progs/fp/tri-cos.c

   1
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5 #define GL_GLEXT_PROTOTYPES
   6 #include <GL/glut.h>
   7 #include "GL/gl.h"
   8
   9
  10
  11 static void Init( void )
  12 {
  13    static const char *modulate2D =
  14       "!!ARBfp1.0\n"
  15       "TEMP R0; \n"
  16       "MUL R0, fragment.color, {3.14}.x; \n"
  17       "COS result.color.x, R0.x; \n"
  18       "COS result.color.y, R0.y; \n"
  19       "COS result.color.z, R0.z; \n"
  20       "END"
  21       ;
  22    GLuint modulateProg;
  23
  24    if (!glutExtensionSupported("GL_ARB_fragment_program")) {
  25       printf("Error: GL_ARB_fragment_program not supported!\n");
  26       exit(1);
  27    }
  28    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
  29
  30    /* Setup the fragment program */
  31    glGenProgramsARB(1, &modulateProg);
  32    glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, modulateProg);
  33    glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
  34                         strlen(modulate2D), (const GLubyte *)modulate2D);
  35
  36    printf("glGetError = 0x%x\n", (int) glGetError());
  37    printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n",
  38           (char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB));
  39
  40    glEnable(GL_FRAGMENT_PROGRAM_ARB);
  41
  42    glClearColor(.3, .3, .3, 0);
  43 }
  44
  45 static void Reshape(int width, int height)
  46 {
  47
  48     glViewport(0, 0, (GLint)width, (GLint)height);
  49
  50     glMatrixMode(GL_PROJECTION);
  51     glLoadIdentity();
  52     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  53     glMatrixMode(GL_MODELVIEW);
  54 }
  55
  56 static void Key(unsigned char key, int x, int y)
  57 {
  58
  59     switch (key) {
  60       case 27:
  61         exit(1);
  62       default:
  63         return;
  64     }
  65
  66     glutPostRedisplay();
  67 }
  68
  69 static void Draw(void)
  70 {
  71    glClear(GL_COLOR_BUFFER_BIT);
  72
  73    glBegin(GL_TRIANGLES);
  74    glColor3f(0,0,1);
  75    glVertex3f( 0.9, -0.9, -30.0);
  76    glColor3f(1,0,0);
  77    glVertex3f( 0.9,  0.9, -30.0);
  78    glColor3f(0,1,0);
  79    glVertex3f(-0.9,  0.0, -30.0);
  80    glEnd();
  81
  82    glFlush();
  83
  84
  85 }
  86
  87
  88
  89 int main(int argc, char **argv)
  90 {
  91     GLenum type;
  92
  93     glutInit(&argc, argv);
  94
  95
  96     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
  97
  98     type = GLUT_RGB;
  99     type |= GLUT_SINGLE;
 100     glutInitDisplayMode(type);
 101
 102     if (glutCreateWindow("First Tri") == GL_FALSE) {
 103         exit(1);
 104     }
 105
 106     Init();
 107
 108     glutReshapeFunc(Reshape);
 109     glutKeyboardFunc(Key);
 110     glutDisplayFunc(Draw);
 111     glutMainLoop();
 112         return 0;
 113 }