+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <GL/glew.h>
+#include <GL/freeglut.h>
+
+struct texture {
+ unsigned int id;
+ int width, height;
+ unsigned int fmt;
+ unsigned int compsize;
+ void *data;
+};
+
+int init(void);
+void disp(void);
+void reshape(int x, int y);
+void keyb(unsigned char key, int x, int y);
+void idle(void);
+int load_texture(const char *fname, struct texture *tex);
+const char *fmtstr(int fmt);
+void print_compressed_formats(void);
+
+struct texture tex;
+unsigned int tex2;
+const char *texfile;
+int subtest, copytest;
+
+int main(int argc, char **argv)
+{
+ int i, loop = 0;
+ unsigned int glut_flags = GLUT_RGB | GLUT_DOUBLE;
+
+ for(i=1; i<argc; i++) {
+ if(argv[i][0] == '-') {
+ if(strcmp(argv[i], "-subtest") == 0) {
+ subtest = 1;
+ } else if(strcmp(argv[i], "-copytest") == 0) {
+ copytest = 1;
+ } else if(strcmp(argv[i], "-copytest-loop") == 0) {
+ copytest = 1;
+ loop = 1;
+ } else {
+ fprintf(stderr, "invalid option: %s\n", argv[i]);
+ return 1;
+ }
+ } else {
+ if(texfile) {
+ fprintf(stderr, "unexpected argument: %s\n", argv[i]);
+ return 1;
+ }
+ texfile = argv[i];
+ }
+ }
+
+ if(!texfile) {
+ fprintf(stderr, "you must specify a compressed texture file\n");
+ return 1;
+ }
+
+ glutInit(&argc, argv);
+ glutInitDisplayMode(glut_flags);
+ glutCreateWindow("test");
+
+ glutDisplayFunc(disp);
+ glutReshapeFunc(reshape);
+ glutKeyboardFunc(keyb);
+ if(loop) {
+ glutIdleFunc(idle);
+ }
+
+ glewInit();
+
+ if(init() == -1) {
+ return 1;
+ }
+
+ glutMainLoop();
+ return 0;
+}
+
+int init(void)
+{
+ unsigned char *buf;
+ int is_comp = 0;
+ int tmp;
+ unsigned int intfmt;
+
+ print_compressed_formats();
+
+ if(load_texture(texfile, &tex) == -1) {
+ fprintf(stderr, "failed to load texture %s\n", texfile);
+ return -1;
+ }
+
+ glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, (int*)&intfmt);
+ if(intfmt != tex.fmt) {
+ fprintf(stderr, "internal format differs (expected: %s [%x], got: %s [%x])\n",
+ fmtstr(tex.fmt), tex.fmt, fmtstr(intfmt), intfmt);
+ return -1;
+ }
+ glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_COMPRESSED, &is_comp);
+ if(!is_comp) {
+ fprintf(stderr, "texture is not compressed\n");
+ return -1;
+ }
+ glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_COMPRESSED_IMAGE_SIZE, &tmp);
+ if(tmp != tex.compsize) {
+ fprintf(stderr, "internal compressed size differs (expected: %d, got: %d)!\n", tex.compsize, tmp);
+ return -1;
+ }
+
+ if(!(buf = malloc(tex.compsize))) {
+ fprintf(stderr, "failed to allocate comparison image buffer (%d bytes)\n", tex.compsize);
+ return -1;
+ }
+ glGetCompressedTexImage(GL_TEXTURE_2D, 0, buf);
+
+ if(memcmp(tex.data, buf, tex.compsize) != 0) {
+ int i;
+ unsigned char *a = tex.data, *b = buf;
+
+ for(i=0; i<tex.compsize; i++) {
+ if(*a++ != *b++) break;
+ }
+ assert(i < tex.compsize);
+ fprintf(stderr, "submitted and retrieved pixel data differ! (at offset %d)\n", i);
+ } else {
+ printf("submitted and retrieved sizes match (%d bytes)\n", tex.compsize);
+ }
+
+ if(subtest) {
+ printf("testing glGetCompressedTextureSubImage and glCompressedTexSubImage2D\n");
+ memset(buf, 0, tex.compsize);
+ glGetCompressedTextureSubImage(tex.id, 0, 192, 64, 0, 64, 64, 1, tex.compsize, buf);
+ glCompressedTexSubImage2D(GL_TEXTURE_2D, 0, 32, 32, 64, 64, tex.fmt, 2048, buf);
+ }
+
+ if(copytest) {
+ printf("testing glCopyImageSubData\n");
+
+ glGenTextures(1, &tex2);
+ glBindTexture(GL_TEXTURE_2D, tex2);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+ glCompressedTexImage2D(GL_TEXTURE_2D, 0, tex.fmt, tex.width, tex.height, 0, tex.compsize, tex.data);
+ glBindTexture(GL_TEXTURE_2D, 0);
+
+ glCopyImageSubData(tex2, GL_TEXTURE_2D, 0, 128, 64, 0,
+ tex.id, GL_TEXTURE_2D, 0, 32, 32, 0, 64, 64, 1);
+
+ glBindTexture(GL_TEXTURE_2D, tex.id);
+ }
+
+ free(buf);
+
+ glEnable(GL_TEXTURE_2D);
+ return 0;
+}
+
+void disp(void)
+{
+ int x = 0, y = 0;
+ int xsz = tex.width;
+ int ysz = tex.height;
+
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ glBindTexture(GL_TEXTURE_2D, tex.id);
+ glEnable(GL_TEXTURE_2D);
+
+ glBegin(GL_QUADS);
+ glTexCoord2f(0, 1); glVertex2f(0, 0);
+ glTexCoord2f(1, 1); glVertex2f(xsz, 0);
+ glTexCoord2f(1, 0); glVertex2f(xsz, ysz);
+ glTexCoord2f(0, 0); glVertex2f(0, ysz);
+
+ x += xsz;
+ xsz /= 2;
+ ysz /= 2;
+
+ while(xsz & ysz) {
+ glTexCoord2f(0, 1); glVertex2f(x, y);
+ glTexCoord2f(1, 1); glVertex2f(x + xsz, y);
+ glTexCoord2f(1, 0); glVertex2f(x + xsz, y + ysz);
+ glTexCoord2f(0, 0); glVertex2f(x, y + ysz);
+
+ y += ysz;
+
+ xsz /= 2;
+ ysz /= 2;
+ }
+ glEnd();
+
+ glutSwapBuffers();
+ assert(glGetError() == GL_NO_ERROR);
+}
+
+void reshape(int x, int y)
+{
+ glViewport(0, 0, x, y);
+
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(0, x, 0, y, -1, 1);
+}
+
+void keyb(unsigned char key, int x, int y)
+{
+ if(key == 27) {
+ exit(0);
+ }
+}
+
+void idle(void)
+{
+ glutPostRedisplay();
+}
+
+struct header {
+ char magic[8];
+ uint32_t glfmt;
+ uint16_t flags;
+ uint16_t levels;
+ uint32_t width, height;
+ struct {
+ uint32_t offset, size;
+ } datadesc[20];
+ char unused[8];
+};
+
+int load_texture(const char *fname, struct texture *tex)
+{
+ int i;
+ FILE *fp;
+ struct header hdr;
+ void *buf;
+
+ if(!(fp = fopen(fname, "rb"))) {
+ fprintf(stderr, "failed to open file: %s: %s\n", fname, strerror(errno));
+ return -1;
+ }
+ if(fread(&hdr, 1, sizeof hdr, fp) != sizeof hdr) {
+ fprintf(stderr, "failed to read image file header: %s: %s\n", fname, strerror(errno));
+ fclose(fp);
+ return -1;
+ }
+ if(memcmp(hdr.magic, "COMPTEX0", sizeof hdr.magic) != 0 || hdr.levels < 0 ||
+ hdr.levels > 20 || !hdr.datadesc[0].size) {
+ fprintf(stderr, "%s is not a compressed texture file, or is corrupted\n", fname);
+ fclose(fp);
+ return -1;
+ }
+
+ if(!(buf = malloc(hdr.datadesc[0].size))) {
+ fprintf(stderr, "failed to allocate compressed texture buffer (%d bytes): %s\n",
+ hdr.datadesc[0].size, strerror(errno));
+ fclose(fp);
+ return -1;
+ }
+ if(!(tex->data = malloc(hdr.datadesc[0].size))) {
+ fprintf(stderr, "failed to allocate data buffer\n");
+ fclose(fp);
+ free(buf);
+ return -1;
+ }
+
+
+ glGenTextures(1, &tex->id);
+ glBindTexture(GL_TEXTURE_2D, tex->id);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
+ hdr.levels > 1 ? GL_NEAREST_MIPMAP_NEAREST : GL_NEAREST);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, 1);
+
+ tex->fmt = hdr.glfmt;
+ tex->width = hdr.width;
+ tex->height = hdr.height;
+ tex->compsize = hdr.datadesc[0].size;
+
+ printf("%s: %dx%d format: %s\n", fname, tex->width, tex->height, fmtstr(tex->fmt));
+ glutReshapeWindow(tex->width + tex->width / 2, tex->height);
+
+ for(i=0; i<hdr.levels; i++) {
+ if(!hdr.datadesc[i].size) {
+ continue;
+ }
+
+ if(fread(buf, 1, hdr.datadesc[i].size, fp) != hdr.datadesc[i].size) {
+ fprintf(stderr, "unexpected EOF while reading texture: %s\n", fname);
+ fclose(fp);
+ free(buf);
+ glDeleteTextures(1, &tex->id);
+ return -1;
+ }
+ if(i == 0) {
+ memcpy(tex->data, buf, hdr.datadesc[0].size);
+ }
+ glCompressedTexImage2D(GL_TEXTURE_2D, i, hdr.glfmt, hdr.width, hdr.height, 0,
+ hdr.datadesc[i].size, buf);
+
+ hdr.width /= 2;
+ hdr.height /= 2;
+ }
+
+ free(buf);
+ fclose(fp);
+ return 0;
+}
+
+const char *fmtstr(int fmt)
+{
+ switch(fmt) {
+ case 0x86b0: return "GL_COMPRESSED_RGB_FXT1_3DFX";
+ case 0x86b1: return "GL_COMPRESSED_RGBA_FXT1_3DFX";
+ case 0x8dbb: return "GL_COMPRESSED_RED_RGTC1";
+ case 0x8dbc: return "GL_COMPRESSED_SIGNED_RED_RGTC1";
+ case 0x8dbd: return "GL_COMPRESSED_RG_RGTC2";
+ case 0x8dbe: return "GL_COMPRESSED_SIGNED_RG_RGTC2";
+ case 0x8e8c: return "GL_COMPRESSED_RGBA_BPTC_UNORM";
+ case 0x8e8d: return "GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM";
+ case 0x8e8e: return "GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT";
+ case 0x8e8f: return "GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT";
+ case 0x9274: return "GL_COMPRESSED_RGB8_ETC2";
+ case 0x9275: return "GL_COMPRESSED_SRGB8_ETC2";
+ case 0x9276: return "GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2";
+ case 0x9277: return "GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2";
+ case 0x9278: return "GL_COMPRESSED_RGBA8_ETC2_EAC";
+ case 0x9279: return "GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC";
+ case 0x9270: return "GL_COMPRESSED_R11_EAC";
+ case 0x9271: return "GL_COMPRESSED_SIGNED_R11_EAC";
+ case 0x9272: return "GL_COMPRESSED_RG11_EAC";
+ case 0x9273: return "GL_COMPRESSED_SIGNED_RG11_EAC";
+ case 0x83F0: return "GL_COMPRESSED_RGB_S3TC_DXT1_EXT";
+ case 0x83F1: return "GL_COMPRESSED_RGBA_S3TC_DXT1_EXT";
+ case 0x83F2: return "GL_COMPRESSED_RGBA_S3TC_DXT3_EXT";
+ case 0x83F3: return "GL_COMPRESSED_RGBA_S3TC_DXT5_EXT";
+ case 0x8C48: return "GL_COMPRESSED_SRGB_EXT";
+ case 0x8C49: return "GL_COMPRESSED_SRGB_ALPHA_EXT";
+ case 0x8C4A: return "GL_COMPRESSED_SLUMINANCE_EXT";
+ case 0x8C4B: return "GL_COMPRESSED_SLUMINANCE_ALPHA_EXT";
+ case 0x8C4C: return "GL_COMPRESSED_SRGB_S3TC_DXT1_EXT";
+ case 0x8C4D: return "GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT";
+ case 0x8C4E: return "GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT";
+ case 0x8C4F: return "GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT";
+ case 0x8B90: return "GL_PALETTE4_RGB8_OES";
+ case 0x8B91: return "GL_PALETTE4_RGBA8_OES";
+ case 0x8B92: return "GL_PALETTE4_R5_G6_B5_OES";
+ case 0x8B93: return "GL_PALETTE4_RGBA4_OES";
+ case 0x8B94: return "GL_PALETTE4_RGB5_A1_OES";
+ case 0x8B95: return "GL_PALETTE8_RGB8_OES";
+ case 0x8B96: return "GL_PALETTE8_RGBA8_OES";
+ case 0x8B97: return "GL_PALETTE8_R5_G6_B5_OES";
+ case 0x8B98: return "GL_PALETTE8_RGBA4_OES";
+ case 0x8B99: return "GL_PALETTE8_RGB5_A1_OES";
+ case 0x93B0: return "GL_COMPRESSED_RGBA_ASTC_4";
+ case 0x93B1: return "GL_COMPRESSED_RGBA_ASTC_5";
+ case 0x93B2: return "GL_COMPRESSED_RGBA_ASTC_5";
+ case 0x93B3: return "GL_COMPRESSED_RGBA_ASTC_6";
+ case 0x93B4: return "GL_COMPRESSED_RGBA_ASTC_6";
+ case 0x93B5: return "GL_COMPRESSED_RGBA_ASTC_8";
+ case 0x93B6: return "GL_COMPRESSED_RGBA_ASTC_8";
+ case 0x93B7: return "GL_COMPRESSED_RGBA_ASTC_8";
+ case 0x93B8: return "GL_COMPRESSED_RGBA_ASTC_10";
+ case 0x93B9: return "GL_COMPRESSED_RGBA_ASTC_10";
+ case 0x93BA: return "GL_COMPRESSED_RGBA_ASTC_10";
+ case 0x93BB: return "GL_COMPRESSED_RGBA_ASTC_10";
+ case 0x93BC: return "GL_COMPRESSED_RGBA_ASTC_12";
+ case 0x93BD: return "GL_COMPRESSED_RGBA_ASTC_12";
+ case 0x93D0: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4";
+ case 0x93D1: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5";
+ case 0x93D2: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5";
+ case 0x93D3: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6";
+ case 0x93D4: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6";
+ case 0x93D5: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8";
+ case 0x93D6: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8";
+ case 0x93D7: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8";
+ case 0x93D8: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10";
+ case 0x93D9: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10";
+ case 0x93DA: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10";
+ case 0x93DB: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10";
+ case 0x93DC: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12";
+ case 0x93DD: return "GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12";
+ case GL_LUMINANCE:
+ case 1:
+ return "GL_LUMINANCE";
+ case GL_RGB:
+ case 3:
+ return "GL_RGB";
+ case GL_RGBA:
+ case 4:
+ return "GL_RGBA";
+ case GL_BGR: return "GL_BGR";
+ case GL_BGRA: return "GL_BGRA";
+ case GL_SLUMINANCE: return "GL_SLUMINANCE";
+ case GL_SLUMINANCE8: return "GL_SLUMINANCE8";
+ case GL_SLUMINANCE_ALPHA: return "GL_SLUMINANCE_ALPHA";
+ case GL_SLUMINANCE8_ALPHA8: return "GL_SLUMINANCE8_ALPHA8";
+ case GL_SRGB: return "GL_SRGB";
+ case GL_SRGB8: return "GL_SRGB8";
+ case GL_SRGB_ALPHA: return "GL_SRGB_ALPHA";
+ case GL_SRGB8_ALPHA8: return "GL_SRGB8_ALPHA8";
+ default:
+ break;
+ }
+ return "unknown";
+}
+
+void print_compressed_formats(void)
+{
+ int i, num_fmt;
+ int *fmtlist;
+
+ glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS, &num_fmt);
+ printf("%d generic compressed texture formats available:\n", num_fmt);
+
+ if(!(fmtlist = malloc(num_fmt * sizeof *fmtlist))) {
+ fprintf(stderr, "failed to allocate texture formats enumeration buffer\n");
+ return;
+ }
+ glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS, fmtlist);
+
+ for(i=0; i<num_fmt; i++) {
+ printf(" %05x: %s ", fmtlist[i], fmtstr(fmtlist[i]));
+ GLint params;
+ glGetInternalformativ(GL_TEXTURE_2D, fmtlist[i], GL_TEXTURE_COMPRESSED, 1, ¶ms);
+ printf("(%s format)\n", params == GL_TRUE ? "compressed" : "not compressed");
+ }
+ free(fmtlist);
+}