irrlicht/source/Irrlicht/CImageLoaderBMP.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 "CImageLoaderBMP.h"
#include "IReadFile.h"
#include "SColor.h"
#include "CColorConverter.h"
#include "CImage.h"
#include "os.h"
#include "irrString.h"
namespace irr
{
namespace video
{
//! constructor
CImageLoaderBMP::CImageLoaderBMP()
{
#ifdef _DEBUG
setDebugName("CImageLoaderBMP");
#endif
}
//! returns true if the file maybe is able to be loaded by this class
//! based on the file extension (e.g. ".tga")
bool CImageLoaderBMP::isALoadableFileExtension(const io::path& filename) const
{
return core::hasFileExtension ( filename, "bmp" );
}
//! returns true if the file maybe is able to be loaded by this class
bool CImageLoaderBMP::isALoadableFileFormat(io::IReadFile* file) const
{
u16 headerID;
file->read(&headerID, sizeof(u16));
#ifdef __BIG_ENDIAN__
headerID = os::Byteswap::byteswap(headerID);
#endif
return headerID == 0x4d42;
}
void CImageLoaderBMP::decompress8BitRLE(u8*& bmpData, s32 size, s32 width, s32 height, s32 pitch) const
{
u8* p = bmpData;
u8* newBmp = new u8[(width+pitch)*height];
u8* d = newBmp;
u8* destEnd = newBmp + (width+pitch)*height;
s32 line = 0;
while (bmpData - p < size && d < destEnd)
{
if (*p == 0)
{
++p;
switch(*p)
{
case 0: // end of line
++p;
++line;
d = newBmp + (line*(width+pitch));
break;
case 1: // end of bmp
delete [] bmpData;
bmpData = newBmp;
return;
case 2:
++p; d +=(u8)*p; // delta
++p; d += ((u8)*p)*(width+pitch);
++p;
break;
default:
{
// absolute mode
s32 count = (u8)*p; ++p;
s32 readAdditional = ((2-(count%2))%2);
s32 i;
for (i=0; i<count; ++i)
{
*d = *p;
++p;
++d;
}
for (i=0; i<readAdditional; ++i)
++p;
}
}
}
else
{
s32 count = (u8)*p; ++p;
u8 color = *p; ++p;
for (s32 i=0; i<count; ++i)
{
*d = color;
++d;
}
}
}
delete [] bmpData;
bmpData = newBmp;
}
void CImageLoaderBMP::decompress4BitRLE(u8*& bmpData, s32 size, s32 width, s32 height, s32 pitch) const
{
s32 lineWidth = (width+1)/2+pitch;
u8* p = bmpData;
u8* newBmp = new u8[lineWidth*height];
u8* d = newBmp;
u8* destEnd = newBmp + lineWidth*height;
s32 line = 0;
s32 shift = 4;
while (bmpData - p < size && d < destEnd)
{
if (*p == 0)
{
++p;
switch(*p)
{
case 0: // end of line
++p;
++line;
d = newBmp + (line*lineWidth);
shift = 4;
break;
case 1: // end of bmp
delete [] bmpData;
bmpData = newBmp;
return;
case 2:
{
++p;
s32 x = (u8)*p; ++p;
s32 y = (u8)*p; ++p;
d += x/2 + y*lineWidth;
shift = x%2==0 ? 4 : 0;
}
break;
default:
{
// absolute mode
s32 count = (u8)*p; ++p;
s32 readAdditional = ((2-((count)%2))%2);
s32 readShift = 4;
s32 i;
for (i=0; i<count; ++i)
{
s32 color = (((u8)*p) >> readShift) & 0x0f;
readShift -= 4;
if (readShift < 0)
{
++*p;
readShift = 4;
}
u8 mask = 0x0f << shift;
*d = (*d & (~mask)) | ((color << shift) & mask);
shift -= 4;
if (shift < 0)
{
shift = 4;
++d;
}
}
for (i=0; i<readAdditional; ++i)
++p;
}
}
}
else
{
s32 count = (u8)*p; ++p;
s32 color1 = (u8)*p; color1 = color1 & 0x0f;
s32 color2 = (u8)*p; color2 = (color2 >> 4) & 0x0f;
++p;
for (s32 i=0; i<count; ++i)
{
u8 mask = 0x0f << shift;
u8 toSet = (shift==0 ? color1 : color2) << shift;
*d = (*d & (~mask)) | (toSet & mask);
shift -= 4;
if (shift < 0)
{
shift = 4;
++d;
}
}
}
}
delete [] bmpData;
bmpData = newBmp;
}
//! creates a surface from the file
IImage* CImageLoaderBMP::loadImage(io::IReadFile* file) const
{
SBMPHeader header;
file->read(&header, sizeof(header));
#ifdef __BIG_ENDIAN__
header.Id = os::Byteswap::byteswap(header.Id);
header.FileSize = os::Byteswap::byteswap(header.FileSize);
header.BitmapDataOffset = os::Byteswap::byteswap(header.BitmapDataOffset);
header.BitmapHeaderSize = os::Byteswap::byteswap(header.BitmapHeaderSize);
header.Width = os::Byteswap::byteswap(header.Width);
header.Height = os::Byteswap::byteswap(header.Height);
header.Planes = os::Byteswap::byteswap(header.Planes);
header.BPP = os::Byteswap::byteswap(header.BPP);
header.Compression = os::Byteswap::byteswap(header.Compression);
header.BitmapDataSize = os::Byteswap::byteswap(header.BitmapDataSize);
header.PixelPerMeterX = os::Byteswap::byteswap(header.PixelPerMeterX);
header.PixelPerMeterY = os::Byteswap::byteswap(header.PixelPerMeterY);
header.Colors = os::Byteswap::byteswap(header.Colors);
header.ImportantColors = os::Byteswap::byteswap(header.ImportantColors);
#endif
s32 pitch = 0;
//! return if the header is false
if (header.Id != 0x4d42)
return 0;
if (header.Compression > 2) // we'll only handle RLE-Compression
{
os::Printer::log("Compression mode not supported.", ELL_ERROR);
return 0;
}
if (header.BPP > 32 || !checkImageDimensions(header.Width, header.Height))
{
os::Printer::log("Rejecting BMP with unreasonable size or BPP.", ELL_ERROR);
return 0;
}
// adjust bitmap data size to dword boundary
header.BitmapDataSize += (4-(header.BitmapDataSize%4))%4;
// read palette
long pos = file->getPos();
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constexpr s32 paletteAllocSize = 256;
s32 paletteSize = (header.BitmapDataOffset - pos) / 4;
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paletteSize = core::clamp(paletteSize, 0, paletteAllocSize);
s32* paletteData = 0;
if (paletteSize)
{
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// always allocate an 8-bit palette to ensure enough space
paletteData = new s32[paletteAllocSize];
memset(paletteData, 0, paletteAllocSize * sizeof(s32));
file->read(paletteData, paletteSize * sizeof(s32));
#ifdef __BIG_ENDIAN__
for (s32 i=0; i<paletteSize; ++i)
paletteData[i] = os::Byteswap::byteswap(paletteData[i]);
#endif
}
// read image data
if (!header.BitmapDataSize)
{
// okay, lets guess the size
// some tools simply don't set it
header.BitmapDataSize = static_cast<u32>(file->getSize()) - header.BitmapDataOffset;
}
file->seek(header.BitmapDataOffset);
f32 t = (header.Width) * (header.BPP / 8.0f);
s32 widthInBytes = (s32)t;
t -= widthInBytes;
if (t!=0.0f)
++widthInBytes;
s32 lineData = widthInBytes + ((4-(widthInBytes%4)))%4;
pitch = lineData - widthInBytes;
u8* bmpData = new u8[header.BitmapDataSize];
file->read(bmpData, header.BitmapDataSize);
// decompress data if needed
switch(header.Compression)
{
case 1: // 8 bit rle
decompress8BitRLE(bmpData, header.BitmapDataSize, header.Width, header.Height, pitch);
break;
case 2: // 4 bit rle
decompress4BitRLE(bmpData, header.BitmapDataSize, header.Width, header.Height, pitch);
break;
}
// create surface
// no default constructor from packed area! ARM problem!
core::dimension2d<u32> dim;
dim.Width = header.Width;
dim.Height = header.Height;
IImage* image = 0;
switch(header.BPP)
{
case 1:
image = new CImage(ECF_A1R5G5B5, dim);
if (image)
CColorConverter::convert1BitTo16Bit(bmpData, (s16*)image->getData(), header.Width, header.Height, pitch, true);
break;
case 4:
image = new CImage(ECF_A1R5G5B5, dim);
if (image)
CColorConverter::convert4BitTo16Bit(bmpData, (s16*)image->getData(), header.Width, header.Height, paletteData, pitch, true);
break;
case 8:
image = new CImage(ECF_A1R5G5B5, dim);
if (image)
CColorConverter::convert8BitTo16Bit(bmpData, (s16*)image->getData(), header.Width, header.Height, paletteData, pitch, true);
break;
case 16:
image = new CImage(ECF_A1R5G5B5, dim);
if (image)
CColorConverter::convert16BitTo16Bit((s16*)bmpData, (s16*)image->getData(), header.Width, header.Height, pitch, true);
break;
case 24:
image = new CImage(ECF_R8G8B8, dim);
if (image)
CColorConverter::convert24BitTo24Bit(bmpData, (u8*)image->getData(), header.Width, header.Height, pitch, true, true);
break;
case 32: // thx to Reinhard Ostermeier
image = new CImage(ECF_A8R8G8B8, dim);
if (image)
CColorConverter::convert32BitTo32Bit((s32*)bmpData, (s32*)image->getData(), header.Width, header.Height, pitch, true);
break;
};
// clean up
delete [] paletteData;
delete [] bmpData;
return image;
}
//! creates a loader which is able to load windows bitmaps
IImageLoader* createImageLoaderBMP()
{
return new CImageLoaderBMP;
}
} // end namespace video
} // end namespace irr