X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/4a84fce79ab5326aae7aa9f99ccb38b5063b714a..0ae0a344200291ae958fcb3c9c3ece9c5b604f6e:/src/image.c diff --git a/src/image.c b/src/image.c index 9b9b1dd..4f1a2bd 100644 --- a/src/image.c +++ b/src/image.c @@ -14,8 +14,9 @@ struct lbx_image { uint16_t width, height; - uint16_t wtf1, wtf2; + uint16_t wtf1; uint16_t offs, frames; + uint16_t pal; FILE *f; long foff; @@ -29,21 +30,31 @@ struct lbx_image { struct lbx_image *lbximg_fopen(FILE *f) { - struct lbx_image tmp = {.f = f}, *new; + struct lbx_image tmp = {.f = f}, *new = NULL; if (fread(&tmp.width, sizeof tmp.width, 1, f) != 1) goto readerr; if (fread(&tmp.height, sizeof tmp.height, 1, f) != 1) goto readerr; if (fread(&tmp.wtf1, sizeof tmp.wtf1, 1, f) != 1) goto readerr; if (fread(&tmp.offs, sizeof tmp.offs, 1, f) != 1) goto readerr; if (fread(&tmp.frames, sizeof tmp.frames, 1, f) != 1) goto readerr; - if (fread(&tmp.wtf2, sizeof tmp.wtf2, 1, f) != 1) goto readerr; + if (fread(&tmp.pal, sizeof tmp.pal, 1, f) != 1) goto readerr; tmp.width = letohs(tmp.width); tmp.foff += sizeof tmp.width; tmp.height = letohs(tmp.height); tmp.foff += sizeof tmp.height; tmp.wtf1 = letohs(tmp.wtf1); tmp.foff += sizeof tmp.wtf1; tmp.offs = letohs(tmp.offs); tmp.foff += sizeof tmp.offs; tmp.frames = letohs(tmp.frames); tmp.foff += sizeof tmp.frames; - tmp.wtf2 = letohs(tmp.wtf2); tmp.foff += sizeof tmp.wtf2; + tmp.pal = letohs(tmp.pal); tmp.foff += sizeof tmp.pal; + + /* For some reason, the format seems to need this. */ + tmp.offs++; + tmp.frames++; + + /* Format constraints. */ + if (tmp.offs <= tmp.frames) { + lbx_errno = LBX_EFORMAT; + return NULL; + } /* * DEBUG ONLY. These assertions exist to catch otherwise valid image @@ -51,8 +62,9 @@ struct lbx_image *lbximg_fopen(FILE *f) * If we never find any exceptions, we can replace the assertions with * assumptions. */ - assert(tmp.wtf1 == 0); - assert(tmp.offs == tmp.frames + 1); + _lbx_assert(tmp.wtf1 == 0); + _lbx_assert(tmp.offs == tmp.frames + 1); + _lbx_assert(tmp.pal == 0 || tmp.pal == 0x1000); new = malloc(sizeof *new + tmp.offs * sizeof *new->offsets); if (!new) { @@ -100,18 +112,17 @@ static int _lbx_drawrow(int first, struct lbx_image *img) if (type == 0) { if (fread(&yval, sizeof yval, 1, img->f) != 1) goto readerr; yval = letohs(yval); img->foff += sizeof yval; - if (yval == 1000) return 1; - if (fread(&count, sizeof count, 1, img->f) != 1) goto readerr; count = letohs(count); img->foff += sizeof count; if (fread(&xval, sizeof xval, 1, img->f) != 1) goto readerr; xval = letohs(xval); img->foff += sizeof xval; + if (xval == 1000) + return 1; /* Ensure that the row fits in the image. */ - if (img->height - img->currenty <= yval - || xval >= img->width || count > img->width - xval) { + if (img->height - img->currenty <= yval || xval >= img->width) { lbx_errno = LBX_EFORMAT; return -1; } @@ -119,17 +130,22 @@ static int _lbx_drawrow(int first, struct lbx_image *img) img->currenty += yval; img->currentx = xval; } else { - if (fread(&yval, sizeof yval, 1, img->f) != 1) goto readerr; - yval = letohs(yval); img->foff += sizeof yval; - - /* FIXME Still have to figure out what to do here. */ - - count = type; + if (fread(&xval, sizeof xval, 1, img->f) != 1) goto readerr; + xval = letohs(xval); img->foff += sizeof xval; - if (count > img->width - img->currentx) { + if (img->width - img->currentx <= xval) { lbx_errno = LBX_EFORMAT; return -1; } + img->currentx += xval; + + count = type; + + } + + if (count > img->width - img->currentx) { + lbx_errno = LBX_EFORMAT; + return -1; } pos = &img->framedata[img->currenty][img->currentx]; @@ -207,7 +223,7 @@ unsigned char **lbximg_getframe(struct lbx_image *img, int frame) return NULL; first = 0; - if (img->foff > img->offsets[frame+1]) { + if (!rc && img->foff > img->offsets[frame+1]) { lbx_errno = LBX_EFORMAT; return NULL; } @@ -247,18 +263,38 @@ int lbximg_loadpalette(FILE *f, struct lbx_colour palette[static 256]) int lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256]) { - int index = 0; + size_t hdrlen = 6*(sizeof img->pal)+(img->offs)*(sizeof *img->offsets); + unsigned int i; size_t rc; - size_t hdrlen = 6*(sizeof img->width) - + (img->offs)*(sizeof *img->offsets); - - uint8_t entry[4]; + + uint16_t zero, count; + uint8_t entry[4]; + + /* Do nothing if the image doesn't have embedded palette data. */ + if (img->pal == 0) + return 0; /* Palette data is located right after the header. */ if (_lbx_fseek(img->f, &img->foff, hdrlen) == -1) return -1; - while (img->foff + sizeof entry <= img->offsets[0]) { + /* Palette header */ + if (fread(&zero, sizeof zero, 1, img->f) != 1) goto readerr; + if (fread(&count, sizeof count, 1, img->f) != 1) goto readerr; + zero = letohs(zero); img->foff += sizeof zero; + count = letohs(count); img->foff += sizeof count; + + if (zero != 0 || count > 256) { + lbx_errno = LBX_EFORMAT; + return -1; + } + + if (hdrlen + 2*(sizeof zero) + count*(sizeof entry) > img->offsets[0]) { + lbx_errno = LBX_EFORMAT; + return -1; + } + + for (i = 0; i < count; i++) { rc = fread(entry, 1, sizeof entry, img->f); img->foff += rc; @@ -266,13 +302,12 @@ lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256]) goto readerr; } - if (entry[0] == 0) { - index++; - } else { - index = entry[0]; + if (entry[0] != 0) { + lbx_errno = LBX_EFORMAT; + return -1; } - palette[index] = (struct lbx_colour){ + palette[i] = (struct lbx_colour){ .red = entry[1] << 2, .green = entry[2] << 2, .blue = entry[3] << 2, @@ -281,13 +316,19 @@ lbximg_getpalette(struct lbx_image *img, struct lbx_colour palette[static 256]) return 0; readerr: - if (feof(img->f)) - lbx_errno = LBX_EEOF; - else - lbx_errno = -errno; + lbx_errno = feof(img->f) ? LBX_EEOF : -errno; return -1; } +void lbximg_getinfo(struct lbx_image *img, struct lbx_imginfo *info) +{ + *info = (struct lbx_imginfo) { + .width = img->width, + .height = img->height, + .nframes = img->frames, + }; +} + void lbximg_close(struct lbx_image *img) { if (!img) return;