progs/fp/fp-tri.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 <unistd.h>
   8 #include <signal.h>
   9
  10 unsigned show_fps = 0;
  11 unsigned int frame_cnt = 0;
  12 void alarmhandler(int);
  13 static const char *filename = NULL;
  14
  15 static void usage(char *name)
  16 {
  17    fprintf(stderr, "usage: %s [ options ] shader_filename\n", name);
  18    fprintf(stderr, "\n" );
  19    fprintf(stderr, "options:\n");
  20    fprintf(stderr, "    -fps  show frames per second\n");
  21 }
  22
  23 void alarmhandler (int sig)
  24 {
  25    if (sig == SIGALRM) {
  26       printf("%d frames in 5.0 seconds = %.3f FPS\n", frame_cnt,
  27              frame_cnt / 5.0);
  28
  29       frame_cnt = 0;
  30    }
  31    signal(SIGALRM, alarmhandler);
  32    alarm(5);
  33 }
  34
  35 static void args(int argc, char *argv[])
  36 {
  37    GLint i;
  38
  39    for (i = 1; i < argc; i++) {
  40       if (strcmp(argv[i], "-fps") == 0) {
  41          show_fps = 1;
  42       }
  43       else if (i == argc - 1) {
  44          filename = argv[i];
  45       }
  46       else {
  47          usage(argv[0]);
  48          exit(1);
  49       }
  50    }
  51
  52    if (!filename) {
  53       usage(argv[0]);
  54       exit(1);
  55    }
  56 }
  57
  58 static void Init( void )
  59 {
  60    GLint errno;
  61    GLuint prognum;
  62    char buf[4096];
  63    GLuint sz;
  64    FILE *f;
  65
  66    if ((f = fopen(filename, "r")) == NULL) {
  67       fprintf(stderr, "Couldn't open %s\n", filename);
  68       exit(1);
  69    }
  70
  71    sz = fread(buf, 1, sizeof(buf), f);
  72    if (!feof(f)) {
  73       fprintf(stderr, "file too long\n");
  74       exit(1);
  75    }
  76    fprintf(stderr, "%.*s\n", sz, buf);
  77
  78    if (!glutExtensionSupported("GL_ARB_fragment_program")) {
  79       printf("Error: GL_ARB_fragment_program not supported!\n");
  80       exit(1);
  81    }
  82    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
  83
  84    /* Setup the fragment program */
  85    glGenProgramsARB(1, &prognum);
  86    glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, prognum);
  87    glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
  88                       sz, (const GLubyte *)buf);
  89
  90    errno = glGetError();
  91    printf("glGetError = 0x%x\n", errno);
  92    if (errno != GL_NO_ERROR) {
  93       GLint errorpos;
  94
  95       glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &errorpos);
  96       printf("errorpos: %d\n", errorpos);
  97       printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n",
  98              (char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB));
  99    }
 100    glEnable(GL_FRAGMENT_PROGRAM_ARB);
 101
 102    glClearColor(.3, .3, .3, 0);
 103 }
 104
 105 static void Reshape(int width, int height)
 106 {
 107
 108     glViewport(0, 0, (GLint)width, (GLint)height);
 109
 110     glMatrixMode(GL_PROJECTION);
 111     glLoadIdentity();
 112     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
 113     glMatrixMode(GL_MODELVIEW);
 114 }
 115
 116 static void Key(unsigned char key, int x, int y)
 117 {
 118
 119     switch (key) {
 120       case 27:
 121         exit(1);
 122       default:
 123         return;
 124     }
 125
 126     glutPostRedisplay();
 127 }
 128
 129 static void Display(void)
 130 {
 131    glClear(GL_COLOR_BUFFER_BIT);
 132
 133    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 0, 1.0, 1.0, 0.0, 0.0);
 134    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 1, 0.0, 0.0, 1.0, 1.0);
 135    glBegin(GL_TRIANGLES);
 136    glColor3f(0,0,1);
 137    glVertex3f( 0.9, -0.9, -30.0);
 138    glColor3f(1,0,0);
 139    glVertex3f( 0.9,  0.9, -30.0);
 140    glColor3f(0,1,0);
 141    glVertex3f(-0.9,  0.0, -30.0);
 142    glEnd();
 143
 144    glFlush();
 145
 146    if (show_fps) {
 147       ++frame_cnt;
 148       glutPostRedisplay();
 149    }
 150 }
 151
 152
 153 int main(int argc, char **argv)
 154 {
 155    glutInit(&argc, argv);
 156    glutInitWindowPosition(0, 0);
 157    glutInitWindowSize(250, 250);
 158    glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH);
 159    glutCreateWindow(argv[0]);
 160    glutReshapeFunc(Reshape);
 161    glutKeyboardFunc(Key);
 162    glutDisplayFunc(Display);
 163    args(argc, argv);
 164    Init();
 165    if (show_fps) {
 166       signal(SIGALRM, alarmhandler);
 167       alarm(5);
 168    }
 169    glutMainLoop();
 170    return 0;
 171 }