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