progs/fp/tri-param.c

   1
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5 #include <GL/glew.h>
   6 #include <GL/glut.h>
   7
   8
   9 static void Init( void )
  10 {
  11    static const char *modulate2D =
  12       "!!ARBfp1.0\n"
  13       "MOV result.color, program.local[32]; \n"
  14       "END"
  15       ;
  16    GLuint modulateProg;
  17
  18    if (!GLEW_ARB_fragment_program) {
  19       printf("Error: GL_ARB_fragment_program not supported!\n");
  20       exit(1);
  21    }
  22    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
  23
  24    /* Setup the fragment program */
  25    glGenProgramsARB(1, &modulateProg);
  26    glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, modulateProg);
  27    glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
  28                         strlen(modulate2D), (const GLubyte *)modulate2D);
  29
  30    printf("glGetError = 0x%x\n", (int) glGetError());
  31    printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n",
  32           (char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB));
  33
  34    glEnable(GL_FRAGMENT_PROGRAM_ARB);
  35
  36    glClearColor(.3, .3, .3, 0);
  37 }
  38
  39 static void Reshape(int width, int height)
  40 {
  41
  42     glViewport(0, 0, (GLint)width, (GLint)height);
  43
  44     glMatrixMode(GL_PROJECTION);
  45     glLoadIdentity();
  46     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  47     glMatrixMode(GL_MODELVIEW);
  48 }
  49
  50 static void Key(unsigned char key, int x, int y)
  51 {
  52
  53     switch (key) {
  54       case 27:
  55         exit(1);
  56       default:
  57         return;
  58     }
  59
  60     glutPostRedisplay();
  61 }
  62
  63 static void Draw(void)
  64 {
  65    glClear(GL_COLOR_BUFFER_BIT);
  66    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 32, 0.25, .5, 0.25, 1);
  67
  68    glBegin(GL_TRIANGLES);
  69    glColor3f(0,0,1);
  70    glVertex3f( 0.9, -0.9, -30.0);
  71    glColor3f(1,0,0);
  72    glVertex3f( 0.9,  0.0, -30.0);
  73    glColor3f(0,1,0);
  74    glVertex3f(-0.9,  0.0, -30.0);
  75    glEnd();
  76
  77    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 32, 0.25, 0, 0.25, 1);
  78
  79    glBegin(GL_TRIANGLES);
  80    glColor3f(0,0,1);
  81    glVertex3f( 0.9,  0.0, -30.0);
  82    glColor3f(1,0,0);
  83    glVertex3f( 0.9,  0.9, -30.0);
  84    glColor3f(0,1,0);
  85    glVertex3f(-0.9,  0.0, -30.0);
  86    glEnd();
  87
  88    glFlush();
  89 }
  90
  91
  92 int main(int argc, char **argv)
  93 {
  94     GLenum type;
  95
  96     glutInit(&argc, argv);
  97
  98     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
  99
 100     type = GLUT_RGB | GLUT_SINGLE;
 101     glutInitDisplayMode(type);
 102
 103     if (glutCreateWindow("First Tri") == GL_FALSE) {
 104         exit(1);
 105     }
 106
 107     glewInit();
 108
 109     Init();
 110
 111     glutReshapeFunc(Reshape);
 112     glutKeyboardFunc(Key);
 113     glutDisplayFunc(Draw);
 114     glutMainLoop();
 115         return 0;
 116 }