stb_image: support for 1-bit BMP

This commit is contained in:
Mikhail Morozov 2017-09-01 02:06:06 +03:00
parent 9d9f75eb68
commit 350173026a

View File

@ -5007,7 +5007,6 @@ static void *stbi__bmp_parse_header(stbi__context *s, stbi__bmp_data *info)
}
if (stbi__get16le(s) != 1) return stbi__errpuc("bad BMP", "bad BMP");
info->bpp = stbi__get16le(s);
if (info->bpp == 1) return stbi__errpuc("monochrome", "BMP type not supported: 1-bit");
if (hsz != 12) {
int compress = stbi__get32le(s);
if (compress == 1 || compress == 2) return stbi__errpuc("BMP RLE", "BMP type not supported: RLE");
@ -5125,29 +5124,47 @@ static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req
pal[i][3] = 255;
}
stbi__skip(s, info.offset - 14 - info.hsz - psize * (info.hsz == 12 ? 3 : 4));
if (info.bpp == 4) width = (s->img_x + 1) >> 1;
if (info.bpp == 1) width = (s->img_x + 7) >> 3;
else if (info.bpp == 4) width = (s->img_x + 1) >> 1;
else if (info.bpp == 8) width = s->img_x;
else { STBI_FREE(out); return stbi__errpuc("bad bpp", "Corrupt BMP"); }
pad = (-width)&3;
for (j=0; j < (int) s->img_y; ++j) {
for (i=0; i < (int) s->img_x; i += 2) {
int v=stbi__get8(s),v2=0;
if (info.bpp == 4) {
v2 = v & 15;
v >>= 4;
if (info.bpp == 1) {
for (j=0; j < (int) s->img_y; ++j) {
int bit_offset = 7, v = stbi__get8(s);
for (i=0; i < (int) s->img_x; ++i) {
int color = (v>>bit_offset)&0x1;
out[z++] = pal[color][0];
out[z++] = pal[color][1];
out[z++] = pal[color][2];
if((--bit_offset) < 0) {
bit_offset = 7;
v = stbi__get8(s);
}
}
out[z++] = pal[v][0];
out[z++] = pal[v][1];
out[z++] = pal[v][2];
if (target == 4) out[z++] = 255;
if (i+1 == (int) s->img_x) break;
v = (info.bpp == 8) ? stbi__get8(s) : v2;
out[z++] = pal[v][0];
out[z++] = pal[v][1];
out[z++] = pal[v][2];
if (target == 4) out[z++] = 255;
stbi__skip(s, pad);
}
} else {
for (j=0; j < (int) s->img_y; ++j) {
for (i=0; i < (int) s->img_x; i += 2) {
int v=stbi__get8(s),v2=0;
if (info.bpp == 4) {
v2 = v & 15;
v >>= 4;
}
out[z++] = pal[v][0];
out[z++] = pal[v][1];
out[z++] = pal[v][2];
if (target == 4) out[z++] = 255;
if (i+1 == (int) s->img_x) break;
v = (info.bpp == 8) ? stbi__get8(s) : v2;
out[z++] = pal[v][0];
out[z++] = pal[v][1];
out[z++] = pal[v][2];
if (target == 4) out[z++] = 255;
}
stbi__skip(s, pad);
}
stbi__skip(s, pad);
}
} else {
int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0;