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Changes in stb lib to avoid returning alpha bitmaps when no pixel has alpha

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This commit is contained in:
Bertrand Songis
2016-02-29 18:41:35 +01:00
parent d28c71db86
commit 301cd0538b
1 changed files with 25 additions and 16 deletions
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radio/src/thirdparty/Stb/stb_image.h
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+25 -16
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@@ -3844,7 +3844,7 @@ STBIDEF char *stbi_zlib_decode_malloc_guesssize(const char *buffer, int len, int
char * r;
stbi__zbuf * a;
a = (stbi__zbuf *) stbi__malloc(sizeof(stbi__zbuf));
if (!a) return 0;
if (!a) return 0;
char *p = (char *) stbi__malloc(initial_size);
if (p == NULL) {
STBI_FREE(a);
@@ -3874,7 +3874,7 @@ STBIDEF char *stbi_zlib_decode_malloc_guesssize_headerflag(const char *buffer, i
char * r;
stbi__zbuf * a;
a = (stbi__zbuf *) stbi__malloc(sizeof(stbi__zbuf));
if (!a) return 0;
if (!a) return 0;
char *p = (char *) stbi__malloc(initial_size);
if (p == NULL) {
STBI_FREE(a);
@@ -3899,7 +3899,7 @@ STBIDEF int stbi_zlib_decode_buffer(char *obuffer, int olen, char const *ibuffer
int r;
stbi__zbuf * a;
a = (stbi__zbuf *) stbi__malloc(sizeof(stbi__zbuf));
if (!a) return -1;
if (!a) return -1;
a->zbuffer = (stbi_uc *) ibuffer;
a->zbuffer_end = (stbi_uc *) ibuffer + ilen;
if (stbi__do_zlib(a, obuffer, olen, 0, 1)) {
@@ -3918,7 +3918,7 @@ STBIDEF char *stbi_zlib_decode_noheader_malloc(char const *buffer, int len, int
char * r;
stbi__zbuf * a;
a = (stbi__zbuf *) stbi__malloc(sizeof(stbi__zbuf));
if (!a) return NULL;
if (!a) return NULL;
char *p = (char *) stbi__malloc(16384);
if (p == NULL) {
STBI_FREE(a);
@@ -3943,7 +3943,7 @@ STBIDEF int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const char
int r;
stbi__zbuf * a;
a = (stbi__zbuf *) stbi__malloc(sizeof(stbi__zbuf));
if (!a) return -1;
if (!a) return -1;
a->zbuffer = (stbi_uc *) ibuffer;
a->zbuffer_end = (stbi_uc *) ibuffer + ilen;
if (stbi__do_zlib(a, obuffer, olen, 0, 0)) {
@@ -4045,6 +4045,7 @@ static int stbi__create_png_image_raw(stbi__png *a, stbi_uc *raw, stbi__uint32 r
a->out = (stbi_uc *) stbi__malloc(x * y * out_n); // extra bytes to write off the end into
if (!a->out) return stbi__err("outofmem", "Out of memory");
s->img_out_n = 3;
img_width_bytes = (((img_n * x * depth) + 7) >> 3);
img_len = (img_width_bytes + 1) * y;
if (s->img_x == x && s->img_y == y) {
@@ -4106,12 +4107,12 @@ static int stbi__create_png_image_raw(stbi__png *a, stbi_uc *raw, stbi__uint32 r
switch (filter) {
// "none" filter turns into a memcpy here; make that explicit.
case STBI__F_none: memcpy(cur, raw, nk); break;
CASE(STBI__F_sub) cur[k] = STBI__BYTECAST(raw[k] + cur[k-filter_bytes]); break;
CASE(STBI__F_up) cur[k] = STBI__BYTECAST(raw[k] + prior[k]); break;
CASE(STBI__F_avg) cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k-filter_bytes])>>1)); break;
CASE(STBI__F_paeth) cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],prior[k],prior[k-filter_bytes])); break;
CASE(STBI__F_avg_first) cur[k] = STBI__BYTECAST(raw[k] + (cur[k-filter_bytes] >> 1)); break;
CASE(STBI__F_paeth_first) cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],0,0)); break;
CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k-filter_bytes]); if ((k&0x03) == 0x03 && cur[k]!=255) s->img_out_n = 4; } break;
CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); if ((k&0x03) == 0x03 && cur[k]!=255) s->img_out_n = 4; } break;
CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k-filter_bytes])>>1)); if ((k&0x03) == 0x03 && cur[k]!=255) s->img_out_n = 4; } break;
CASE(STBI__F_paeth) {cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],prior[k],prior[k-filter_bytes])); if ((k&0x03) == 0x03 && cur[k]!=255) s->img_out_n = 4; } break;
CASE(STBI__F_avg_first) {cur[k] = STBI__BYTECAST(raw[k] + (cur[k-filter_bytes] >> 1)); if ((k&0x03) == 0x03 && cur[k]!=255) s->img_out_n = 4; } break;
CASE(STBI__F_paeth_first) {cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],0,0)); if ((k&0x03) == 0x03 && cur[k]!=255) s->img_out_n = 4; } break;
}
#undef CASE
raw += nk;
@@ -4538,11 +4539,13 @@ static unsigned char *stbi__do_png(stbi__png *p, int *x, int *y, int *n, int req
if (stbi__parse_png_file(p, STBI__SCAN_load, req_comp)) {
result = p->out;
p->out = NULL;
#if 0
if (req_comp && req_comp != p->s->img_out_n) {
result = stbi__convert_format(result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y);
p->s->img_out_n = req_comp;
if (result == NULL) return result;
}
#endif
*x = p->s->img_x;
*y = p->s->img_y;
if (n) *n = p->s->img_out_n;
@@ -4670,7 +4673,7 @@ static void *stbi__bmp_parse_header(stbi__context *s, stbi__bmp_data *info)
stbi__get16le(s); // discard reserved
info->offset = stbi__get32le(s);
info->hsz = hsz = stbi__get32le(s);
if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108 && hsz != 124) return stbi__errpuc("unknown BMP", "BMP type not supported: unknown");
if (hsz == 12) {
s->img_x = stbi__get16le(s);
@@ -4755,7 +4758,7 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int
int flip_vertically, pad, target;
stbi__bmp_data info;
info.all_a = 255;
info.all_a = 255;
if (stbi__bmp_parse_header(s, &info) == NULL)
return NULL; // error code already set
@@ -4785,6 +4788,7 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int
out = (stbi_uc *) stbi__malloc(target * s->img_x * s->img_y);
if (!out) return stbi__errpuc("outofmem", "Out of memory");
if (info.bpp < 16) {
s->img_n = 3;
int z=0;
if (psize == 0 || psize > 256) { STBI_FREE(out); return stbi__errpuc("invalid", "Corrupt BMP"); }
for (i=0; i < psize; ++i) {
@@ -4856,6 +4860,7 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int
}
} else {
int bpp = info.bpp;
s->img_n = 3;
for (i=0; i < (int) s->img_x; ++i) {
stbi__uint32 v = (bpp == 16 ? (stbi__uint32) stbi__get16le(s) : stbi__get32le(s));
int a;
@@ -4864,13 +4869,17 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int
out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mb, bshift, bcount));
a = (ma ? stbi__shiftsigned(v & ma, ashift, acount) : 255);
all_a |= a;
if (target == 4) out[z++] = STBI__BYTECAST(a);
if (target == 4) {
uint8_t alpha = STBI__BYTECAST(a);
if (alpha != 255) s->img_n = 4;
out[z++] = alpha;
}
}
}
stbi__skip(s, pad);
}
}
// if alpha channel is all 0s, replace with all 255s
if (target == 4 && all_a == 0)
for (i=4*s->img_x*s->img_y-1; i >= 0; i -= 4)
@@ -6222,7 +6231,7 @@ static int stbi__bmp_info(stbi__context *s, int *x, int *y, int *comp)
void *p;
stbi__bmp_data info;
info.all_a = 255;
info.all_a = 255;
p = stbi__bmp_parse_header(s, &info);
stbi__rewind( s );
if (p == NULL)