progs/tests/texcompress2.c

   1 /*
   2  * Test texture compression.
   3  */
   4
   5
   6 #define GL_GLEXT_PROTOTYPES
   7 #include <assert.h>
   8 #include <stdio.h>
   9 #include <GL/glut.h>
  10 #include <GL/glx.h>
  11 #include "readtex.c"
  12
  13 #define IMAGE_FILE "../images/arch.rgb"
  14
  15 static int ImgWidth, ImgHeight;
  16 static GLenum ImgFormat;
  17 static GLenum CompFormat;
  18 static GLfloat EyeDist = 5.0;
  19 static GLfloat Rot = 0.0;
  20 const GLenum Target = GL_TEXTURE_2D;
  21
  22
  23 static void
  24 CheckError(int line)
  25 {
  26    GLenum err = glGetError();
  27    if (err) {
  28       printf("GL Error %d at line %d\n", (int) err, line);
  29    }
  30 }
  31
  32
  33 static const char *
  34 LookupFormat(GLenum format)
  35 {
  36    switch (format) {
  37    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
  38       return "GL_COMPRESSED_RGB_S3TC_DXT1_EXT";
  39    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
  40       return "GL_COMPRESSED_RGBA_S3TC_DXT1_EXT";
  41    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
  42       return "GL_COMPRESSED_RGBA_S3TC_DXT3_EXT";
  43    default:
  44       return "other";
  45    }
  46 }
  47
  48
  49 static void
  50 TestSubTex(void)
  51 {
  52    GLboolean all = 0*GL_TRUE;
  53    GLubyte *buffer;
  54    GLint size, fmt;
  55    int i;
  56
  57    glGetTexLevelParameteriv(Target, 0,
  58                             GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &size);
  59    glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &fmt);
  60
  61    buffer = (GLubyte *) malloc(size);
  62    glGetCompressedTexImageARB(Target, 0, buffer);
  63
  64    printf("Testing sub-texture replacement\n");
  65    if (all)
  66       glCompressedTexImage2DARB(Target, 0,
  67                                 fmt, ImgWidth, ImgHeight, 0,
  68                                 size, buffer);
  69    else {
  70       /* bottom half */
  71       glCompressedTexSubImage2DARB(Target, 0,
  72                                    0, 0, /* pos */
  73                                    ImgWidth, ImgHeight / 2,
  74                                    fmt, size/2, buffer);
  75       /* top half */
  76       glCompressedTexSubImage2DARB(Target, 0,
  77                                    0, ImgHeight / 2, /* pos */
  78                                    ImgWidth, ImgHeight / 2,
  79                                    fmt, size/2, buffer + size / 2);
  80    }
  81
  82    free(buffer);
  83 }
  84
  85
  86 static void
  87 LoadCompressedImage(const char *file)
  88 {
  89    const GLenum filter = GL_LINEAR;
  90    GLubyte *image;
  91    GLint p;
  92
  93    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  94    glPixelStorei(GL_PACK_ALIGNMENT, 1);
  95
  96    /*
  97     * Load image and scale if needed.
  98     */
  99    image = LoadRGBImage( file, &ImgWidth, &ImgHeight, &ImgFormat );
 100    if (!image) {
 101       printf("Couldn't read %s\n", IMAGE_FILE);
 102       exit(0);
 103    }
 104    printf("Image is %d x %d\n", ImgWidth, ImgHeight);
 105
 106    /* power of two */
 107    assert(ImgWidth == 128 || ImgWidth == 256 || ImgWidth == 512);
 108    assert(ImgWidth == 128 || ImgHeight == 256 || ImgHeight == 512);
 109
 110    if (ImgFormat == GL_RGB)
 111       CompFormat = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 112    else
 113       CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 114
 115    if (ImgFormat == GL_RGBA) {
 116       int i, numAlpha = 0;
 117       for (i = 0; i < ImgWidth * ImgHeight; i++) {
 118          if (image[i*4+3] != 0 && image[i*4+3] != 0xff) {
 119             numAlpha++;
 120          }
 121          if (image[i*4+3] == 0)
 122             image[i*4+3] = 4 * i / ImgWidth;
 123       }
 124       printf("Num Alpha !=0,255: %d\n", numAlpha);
 125    }
 126
 127    CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 128
 129
 130    /*
 131     * Give image to OpenGL and have it compress it.
 132     */
 133    glTexImage2D(Target, 0, CompFormat, ImgWidth, ImgHeight, 0,
 134                 ImgFormat, GL_UNSIGNED_BYTE, image);
 135    CheckError(__LINE__);
 136
 137    free(image);
 138
 139    glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &p);
 140    printf("Compressed Internal Format: %s (0x%x)\n", LookupFormat(p), p);
 141    assert(p == CompFormat);
 142
 143    printf("Original size:   %d bytes\n", ImgWidth * ImgHeight * 3);
 144    glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &p);
 145    printf("Compressed size: %d bytes\n", p);
 146
 147    glTexParameteri(Target, GL_TEXTURE_MIN_FILTER, filter);
 148    glTexParameteri(Target, GL_TEXTURE_MAG_FILTER, filter);
 149
 150    TestSubTex();
 151
 152 }
 153
 154
 155 static void
 156 Init(const char *file)
 157 {
 158    GLint numFormats, formats[100];
 159    GLint p;
 160
 161    if (!glutExtensionSupported("GL_ARB_texture_compression")) {
 162       printf("Sorry, GL_ARB_texture_compression is required.\n");
 163       exit(1);
 164    }
 165    if (!glutExtensionSupported("GL_EXT_texture_compression_s3tc")) {
 166       printf("Sorry, GL_EXT_texture_compression_s3tc is required.\n");
 167       exit(1);
 168    }
 169
 170    printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
 171    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 172
 173    glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS_ARB, &numFormats);
 174    glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS_ARB, formats);
 175    printf("%d supported compression formats: ", numFormats);
 176    for (p = 0; p < numFormats; p++)
 177       printf("0x%x ", formats[p]);
 178    printf("\n");
 179
 180    LoadCompressedImage(file);
 181
 182    glEnable(GL_TEXTURE_2D);
 183
 184    if (ImgFormat == GL_RGBA) {
 185       glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 186       glEnable(GL_BLEND);
 187    }
 188 }
 189
 190
 191 static void
 192 Reshape( int width, int height )
 193 {
 194    glViewport( 0, 0, width, height );
 195    glMatrixMode( GL_PROJECTION );
 196    glLoadIdentity();
 197    glFrustum(-1, 1, -1, 1, 4, 100);
 198    glMatrixMode( GL_MODELVIEW );
 199    glLoadIdentity();
 200 }
 201
 202
 203 static void
 204 Key( unsigned char key, int x, int y )
 205 {
 206    (void) x;
 207    (void) y;
 208    switch (key) {
 209       case 'd':
 210          EyeDist -= 1.0;
 211          if (EyeDist < 4.0)
 212             EyeDist = 4.0;
 213          break;
 214       case 'D':
 215          EyeDist += 1.0;
 216          break;
 217       case 'z':
 218          Rot += 5.0;
 219          break;
 220       case 'Z':
 221          Rot -= 5.0;
 222          break;
 223       case 27:
 224          exit(0);
 225          break;
 226    }
 227    glutPostRedisplay();
 228 }
 229
 230
 231 static void
 232 Draw( void )
 233 {
 234    glClearColor(0.3, 0.3, .8, 0);
 235    glClear(GL_COLOR_BUFFER_BIT);
 236
 237    glPushMatrix();
 238    glTranslatef(0, 0, -(EyeDist+0.01));
 239    glRotatef(Rot, 0, 0, 1);
 240    glBegin(GL_POLYGON);
 241    glTexCoord2f(0, 0);  glVertex2f(-1, -1);
 242    glTexCoord2f(1, 0);  glVertex2f( 1, -1);
 243    glTexCoord2f(1, 1);  glVertex2f( 1,  1);
 244    glTexCoord2f(0, 1);  glVertex2f(-1,  1);
 245    glEnd();
 246    glPopMatrix();
 247
 248    glutSwapBuffers();
 249 }
 250
 251
 252 int
 253 main( int argc, char *argv[] )
 254 {
 255    glutInit( &argc, argv );
 256    glutInitWindowSize( 600, 600 );
 257
 258    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
 259
 260    glutCreateWindow(argv[0]);
 261
 262    glutReshapeFunc( Reshape );
 263    glutKeyboardFunc( Key );
 264    glutDisplayFunc( Draw );
 265
 266    if (argc > 1)
 267       Init(argv[1]);
 268    else
 269       Init(IMAGE_FILE);
 270
 271    glutMainLoop();
 272    return 0;
 273 }