RADRT_API bool RADRT_CALL Decode(const void *buff, AddrSize buffLength, Image &out)
{
RAD_ASSERT(buff&&buffLength);
RAD_ASSERT(buffLength <= std::numeric_limits<stream::SPos>::max());
out.Free();
stream::MemInputBuffer ib(buff, (stream::SPos)buffLength);
stream::InputStream is(ib);
{
char sig[SigSize];
if (is.Read(sig, SigSize, 0) != SigSize)
return false;
// NOTE: png_sig_cmp() returns 0 if the sig matches the PNG sig.
if (png_sig_cmp((png_bytep)sig, 0, SigSize))
return false;
}
png_structp png;
png_infop info;
png = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, 0, PNGErrorHandler, PNGWarningHandler, 0, PNGMalloc, PNGFree);
if (!png)
return false;
info = png_create_info_struct(png);
if (!info)
{
png_destroy_read_struct(&png, 0, 0);
return false;
}
png_set_read_fn(png, &is, PNGRead);
png_set_sig_bytes(png, SigSize);
try
{
png_uint_32 w, h;
int bd, color, interlace;
png_read_info(png, info);
png_get_IHDR(png, info, &w, &h, &bd, &color, &interlace, 0, 0);
if (!out.AllocateFrames(1)||!out.AllocateMipmaps(0, 1))
{
png_destroy_read_struct(&png, &info, 0);
return false;
}
Mipmap &m = out.frames[0].mipmaps[0];
out.format = Format(png, info, bd, color);
if (out.format == InvalidFormat)
{
out.Free();
png_destroy_read_struct(&png, &info, 0);
return false;
}
out.bpp = FormatBPP(out.format);
if (!out.AllocateMipmap(0, 0, w, h, w * out.bpp, w * h * out.bpp))
{
out.Free();
png_destroy_read_struct(&png, &info, 0);
return false;
}
png_set_strip_16(png);
if (color == PNG_COLOR_TYPE_PALETTE)
{
png_set_palette_to_rgb(png);
}
if (color == PNG_COLOR_TYPE_GRAY && bd < 8)
{
png_set_expand_gray_1_2_4_to_8(png);
}
if (png_get_valid(png, info, PNG_INFO_tRNS))
{
png_set_tRNS_to_alpha(png);
}
png_set_swap(png);
int passes = png_set_interlace_handling(png);
png_bytep dstRow = 0;
png_bytep imgRow = 0;
png_uint_32 stride = (png_uint_32)png_get_rowbytes(png, info);
RAD_ASSERT(stride >= m.stride);
if (stride != m.stride)
{
dstRow = (png_bytep)safe_zone_malloc(ZImageCodec, stride, 0);
}
for (int pass = 0; pass < passes; ++pass)
{
if (stride == m.stride)
{
dstRow = (png_bytep)m.data; // reset.
}
imgRow = (png_bytep)m.data;
for (png_uint_32 y = 0; y < h; ++y)
{
if (pass > 0 && stride != m.stride)
{
RAD_ASSERT(imgRow != dstRow);
// interlaced image, copy the result of the last pass.
memcpy(dstRow, imgRow, m.stride);
}
png_read_rows(png, &dstRow, 0, 1);
if (stride != m.stride)
{
// imgRow/dstRow are correct, we are copying from dstRow to imgRow.
memcpy(imgRow, dstRow, m.stride);
}
else
{
dstRow += m.stride;
}
imgRow += m.stride;
}
}
if (stride != m.stride)
{
RAD_ASSERT(dstRow);
zone_free(dstRow);
}
png_read_end(png, info);
}
catch (PNGException&)
{
out.Free();
png_destroy_read_struct(&png, &info, 0);
return false;
}
png_destroy_read_struct(&png, &info, 0);
return true;
}
RADRT_API bool RADRT_CALL DecodeHeader(const void *buff, AddrSize buffLength, Image &out)
{
RAD_ASSERT(buff&&buffLength);
RAD_ASSERT(buffLength <= std::numeric_limits<stream::SPos>::max());
out.Free();
stream::MemInputBuffer ib(buff, (stream::SPos)buffLength);
stream::InputStream is(ib);
{
char sig[SigSize];
if (is.Read(sig, SigSize, 0) != SigSize)
return false;
// NOTE: png_sig_cmp() returns 0 if the sig matches the PNG sig.
if (png_sig_cmp((png_bytep)sig, 0, SigSize))
return false;
}
png_structp png;
png_infop info;
png = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, 0, PNGErrorHandler, PNGWarningHandler, 0, PNGMalloc, PNGFree);
if (!png) return false;
info = png_create_info_struct(png);
if (!info)
{
png_destroy_read_struct(&png, 0, 0);
return false;
}
png_set_read_fn(png, &is, PNGRead);
png_set_sig_bytes(png, SigSize);
try
{
png_uint_32 w, h;
int bd, color, interlace;
png_read_info(png, info);
png_get_IHDR(png, info, &w, &h, &bd, &color, &interlace, 0, 0);
if (!out.AllocateFrames(1)||!out.AllocateMipmaps(0, 1))
return false;
Mipmap &m = out.frames[0].mipmaps[0];
out.format = Format(png, info, bd, color);
if (out.format == InvalidFormat)
{
out.Free();
png_destroy_read_struct(&png, &info, 0);
return false;
}
out.bpp = FormatBPP(out.format);
m.width = w;
m.height = h;
m.stride = w * out.bpp;
}
catch (PNGException&)
{
out.Free();
png_destroy_read_struct(&png, &info, 0);
return false;
}
png_destroy_read_struct(&png, &info, 0);
return true;
}
