| /* |
| * Test texture compression. |
| */ |
| |
| |
| #include <assert.h> |
| #include <stdio.h> |
| #include <GL/glew.h> |
| #include <GL/glut.h> |
| #include "readtex.c" |
| |
| #define IMAGE_FILE "../images/arch.rgb" |
| |
| static int ImgWidth, ImgHeight; |
| static GLenum ImgFormat; |
| static GLenum CompFormat; |
| static GLfloat EyeDist = 5.0; |
| static GLfloat Rot = 0.0; |
| const GLenum Target = GL_TEXTURE_2D; |
| |
| |
| static void |
| CheckError(int line) |
| { |
| GLenum err = glGetError(); |
| if (err) { |
| printf("GL Error %d at line %d\n", (int) err, line); |
| } |
| } |
| |
| |
| static const char * |
| LookupFormat(GLenum format) |
| { |
| switch (format) { |
| case GL_COMPRESSED_RGB_S3TC_DXT1_EXT: |
| return "GL_COMPRESSED_RGB_S3TC_DXT1_EXT"; |
| case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT: |
| return "GL_COMPRESSED_RGBA_S3TC_DXT1_EXT"; |
| case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT: |
| return "GL_COMPRESSED_RGBA_S3TC_DXT3_EXT"; |
| default: |
| return "other"; |
| } |
| } |
| |
| |
| static void |
| TestSubTex(void) |
| { |
| GLboolean all = 0*GL_TRUE; |
| GLubyte *buffer; |
| GLint size, fmt; |
| |
| glGetTexLevelParameteriv(Target, 0, |
| GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &size); |
| glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &fmt); |
| |
| buffer = (GLubyte *) malloc(size); |
| glGetCompressedTexImageARB(Target, 0, buffer); |
| |
| printf("Testing sub-texture replacement\n"); |
| if (all) |
| glCompressedTexImage2DARB(Target, 0, |
| fmt, ImgWidth, ImgHeight, 0, |
| size, buffer); |
| else { |
| /* bottom half */ |
| glCompressedTexSubImage2DARB(Target, 0, |
| 0, 0, /* pos */ |
| ImgWidth, ImgHeight / 2, |
| fmt, size/2, buffer); |
| /* top half */ |
| glCompressedTexSubImage2DARB(Target, 0, |
| 0, ImgHeight / 2, /* pos */ |
| ImgWidth, ImgHeight / 2, |
| fmt, size/2, buffer + size / 2); |
| } |
| |
| free(buffer); |
| } |
| |
| |
| static void |
| TestGetTex(void) |
| { |
| GLubyte *buffer; |
| |
| buffer = (GLubyte *) malloc(3 * ImgWidth * ImgHeight); |
| |
| glGetTexImage(GL_TEXTURE_2D, |
| 0, |
| GL_RGB, |
| GL_UNSIGNED_BYTE, |
| buffer); |
| |
| free(buffer); |
| } |
| |
| |
| static void |
| LoadCompressedImage(const char *file) |
| { |
| const GLenum filter = GL_LINEAR; |
| GLubyte *image; |
| GLint p; |
| |
| glPixelStorei(GL_UNPACK_ALIGNMENT, 1); |
| glPixelStorei(GL_PACK_ALIGNMENT, 1); |
| |
| /* |
| * Load image and scale if needed. |
| */ |
| image = LoadRGBImage( file, &ImgWidth, &ImgHeight, &ImgFormat ); |
| if (!image) { |
| printf("Couldn't read %s\n", IMAGE_FILE); |
| exit(0); |
| } |
| printf("Image is %d x %d\n", ImgWidth, ImgHeight); |
| |
| /* power of two */ |
| assert(ImgWidth == 128 || ImgWidth == 256 || ImgWidth == 512); |
| assert(ImgWidth == 128 || ImgHeight == 256 || ImgHeight == 512); |
| |
| if (ImgFormat == GL_RGB) |
| CompFormat = GL_COMPRESSED_RGB_S3TC_DXT1_EXT; |
| else |
| CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT; |
| |
| if (ImgFormat == GL_RGBA) { |
| int i, numAlpha = 0; |
| for (i = 0; i < ImgWidth * ImgHeight; i++) { |
| if (image[i*4+3] != 0 && image[i*4+3] != 0xff) { |
| numAlpha++; |
| } |
| if (image[i*4+3] == 0) |
| image[i*4+3] = 4 * i / ImgWidth; |
| } |
| printf("Num Alpha !=0,255: %d\n", numAlpha); |
| } |
| |
| CompFormat = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT; |
| |
| |
| /* |
| * Give image to OpenGL and have it compress it. |
| */ |
| glTexImage2D(Target, 0, CompFormat, ImgWidth, ImgHeight, 0, |
| ImgFormat, GL_UNSIGNED_BYTE, image); |
| CheckError(__LINE__); |
| |
| free(image); |
| |
| glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_INTERNAL_FORMAT, &p); |
| printf("Compressed Internal Format: %s (0x%x)\n", LookupFormat(p), p); |
| assert(p == CompFormat); |
| |
| printf("Original size: %d bytes\n", ImgWidth * ImgHeight * 3); |
| glGetTexLevelParameteriv(Target, 0, GL_TEXTURE_COMPRESSED_IMAGE_SIZE_ARB, &p); |
| printf("Compressed size: %d bytes\n", p); |
| |
| glTexParameteri(Target, GL_TEXTURE_MIN_FILTER, filter); |
| glTexParameteri(Target, GL_TEXTURE_MAG_FILTER, filter); |
| |
| if (0) |
| TestSubTex(); |
| else |
| TestGetTex(); |
| |
| } |
| |
| |
| static void |
| Init(const char *file) |
| { |
| GLint numFormats, formats[100]; |
| GLint p; |
| |
| if (!glutExtensionSupported("GL_ARB_texture_compression")) { |
| printf("Sorry, GL_ARB_texture_compression is required.\n"); |
| exit(1); |
| } |
| if (!glutExtensionSupported("GL_EXT_texture_compression_s3tc")) { |
| printf("Sorry, GL_EXT_texture_compression_s3tc is required.\n"); |
| exit(1); |
| } |
| |
| printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION)); |
| printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); |
| |
| glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS_ARB, &numFormats); |
| glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS_ARB, formats); |
| printf("%d supported compression formats: ", numFormats); |
| for (p = 0; p < numFormats; p++) |
| printf("0x%x ", formats[p]); |
| printf("\n"); |
| |
| LoadCompressedImage(file); |
| |
| glEnable(GL_TEXTURE_2D); |
| |
| if (ImgFormat == GL_RGBA) { |
| glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); |
| glEnable(GL_BLEND); |
| } |
| } |
| |
| |
| static void |
| Reshape( int width, int height ) |
| { |
| glViewport( 0, 0, width, height ); |
| glMatrixMode( GL_PROJECTION ); |
| glLoadIdentity(); |
| glFrustum(-1, 1, -1, 1, 4, 100); |
| glMatrixMode( GL_MODELVIEW ); |
| glLoadIdentity(); |
| } |
| |
| |
| static void |
| Key( unsigned char key, int x, int y ) |
| { |
| (void) x; |
| (void) y; |
| switch (key) { |
| case 'd': |
| EyeDist -= 1.0; |
| if (EyeDist < 4.0) |
| EyeDist = 4.0; |
| break; |
| case 'D': |
| EyeDist += 1.0; |
| break; |
| case 'z': |
| Rot += 5.0; |
| break; |
| case 'Z': |
| Rot -= 5.0; |
| break; |
| case 27: |
| exit(0); |
| break; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| static void |
| Draw( void ) |
| { |
| glClearColor(0.3, 0.3, .8, 0); |
| glClear(GL_COLOR_BUFFER_BIT); |
| |
| glPushMatrix(); |
| glTranslatef(0, 0, -(EyeDist+0.01)); |
| glRotatef(Rot, 0, 0, 1); |
| glBegin(GL_POLYGON); |
| glTexCoord2f(0, 0); glVertex2f(-1, -1); |
| glTexCoord2f(1, 0); glVertex2f( 1, -1); |
| glTexCoord2f(1, 1); glVertex2f( 1, 1); |
| glTexCoord2f(0, 1); glVertex2f(-1, 1); |
| glEnd(); |
| glPopMatrix(); |
| |
| glutSwapBuffers(); |
| } |
| |
| |
| int |
| main( int argc, char *argv[] ) |
| { |
| glutInit( &argc, argv ); |
| glutInitWindowSize( 600, 600 ); |
| |
| glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE); |
| |
| glutCreateWindow(argv[0]); |
| glewInit(); |
| |
| glutReshapeFunc( Reshape ); |
| glutKeyboardFunc( Key ); |
| glutDisplayFunc( Draw ); |
| |
| if (argc > 1) |
| Init(argv[1]); |
| else |
| Init(IMAGE_FILE); |
| |
| glutMainLoop(); |
| return 0; |
| } |