public static int stbi__zexpand(stbi__zbuf *z, sbyte *zout, int n)
{
sbyte *q;
var cur = 0;
var limit = 0;
var old_limit = 0;
z->zout = zout;
if (z->z_expandable == 0)
{
return(stbi__err("output buffer limit"));
}
cur = (int)(z->zout - z->zout_start);
limit = old_limit = (int)(z->zout_end - z->zout_start);
while (cur + n > limit)
{
limit *= 2;
}
q = (sbyte *)CRuntime.realloc(z->zout_start, (ulong)limit);
if (q == null)
{
return(stbi__err("outofmem"));
}
z->zout_start = q;
z->zout = q + cur;
z->zout_end = q + limit;
return(1);
}
public static void *stbi__load_gif_main(stbi__context s, int **delays, int *x, int *y, int *z, int *comp,
int req_comp)
{
if (stbi__gif_test(s) != 0)
{
var layers = 0;
byte *u = null;
byte *_out_ = null;
byte *two_back = null;
var g = new stbi__gif();
var stride = 0;
var out_size = 0;
var delays_size = 0;
if (delays != null)
{
*delays = null;
}
do
{
u = stbi__gif_load_next(s, g, comp, req_comp, two_back);
if (u != null)
{
*x = g.w;
*y = g.h;
++layers;
stride = g.w * g.h * 4;
if (_out_ != null)
{
void *tmp = (byte *)CRuntime.realloc(_out_, (ulong)(layers * stride));
if (tmp == null)
{
return(stbi__load_gif_main_outofmem(g, _out_, delays));
}
_out_ = (byte *)tmp;
out_size = layers * stride;
if (delays != null)
{
var new_delays = (int *)CRuntime.realloc(*delays, (ulong)(sizeof(int) * layers));
if (new_delays == null)
{
return(stbi__load_gif_main_outofmem(g, _out_, delays));
}
*delays = new_delays;
delays_size = layers * sizeof(int);
}
}
else
{
_out_ = (byte *)stbi__malloc((ulong)(layers * stride));
if (_out_ == null)
{
return(stbi__load_gif_main_outofmem(g, _out_, delays));
}
out_size = layers * stride;
if (delays != null)
{
*delays = (int *)stbi__malloc((ulong)(layers * sizeof(int)));
if (*delays == null)
{
return(stbi__load_gif_main_outofmem(g, _out_, delays));
}
delays_size = layers * sizeof(int);
}
}
CRuntime.memcpy(_out_ + (layers - 1) * stride, u, (ulong)stride);
if (layers >= 2)
{
two_back = _out_ - 2 * stride;
}
if (delays != null)
{
(*delays)[layers - 1U] = g.delay;
}
}
} while (u != null);
CRuntime.free(g._out_);
CRuntime.free(g.history);
CRuntime.free(g.background);
if (req_comp != 0 && req_comp != 4)
{
_out_ = stbi__convert_format(_out_, 4, req_comp, (uint)(layers * g.w), (uint)g.h);
}
*z = layers;
return(_out_);
}
return((byte *)(ulong)(stbi__err("not GIF") != 0 ? 0 : 0));
}
){kind=link}
public static int stbi__parse_png_file(stbi__png z, int scan, int req_comp)
{
var palette = stackalloc byte[1024];
var pal_img_n = (byte)0;
var has_trans = (byte)0;
var tc = stackalloc byte[3];
tc[0] = 0;
var tc16 = stackalloc ushort[3];
var ioff = (uint)0;
var idata_limit = (uint)0;
uint i = 0;
var pal_len = (uint)0;
var first = 1;
var k = 0;
var interlace = 0;
var color = 0;
var is_iphone = 0;
var s = z.s;
z.expanded = null;
z.idata = null;
z._out_ = null;
if (stbi__check_png_header(s) == 0)
{
return(0);
}
if (scan == STBI__SCAN_type)
{
return(1);
}
for (; ;)
{
var c = stbi__get_chunk_header(s);
switch (c.type)
{
case ((uint)'C' << 24) + ((uint)'g' << 16) + ((uint)'B' << 8) + 'I':
is_iphone = 1;
stbi__skip(s, (int)c.length);
break;
case ((uint)'I' << 24) + ((uint)'H' << 16) + ((uint)'D' << 8) + 'R':
{
var comp = 0;
var filter = 0;
if (first == 0)
{
return(stbi__err("multiple IHDR"));
}
first = 0;
if (c.length != 13)
{
return(stbi__err("bad IHDR len"));
}
s.img_x = stbi__get32be(s);
if (s.img_x > 1 << 24)
{
return(stbi__err("too large"));
}
s.img_y = stbi__get32be(s);
if (s.img_y > 1 << 24)
{
return(stbi__err("too large"));
}
z.depth = stbi__get8(s);
if (z.depth != 1 && z.depth != 2 && z.depth != 4 && z.depth != 8 && z.depth != 16)
{
return(stbi__err("1/2/4/8/16-bit only"));
}
color = stbi__get8(s);
if (color > 6)
{
return(stbi__err("bad ctype"));
}
if (color == 3 && z.depth == 16)
{
return(stbi__err("bad ctype"));
}
if (color == 3)
{
pal_img_n = 3;
}
else if ((color & 1) != 0)
{
return(stbi__err("bad ctype"));
}
comp = stbi__get8(s);
if (comp != 0)
{
return(stbi__err("bad comp method"));
}
filter = stbi__get8(s);
if (filter != 0)
{
return(stbi__err("bad filter method"));
}
interlace = stbi__get8(s);
if (interlace > 1)
{
return(stbi__err("bad interlace method"));
}
if (s.img_x == 0 || s.img_y == 0)
{
return(stbi__err("0-pixel image"));
}
if (pal_img_n == 0)
{
s.img_n = ((color & 2) != 0 ? 3 : 1) + ((color & 4) != 0 ? 1 : 0);
if ((1 << 30) / s.img_x / s.img_n < s.img_y)
{
return(stbi__err("too large"));
}
if (scan == STBI__SCAN_header)
{
return(1);
}
}
else
{
s.img_n = 1;
if ((1 << 30) / s.img_x / 4 < s.img_y)
{
return(stbi__err("too large"));
}
}
break;
}
case ((uint)'P' << 24) + ((uint)'L' << 16) + ((uint)'T' << 8) + 'E':
{
if (first != 0)
{
return(stbi__err("first not IHDR"));
}
if (c.length > 256 * 3)
{
return(stbi__err("invalid PLTE"));
}
pal_len = c.length / 3;
if (pal_len * 3 != c.length)
{
return(stbi__err("invalid PLTE"));
}
for (i = (uint)0; i < pal_len; ++i)
{
palette[i * 4 + 0] = stbi__get8(s);
palette[i * 4 + 1] = stbi__get8(s);
palette[i * 4 + 2] = stbi__get8(s);
palette[i * 4 + 3] = 255;
}
break;
}
case ((uint)'t' << 24) + ((uint)'R' << 16) + ((uint)'N' << 8) + 'S':
{
if (first != 0)
{
return(stbi__err("first not IHDR"));
}
if (z.idata != null)
{
return(stbi__err("tRNS after IDAT"));
}
if (pal_img_n != 0)
{
if (scan == STBI__SCAN_header)
{
s.img_n = 4;
return(1);
}
if (pal_len == 0)
{
return(stbi__err("tRNS before PLTE"));
}
if (c.length > pal_len)
{
return(stbi__err("bad tRNS len"));
}
pal_img_n = 4;
for (i = (uint)0; i < c.length; ++i)
{
palette[i * 4 + 3] = stbi__get8(s);
}
}
else
{
if ((s.img_n & 1) == 0)
{
return(stbi__err("tRNS with alpha"));
}
if (c.length != (uint)s.img_n * 2)
{
return(stbi__err("bad tRNS len"));
}
has_trans = 1;
if (z.depth == 16)
{
for (k = 0; k < s.img_n; ++k)
{
tc16[k] = (ushort)stbi__get16be(s);
}
}
else
{
for (k = 0; k < s.img_n; ++k)
{
tc[k] = (byte)((byte)(stbi__get16be(s) & 255) * stbi__depth_scale_table[z.depth]);
}
}
}
break;
}
case ((uint)'I' << 24) + ((uint)'D' << 16) + ((uint)'A' << 8) + 'T':
{
if (first != 0)
{
return(stbi__err("first not IHDR"));
}
if (pal_img_n != 0 && pal_len == 0)
{
return(stbi__err("no PLTE"));
}
if (scan == STBI__SCAN_header)
{
s.img_n = pal_img_n;
return(1);
}
if ((int)(ioff + c.length) < (int)ioff)
{
return(0);
}
if (ioff + c.length > idata_limit)
{
var idata_limit_old = idata_limit;
byte *p;
if (idata_limit == 0)
{
idata_limit = c.length > 4096 ? c.length : 4096;
}
while (ioff + c.length > idata_limit)
{
idata_limit *= 2;
}
p = (byte *)CRuntime.realloc(z.idata, (ulong)idata_limit);
if (p == null)
{
return(stbi__err("outofmem"));
}
z.idata = p;
}
if (stbi__getn(s, z.idata + ioff, (int)c.length) == 0)
{
return(stbi__err("outofdata"));
}
ioff += c.length;
break;
}
case ((uint)'I' << 24) + ((uint)'E' << 16) + ((uint)'N' << 8) + 'D':
{
uint raw_len = 0;
uint bpl = 0;
if (first != 0)
{
return(stbi__err("first not IHDR"));
}
if (scan != STBI__SCAN_load)
{
return(1);
}
if (z.idata == null)
{
return(stbi__err("no IDAT"));
}
bpl = (uint)((s.img_x * z.depth + 7) / 8);
raw_len = (uint)(bpl * s.img_y * s.img_n + s.img_y);
z.expanded = (byte *)stbi_zlib_decode_malloc_guesssize_headerflag((sbyte *)z.idata, (int)ioff,
(int)raw_len, (int *)&raw_len, is_iphone != 0 ? 0 : 1);
if (z.expanded == null)
{
return(0);
}
CRuntime.free(z.idata);
z.idata = null;
if (req_comp == s.img_n + 1 && req_comp != 3 && pal_img_n == 0 || has_trans != 0)
{
s.img_out_n = s.img_n + 1;
}
else
{
s.img_out_n = s.img_n;
}
if (stbi__create_png_image(z, z.expanded, raw_len, s.img_out_n, z.depth, color, interlace) == 0)
{
return(0);
}
if (has_trans != 0)
{
if (z.depth == 16)
{
if (stbi__compute_transparency16(z, tc16, s.img_out_n) == 0)
{
return(0);
}
}
else
{
if (stbi__compute_transparency(z, tc, s.img_out_n) == 0)
{
return(0);
}
}
}
if (is_iphone != 0 && stbi__de_iphone_flag != 0 && s.img_out_n > 2)
{
stbi__de_iphone(z);
}
if (pal_img_n != 0)
{
s.img_n = pal_img_n;
s.img_out_n = pal_img_n;
if (req_comp >= 3)
{
s.img_out_n = req_comp;
}
if (stbi__expand_png_palette(z, palette, (int)pal_len, s.img_out_n) == 0)
{
return(0);
}
}
else if (has_trans != 0)
{
++s.img_n;
}
CRuntime.free(z.expanded);
z.expanded = null;
return(1);
}
default:
if (first != 0)
{
return(stbi__err("first not IHDR"));
}
if ((c.type & (1 << 29)) == 0)
{
var invalid_chunk = c.type + " PNG chunk not known";
return(stbi__err(invalid_chunk));
}
stbi__skip(s, (int)c.length);
break;
}
stbi__get32be(s);
}
}