diff options
| -rw-r--r-- | src/gif.c | 75 |
1 files changed, 73 insertions, 2 deletions
@@ -11,7 +11,7 @@ unsigned char *loadgif(FILE *infile, int *bufwidth, int *bufheight){ int version; unsigned char *palette; int pallen; - unsigned char *buf; + unsigned char *buf = NULL; unsigned int bpp; { @@ -88,14 +88,85 @@ unsigned char *loadgif(FILE *infile, int *bufwidth, int *bufheight){ return NULL; } + buf = malloc((*bufwidth) * (*bufheight) * 3); + { - int initcodesize, curcodesize; + unsigned int initcodesize, curcodesize; + unsigned int clearcode, endcode, newcode; + int bytesleft = 0; + int i; + + /* Get code size */ initcodesize = fgetc(infile); if(initcodesize < 1 || initcodesize > 9){ printf("bad code size %i\n", initcodesize); return NULL; } curcodesize = initcodesize + 1; + clearcode = 1 << initcodesize; + endcode = clearcode + 1; + newcode = endcode + 1; + + int count = 0; + for(;;){ + int byte0 = -1, byte1 = -1, byteshift = 0; + if(1){ + bytesleft = fgetc(infile); + printf("%i\n", bytesleft); + if(bytesleft < 0){ + printf("unexpected EOF (0)\n"); + return NULL; + }else if(bytesleft == 0) + break; + } + printf("start %i, %i\n", count++, bytesleft); + for(;;){ + int code; + /* get code */ + + while(byte1 == -1){ + if((byte1 = fgetc(infile)) == EOF){ + printf("unexpected EOF (1)\n"); + return NULL; + } + if(byte0 == -1){ + byte0 = byte1; + } + bytesleft--; + } + if(bytesleft < 0){ + break; + } + code = (byte0 | byte1 << 8) >> byteshift & ((1 << curcodesize) - 1); + byteshift += curcodesize; + while(byteshift >= 8){ + byte0 = byte1; + byte1 = -1; + byteshift -= 8; + } + + if(code == clearcode){ + printf("clearcode\n"); + curcodesize = initcodesize + 1; + newcode = endcode + 1; + }else if(code == endcode){ + printf("endcode with %i bytes left\n", bytesleft); + break; + }else{ + newcode++; + } + + /* process code */ + if(newcode == 1 << curcodesize){ + curcodesize++; + } + } + } + + /*for(i = 0; i < (*bufwidth) * (*bufheight); i++){ + }*/ + printf("good end\n"); + return buf; } break; |