Files
UnrealEngineUWP/Engine/Source/Developer/ImageWrapper/Private/PngImageWrapper.cpp
Max Preussner 00f53f4c6b Fixed non-Windows builds
#CodeReview: richard.talbotwatkin

[CL 2696496 by Max Preussner in Main branch]
2015-09-17 21:36:26 -04:00

450 lines
12 KiB
C++

// Copyright 1998-2015 Epic Games, Inc. All Rights Reserved.
#include "ImageWrapperPrivatePCH.h"
#if WITH_UNREALPNG
// Disable warning "interaction between '_setjmp' and C++ object destruction is non-portable"
#if _MSC_VER
#pragma warning(push)
#pragma warning(disable:4611)
#endif
/** Only allow one thread to use libpng at a time (it's not thread safe) */
FCriticalSection GPNGSection;
/* Local helper classes
*****************************************************************************/
/**
* Guard that safely releases PNG reader resources.
*/
class PNGReadGuard
{
public:
PNGReadGuard( png_structp* InReadStruct, png_infop* InInfo )
: png_ptr(InReadStruct)
, info_ptr(InInfo)
, PNGRowPointers(NULL)
{
}
~PNGReadGuard()
{
if (PNGRowPointers != NULL)
{
png_free( *png_ptr, *PNGRowPointers );
}
png_destroy_read_struct( png_ptr, info_ptr, NULL );
}
void SetRowPointers( png_bytep** InRowPointers )
{
PNGRowPointers = InRowPointers;
}
private:
png_structp* png_ptr;
png_infop* info_ptr;
png_bytep** PNGRowPointers;
};
/**
* Guard that safely releases PNG Writer resources
*/
class PNGWriteGuard
{
public:
PNGWriteGuard( png_structp* InWriteStruct, png_infop* InInfo )
: PNGWriteStruct(InWriteStruct)
, info_ptr(InInfo)
, PNGRowPointers(NULL)
{
}
~PNGWriteGuard()
{
if (PNGRowPointers != NULL)
{
png_free( *PNGWriteStruct, *PNGRowPointers );
}
png_destroy_write_struct( PNGWriteStruct, info_ptr );
}
void SetRowPointers( png_bytep** InRowPointers )
{
PNGRowPointers = InRowPointers;
}
private:
png_structp* PNGWriteStruct;
png_infop* info_ptr;
png_bytep** PNGRowPointers;
};
/* FPngImageWrapper structors
*****************************************************************************/
FPngImageWrapper::FPngImageWrapper()
: FImageWrapperBase()
, ReadOffset( 0 )
, ColorType(0)
, Channels(0)
{ }
/* FImageWrapper interface
*****************************************************************************/
void FPngImageWrapper::Compress( int32 Quality )
{
if (!CompressedData.Num())
{
// thread safety
FScopeLock PNGLock(&GPNGSection);
check(RawData.Num());
check(Width > 0);
check(Height > 0);
// Reset to the beginning of file so we can use png_read_png(), which expects to start at the beginning.
ReadOffset = 0;
png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, this, FPngImageWrapper::user_error_fn, FPngImageWrapper::user_warning_fn );
check(png_ptr);
png_infop info_ptr = png_create_info_struct( png_ptr );
check(info_ptr);
PNGWriteGuard PNGGuard(&png_ptr, &info_ptr);
{
png_set_compression_level(png_ptr, Z_BEST_SPEED);
png_set_IHDR(png_ptr, info_ptr, Width, Height, RawBitDepth, (RawFormat == ERGBFormat::Gray) ? PNG_COLOR_TYPE_GRAY : PNG_COLOR_TYPE_RGBA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_set_write_fn(png_ptr, this, FPngImageWrapper::user_write_compressed, FPngImageWrapper::user_flush_data);
png_bytep* row_pointers = (png_bytep*) png_malloc( png_ptr, Height*sizeof(png_bytep) );
const uint32 PixelChannels = (RawFormat == ERGBFormat::Gray) ? 1 : 4;
const uint32 BytesPerPixel = (RawBitDepth * PixelChannels) / 8;
const uint32 BytesPerRow = BytesPerPixel * Width;
PNGGuard.SetRowPointers( &row_pointers );
for (int32 i = 0; i < Height; i++)
{
row_pointers[i]= &RawData[i * BytesPerRow];
}
png_set_rows(png_ptr, info_ptr, row_pointers);
uint32 Transform = (RawFormat == ERGBFormat::BGRA) ? PNG_TRANSFORM_BGR : PNG_TRANSFORM_IDENTITY;
// PNG files store 16-bit pixels in network byte order (big-endian, ie. most significant bits first).
#if PLATFORM_LITTLE_ENDIAN
// We're little endian so we need to swap
if (RawBitDepth == 16)
{
Transform |= PNG_TRANSFORM_SWAP_ENDIAN;
}
#endif
if (!setjmp(SetjmpBuffer))
{
png_write_png(png_ptr, info_ptr, Transform, NULL);
}
}
}
}
void FPngImageWrapper::Reset( )
{
FImageWrapperBase::Reset();
ReadOffset = 0;
ColorType = 0;
Channels = 0;
}
bool FPngImageWrapper::SetCompressed( const void* InCompressedData, int32 InCompressedSize )
{
bool bResult = FImageWrapperBase::SetCompressed( InCompressedData, InCompressedSize );
return bResult && LoadPNGHeader(); // Fetch the variables from the header info
}
void FPngImageWrapper::Uncompress( const ERGBFormat::Type InFormat, const int32 InBitDepth )
{
if( !RawData.Num() || InFormat != RawFormat || InBitDepth != RawBitDepth)
{
check( CompressedData.Num() );
UncompressPNGData( InFormat, InBitDepth );
}
}
void FPngImageWrapper::UncompressPNGData( const ERGBFormat::Type InFormat, const int32 InBitDepth )
{
// thread safety
FScopeLock PNGLock(&GPNGSection);
check( CompressedData.Num() );
check( Width > 0 );
check( Height > 0 );
// Note that PNGs on PC tend to be BGR
check( InFormat == ERGBFormat::BGRA || InFormat == ERGBFormat::RGBA || InFormat == ERGBFormat::Gray ) // Other formats unsupported at present
check( InBitDepth == 8 || InBitDepth == 16 ) // Other formats unsupported at present
// Reset to the beginning of file so we can use png_read_png(), which expects to start at the beginning.
ReadOffset = 0;
png_structp png_ptr = png_create_read_struct_2( PNG_LIBPNG_VER_STRING, this, FPngImageWrapper::user_error_fn, FPngImageWrapper::user_warning_fn, NULL, FPngImageWrapper::user_malloc, FPngImageWrapper::user_free);
check( png_ptr );
png_infop info_ptr = png_create_info_struct( png_ptr );
check( info_ptr );
PNGReadGuard PNGGuard( &png_ptr, &info_ptr );
{
if (ColorType == PNG_COLOR_TYPE_PALETTE)
{
png_set_palette_to_rgb(png_ptr);
}
if ((ColorType & PNG_COLOR_MASK_COLOR) == 0 && BitDepth < 8)
{
png_set_expand_gray_1_2_4_to_8(png_ptr);
}
// Insert alpha channel with full opacity for RGB images without alpha
if ((ColorType & PNG_COLOR_MASK_ALPHA) == 0 && (InFormat == ERGBFormat::BGRA || InFormat == ERGBFormat::RGBA))
{
// png images don't set PNG_COLOR_MASK_ALPHA if they have alpha from a tRNS chunk, but png_set_add_alpha seems to be safe regardless
if ((ColorType & PNG_COLOR_MASK_COLOR) == 0)
{
png_set_tRNS_to_alpha(png_ptr);
}
else if (ColorType == PNG_COLOR_TYPE_PALETTE)
{
png_set_tRNS_to_alpha(png_ptr);
}
if (InBitDepth == 8)
{
png_set_add_alpha(png_ptr, 0xff , PNG_FILLER_AFTER);
}
else if (InBitDepth == 16)
{
png_set_add_alpha(png_ptr, 0xffff , PNG_FILLER_AFTER);
}
}
// Calculate Pixel Depth
const uint32 PixelChannels = (InFormat == ERGBFormat::Gray) ? 1 : 4;
const uint32 BytesPerPixel = (InBitDepth * PixelChannels) / 8;
const uint32 BytesPerRow = BytesPerPixel * Width;
RawData.Empty(Height * BytesPerRow);
RawData.AddUninitialized(Height * BytesPerRow);
png_set_read_fn( png_ptr, this, FPngImageWrapper::user_read_compressed );
png_bytep* row_pointers = (png_bytep*) png_malloc( png_ptr, Height*sizeof(png_bytep) );
PNGGuard.SetRowPointers(&row_pointers);
for (int32 i = 0; i < Height; i++)
{
row_pointers[i]= &RawData[i * BytesPerRow];
}
png_set_rows(png_ptr, info_ptr, row_pointers);
uint32 Transform = (InFormat == ERGBFormat::BGRA) ? PNG_TRANSFORM_BGR : PNG_TRANSFORM_IDENTITY;
// PNG files store 16-bit pixels in network byte order (big-endian, ie. most significant bits first).
#if PLATFORM_LITTLE_ENDIAN
// We're little endian so we need to swap
if (BitDepth == 16)
{
Transform |= PNG_TRANSFORM_SWAP_ENDIAN;
}
#endif
// Convert grayscale png to RGB if requested
if ((ColorType & PNG_COLOR_MASK_COLOR) == 0 &&
(InFormat == ERGBFormat::RGBA || InFormat == ERGBFormat::BGRA))
{
Transform |= PNG_TRANSFORM_GRAY_TO_RGB;
}
// Convert RGB png to grayscale if requested
if ((ColorType & PNG_COLOR_MASK_COLOR) != 0 && InFormat == ERGBFormat::Gray)
{
png_set_rgb_to_gray_fixed(png_ptr, 2 /* warn if image is in color */, -1, -1);
}
// Strip alpha channel if requested output is grayscale
if (InFormat == ERGBFormat::Gray)
{
// this is not necessarily the best option, instead perhaps:
// png_color background = {0,0,0};
// png_set_background(png_ptr, &background, PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
Transform |= PNG_TRANSFORM_STRIP_ALPHA;
}
// Reduce 16-bit to 8-bit if requested
if (BitDepth == 16 && InBitDepth == 8)
{
#if PNG_LIBPNG_VER >= 10504
check(0); // Needs testing
Transform |= PNG_TRANSFORM_SCALE_16;
#else
Transform |= PNG_TRANSFORM_STRIP_16;
#endif
}
// Increase 8-bit to 16-bit if requested
if (BitDepth <= 8 && InBitDepth == 16)
{
#if PNG_LIBPNG_VER >= 10504
check(0); // Needs testing
Transform |= PNG_TRANSFORM_EXPAND_16;
#else
// Expanding 8-bit images to 16-bit via transform needs a libpng update
check(0);
#endif
}
if (!setjmp(SetjmpBuffer))
{
png_read_png(png_ptr, info_ptr, Transform, NULL);
}
}
RawFormat = InFormat;
RawBitDepth = InBitDepth;
}
/* FPngImageWrapper implementation
*****************************************************************************/
bool FPngImageWrapper::IsPNG() const
{
check( CompressedData.Num() );
const int32 PNGSigSize = sizeof(png_size_t);
if (CompressedData.Num() > PNGSigSize)
{
png_size_t PNGSignature = *reinterpret_cast<const png_size_t*>(CompressedData.GetData());
return (0 == png_sig_cmp(reinterpret_cast<png_bytep>(&PNGSignature), 0, PNGSigSize));
}
return false;
}
bool FPngImageWrapper::LoadPNGHeader()
{
check(CompressedData.Num());
// Test whether the data this PNGLoader is pointing at is a PNG or not.
if (IsPNG())
{
// thread safety
FScopeLock PNGLock(&GPNGSection);
png_structp png_ptr = png_create_read_struct_2( PNG_LIBPNG_VER_STRING, this, FPngImageWrapper::user_error_fn, FPngImageWrapper::user_warning_fn, NULL, FPngImageWrapper::user_malloc, FPngImageWrapper::user_free );
check(png_ptr);
png_infop info_ptr = png_create_info_struct( png_ptr );
check(info_ptr);
PNGReadGuard PNGGuard(&png_ptr, &info_ptr);
{
png_set_read_fn(png_ptr, this, FPngImageWrapper::user_read_compressed);
png_read_info(png_ptr, info_ptr);
Width = info_ptr->width;
Height = info_ptr->height;
ColorType = info_ptr->color_type;
BitDepth = info_ptr->bit_depth;
Channels = info_ptr->channels;
Format = (ColorType & PNG_COLOR_MASK_COLOR) ? ERGBFormat::RGBA : ERGBFormat::Gray;
}
return true;
}
return false;
}
/* FPngImageWrapper static implementation
*****************************************************************************/
void FPngImageWrapper::user_read_compressed( png_structp png_ptr, png_bytep data, png_size_t length )
{
FPngImageWrapper* ctx = (FPngImageWrapper*) png_get_io_ptr(png_ptr);
check(ctx->ReadOffset + length <= (uint32)ctx->CompressedData.Num());
FMemory::Memcpy(data, &ctx->CompressedData[ctx->ReadOffset], length);
ctx->ReadOffset += length;
}
void FPngImageWrapper::user_write_compressed( png_structp png_ptr, png_bytep data, png_size_t length )
{
FPngImageWrapper* ctx = (FPngImageWrapper*) png_get_io_ptr(png_ptr);
int32 Offset = ctx->CompressedData.AddUninitialized( length);
FMemory::Memcpy(&ctx->CompressedData[Offset], data, length);
}
void FPngImageWrapper::user_flush_data( png_structp png_ptr )
{
}
void FPngImageWrapper::user_error_fn( png_structp png_ptr, png_const_charp error_msg )
{
FPngImageWrapper* ctx = (FPngImageWrapper*)png_get_io_ptr(png_ptr);
{
FString ErrorMsg = ANSI_TO_TCHAR(error_msg);
ctx->SetError(*ErrorMsg);
UE_LOG(LogImageWrapper, Error, TEXT("PNG Error: %s"), *ErrorMsg);
}
// Ensure that FString is destructed prior to executing the longjmp
longjmp(ctx->SetjmpBuffer, 1);
}
void FPngImageWrapper::user_warning_fn( png_structp png_ptr, png_const_charp warning_msg )
{
UE_LOG(LogImageWrapper, Warning, TEXT("PNG Warning: %s"), ANSI_TO_TCHAR(warning_msg));
}
void* FPngImageWrapper::user_malloc( png_structp /*png_ptr*/, png_size_t size)
{
check(size > 0);
return FMemory::Malloc(size);
}
void FPngImageWrapper::user_free(png_structp /*png_ptr*/, png_voidp struct_ptr )
{
check(struct_ptr);
FMemory::Free(struct_ptr);
}
// Renable warning "interaction between '_setjmp' and C++ object destruction is non-portable"
#if _MSC_VER
#pragma warning(pop)
#endif
#endif //WITH_UNREALPNG