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"
#ifdef _IRR_COMPILE_WITH_BMP_LOADER_
#include "IReadFile.h"
#include "SColor.h"
#include "CColorConverter.h"
#include "CImage.h"
#include "os.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;
}
// UB-safe overflow check
static inline bool doesOverflow(const void *base, size_t numElements, const void *end)
{
// TODO: uintptr_t (as in original patch from sfan5) would be nicer than size_t, use once we allow c++11
size_t baseI = reinterpret_cast<size_t>(base);
size_t endI = reinterpret_cast<size_t>(end);
return baseI > endI || numElements >= (endI - baseI);
}
// check whether &p[0] to &p[_off - 1] can be accessed
#define EXIT_P_OVERFLOW(_off) if (doesOverflow(p, _off, pEnd)) goto exit
// same for d
#define EXIT_D_OVERFLOW(_off) if (doesOverflow(d, _off, destEnd)) goto exit
void CImageLoaderBMP::decompress8BitRLE(u8*& bmpData, s32 size, s32 width, s32 height, s32 pitch) const
{
u8* p = bmpData;
const u8* pEnd = bmpData + size;
u8* newBmp = new u8[(width+pitch)*height];
u8* d = newBmp;
const u8* destEnd = newBmp + (width+pitch)*height;
s32 line = 0;
while (p < pEnd && d < destEnd)
{
if (*p == 0)
{
++p;
EXIT_P_OVERFLOW(1);
switch(*p)
{
case 0: // end of line
++p;
++line;
d = newBmp + (line*(width+pitch));
break;
case 1: // end of bmp
goto exit;
case 2:
++p;
EXIT_P_OVERFLOW(2);
d += (u8)*p; // delta
++p;
d += ((u8)*p)*(width+pitch);
++p;
break;
default:
{
// absolute mode
const s32 count = (u8)*p;
++p;
EXIT_P_OVERFLOW(count);
EXIT_D_OVERFLOW(count);
for (s32 i=0; i<count; ++i)
{
*d = *p;
++p;
++d;
}
const s32 readAdditional = ((2-(count%2))%2);
EXIT_P_OVERFLOW(readAdditional);
for (s32 i=0; i<readAdditional; ++i)
++p;
}
}
}
else
{
const s32 count = (u8)*p; ++p;
EXIT_P_OVERFLOW(1);
u8 color = *p; ++p;
EXIT_D_OVERFLOW(count);
for (s32 i=0; i<count; ++i)
{
*d = color;
++d;
}
}
}
exit:
delete [] bmpData;
bmpData = newBmp;
}
// how many new bytes will be touched given the current state of decompress4BitRLE
static inline u32 shiftedCount(s32 count, s32 shift)
{
IRR_DEBUG_BREAK_IF(count <= 0)
u32 ret = 0;
if ( shift == 0 ) // using up half of an old byte
{
--count;
}
ret += (count / 2) + (count % 2);
return ret;
}
// Ensure current row/line are inside width/height
// Didn't find any documentation how BMP's are supposed to handle this
// I think in general "good" bmp's are supposed to not go over line-ends
#define KEEP_ROW_LINE_INSIDE \
if ( row >= width ) \
{ \
line += row/width; \
row %= width; \
} \
if ( line >= height ) \
{ \
line = 0; /* bug anyway, this way more visible maybe */ \
}
void CImageLoaderBMP::decompress4BitRLE(u8*& bmpData, s32 size, s32 width, s32 height, s32 pitch) const
{
const s32 lineWidth = (width+1)/2+pitch;
u8* p = bmpData;
const u8* pEnd = bmpData + size;
u8* newBmp = new u8[lineWidth*height];
memset(newBmp, 0, lineWidth*height); // Extra cost, but otherwise we have to code pixel skipping stuff
const u8* destEnd = newBmp + lineWidth*height;
s32 line = 0;
s32 row = 0;
while (p < pEnd)
{
if (*p == 0)
{
++p;
EXIT_P_OVERFLOW(1);
switch(*p)
{
case 0: // end of line
++p;
++line;
row = 0;
break;
case 1: // end of bmp
goto exit;
case 2: // delta
{
++p;
EXIT_P_OVERFLOW(2);
s32 x = (u8)*p; ++p;
s32 y = (u8)*p; ++p;
row += x;
line += y;
}
break;
default:
{
// absolute mode
const u32 count = (u8)*p; ++p;
s32 readShift = 4;
KEEP_ROW_LINE_INSIDE;
s32 shift = row%2 == 0 ? 4 : 0;
u8* d = newBmp + (lineWidth*line + row/2);
EXIT_P_OVERFLOW(shiftedCount(count, readShift));
EXIT_D_OVERFLOW(shiftedCount(count, shift));
for (u32 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;
}
}
row += count;
// pixels always come in 2-byte packages with unused half-bytes filled with zeroes
const u32 modCount = (count%4);
const u32 readAdditional = modCount == 1 ? 2 : (modCount==0?0:1); // jump 2,1,1,0 for count 1,2,3,4
EXIT_P_OVERFLOW(readAdditional);
for (u32 i=0; i<readAdditional; ++i)
++p;
}
}
}
else // encoded mode
{
const s32 count = (u8)*p; // pixels to draw
++p;
EXIT_P_OVERFLOW(1);
s32 color1 = (u8)*p; color1 = color1 & 0x0f; // lo bit (2nd,4th,... pixel)
s32 color2 = (u8)*p; color2 = (color2 >> 4) & 0x0f; // hi bits (1st,3rd,... pixel)
++p;
KEEP_ROW_LINE_INSIDE;
s32 shift = row%2 == 0 ? 4 : 0;
u8* d = newBmp + (lineWidth*line + row/2);
EXIT_D_OVERFLOW(shiftedCount(count, shift));
for (s32 i=0; i<count; ++i)
{
u8 mask = 0x0f << shift;
u8 toSet = ((i%2==0) ? color2 : color1) << shift;
*d = (*d & (~mask)) | toSet;
shift -= 4;
if (shift < 0)
{
shift = 4;
++d;
}
}
row += count;
}
}
exit:
delete [] bmpData;
bmpData = newBmp;
}
#undef EXIT_P_OVERFLOW
#undef EXIT_D_OVERFLOW
#undef KEEP_ROW_LINE_INSIDE
//! 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
//! return if the header is false
bool topDown = false;
if (header.Id == 0x4d42) // BM = Windows header
{
// Sizes are signed integer with Windows header (unsigned with OS/2)
// Not sure if negative Width has any meaning, but negative height is for upside-down
header.Width = core::abs_((s32)header.Width);
if ( (s32)header.Height < 0 )
{
topDown = true;
header.Height = core::abs_((s32)header.Height);
}
}
else
{
os::Printer::log("BMP files with OS/2 Headers not supported.", ELL_ERROR);
return 0;
}
if (header.Compression > 2) // we'll only handle RLE-Compression
{
os::Printer::log("Compression mode not supported.", ELL_ERROR);
return 0;
}
// adjust bitmap data size to dword boundary
header.BitmapDataSize += (4-(header.BitmapDataSize%4))%4;
// read palette
long pos = file->getPos();
s32 paletteSize = (header.BitmapDataOffset - pos) / 4;
s32* paletteData = 0;
if (paletteSize)
{
paletteData = new s32[paletteSize];
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);
const s32 widthInBytes = core::ceil32(header.Width * (header.BPP / 8.0f));
const s32 lineSize = widthInBytes + ((4-(widthInBytes%4)))%4;
const s32 pitch = lineSize - 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);
header.BitmapDataSize = (header.Width + pitch) * header.Height;
break;
case 2: // 4 bit RLE
decompress4BitRLE(bmpData, header.BitmapDataSize, header.Width, header.Height, pitch);
header.BitmapDataSize = ((header.Width+1)/2 + pitch) * header.Height;
break;
}
if (header.BitmapDataSize < lineSize * header.Height)
{
os::Printer::log("Bitmap data is cut off.", ELL_ERROR);
delete [] paletteData;
delete [] bmpData;
return 0;
}
// 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;
if ( !IImage::checkDataSizeLimit( (size_t)header.Width*header.Height*header.BPP) )
{
os::Printer::log("Image dimensions too large for file", file->getFileName(), ELL_WARNING);
goto cleanup;
}
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
cleanup:
delete [] paletteData;
delete [] bmpData;
if ( image && topDown )
image->flip(true, false);
return image;
}
//! creates a loader which is able to load windows bitmaps
IImageLoader* createImageLoaderBMP()
{
return new CImageLoaderBMP;
}
} // end namespace video
} // end namespace irr
#endif