progs/fp/fp-tri.c

   1
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5
   6 #ifndef WIN32
   7 #include <unistd.h>
   8 #include <signal.h>
   9 #endif
  10
  11 #include <GL/glew.h>
  12 #include <GL/glut.h>
  13
  14 unsigned show_fps = 0;
  15 unsigned int frame_cnt = 0;
  16 void alarmhandler(int);
  17 static const char *filename = NULL;
  18
  19 static void usage(char *name)
  20 {
  21    fprintf(stderr, "usage: %s [ options ] shader_filename\n", name);
  22 #ifndef WIN32
  23    fprintf(stderr, "\n" );
  24    fprintf(stderr, "options:\n");
  25    fprintf(stderr, "    -fps  show frames per second\n");
  26 #endif
  27 }
  28
  29 #ifndef WIN32
  30 void alarmhandler (int sig)
  31 {
  32    if (sig == SIGALRM) {
  33       printf("%d frames in 5.0 seconds = %.3f FPS\n", frame_cnt,
  34              frame_cnt / 5.0);
  35
  36       frame_cnt = 0;
  37    }
  38    signal(SIGALRM, alarmhandler);
  39    alarm(5);
  40 }
  41 #endif
  42
  43 static void args(int argc, char *argv[])
  44 {
  45    GLint i;
  46
  47    for (i = 1; i < argc; i++) {
  48       if (strcmp(argv[i], "-fps") == 0) {
  49          show_fps = 1;
  50       }
  51       else if (i == argc - 1) {
  52          filename = argv[i];
  53       }
  54       else {
  55          usage(argv[0]);
  56          exit(1);
  57       }
  58    }
  59
  60    if (!filename) {
  61       usage(argv[0]);
  62       exit(1);
  63    }
  64 }
  65
  66 static void Init( void )
  67 {
  68    GLint errno;
  69    GLuint prognum;
  70    char buf[4096];
  71    GLuint sz;
  72    FILE *f;
  73
  74    if ((f = fopen(filename, "r")) == NULL) {
  75       fprintf(stderr, "Couldn't open %s\n", filename);
  76       exit(1);
  77    }
  78
  79    sz = fread(buf, 1, sizeof(buf), f);
  80    if (!feof(f)) {
  81       fprintf(stderr, "file too long\n");
  82       exit(1);
  83    }
  84    fprintf(stderr, "%.*s\n", sz, buf);
  85
  86    if (!glutExtensionSupported("GL_ARB_fragment_program")) {
  87       printf("Error: GL_ARB_fragment_program not supported!\n");
  88       exit(1);
  89    }
  90    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
  91
  92    /* Setup the fragment program */
  93    glGenProgramsARB(1, &prognum);
  94    glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, prognum);
  95    glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
  96                       sz, (const GLubyte *)buf);
  97
  98    errno = glGetError();
  99    printf("glGetError = 0x%x\n", errno);
 100    if (errno != GL_NO_ERROR) {
 101       GLint errorpos;
 102
 103       glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &errorpos);
 104       printf("errorpos: %d\n", errorpos);
 105       printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n",
 106              (char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB));
 107    }
 108    glEnable(GL_FRAGMENT_PROGRAM_ARB);
 109
 110    glClearColor(.3, .3, .3, 0);
 111 }
 112
 113 static void Reshape(int width, int height)
 114 {
 115
 116     glViewport(0, 0, (GLint)width, (GLint)height);
 117
 118     glMatrixMode(GL_PROJECTION);
 119     glLoadIdentity();
 120     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
 121     glMatrixMode(GL_MODELVIEW);
 122 }
 123
 124 static void Key(unsigned char key, int x, int y)
 125 {
 126
 127     switch (key) {
 128       case 27:
 129         exit(1);
 130       default:
 131         return;
 132     }
 133
 134     glutPostRedisplay();
 135 }
 136
 137 static void Display(void)
 138 {
 139    glClear(GL_COLOR_BUFFER_BIT);
 140
 141    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 0, 1.0, 1.0, 0.0, 0.0);
 142    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 1, 0.0, 0.0, 1.0, 1.0);
 143    glBegin(GL_TRIANGLES);
 144    glColor3f(0,0,1);
 145    glVertex3f( 0.9, -0.9, -30.0);
 146    glColor3f(1,0,0);
 147    glVertex3f( 0.9,  0.9, -30.0);
 148    glColor3f(0,1,0);
 149    glVertex3f(-0.9,  0.0, -30.0);
 150    glEnd();
 151
 152    glFlush();
 153    if (show_fps) {
 154       ++frame_cnt;
 155       glutPostRedisplay();
 156    }
 157 }
 158
 159
 160 int main(int argc, char **argv)
 161 {
 162    glutInit(&argc, argv);
 163    glutInitWindowPosition(0, 0);
 164    glutInitWindowSize(250, 250);
 165    glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH);
 166    args(argc, argv);
 167    glutCreateWindow(filename);
 168    glewInit();
 169    glutReshapeFunc(Reshape);
 170    glutKeyboardFunc(Key);
 171    glutDisplayFunc(Display);
 172    Init();
 173 #ifndef WIN32
 174    if (show_fps) {
 175       signal(SIGALRM, alarmhandler);
 176       alarm(5);
 177    }
 178 #endif
 179    glutMainLoop();
 180    return 0;
 181 }