture(GL_TEXTURE0 + i);
	glBindTexture(GL_TEXTURE_2D, 42 + i);
	gluBuild2DMipmaps(GL_TEXTURE_2D, 4, imgWidth, imgHeight,
	imgFormat, GL_UNSIGNED_BYTE, image);
	free(image);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter);
	}
	}


	static GLuint
	CreateProgram(const char vertProgFile, const char fragProgFile,
	struct uniform_info *uniforms)
	{
	GLuint fragShader, vertShader, program;

	vertShader = CompileShaderFile(GL_VERTEX_SHADER, vertProgFile);
	fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, fragProgFile);
	assert(vertShader);
	program = LinkShaders(vertShader, fragShader);

	glUseProgram(program);

	SetUniformValues(program, uniforms);
	PrintUniforms(Uniforms);

	assert(ValidateShaderProgram(program));

	VertCoord_attr = glGetAttribLocation(program, "VertCoord");
	if (VertCoord_attr > 0) {
	/* We want the VertCoord attrib to have position zero so that
	* the call to glVertexAttrib(0, xyz) triggers vertex processing.
	* Otherwise, if TexCoord0 or TexCoord1 gets position 0 we'd have
	* to set that attribute last (which is a PITA to manage).
	*/
	glBindAttribLocation(program, 0, "VertCoord");
	/* re-link */
	glLinkProgram(program);
	/* VertCoord_attr should be zero now */
	VertCoord_attr = glGetAttribLocation(program, "VertCoord");
	assert(VertCoord_attr == 0);
	}

	TexCoord0_attr = glGetAttribLocation(program, "TexCoord0");
	TexCoord1_attr = glGetAttribLocation(program, "TexCoord1");

	printf("TexCoord0_attr = %d\n", TexCoord0_attr);
	printf("TexCoord1_attr = %d\n", TexCoord1_attr);
	printf("VertCoord_attr = %d\n", VertCoord_attr);

	return program;
	}


	static void
	InitPrograms(void)
	{
	Program = CreateProgram(VertFile, FragFile, Uniforms);
	}


	static void
	InitGL(void)
	{
	if (!ShadersSupported())
	exit(1);

	printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
	printf("Usage:\n");
	printf(" a - toggle arrays vs. immediate mode rendering\n");
	printf(" v - toggle VBO usage for array rendering\n");
	printf(" z/Z - change viewing distance\n");
	printf(" SPACE - toggle animation\n");
	printf(" Esc - exit\n");

	InitTextures();
	InitPrograms();

	SetupVertexBuffer();

	glEnable(GL_DEPTH_TEST);

	glClearColor(.6, .6, .9, 0);
	glColor3f(1.0, 1.0, 1.0);
	}


	int
	main(int argc, char *argv[])
	{
	glutInit(&argc, argv);
	glutInitWindowSize(500, 400);
	glutInitDisplayMode(GLUT_RGB \| GLUT_DEPTH \| GLUT_DOUBLE);
	glutCreateWindow(Demo);
	glewInit();
	glutReshapeFunc(Reshape);
	glutKeyboardFunc(key);
	glutSpecialFunc(specialkey);
	glutDisplayFunc(draw);
	if (Anim)
	glutIdleFunc(idle);
	InitGL();
	glutMainLoop();
	return 0;
	}