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