irrlicht/source/Irrlicht/CImageLoaderTGA.cpp

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// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#include "CImageLoaderTGA.h"
#include "IReadFile.h"
#include "os.h"
#include "CColorConverter.h"
#include "CImage.h"
#include "irrString.h"
namespace irr
{
namespace video
{
//! returns true if the file maybe is able to be loaded by this class
//! based on the file extension (e.g. ".tga")
bool CImageLoaderTGA::isALoadableFileExtension(const io::path& filename) const
{
return core::hasFileExtension ( filename, "tga" );
}
//! loads a compressed tga.
u8 *CImageLoaderTGA::loadCompressedImage(io::IReadFile *file, const STGAHeader& header) const
{
// This was written and sent in by Jon Pry, thank you very much!
// I only changed the formatting a little bit.
s32 bytesPerPixel = header.PixelDepth/8;
s32 imageSize = header.ImageHeight * header.ImageWidth * bytesPerPixel;
u8* data = new u8[imageSize];
s32 currentByte = 0;
while(currentByte < imageSize)
{
u8 chunkheader = 0;
file->read(&chunkheader, sizeof(u8)); // Read The Chunk's Header
if(chunkheader < 128) // If The Chunk Is A 'RAW' Chunk
{
chunkheader++; // Add 1 To The Value To Get Total Number Of Raw Pixels
file->read(&data[currentByte], bytesPerPixel * chunkheader);
currentByte += bytesPerPixel * chunkheader;
}
else
{
// thnx to neojzs for some fixes with this code
// If It's An RLE Header
chunkheader -= 127; // Subtract 127 To Get Rid Of The ID Bit
s32 dataOffset = currentByte;
file->read(&data[dataOffset], bytesPerPixel);
currentByte += bytesPerPixel;
for(s32 counter = 1; counter < chunkheader; counter++)
{
for(s32 elementCounter=0; elementCounter < bytesPerPixel; elementCounter++)
data[currentByte + elementCounter] = data[dataOffset + elementCounter];
currentByte += bytesPerPixel;
}
}
}
return data;
}
//! returns true if the file maybe is able to be loaded by this class
bool CImageLoaderTGA::isALoadableFileFormat(io::IReadFile* file) const
{
if (!file)
return false;
STGAFooter footer;
memset(&footer, 0, sizeof(STGAFooter));
file->seek(file->getSize()-sizeof(STGAFooter));
file->read(&footer, sizeof(STGAFooter));
return (!strcmp(footer.Signature,"TRUEVISION-XFILE.")); // very old tgas are refused.
}
//! creates a surface from the file
IImage* CImageLoaderTGA::loadImage(io::IReadFile* file) const
{
STGAHeader header;
u32 *palette = 0;
file->read(&header, sizeof(STGAHeader));
#ifdef __BIG_ENDIAN__
header.ColorMapLength = os::Byteswap::byteswap(header.ColorMapLength);
header.ImageWidth = os::Byteswap::byteswap(header.ImageWidth);
header.ImageHeight = os::Byteswap::byteswap(header.ImageHeight);
#endif
if (!checkImageDimensions(header.ImageWidth, header.ImageHeight))
{
os::Printer::log("Image dimensions too large in file", file->getFileName(), ELL_ERROR);
return 0;
}
// skip image identification field
if (header.IdLength)
file->seek(header.IdLength, true);
if (header.ColorMapType)
{
// create 32 bit palette
palette = new u32[ header.ColorMapLength];
// read color map
u8 * colorMap = new u8[header.ColorMapEntrySize/8 * header.ColorMapLength];
file->read(colorMap,header.ColorMapEntrySize/8 * header.ColorMapLength);
// convert to 32-bit palette
switch ( header.ColorMapEntrySize )
{
case 16:
CColorConverter::convert_A1R5G5B5toA8R8G8B8(colorMap, header.ColorMapLength, palette);
break;
case 24:
CColorConverter::convert_B8G8R8toA8R8G8B8(colorMap, header.ColorMapLength, palette);
break;
case 32:
CColorConverter::convert_B8G8R8A8toA8R8G8B8(colorMap, header.ColorMapLength, palette);
break;
}
delete [] colorMap;
}
// read image
u8* data = 0;
if ( header.ImageType == 1 || // Uncompressed, color-mapped images.
header.ImageType == 2 || // Uncompressed, RGB images
header.ImageType == 3 // Uncompressed, black and white images
)
{
const s32 imageSize = header.ImageHeight * header.ImageWidth * header.PixelDepth/8;
data = new u8[imageSize];
file->read(data, imageSize);
}
else
if(header.ImageType == 10)
{
// Runlength encoded RGB images
data = loadCompressedImage(file, header);
}
else
{
os::Printer::log("Unsupported TGA file type", file->getFileName(), ELL_ERROR);
delete [] palette;
return 0;
}
IImage* image = 0;
switch(header.PixelDepth)
{
case 8:
{
if (header.ImageType==3) // grey image
{
image = new CImage(ECF_R8G8B8,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert8BitTo24Bit((u8*)data,
(u8*)image->getData(),
header.ImageWidth,header.ImageHeight,
0, 0, (header.ImageDescriptor&0x20)==0);
}
else
{
image = new CImage(ECF_A1R5G5B5,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert8BitTo16Bit((u8*)data,
(s16*)image->getData(),
header.ImageWidth,header.ImageHeight,
(s32*) palette, 0,
(header.ImageDescriptor&0x20)==0);
}
}
break;
case 16:
image = new CImage(ECF_A1R5G5B5,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert16BitTo16Bit((s16*)data,
(s16*)image->getData(), header.ImageWidth, header.ImageHeight, 0, (header.ImageDescriptor&0x20)==0);
break;
case 24:
image = new CImage(ECF_R8G8B8,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert24BitTo24Bit(
(u8*)data, (u8*)image->getData(), header.ImageWidth, header.ImageHeight, 0, (header.ImageDescriptor&0x20)==0, true);
break;
case 32:
image = new CImage(ECF_A8R8G8B8,
core::dimension2d<u32>(header.ImageWidth, header.ImageHeight));
if (image)
CColorConverter::convert32BitTo32Bit((s32*)data,
(s32*)image->getData(), header.ImageWidth, header.ImageHeight, 0, (header.ImageDescriptor&0x20)==0);
break;
default:
os::Printer::log("Unsupported TGA format", file->getFileName(), ELL_ERROR);
break;
}
delete [] data;
delete [] palette;
return image;
}
//! creates a loader which is able to load tgas
IImageLoader* createImageLoaderTGA()
{
return new CImageLoaderTGA();
}
} // end namespace video
} // end namespace irr