public static byte[] stbi_zlib_decode_malloc_guesssize_headerflag(byte[] buffer, int len, int initial_size,
out int outlen, int parse_header)
{
outlen = 0;
var a = new ZLib();
var p = new byte[initial_size];
a.zbuffer = new FakePtr <byte>(buffer);
a.zbuffer_end = new FakePtr <byte>(buffer, +len);
if (a.stbi__do_zlib(p, initial_size, 1, parse_header) != 0)
{
outlen = a.zout.Offset;
return(a.zout_start);
}
return(null);
}
private int stbi__parse_png_file(int scan, int req_comp)
{
var palette = new byte[1024];
var pal_img_n = (byte)0;
var has_trans = (byte)0;
var tc = new byte[3];
tc[0] = 0;
var tc16 = new ushort[3];
var ioff = 0;
var idata_limit = 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;
expanded = null;
idata = null;
_out_ = null;
if (!stbi__check_png_header(Stream))
{
return(0);
}
if (scan == STBI__SCAN_type)
{
return(1);
}
for (; ;)
{
var c = stbi__get_chunk_header();
switch (c.type)
{
case ((uint)'C' << 24) + ((uint)'g' << 16) + ((uint)'B' << 8) + 'I':
is_iphone = 1;
stbi__skip((int)c.length);
break;
case ((uint)'I' << 24) + ((uint)'H' << 16) + ((uint)'D' << 8) + 'R':
{
var comp = 0;
var filter = 0;
if (first == 0)
{
stbi__err("multiple IHDR");
}
first = 0;
if (c.length != 13)
{
stbi__err("bad IHDR len");
}
img_x = (int)stbi__get32be();
if (img_x > 1 << 24)
{
stbi__err("too large");
}
img_y = (int)stbi__get32be();
if (img_y > 1 << 24)
{
stbi__err("too large");
}
depth = stbi__get8();
if (depth != 1 && depth != 2 && depth != 4 && depth != 8 && depth != 16)
{
stbi__err("1/2/4/8/16-bit only");
}
color = stbi__get8();
if (color > 6)
{
stbi__err("bad ctype");
}
if (color == 3 && depth == 16)
{
stbi__err("bad ctype");
}
if (color == 3)
{
pal_img_n = 3;
}
else if ((color & 1) != 0)
{
stbi__err("bad ctype");
}
comp = stbi__get8();
if (comp != 0)
{
stbi__err("bad comp method");
}
filter = stbi__get8();
if (filter != 0)
{
stbi__err("bad filter method");
}
interlace = stbi__get8();
if (interlace > 1)
{
stbi__err("bad interlace method");
}
if (img_x == 0 || img_y == 0)
{
stbi__err("0-pixel image");
}
if (pal_img_n == 0)
{
img_n = ((color & 2) != 0 ? 3 : 1) + ((color & 4) != 0 ? 1 : 0);
if ((1 << 30) / img_x / img_n < img_y)
{
stbi__err("too large");
}
if (scan == STBI__SCAN_header)
{
return(1);
}
}
else
{
img_n = 1;
if ((1 << 30) / img_x / 4 < img_y)
{
stbi__err("too large");
}
}
break;
}
case ((uint)'P' << 24) + ((uint)'L' << 16) + ((uint)'T' << 8) + 'E':
{
if (first != 0)
{
stbi__err("first not IHDR");
}
if (c.length > 256 * 3)
{
stbi__err("invalid PLTE");
}
pal_len = c.length / 3;
if (pal_len * 3 != c.length)
{
stbi__err("invalid PLTE");
}
for (i = (uint)0; i < pal_len; ++i)
{
palette[i * 4 + 0] = stbi__get8();
palette[i * 4 + 1] = stbi__get8();
palette[i * 4 + 2] = stbi__get8();
palette[i * 4 + 3] = 255;
}
break;
}
case ((uint)'t' << 24) + ((uint)'R' << 16) + ((uint)'N' << 8) + 'S':
{
if (first != 0)
{
stbi__err("first not IHDR");
}
if (idata != null)
{
stbi__err("tRNS after IDAT");
}
if (pal_img_n != 0)
{
if (scan == STBI__SCAN_header)
{
img_n = 4;
return(1);
}
if (pal_len == 0)
{
stbi__err("tRNS before PLTE");
}
if (c.length > pal_len)
{
stbi__err("bad tRNS len");
}
pal_img_n = 4;
for (i = (uint)0; i < c.length; ++i)
{
palette[i * 4 + 3] = stbi__get8();
}
}
else
{
if ((img_n & 1) == 0)
{
stbi__err("tRNS with alpha");
}
if (c.length != (uint)img_n * 2)
{
stbi__err("bad tRNS len");
}
has_trans = 1;
if (depth == 16)
{
for (k = 0; k < img_n; ++k)
{
tc16[k] = (ushort)stbi__get16be();
}
}
else
{
for (k = 0; k < img_n; ++k)
{
tc[k] = (byte)((byte)(stbi__get16be() & 255) * stbi__depth_scale_table[depth]);
}
}
}
break;
}
case ((uint)'I' << 24) + ((uint)'D' << 16) + ((uint)'A' << 8) + 'T':
{
if (first != 0)
{
stbi__err("first not IHDR");
}
if (pal_img_n != 0 && pal_len == 0)
{
stbi__err("no PLTE");
}
if (scan == STBI__SCAN_header)
{
img_n = pal_img_n;
return(1);
}
if ((int)(ioff + c.length) < ioff)
{
return(0);
}
if (ioff + c.length > idata_limit)
{
var idata_limit_old = (uint)idata_limit;
if (idata_limit == 0)
{
idata_limit = (int)(c.length > 4096 ? c.length : 4096);
}
while (ioff + c.length > idata_limit)
{
idata_limit *= 2;
}
Array.Resize(ref idata, idata_limit);
}
if (!stbi__getn(idata, ioff, (int)c.length))
{
stbi__err("outofdata");
}
ioff += (int)c.length;
break;
}
case ((uint)'I' << 24) + ((uint)'E' << 16) + ((uint)'N' << 8) + 'D':
{
var raw_len = 0;
uint bpl = 0;
if (first != 0)
{
stbi__err("first not IHDR");
}
if (scan != STBI__SCAN_load)
{
return(1);
}
if (idata == null)
{
stbi__err("no IDAT");
}
bpl = (uint)((img_x * depth + 7) / 8);
raw_len = (int)(bpl * img_y * img_n + img_y);
expanded = ZLib.stbi_zlib_decode_malloc_guesssize_headerflag(idata, ioff, raw_len, out raw_len,
is_iphone != 0 ? 0 : 1);
if (expanded == null)
{
return(0);
}
idata = null;
if (req_comp == img_n + 1 && req_comp != 3 && pal_img_n == 0 || has_trans != 0)
{
img_out_n = img_n + 1;
}
else
{
img_out_n = img_n;
}
if (stbi__create_png_image(new FakePtr <byte>(expanded), (uint)raw_len, img_out_n, depth, color,
interlace) == 0)
{
return(0);
}
if (has_trans != 0)
{
if (depth == 16)
{
if (stbi__compute_transparency16(tc16, img_out_n) == 0)
{
return(0);
}
}
else
{
if (stbi__compute_transparency(tc, img_out_n) == 0)
{
return(0);
}
}
}
if (is_iphone != 0 && stbi__de_iphone_flag != 0 && img_out_n > 2)
{
stbi__de_iphone();
}
if (pal_img_n != 0)
{
img_n = pal_img_n;
img_out_n = pal_img_n;
if (req_comp >= 3)
{
img_out_n = req_comp;
}
if (stbi__expand_png_palette(palette, (int)pal_len, img_out_n) == 0)
{
return(0);
}
}
else if (has_trans != 0)
{
++img_n;
}
expanded = null;
return(1);
}
default:
if (first != 0)
{
stbi__err("first not IHDR");
}
if ((c.type & (1 << 29)) == 0)
{
var invalid_chunk = c.type + " PNG chunk not known";
stbi__err(invalid_chunk);
}
stbi__skip((int)c.length);
break;
}
stbi__get32be();
}
}