progs/vp/vp-tris.c

   1 /* Test glGenProgramsNV(), glIsProgramNV(), glLoadProgramNV() */
   2
   3 #include <assert.h>
   4 #include <string.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <math.h>
   8 #include <GL/glut.h>
   9
  10 #ifndef WIN32
  11 #include <unistd.h>
  12 #include <signal.h>
  13 #define GL_GLEXT_PROTOTYPES
  14 #else
  15 #include <GL/glext.h>
  16 #endif
  17
  18 #ifdef WIN32
  19 static PFNGLBINDPROGRAMARBPROC glBindProgramARB = NULL;
  20 static PFNGLGENPROGRAMSARBPROC glGenProgramsARB = NULL;
  21 static PFNGLPROGRAMSTRINGARBPROC glProgramStringARB = NULL;
  22 static PFNGLISPROGRAMARBPROC glIsProgramARB = NULL;
  23
  24 static PFNGLBINDPROGRAMNVPROC glBindProgramNV = NULL;
  25 static PFNGLGENPROGRAMSNVPROC glGenProgramsNV = NULL;
  26 static PFNGLLOADPROGRAMNVPROC glLoadProgramNV = NULL;
  27 static PFNGLISPROGRAMNVPROC glIsProgramNV = NULL;
  28 #endif
  29
  30 static const char *filename = NULL;
  31 static GLuint nr_steps = 4;
  32
  33 static void usage( char *name )
  34 {
  35    fprintf( stderr, "usage: %s [ options ] shader_filename\n", name );
  36    fprintf( stderr, "\n" );
  37    fprintf( stderr, "options:\n" );
  38    fprintf( stderr, "    -f     flat shaded\n" );
  39    fprintf( stderr, "    -nNr  subdivision steps\n" );
  40    fprintf( stderr, "    -fps  show frames per second\n" );
  41 }
  42
  43 unsigned show_fps = 0;
  44 unsigned int frame_cnt = 0;
  45
  46 #ifndef WIN32
  47
  48 void alarmhandler(int);
  49
  50 void alarmhandler (int sig)
  51 {
  52    if (sig == SIGALRM) {
  53       printf("%d frames in 5.0 seconds = %.3f FPS\n", frame_cnt,
  54              frame_cnt / 5.0);
  55
  56       frame_cnt = 0;
  57    }
  58    signal(SIGALRM, alarmhandler);
  59    alarm(5);
  60 }
  61
  62 #endif
  63
  64 static void args(int argc, char *argv[])
  65 {
  66    GLint i;
  67
  68    for (i = 1; i < argc; i++) {
  69       if (strncmp(argv[i], "-n", 2) == 0) {
  70          nr_steps = atoi((argv[i]) + 2);
  71       }
  72       else if (strcmp(argv[i], "-f") == 0) {
  73          glShadeModel(GL_FLAT);
  74       }
  75       else if (strcmp(argv[i], "-fps") == 0) {
  76          show_fps = 1;
  77       }
  78       else if (i == argc - 1) {
  79          filename = argv[i];
  80       }
  81       else {
  82          usage(argv[0]);
  83          exit(1);
  84       }
  85    }
  86
  87    if (!filename) {
  88       usage(argv[0]);
  89       exit(1);
  90    }
  91 }
  92
  93
  94
  95 static void Init( void )
  96 {
  97    GLint errno;
  98    GLuint prognum;
  99    char buf[4096];
 100    GLuint sz;
 101    FILE *f;
 102
 103    if ((f = fopen(filename, "r")) == NULL) {
 104       fprintf(stderr, "couldn't open %s\n", filename);
 105       exit(1);
 106    }
 107
 108    sz = (GLuint) fread(buf, 1, sizeof(buf), f);
 109    if (!feof(f)) {
 110       fprintf(stderr, "file too long\n");
 111       exit(1);
 112    }
 113
 114    fprintf(stderr, "%.*s\n", sz, buf);
 115
 116    if (strncmp( buf, "!!VP", 4 ) == 0) {
 117 #ifdef WIN32
 118       glBindProgramNV = (PFNGLBINDPROGRAMNVPROC) wglGetProcAddress( "glBindProgramNV" );
 119       glGenProgramsNV = (PFNGLGENPROGRAMSNVPROC) wglGetProcAddress( "glGenProgramsNV" );
 120       glLoadProgramNV = (PFNGLLOADPROGRAMNVPROC) wglGetProcAddress( "glLoadProgramNV" );
 121       glIsProgramNV = (PFNGLISPROGRAMNVPROC) wglGetProcAddress( "glIsProgramNV" );
 122 #endif
 123
 124       glEnable( GL_VERTEX_PROGRAM_NV );
 125       glGenProgramsNV( 1, &prognum );
 126       glBindProgramNV( GL_VERTEX_PROGRAM_NV, prognum );
 127       glLoadProgramNV( GL_VERTEX_PROGRAM_NV, prognum, sz, (const GLubyte *) buf );
 128       assert( glIsProgramNV( prognum ) );
 129    }
 130    else {
 131 #ifdef WIN32
 132       glBindProgramARB = (PFNGLBINDPROGRAMARBPROC) wglGetProcAddress( "glBindProgramARB" );
 133       glGenProgramsARB = (PFNGLGENPROGRAMSARBPROC) wglGetProcAddress( "glGenProgramsARB" );
 134       glProgramStringARB = (PFNGLPROGRAMSTRINGARBPROC) wglGetProcAddress( "glProgramStringARB" );
 135       glIsProgramARB = (PFNGLISPROGRAMARBPROC) wglGetProcAddress( "glIsProgramARB" );
 136 #endif
 137
 138       glEnable(GL_VERTEX_PROGRAM_ARB);
 139
 140       glGenProgramsARB(1, &prognum);
 141
 142       glBindProgramARB(GL_VERTEX_PROGRAM_ARB, prognum);
 143       glProgramStringARB(GL_VERTEX_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
 144                         sz, (const GLubyte *) buf);
 145       assert(glIsProgramARB(prognum));
 146    }
 147
 148    errno = glGetError();
 149    printf("glGetError = %d\n", errno);
 150    if (errno != GL_NO_ERROR)
 151    {
 152       GLint errorpos;
 153
 154       glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &errorpos);
 155       printf("errorpos: %d\n", errorpos);
 156       printf("%s\n", (char *)glGetString(GL_PROGRAM_ERROR_STRING_ARB));
 157    }
 158 }
 159
 160
 161 union vert {
 162    struct {
 163       GLfloat color[3];
 164       GLfloat pos[3];
 165    } v;
 166    GLfloat f[6];
 167 };
 168
 169 static void make_midpoint( union vert *out,
 170                            const union vert *v0,
 171                            const union vert *v1)
 172 {
 173    int i;
 174    for (i = 0; i < 6; i++)
 175       out->f[i] = v0->f[i] + .5 * (v1->f[i] - v0->f[i]);
 176 }
 177
 178 static void subdiv( union vert *v0,
 179                     union vert *v1,
 180                     union vert *v2,
 181                     GLuint depth )
 182 {
 183    if (depth == 0) {
 184       glColor3fv(v0->v.color);
 185       glVertex3fv(v0->v.pos);
 186       glColor3fv(v1->v.color);
 187       glVertex3fv(v1->v.pos);
 188       glColor3fv(v2->v.color);
 189       glVertex3fv(v2->v.pos);
 190    }
 191    else {
 192       union vert m[3];
 193
 194       make_midpoint(&m[0], v0, v1);
 195       make_midpoint(&m[1], v1, v2);
 196       make_midpoint(&m[2], v2, v0);
 197
 198       subdiv(&m[0], &m[2], v0, depth-1);
 199       subdiv(&m[1], &m[0], v1, depth-1);
 200       subdiv(&m[2], &m[1], v2, depth-1);
 201       subdiv(&m[0], &m[1], &m[2], depth-1);
 202    }
 203 }
 204
 205 /** Assignment */
 206 #define ASSIGN_3V( V, V0, V1, V2 )  \
 207 do {                                \
 208     V[0] = V0;                      \
 209     V[1] = V1;                      \
 210     V[2] = V2;                      \
 211 } while(0)
 212
 213 static void Display( void )
 214 {
 215    glClearColor(0.3, 0.3, 0.3, 1);
 216    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
 217
 218    glBegin(GL_TRIANGLES);
 219
 220
 221    {
 222       union vert v[3];
 223
 224       ASSIGN_3V(v[0].v.color, 0,0,1);
 225       ASSIGN_3V(v[0].v.pos,  0.9, -0.9, 0.0);
 226       ASSIGN_3V(v[1].v.color, 1,0,0);
 227       ASSIGN_3V(v[1].v.pos, 0.9, 0.9, 0.0);
 228       ASSIGN_3V(v[2].v.color, 0,1,0);
 229       ASSIGN_3V(v[2].v.pos, -0.9, 0, 0.0);
 230
 231       subdiv(&v[0], &v[1], &v[2], nr_steps);
 232    }
 233
 234    glEnd();
 235
 236
 237    glFlush();
 238    if (show_fps) {
 239       ++frame_cnt;
 240       glutPostRedisplay();
 241    }
 242 }
 243
 244
 245 static void Reshape( int width, int height )
 246 {
 247    glViewport( 0, 0, width, height );
 248    glMatrixMode( GL_PROJECTION );
 249    glLoadIdentity();
 250    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
 251    glMatrixMode( GL_MODELVIEW );
 252    glLoadIdentity();
 253    /*glTranslatef( 0.0, 0.0, -15.0 );*/
 254 }
 255
 256
 257 static void Key( unsigned char key, int x, int y )
 258 {
 259    (void) x;
 260    (void) y;
 261    switch (key) {
 262       case 27:
 263          exit(0);
 264          break;
 265    }
 266    glutPostRedisplay();
 267 }
 268
 269
 270
 271
 272 int main( int argc, char *argv[] )
 273 {
 274    glutInit( &argc, argv );
 275    glutInitWindowPosition( 0, 0 );
 276    glutInitWindowSize( 250, 250 );
 277    glutInitDisplayMode( GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH );
 278    glutCreateWindow(argv[argc-1]);
 279    glutReshapeFunc( Reshape );
 280    glutKeyboardFunc( Key );
 281    glutDisplayFunc( Display );
 282    args( argc, argv );
 283    Init();
 284 #ifndef WIN32
 285    if (show_fps) {
 286       signal(SIGALRM, alarmhandler);
 287       alarm(5);
 288    }
 289 #endif
 290    glutMainLoop();
 291    return 0;
 292 }