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external: Update stb_image.h to reduce warnings

This commit is contained in:
BearOso 2024-07-26 17:06:17 -05:00
parent 4a20cfc024
commit cc49a06c77
1 changed files with 289 additions and 198 deletions
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487
external/stb/stb_image.h vendored
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@ -1,4 +1,4 @@
/* stb_image - v2.27 - public domain image loader - http://nothings.org/stb
/* stb_image - v2.30 - public domain image loader - http://nothings.org/stb
no warranty implied; use at your own risk
Do this:
@ -48,6 +48,9 @@ LICENSE
RECENT REVISION HISTORY:
2.30 (2024-05-31) avoid erroneous gcc warning
2.29 (2023-05-xx) optimizations
2.28 (2023-01-29) many error fixes, security errors, just tons of stuff
2.27 (2021-07-11) document stbi_info better, 16-bit PNM support, bug fixes
2.26 (2020-07-13) many minor fixes
2.25 (2020-02-02) fix warnings
@ -108,7 +111,7 @@ RECENT REVISION HISTORY:
Cass Everitt Ryamond Barbiero github:grim210
Paul Du Bois Engin Manap Aldo Culquicondor github:sammyhw
Philipp Wiesemann Dale Weiler Oriol Ferrer Mesia github:phprus
Josh Tobin Matthew Gregan github:poppolopoppo
Josh Tobin Neil Bickford Matthew Gregan github:poppolopoppo
Julian Raschke Gregory Mullen Christian Floisand github:darealshinji
Baldur Karlsson Kevin Schmidt JR Smith github:Michaelangel007
Brad Weinberger Matvey Cherevko github:mosra
@ -140,7 +143,7 @@ RECENT REVISION HISTORY:
// // ... x = width, y = height, n = # 8-bit components per pixel ...
// // ... replace '0' with '1'..'4' to force that many components per pixel
// // ... but 'n' will always be the number that it would have been if you said 0
// stbi_image_free(data)
// stbi_image_free(data);
//
// Standard parameters:
// int *x -- outputs image width in pixels
@ -635,7 +638,7 @@ STBIDEF int stbi_zlib_decode_noheader_buffer(char *obuffer, int olen, const ch
#endif
#endif
#ifdef _MSC_VER
#if defined(_MSC_VER) || defined(__SYMBIAN32__)
typedef unsigned short stbi__uint16;
typedef signed short stbi__int16;
typedef unsigned int stbi__uint32;
@ -1063,6 +1066,23 @@ static void *stbi__malloc_mad4(int a, int b, int c, int d, int add)
}
#endif
// returns 1 if the sum of two signed ints is valid (between -2^31 and 2^31-1 inclusive), 0 on overflow.
static int stbi__addints_valid(int a, int b)
{
if ((a >= 0) != (b >= 0)) return 1; // a and b have different signs, so no overflow
if (a < 0 && b < 0) return a >= INT_MIN - b; // same as a + b >= INT_MIN; INT_MIN - b cannot overflow since b < 0.
return a <= INT_MAX - b;
}
// returns 1 if the product of two ints fits in a signed short, 0 on overflow.
static int stbi__mul2shorts_valid(int a, int b)
{
if (b == 0 || b == -1) return 1; // multiplication by 0 is always 0; check for -1 so SHRT_MIN/b doesn't overflow
if ((a >= 0) == (b >= 0)) return a <= SHRT_MAX/b; // product is positive, so similar to mul2sizes_valid
if (b < 0) return a <= SHRT_MIN / b; // same as a * b >= SHRT_MIN
return a >= SHRT_MIN / b;
}
// stbi__err - error
// stbi__errpf - error returning pointer to float
// stbi__errpuc - error returning pointer to unsigned char
@ -1985,9 +2005,12 @@ static int stbi__build_huffman(stbi__huffman *h, int *count)
int i,j,k=0;
unsigned int code;
// build size list for each symbol (from JPEG spec)
for (i=0; i < 16; ++i)
for (j=0; j < count[i]; ++j)
for (i=0; i < 16; ++i) {
for (j=0; j < count[i]; ++j) {
h->size[k++] = (stbi_uc) (i+1);
if(k >= 257) return stbi__err("bad size list","Corrupt JPEG");
}
}
h->size[k] = 0;
// compute actual symbols (from jpeg spec)
@ -2112,6 +2135,8 @@ stbi_inline static int stbi__jpeg_huff_decode(stbi__jpeg *j, stbi__huffman *h)
// convert the huffman code to the symbol id
c = ((j->code_buffer >> (32 - k)) & stbi__bmask[k]) + h->delta[k];
if(c < 0 || c >= 256) // symbol id out of bounds!
return -1;
STBI_ASSERT((((j->code_buffer) >> (32 - h->size[c])) & stbi__bmask[h->size[c]]) == h->code[c]);
// convert the id to a symbol
@ -2130,6 +2155,7 @@ stbi_inline static int stbi__extend_receive(stbi__jpeg *j, int n)
unsigned int k;
int sgn;
if (j->code_bits < n) stbi__grow_buffer_unsafe(j);
if (j->code_bits < n) return 0; // ran out of bits from stream, return 0s intead of continuing
sgn = j->code_buffer >> 31; // sign bit always in MSB; 0 if MSB clear (positive), 1 if MSB set (negative)
k = stbi_lrot(j->code_buffer, n);
@ -2144,6 +2170,7 @@ stbi_inline static int stbi__jpeg_get_bits(stbi__jpeg *j, int n)
{
unsigned int k;
if (j->code_bits < n) stbi__grow_buffer_unsafe(j);
if (j->code_bits < n) return 0; // ran out of bits from stream, return 0s intead of continuing
k = stbi_lrot(j->code_buffer, n);
j->code_buffer = k & ~stbi__bmask[n];
k &= stbi__bmask[n];
@ -2155,6 +2182,7 @@ stbi_inline static int stbi__jpeg_get_bit(stbi__jpeg *j)
{
unsigned int k;
if (j->code_bits < 1) stbi__grow_buffer_unsafe(j);
if (j->code_bits < 1) return 0; // ran out of bits from stream, return 0s intead of continuing
k = j->code_buffer;
j->code_buffer <<= 1;
--j->code_bits;
@ -2192,8 +2220,10 @@ static int stbi__jpeg_decode_block(stbi__jpeg *j, short data[64], stbi__huffman
memset(data,0,64*sizeof(data[0]));
diff = t ? stbi__extend_receive(j, t) : 0;
if (!stbi__addints_valid(j->img_comp[b].dc_pred, diff)) return stbi__err("bad delta","Corrupt JPEG");
dc = j->img_comp[b].dc_pred + diff;
j->img_comp[b].dc_pred = dc;
if (!stbi__mul2shorts_valid(dc, dequant[0])) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
data[0] = (short) (dc * dequant[0]);
// decode AC components, see JPEG spec
@ -2207,6 +2237,7 @@ static int stbi__jpeg_decode_block(stbi__jpeg *j, short data[64], stbi__huffman
if (r) { // fast-AC path
k += (r >> 4) & 15; // run
s = r & 15; // combined length
if (s > j->code_bits) return stbi__err("bad huffman code", "Combined length longer than code bits available");
j->code_buffer <<= s;
j->code_bits -= s;
// decode into unzigzag'd location
@ -2246,8 +2277,10 @@ static int stbi__jpeg_decode_block_prog_dc(stbi__jpeg *j, short data[64], stbi__
if (t < 0 || t > 15) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
diff = t ? stbi__extend_receive(j, t) : 0;
if (!stbi__addints_valid(j->img_comp[b].dc_pred, diff)) return stbi__err("bad delta", "Corrupt JPEG");
dc = j->img_comp[b].dc_pred + diff;
j->img_comp[b].dc_pred = dc;
if (!stbi__mul2shorts_valid(dc, 1 << j->succ_low)) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
data[0] = (short) (dc * (1 << j->succ_low));
} else {
// refinement scan for DC coefficient
@ -2282,6 +2315,7 @@ static int stbi__jpeg_decode_block_prog_ac(stbi__jpeg *j, short data[64], stbi__
if (r) { // fast-AC path
k += (r >> 4) & 15; // run
s = r & 15; // combined length
if (s > j->code_bits) return stbi__err("bad huffman code", "Combined length longer than code bits available");
j->code_buffer <<= s;
j->code_bits -= s;
zig = stbi__jpeg_dezigzag[k++];
@ -3102,6 +3136,7 @@ static int stbi__process_marker(stbi__jpeg *z, int m)
sizes[i] = stbi__get8(z->s);
n += sizes[i];
}
if(n > 256) return stbi__err("bad DHT header","Corrupt JPEG"); // Loop over i < n would write past end of values!
L -= 17;
if (tc == 0) {
if (!stbi__build_huffman(z->huff_dc+th, sizes)) return 0;
@ -3351,6 +3386,28 @@ static int stbi__decode_jpeg_header(stbi__jpeg *z, int scan)
return 1;
}
static stbi_uc stbi__skip_jpeg_junk_at_end(stbi__jpeg *j)
{
// some JPEGs have junk at end, skip over it but if we find what looks
// like a valid marker, resume there
while (!stbi__at_eof(j->s)) {
stbi_uc x = stbi__get8(j->s);
while (x == 0xff) { // might be a marker
if (stbi__at_eof(j->s)) return STBI__MARKER_none;
x = stbi__get8(j->s);
if (x != 0x00 && x != 0xff) {
// not a stuffed zero or lead-in to another marker, looks
// like an actual marker, return it
return x;
}
// stuffed zero has x=0 now which ends the loop, meaning we go
// back to regular scan loop.
// repeated 0xff keeps trying to read the next byte of the marker.
}
}
return STBI__MARKER_none;
}
// decode image to YCbCr format
static int stbi__decode_jpeg_image(stbi__jpeg *j)
{
@ -3367,25 +3424,22 @@ static int stbi__decode_jpeg_image(stbi__jpeg *j)
if (!stbi__process_scan_header(j)) return 0;
if (!stbi__parse_entropy_coded_data(j)) return 0;
if (j->marker == STBI__MARKER_none ) {
// handle 0s at the end of image data from IP Kamera 9060
while (!stbi__at_eof(j->s)) {
int x = stbi__get8(j->s);
if (x == 255) {
j->marker = stbi__get8(j->s);
break;
}
}
j->marker = stbi__skip_jpeg_junk_at_end(j);
// if we reach eof without hitting a marker, stbi__get_marker() below will fail and we'll eventually return 0
}
m = stbi__get_marker(j);
if (STBI__RESTART(m))
m = stbi__get_marker(j);
} else if (stbi__DNL(m)) {
int Ld = stbi__get16be(j->s);
stbi__uint32 NL = stbi__get16be(j->s);
if (Ld != 4) return stbi__err("bad DNL len", "Corrupt JPEG");
if (NL != j->s->img_y) return stbi__err("bad DNL height", "Corrupt JPEG");
m = stbi__get_marker(j);
} else {
if (!stbi__process_marker(j, m)) return 0;
if (!stbi__process_marker(j, m)) return 1;
m = stbi__get_marker(j);
}
m = stbi__get_marker(j);
}
if (j->progressive)
stbi__jpeg_finish(j);
@ -3976,6 +4030,7 @@ static void *stbi__jpeg_load(stbi__context *s, int *x, int *y, int *comp, int re
unsigned char* result;
stbi__jpeg* j = (stbi__jpeg*) stbi__malloc(sizeof(stbi__jpeg));
if (!j) return stbi__errpuc("outofmem", "Out of memory");
memset(j, 0, sizeof(stbi__jpeg));
STBI_NOTUSED(ri);
j->s = s;
stbi__setup_jpeg(j);
@ -3989,6 +4044,7 @@ static int stbi__jpeg_test(stbi__context *s)
int r;
stbi__jpeg* j = (stbi__jpeg*)stbi__malloc(sizeof(stbi__jpeg));
if (!j) return stbi__err("outofmem", "Out of memory");
memset(j, 0, sizeof(stbi__jpeg));
j->s = s;
stbi__setup_jpeg(j);
r = stbi__decode_jpeg_header(j, STBI__SCAN_type);
@ -4014,6 +4070,7 @@ static int stbi__jpeg_info(stbi__context *s, int *x, int *y, int *comp)
int result;
stbi__jpeg* j = (stbi__jpeg*) (stbi__malloc(sizeof(stbi__jpeg)));
if (!j) return stbi__err("outofmem", "Out of memory");
memset(j, 0, sizeof(stbi__jpeg));
j->s = s;
result = stbi__jpeg_info_raw(j, x, y, comp);
STBI_FREE(j);
@ -4121,6 +4178,7 @@ typedef struct
{
stbi_uc *zbuffer, *zbuffer_end;
int num_bits;
int hit_zeof_once;
stbi__uint32 code_buffer;
char *zout;
@ -4187,9 +4245,20 @@ stbi_inline static int stbi__zhuffman_decode(stbi__zbuf *a, stbi__zhuffman *z)
int b,s;
if (a->num_bits < 16) {
if (stbi__zeof(a)) {
return -1; /* report error for unexpected end of data. */
if (!a->hit_zeof_once) {
// This is the first time we hit eof, insert 16 extra padding btis
// to allow us to keep going; if we actually consume any of them
// though, that is invalid data. This is caught later.
a->hit_zeof_once = 1;
a->num_bits += 16; // add 16 implicit zero bits
} else {
// We already inserted our extra 16 padding bits and are again
// out, this stream is actually prematurely terminated.
return -1;
}
} else {
stbi__fill_bits(a);
}
stbi__fill_bits(a);
}
b = z->fast[a->code_buffer & STBI__ZFAST_MASK];
if (b) {
@ -4254,17 +4323,25 @@ static int stbi__parse_huffman_block(stbi__zbuf *a)
int len,dist;
if (z == 256) {
a->zout = zout;
if (a->hit_zeof_once && a->num_bits < 16) {
// The first time we hit zeof, we inserted 16 extra zero bits into our bit
// buffer so the decoder can just do its speculative decoding. But if we
// actually consumed any of those bits (which is the case when num_bits < 16),
// the stream actually read past the end so it is malformed.
return stbi__err("unexpected end","Corrupt PNG");
}
return 1;
}
if (z >= 286) return stbi__err("bad huffman code","Corrupt PNG"); // per DEFLATE, length codes 286 and 287 must not appear in compressed data
z -= 257;
len = stbi__zlength_base[z];
if (stbi__zlength_extra[z]) len += stbi__zreceive(a, stbi__zlength_extra[z]);
z = stbi__zhuffman_decode(a, &a->z_distance);
if (z < 0) return stbi__err("bad huffman code","Corrupt PNG");
if (z < 0 || z >= 30) return stbi__err("bad huffman code","Corrupt PNG"); // per DEFLATE, distance codes 30 and 31 must not appear in compressed data
dist = stbi__zdist_base[z];
if (stbi__zdist_extra[z]) dist += stbi__zreceive(a, stbi__zdist_extra[z]);
if (zout - a->zout_start < dist) return stbi__err("bad dist","Corrupt PNG");
if (zout + len > a->zout_end) {
if (len > a->zout_end - zout) {
if (!stbi__zexpand(a, zout, len)) return 0;
zout = a->zout;
}
@ -4408,6 +4485,7 @@ static int stbi__parse_zlib(stbi__zbuf *a, int parse_header)
if (!stbi__parse_zlib_header(a)) return 0;
a->num_bits = 0;
a->code_buffer = 0;
a->hit_zeof_once = 0;
do {
final = stbi__zreceive(a,1);
type = stbi__zreceive(a,2);
@ -4563,9 +4641,8 @@ enum {
STBI__F_up=2,
STBI__F_avg=3,
STBI__F_paeth=4,
// synthetic filters used for first scanline to avoid needing a dummy row of 0s
STBI__F_avg_first,
STBI__F_paeth_first
// synthetic filter used for first scanline to avoid needing a dummy row of 0s
STBI__F_avg_first
};
static stbi_uc first_row_filter[5] =
@ -4574,29 +4651,56 @@ static stbi_uc first_row_filter[5] =
STBI__F_sub,
STBI__F_none,
STBI__F_avg_first,
STBI__F_paeth_first
STBI__F_sub // Paeth with b=c=0 turns out to be equivalent to sub
};
static int stbi__paeth(int a, int b, int c)
{
int p = a + b - c;
int pa = abs(p-a);
int pb = abs(p-b);
int pc = abs(p-c);
if (pa <= pb && pa <= pc) return a;
if (pb <= pc) return b;
return c;
// This formulation looks very different from the reference in the PNG spec, but is
// actually equivalent and has favorable data dependencies and admits straightforward
// generation of branch-free code, which helps performance significantly.
int thresh = c*3 - (a + b);
int lo = a < b ? a : b;
int hi = a < b ? b : a;
int t0 = (hi <= thresh) ? lo : c;
int t1 = (thresh <= lo) ? hi : t0;
return t1;
}
static const stbi_uc stbi__depth_scale_table[9] = { 0, 0xff, 0x55, 0, 0x11, 0,0,0, 0x01 };
// adds an extra all-255 alpha channel
// dest == src is legal
// img_n must be 1 or 3
static void stbi__create_png_alpha_expand8(stbi_uc *dest, stbi_uc *src, stbi__uint32 x, int img_n)
{
int i;
// must process data backwards since we allow dest==src
if (img_n == 1) {
for (i=x-1; i >= 0; --i) {
dest[i*2+1] = 255;
dest[i*2+0] = src[i];
}
} else {
STBI_ASSERT(img_n == 3);
for (i=x-1; i >= 0; --i) {
dest[i*4+3] = 255;
dest[i*4+2] = src[i*3+2];
dest[i*4+1] = src[i*3+1];
dest[i*4+0] = src[i*3+0];
}
}
}
// create the png data from post-deflated data
static int stbi__create_png_image_raw(stbi__png *a, stbi_uc *raw, stbi__uint32 raw_len, int out_n, stbi__uint32 x, stbi__uint32 y, int depth, int color)
{
int bytes = (depth == 16? 2 : 1);
int bytes = (depth == 16 ? 2 : 1);
stbi__context *s = a->s;
stbi__uint32 i,j,stride = x*out_n*bytes;
stbi__uint32 img_len, img_width_bytes;
stbi_uc *filter_buf;
int all_ok = 1;
int k;
int img_n = s->img_n; // copy it into a local for later
@ -4608,8 +4712,11 @@ static int stbi__create_png_image_raw(stbi__png *a, stbi_uc *raw, stbi__uint32 r
a->out = (stbi_uc *) stbi__malloc_mad3(x, y, output_bytes, 0); // extra bytes to write off the end into
if (!a->out) return stbi__err("outofmem", "Out of memory");
// note: error exits here don't need to clean up a->out individually,
// stbi__do_png always does on error.
if (!stbi__mad3sizes_valid(img_n, x, depth, 7)) return stbi__err("too large", "Corrupt PNG");
img_width_bytes = (((img_n * x * depth) + 7) >> 3);
if (!stbi__mad2sizes_valid(img_width_bytes, y, img_width_bytes)) return stbi__err("too large", "Corrupt PNG");
img_len = (img_width_bytes + 1) * y;
// we used to check for exact match between raw_len and img_len on non-interlaced PNGs,
@ -4617,189 +4724,137 @@ static int stbi__create_png_image_raw(stbi__png *a, stbi_uc *raw, stbi__uint32 r
// so just check for raw_len < img_len always.
if (raw_len < img_len) return stbi__err("not enough pixels","Corrupt PNG");
// Allocate two scan lines worth of filter workspace buffer.
filter_buf = (stbi_uc *) stbi__malloc_mad2(img_width_bytes, 2, 0);
if (!filter_buf) return stbi__err("outofmem", "Out of memory");
// Filtering for low-bit-depth images
if (depth < 8) {
filter_bytes = 1;
width = img_width_bytes;
}
for (j=0; j < y; ++j) {
stbi_uc *cur = a->out + stride*j;
stbi_uc *prior;
// cur/prior filter buffers alternate
stbi_uc *cur = filter_buf + (j & 1)*img_width_bytes;
stbi_uc *prior = filter_buf + (~j & 1)*img_width_bytes;
stbi_uc *dest = a->out + stride*j;
int nk = width * filter_bytes;
int filter = *raw++;
if (filter > 4)
return stbi__err("invalid filter","Corrupt PNG");
if (depth < 8) {
if (img_width_bytes > x) return stbi__err("invalid width","Corrupt PNG");
cur += x*out_n - img_width_bytes; // store output to the rightmost img_len bytes, so we can decode in place
filter_bytes = 1;
width = img_width_bytes;
// check filter type
if (filter > 4) {
all_ok = stbi__err("invalid filter","Corrupt PNG");
break;
}
prior = cur - stride; // bugfix: need to compute this after 'cur +=' computation above
// if first row, use special filter that doesn't sample previous row
if (j == 0) filter = first_row_filter[filter];
// handle first byte explicitly
for (k=0; k < filter_bytes; ++k) {
switch (filter) {
case STBI__F_none : cur[k] = raw[k]; break;
case STBI__F_sub : cur[k] = raw[k]; 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]>>1)); break;
case STBI__F_paeth : cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(0,prior[k],0)); break;
case STBI__F_avg_first : cur[k] = raw[k]; break;
case STBI__F_paeth_first: cur[k] = raw[k]; break;
}
// perform actual filtering
switch (filter) {
case STBI__F_none:
memcpy(cur, raw, nk);
break;
case STBI__F_sub:
memcpy(cur, raw, filter_bytes);
for (k = filter_bytes; k < nk; ++k)
cur[k] = STBI__BYTECAST(raw[k] + cur[k-filter_bytes]);
break;
case STBI__F_up:
for (k = 0; k < nk; ++k)
cur[k] = STBI__BYTECAST(raw[k] + prior[k]);
break;
case STBI__F_avg:
for (k = 0; k < filter_bytes; ++k)
cur[k] = STBI__BYTECAST(raw[k] + (prior[k]>>1));
for (k = filter_bytes; k < nk; ++k)
cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k-filter_bytes])>>1));
break;
case STBI__F_paeth:
for (k = 0; k < filter_bytes; ++k)
cur[k] = STBI__BYTECAST(raw[k] + prior[k]); // prior[k] == stbi__paeth(0,prior[k],0)
for (k = filter_bytes; k < nk; ++k)
cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes], prior[k], prior[k-filter_bytes]));
break;
case STBI__F_avg_first:
memcpy(cur, raw, filter_bytes);
for (k = filter_bytes; k < nk; ++k)
cur[k] = STBI__BYTECAST(raw[k] + (cur[k-filter_bytes] >> 1));
break;
}
if (depth == 8) {
if (img_n != out_n)
cur[img_n] = 255; // first pixel
raw += img_n;
cur += out_n;
prior += out_n;
} else if (depth == 16) {
if (img_n != out_n) {
cur[filter_bytes] = 255; // first pixel top byte
cur[filter_bytes+1] = 255; // first pixel bottom byte
}
raw += filter_bytes;
cur += output_bytes;
prior += output_bytes;
} else {
raw += 1;
cur += 1;
prior += 1;
}
raw += nk;
// this is a little gross, so that we don't switch per-pixel or per-component
if (depth < 8 || img_n == out_n) {
int nk = (width - 1)*filter_bytes;
#define STBI__CASE(f) \
case f: \
for (k=0; k < nk; ++k)
switch (filter) {
// "none" filter turns into a memcpy here; make that explicit.
case STBI__F_none: memcpy(cur, raw, nk); break;
STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k-filter_bytes]); } break;
STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break;
STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k-filter_bytes])>>1)); } break;
STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],prior[k],prior[k-filter_bytes])); } break;
STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k-filter_bytes] >> 1)); } break;
STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k-filter_bytes],0,0)); } break;
}
#undef STBI__CASE
raw += nk;
} else {
STBI_ASSERT(img_n+1 == out_n);
#define STBI__CASE(f) \
case f: \
for (i=x-1; i >= 1; --i, cur[filter_bytes]=255,raw+=filter_bytes,cur+=output_bytes,prior+=output_bytes) \
for (k=0; k < filter_bytes; ++k)
switch (filter) {
STBI__CASE(STBI__F_none) { cur[k] = raw[k]; } break;
STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k- output_bytes]); } break;
STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break;
STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k- output_bytes])>>1)); } break;
STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k- output_bytes],prior[k],prior[k- output_bytes])); } break;
STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k- output_bytes] >> 1)); } break;
STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k- output_bytes],0,0)); } break;
}
#undef STBI__CASE
// the loop above sets the high byte of the pixels' alpha, but for
// 16 bit png files we also need the low byte set. we'll do that here.
if (depth == 16) {
cur = a->out + stride*j; // start at the beginning of the row again
for (i=0; i < x; ++i,cur+=output_bytes) {
cur[filter_bytes+1] = 255;
}
}
}
}
// we make a separate pass to expand bits to pixels; for performance,
// this could run two scanlines behind the above code, so it won't
// intefere with filtering but will still be in the cache.
if (depth < 8) {
for (j=0; j < y; ++j) {
stbi_uc *cur = a->out + stride*j;
stbi_uc *in = a->out + stride*j + x*out_n - img_width_bytes;
// unpack 1/2/4-bit into a 8-bit buffer. allows us to keep the common 8-bit path optimal at minimal cost for 1/2/4-bit
// png guarante byte alignment, if width is not multiple of 8/4/2 we'll decode dummy trailing data that will be skipped in the later loop
// expand decoded bits in cur to dest, also adding an extra alpha channel if desired
if (depth < 8) {
stbi_uc scale = (color == 0) ? stbi__depth_scale_table[depth] : 1; // scale grayscale values to 0..255 range
stbi_uc *in = cur;
stbi_uc *out = dest;
stbi_uc inb = 0;
stbi__uint32 nsmp = x*img_n;
// note that the final byte might overshoot and write more data than desired.
// we can allocate enough data that this never writes out of memory, but it
// could also overwrite the next scanline. can it overwrite non-empty data
// on the next scanline? yes, consider 1-pixel-wide scanlines with 1-bit-per-pixel.
// so we need to explicitly clamp the final ones
// expand bits to bytes first
if (depth == 4) {
for (k=x*img_n; k >= 2; k-=2, ++in) {
*cur++ = scale * ((*in >> 4) );
*cur++ = scale * ((*in ) & 0x0f);
for (i=0; i < nsmp; ++i) {
if ((i & 1) == 0) inb = *in++;
*out++ = scale * (inb >> 4);
inb <<= 4;
}
if (k > 0) *cur++ = scale * ((*in >> 4) );
} else if (depth == 2) {
for (k=x*img_n; k >= 4; k-=4, ++in) {
*cur++ = scale * ((*in >> 6) );
*cur++ = scale * ((*in >> 4) & 0x03);
*cur++ = scale * ((*in >> 2) & 0x03);
*cur++ = scale * ((*in ) & 0x03);
for (i=0; i < nsmp; ++i) {
if ((i & 3) == 0) inb = *in++;
*out++ = scale * (inb >> 6);
inb <<= 2;
}
if (k > 0) *cur++ = scale * ((*in >> 6) );
if (k > 1) *cur++ = scale * ((*in >> 4) & 0x03);
if (k > 2) *cur++ = scale * ((*in >> 2) & 0x03);
} else if (depth == 1) {
for (k=x*img_n; k >= 8; k-=8, ++in) {
*cur++ = scale * ((*in >> 7) );
*cur++ = scale * ((*in >> 6) & 0x01);
*cur++ = scale * ((*in >> 5) & 0x01);
*cur++ = scale * ((*in >> 4) & 0x01);
*cur++ = scale * ((*in >> 3) & 0x01);
*cur++ = scale * ((*in >> 2) & 0x01);
*cur++ = scale * ((*in >> 1) & 0x01);
*cur++ = scale * ((*in ) & 0x01);
} else {
STBI_ASSERT(depth == 1);
for (i=0; i < nsmp; ++i) {
if ((i & 7) == 0) inb = *in++;
*out++ = scale * (inb >> 7);
inb <<= 1;
}
if (k > 0) *cur++ = scale * ((*in >> 7) );
if (k > 1) *cur++ = scale * ((*in >> 6) & 0x01);
if (k > 2) *cur++ = scale * ((*in >> 5) & 0x01);
if (k > 3) *cur++ = scale * ((*in >> 4) & 0x01);
if (k > 4) *cur++ = scale * ((*in >> 3) & 0x01);
if (k > 5) *cur++ = scale * ((*in >> 2) & 0x01);
if (k > 6) *cur++ = scale * ((*in >> 1) & 0x01);
}
if (img_n != out_n) {
int q;
// insert alpha = 255
cur = a->out + stride*j;
// insert alpha=255 values if desired
if (img_n != out_n)
stbi__create_png_alpha_expand8(dest, dest, x, img_n);
} else if (depth == 8) {
if (img_n == out_n)
memcpy(dest, cur, x*img_n);
else
stbi__create_png_alpha_expand8(dest, cur, x, img_n);
} else if (depth == 16) {
// convert the image data from big-endian to platform-native
stbi__uint16 *dest16 = (stbi__uint16*)dest;
stbi__uint32 nsmp = x*img_n;
if (img_n == out_n) {
for (i = 0; i < nsmp; ++i, ++dest16, cur += 2)
*dest16 = (cur[0] << 8) | cur[1];
} else {
STBI_ASSERT(img_n+1 == out_n);
if (img_n == 1) {
for (q=x-1; q >= 0; --q) {
cur[q*2+1] = 255;
cur[q*2+0] = cur[q];
for (i = 0; i < x; ++i, dest16 += 2, cur += 2) {
dest16[0] = (cur[0] << 8) | cur[1];
dest16[1] = 0xffff;
}
} else {
STBI_ASSERT(img_n == 3);
for (q=x-1; q >= 0; --q) {
cur[q*4+3] = 255;
cur[q*4+2] = cur[q*3+2];
cur[q*4+1] = cur[q*3+1];
cur[q*4+0] = cur[q*3+0];
for (i = 0; i < x; ++i, dest16 += 4, cur += 6) {
dest16[0] = (cur[0] << 8) | cur[1];
dest16[1] = (cur[2] << 8) | cur[3];
dest16[2] = (cur[4] << 8) | cur[5];
dest16[3] = 0xffff;
}
}
}
}
} else if (depth == 16) {
// force the image data from big-endian to platform-native.
// this is done in a separate pass due to the decoding relying
// on the data being untouched, but could probably be done
// per-line during decode if care is taken.
stbi_uc *cur = a->out;
stbi__uint16 *cur16 = (stbi__uint16*)cur;
for(i=0; i < x*y*out_n; ++i,cur16++,cur+=2) {
*cur16 = (cur[0] << 8) | cur[1];
}
}
STBI_FREE(filter_buf);
if (!all_ok) return 0;
return 1;
}
@ -4955,7 +5010,7 @@ STBIDEF void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert)
static STBI_THREAD_LOCAL int stbi__unpremultiply_on_load_local, stbi__unpremultiply_on_load_set;
static STBI_THREAD_LOCAL int stbi__de_iphone_flag_local, stbi__de_iphone_flag_set;
STBIDEF void stbi__unpremultiply_on_load_thread(int flag_true_if_should_unpremultiply)
STBIDEF void stbi_set_unpremultiply_on_load_thread(int flag_true_if_should_unpremultiply)
{
stbi__unpremultiply_on_load_local = flag_true_if_should_unpremultiply;
stbi__unpremultiply_on_load_set = 1;
@ -5064,14 +5119,13 @@ static int stbi__parse_png_file(stbi__png *z, int scan, int req_comp)
if (!pal_img_n) {
s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0);
if ((1 << 30) / s->img_x / s->img_n < s->img_y) return stbi__err("too large", "Image too large to decode");
if (scan == STBI__SCAN_header) return 1;
} else {
// if paletted, then pal_n is our final components, and
// img_n is # components to decompress/filter.
s->img_n = 1;
if ((1 << 30) / s->img_x / 4 < s->img_y) return stbi__err("too large","Corrupt PNG");
// if SCAN_header, have to scan to see if we have a tRNS
}
// even with SCAN_header, have to scan to see if we have a tRNS
break;
}
@ -5103,10 +5157,14 @@ static int stbi__parse_png_file(stbi__png *z, int scan, int req_comp)
if (!(s->img_n & 1)) return stbi__err("tRNS with alpha","Corrupt PNG");
if (c.length != (stbi__uint32) s->img_n*2) return stbi__err("bad tRNS len","Corrupt PNG");
has_trans = 1;
// non-paletted with tRNS = constant alpha. if header-scanning, we can stop now.
if (scan == STBI__SCAN_header) { ++s->img_n; return 1; }
if (z->depth == 16) {
for (k = 0; k < s->img_n; ++k) tc16[k] = (stbi__uint16)stbi__get16be(s); // copy the values as-is
for (k = 0; k < s->img_n && k < 3; ++k) // extra loop test to suppress false GCC warning
tc16[k] = (stbi__uint16)stbi__get16be(s); // copy the values as-is
} else {
for (k = 0; k < s->img_n; ++k) tc[k] = (stbi_uc)(stbi__get16be(s) & 255) * stbi__depth_scale_table[z->depth]; // non 8-bit images will be larger
for (k = 0; k < s->img_n && k < 3; ++k)
tc[k] = (stbi_uc)(stbi__get16be(s) & 255) * stbi__depth_scale_table[z->depth]; // non 8-bit images will be larger
}
}
break;
@ -5115,7 +5173,13 @@ static int stbi__parse_png_file(stbi__png *z, int scan, int req_comp)
case STBI__PNG_TYPE('I','D','A','T'): {
if (first) return stbi__err("first not IHDR", "Corrupt PNG");
if (pal_img_n && !pal_len) return stbi__err("no PLTE","Corrupt PNG");
if (scan == STBI__SCAN_header) { s->img_n = pal_img_n; return 1; }
if (scan == STBI__SCAN_header) {
// header scan definitely stops at first IDAT
if (pal_img_n)
s->img_n = pal_img_n;
return 1;
}
if (c.length > (1u << 30)) return stbi__err("IDAT size limit", "IDAT section larger than 2^30 bytes");
if ((int)(ioff + c.length) < (int)ioff) return 0;
if (ioff + c.length > idata_limit) {
stbi__uint32 idata_limit_old = idata_limit;
@ -5498,8 +5562,22 @@ static void *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req
psize = (info.offset - info.extra_read - info.hsz) >> 2;
}
if (psize == 0) {
if (info.offset != s->callback_already_read + (s->img_buffer - s->img_buffer_original)) {
return stbi__errpuc("bad offset", "Corrupt BMP");
// accept some number of extra bytes after the header, but if the offset points either to before
// the header ends or implies a large amount of extra data, reject the file as malformed
int bytes_read_so_far = s->callback_already_read + (int)(s->img_buffer - s->img_buffer_original);
int header_limit = 1024; // max we actually read is below 256 bytes currently.
int extra_data_limit = 256*4; // what ordinarily goes here is a palette; 256 entries*4 bytes is its max size.
if (bytes_read_so_far <= 0 || bytes_read_so_far > header_limit) {
return stbi__errpuc("bad header", "Corrupt BMP");
}
// we established that bytes_read_so_far is positive and sensible.
// the first half of this test rejects offsets that are either too small positives, or
// negative, and guarantees that info.offset >= bytes_read_so_far > 0. this in turn
// ensures the number computed in the second half of the test can't overflow.
if (info.offset < bytes_read_so_far || info.offset - bytes_read_so_far > extra_data_limit) {
return stbi__errpuc("bad offset", "Corrupt BMP");
} else {
stbi__skip(s, info.offset - bytes_read_so_far);
}
}
@ -7187,12 +7265,12 @@ static float *stbi__hdr_load(stbi__context *s, int *x, int *y, int *comp, int re
// Run
value = stbi__get8(s);
count -= 128;
if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
if ((count == 0) || (count > nleft)) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
for (z = 0; z < count; ++z)
scanline[i++ * 4 + k] = value;
} else {
// Dump
if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
if ((count == 0) || (count > nleft)) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
for (z = 0; z < count; ++z)
scanline[i++ * 4 + k] = stbi__get8(s);
}
@ -7446,10 +7524,17 @@ static void *stbi__pnm_load(stbi__context *s, int *x, int *y, int *comp, int req
out = (stbi_uc *) stbi__malloc_mad4(s->img_n, s->img_x, s->img_y, ri->bits_per_channel / 8, 0);
if (!out) return stbi__errpuc("outofmem", "Out of memory");
stbi__getn(s, out, s->img_n * s->img_x * s->img_y * (ri->bits_per_channel / 8));
if (!stbi__getn(s, out, s->img_n * s->img_x * s->img_y * (ri->bits_per_channel / 8))) {
STBI_FREE(out);
return stbi__errpuc("bad PNM", "PNM file truncated");
}
if (req_comp && req_comp != s->img_n) {
out = stbi__convert_format(out, s->img_n, req_comp, s->img_x, s->img_y);
if (ri->bits_per_channel == 16) {
out = (stbi_uc *) stbi__convert_format16((stbi__uint16 *) out, s->img_n, req_comp, s->img_x, s->img_y);
} else {
out = stbi__convert_format(out, s->img_n, req_comp, s->img_x, s->img_y);
}
if (out == NULL) return out; // stbi__convert_format frees input on failure
}
return out;
@ -7486,6 +7571,8 @@ static int stbi__pnm_getinteger(stbi__context *s, char *c)
while (!stbi__at_eof(s) && stbi__pnm_isdigit(*c)) {
value = value*10 + (*c - '0');
*c = (char) stbi__get8(s);
if((value > 214748364) || (value == 214748364 && *c > '7'))
return stbi__err("integer parse overflow", "Parsing an integer in the PPM header overflowed a 32-bit int");
}
return value;
@ -7516,9 +7603,13 @@ static int stbi__pnm_info(stbi__context *s, int *x, int *y, int *comp)
stbi__pnm_skip_whitespace(s, &c);
*x = stbi__pnm_getinteger(s, &c); // read width
if(*x == 0)
return stbi__err("invalid width", "PPM image header had zero or overflowing width");
stbi__pnm_skip_whitespace(s, &c);
*y = stbi__pnm_getinteger(s, &c); // read height
if (*y == 0)
return stbi__err("invalid width", "PPM image header had zero or overflowing width");
stbi__pnm_skip_whitespace(s, &c);
maxv = stbi__pnm_getinteger(s, &c); // read max value