src/demos/multiarb.c

   1 /*
   2  * GL_ARB_multitexture demo
   3  *
   4  * Command line options:
   5  *    -info      print GL implementation information
   6  *
   7  *
   8  * Brian Paul  November 1998  This program is in the public domain.
   9  * Modified on 12 Feb 2002 for > 2 texture units.
  10  */
  11
  12
  13 #include <math.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <glad/glad.h>
  18 #include "glut_wrap.h"
  19
  20 #include "readtex.h"
  21
  22 #define TEXTURE_1_FILE DEMOS_DATA_DIR "girl.rgb"
  23 #define TEXTURE_2_FILE DEMOS_DATA_DIR "reflect.rgb"
  24
  25 #define TEX0 1
  26 #define TEX7 8
  27 #define ANIMATE 10
  28 #define QUIT 100
  29
  30 static GLint T0 = 0;
  31 static GLint Frames = 0;
  32 static GLboolean Animate = GL_TRUE;
  33 static GLint NumUnits = 1;
  34 static GLboolean TexEnabled[8];
  35
  36 static GLfloat Drift = 0.0;
  37 static GLfloat Xrot = 20.0, Yrot = 30.0, Zrot = 0.0;
  38
  39
  40 static void Idle( void )
  41 {
  42    if (Animate) {
  43       GLint i;
  44
  45       Drift = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  46
  47       for (i = 0; i < NumUnits; i++) {
  48          glActiveTextureARB(GL_TEXTURE0_ARB + i);
  49          glMatrixMode(GL_TEXTURE);
  50          glLoadIdentity();
  51          if (i == 0) {
  52             glTranslatef(Drift, 0.0, 0.0);
  53             glScalef(2, 2, 1);
  54          }
  55          else if (i == 1) {
  56             glTranslatef(0.0, Drift, 0.0);
  57          }
  58          else {
  59             float tx = 0.5, ty = 0.5;
  60             glTranslatef(tx, ty, 0.0);
  61             glRotatef(180.0 * Drift, 0, 0, 1);
  62             glScalef(1.0/i, 1.0/i, 1.0/i);
  63             glTranslatef(-tx, -ty + i * 0.1, 0.0);
  64          }
  65       }
  66       glMatrixMode(GL_MODELVIEW);
  67
  68       glutPostRedisplay();
  69    }
  70 }
  71
  72
  73 static void DrawObject(void)
  74 {
  75    static const GLfloat tex_coords[] = {  0.0,  0.0,  1.0,  1.0,  0.0 };
  76    static const GLfloat vtx_coords[] = { -1.0, -1.0,  1.0,  1.0, -1.0 };
  77    GLint i, j;
  78
  79    if (!TexEnabled[0] && !TexEnabled[1])
  80       glColor3f(0.1, 0.1, 0.1);  /* add onto this */
  81    else
  82       glColor3f(1, 1, 1);  /* modulate this */
  83
  84    glBegin(GL_QUADS);
  85    for (j = 0; j < 4; j++ ) {
  86       for (i = 0; i < NumUnits; i++) {
  87          if (TexEnabled[i])
  88             glMultiTexCoord2fARB(GL_TEXTURE0_ARB + i,
  89                                  tex_coords[j], tex_coords[j+1]);
  90       }
  91       glVertex2f( vtx_coords[j], vtx_coords[j+1] );
  92    }
  93    glEnd();
  94 }
  95
  96
  97 static void Display( void )
  98 {
  99    glClear( GL_COLOR_BUFFER_BIT );
 100
 101    glPushMatrix();
 102       glRotatef(Xrot, 1.0, 0.0, 0.0);
 103       glRotatef(Yrot, 0.0, 1.0, 0.0);
 104       glRotatef(Zrot, 0.0, 0.0, 1.0);
 105       glScalef(5.0, 5.0, 5.0);
 106       DrawObject();
 107    glPopMatrix();
 108
 109    glutSwapBuffers();
 110
 111    Frames++;
 112
 113    {
 114       GLint t = glutGet(GLUT_ELAPSED_TIME);
 115       if (t - T0 >= 5000) {
 116          GLfloat seconds = (t - T0) / 1000.0;
 117          GLfloat fps = Frames / seconds;
 118          printf("%d frames in %6.3f seconds = %6.3f FPS\n", Frames, seconds, fps);
 119          fflush(stdout);
 120          T0 = t;
 121          Frames = 0;
 122       }
 123    }
 124 }
 125
 126
 127 static void Reshape( int width, int height )
 128 {
 129    glViewport( 0, 0, width, height );
 130    glMatrixMode( GL_PROJECTION );
 131    glLoadIdentity();
 132    glFrustum( -1.0, 1.0, -1.0, 1.0, 10.0, 100.0 );
 133    /*glOrtho( -6.0, 6.0, -6.0, 6.0, 10.0, 100.0 );*/
 134    glMatrixMode( GL_MODELVIEW );
 135    glLoadIdentity();
 136    glTranslatef( 0.0, 0.0, -70.0 );
 137 }
 138
 139
 140 static void ToggleUnit(int unit)
 141 {
 142    TexEnabled[unit] = !TexEnabled[unit];
 143    glActiveTextureARB(GL_TEXTURE0_ARB + unit);
 144    if (TexEnabled[unit])
 145       glEnable(GL_TEXTURE_2D);
 146    else
 147       glDisable(GL_TEXTURE_2D);
 148    printf("Enabled: ");
 149    for (unit = 0; unit < NumUnits; unit++)
 150       printf("%d ", (int) TexEnabled[unit]);
 151    printf("\n");
 152 }
 153
 154
 155 static void ModeMenu(int entry)
 156 {
 157    if (entry >= TEX0 && entry <= TEX7) {
 158       /* toggle */
 159       GLint i = entry - TEX0;
 160       ToggleUnit(i);
 161    }
 162    else if (entry==ANIMATE) {
 163       Animate = !Animate;
 164       if (Animate)
 165          glutIdleFunc(Idle);
 166       else
 167          glutIdleFunc(NULL);
 168    }
 169    else if (entry==QUIT) {
 170       exit(0);
 171    }
 172
 173    glutPostRedisplay();
 174 }
 175
 176
 177 static void Key( unsigned char key, int x, int y )
 178 {
 179    (void) x;
 180    (void) y;
 181    switch (key) {
 182    case 'a':
 183       Animate = !Animate;
 184       break;
 185    case '0':
 186       ToggleUnit(0);
 187       break;
 188    case '1':
 189       ToggleUnit(1);
 190       break;
 191    case '2':
 192       ToggleUnit(2);
 193       break;
 194    case '3':
 195       ToggleUnit(3);
 196       break;
 197    case '4':
 198       ToggleUnit(4);
 199       break;
 200    case '5':
 201       ToggleUnit(5);
 202       break;
 203    case '6':
 204       ToggleUnit(6);
 205       break;
 206    case '7':
 207       ToggleUnit(7);
 208       break;
 209    case 27:
 210       exit(0);
 211       break;
 212    }
 213    glutPostRedisplay();
 214 }
 215
 216
 217 static void SpecialKey( int key, int x, int y )
 218 {
 219    float step = 3.0;
 220    (void) x;
 221    (void) y;
 222
 223    switch (key) {
 224       case GLUT_KEY_UP:
 225          Xrot += step;
 226          break;
 227       case GLUT_KEY_DOWN:
 228          Xrot -= step;
 229          break;
 230       case GLUT_KEY_LEFT:
 231          Yrot += step;
 232          break;
 233       case GLUT_KEY_RIGHT:
 234          Yrot -= step;
 235          break;
 236    }
 237    glutPostRedisplay();
 238 }
 239
 240
 241 static void Init( int argc, char *argv[] )
 242 {
 243    GLuint texObj[8];
 244    GLint size, i;
 245
 246    const char *exten = (const char *) glGetString(GL_EXTENSIONS);
 247    if (!strstr(exten, "GL_ARB_multitexture")) {
 248       printf("Sorry, GL_ARB_multitexture not supported by this renderer.\n");
 249       exit(1);
 250    }
 251
 252    glGetIntegerv(GL_MAX_TEXTURE_UNITS_ARB, &NumUnits);
 253    printf("%d texture units supported\n", NumUnits);
 254    if (NumUnits > 8)
 255       NumUnits = 8;
 256
 257    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &size);
 258    printf("%d x %d max texture size\n", size, size);
 259
 260    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 261
 262    for (i = 0; i < NumUnits; i++) {
 263       if (i < 2)
 264          TexEnabled[i] = GL_TRUE;
 265       else
 266          TexEnabled[i] = GL_FALSE;
 267    }
 268
 269    /* allocate two texture objects */
 270    glGenTextures(NumUnits, texObj);
 271
 272    /* setup the texture objects */
 273    for (i = 0; i < NumUnits; i++) {
 274
 275       glActiveTextureARB(GL_TEXTURE0_ARB + i);
 276       glBindTexture(GL_TEXTURE_2D, texObj[i]);
 277
 278       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 279       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 280
 281       if (i == 0) {
 282          if (!LoadRGBMipmaps(TEXTURE_1_FILE, GL_RGB)) {
 283             printf("Error: couldn't load texture image\n");
 284             exit(1);
 285          }
 286       }
 287       else if (i == 1) {
 288          if (!LoadRGBMipmaps(TEXTURE_2_FILE, GL_RGB)) {
 289             printf("Error: couldn't load texture image\n");
 290             exit(1);
 291          }
 292       }
 293       else {
 294          /* checker */
 295          GLubyte image[8][8][3];
 296          GLint i, j;
 297          for (i = 0; i < 8; i++) {
 298             for (j = 0; j < 8; j++) {
 299                if ((i + j) & 1) {
 300                   image[i][j][0] = 50;
 301                   image[i][j][1] = 50;
 302                   image[i][j][2] = 50;
 303                }
 304                else {
 305                   image[i][j][0] = 25;
 306                   image[i][j][1] = 25;
 307                   image[i][j][2] = 25;
 308                }
 309             }
 310          }
 311          glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 8, 8, 0,
 312                       GL_RGB, GL_UNSIGNED_BYTE, (GLvoid *) image);
 313       }
 314
 315       /* Bind texObj[i] to ith texture unit */
 316       if (i < 2)
 317          glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 318       else
 319          glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ADD);
 320
 321       if (TexEnabled[i])
 322          glEnable(GL_TEXTURE_2D);
 323    }
 324
 325    glShadeModel(GL_FLAT);
 326    glClearColor(0.3, 0.3, 0.4, 1.0);
 327
 328    if (argc > 1 && strcmp(argv[1], "-info")==0) {
 329       printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
 330       printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
 331       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 332       printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
 333    }
 334 }
 335
 336
 337 int main( int argc, char *argv[] )
 338 {
 339    GLint i;
 340
 341    glutInitWindowSize( 300, 300 );
 342    glutInit( &argc, argv );
 343    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 344    glutCreateWindow(argv[0] );
 345    gladLoadGL();
 346
 347    Init( argc, argv );
 348
 349    glutReshapeFunc( Reshape );
 350    glutKeyboardFunc( Key );
 351    glutSpecialFunc( SpecialKey );
 352    glutDisplayFunc( Display );
 353    if (Animate)
 354       glutIdleFunc(Idle);
 355
 356    glutCreateMenu(ModeMenu);
 357
 358    for (i = 0; i < NumUnits; i++) {
 359       char s[100];
 360       sprintf(s, "Toggle Texture %d", i);
 361       glutAddMenuEntry(s, TEX0 + i);
 362    }
 363    glutAddMenuEntry("Toggle Animation", ANIMATE);
 364    glutAddMenuEntry("Quit", QUIT);
 365    glutAttachMenu(GLUT_RIGHT_BUTTON);
 366
 367    glutMainLoop();
 368    return 0;
 369 }