imagereader.cpp

这个是symbian下的一个蛮庞大的3D游戏源代码！对于学习3D开发的人有很大的帮助！

#include <img/ImageReader.h>
#include <io/InputStream.h>
#include <string.h>
#include <stdint.h>
#include <assert.h>
#include <ctype.h>
#include <config.h>


using namespace io;
using namespace gr;
using namespace lang;


#define OPTIMIZE


namespace img
{


ImageReader::ImageReader( InputStream* in, FileFormat filefmt ) :
	m_in( in ),
	m_width( 0 ),
	m_height( 0 ),
	m_bitsPerPixel( 0 ),
	m_pitch( 0 ),
	m_surfaces( 0 ),
	m_scanlinebuffer(),
	m_fmt(),
	m_palfmt(),
	m_filefmt( filefmt ),
	m_bottomUp( false )
{
	m_scanlinebuffer.resize(1024);
	switch ( m_filefmt )
	{
	//case FILEFORMAT_BMP:	readHeader_bmp(); break;
	case FILEFORMAT_TGA:	readHeader_tga(); break;
	//case FILEFORMAT_JPG:	readHeader_jpg(); break;
	default:				INTERNAL_ERROR(); // throwError( IOException( Format("Unsupported image file format while reading {0}", m_in->toString()) ) );
	}
}

ImageReader::~ImageReader()
{
}
	
bool ImageReader::nextSurface()
{
	return m_surfaces-- > 0;
}

void ImageReader::readSurface( void* bits, int pitch, int w, int h, SurfaceFormat fmt,
	const void* pal, SurfaceFormat palfmt )
{
	assert( w == surfaceWidth() );
	assert( h == surfaceHeight() );

	switch ( m_filefmt )
	{
	//case FILEFORMAT_BMP:	readScanlines( bits, pitch, w, h, fmt, pal, palfmt ); break;
	case FILEFORMAT_TGA:	readScanlines( bits, pitch, w, h, fmt, pal, palfmt ); break;
	//case FILEFORMAT_JPG:	readSurface_jpg( bits, pitch, w, h, fmt, pal, palfmt ); break;
	default:				INTERNAL_ERROR(); // throwError( IOException( Format("Unsupported image file format while reading {0}", m_in->toString()) ) );
	}
}

int ImageReader::surfaces() const
{
	return m_surfaces;
}

SurfaceFormat ImageReader::format() const
{
	return m_fmt;
}

const void* ImageReader::paletteData() const
{
	return &m_colormap[0][0];
}

SurfaceFormat ImageReader::paletteFormat() const
{
	return m_palfmt;
}

int ImageReader::surfaceWidth() const
{
	return m_width;
}

int ImageReader::surfaceHeight() const
{
	return m_height;
}

ImageReader::FileFormat ImageReader::guessFileFormat( const char* )
{
	return ImageReader::FILEFORMAT_TGA;
}

void ImageReader::readFully( io::InputStream* in, void* buf, int bytes )
{
	if ( in->read(buf,bytes) != bytes )
		INTERNAL_ERROR(); // throwError( IOException( Format("Failed to {0} bytes from {1}", bytes, in->toString()) ) );
}

void ImageReader::readColorMap( InputStream* in, int entrysize, int entries, uint8_t* colormap )
{
	uint8_t colr[4];
	for ( int i = 0 ; i < entries ; ++i )
	{
		memset( colr, 0, sizeof(colr) );
		readFully( in, colr, entrysize );
		colormap[i*4+0] = colr[2];
		colormap[i*4+1] = colr[1];
		colormap[i*4+2] = colr[0];
		colormap[i*4+3] = colr[3];
	}
}

uint16_t ImageReader::getUInt16LE( const void* data, int offset )
{
	const uint8_t* bytes = reinterpret_cast<const uint8_t*>(data) + offset;
	return uint16_t( ( unsigned(bytes[1]) << 8 ) + unsigned(bytes[0]) );
}

uint32_t ImageReader::getUInt32LE( const void* data, int offset )
{
	const uint8_t* bytes = reinterpret_cast<const uint8_t*>(data) + offset;
	return ( uint32_t(bytes[3]) << 24 ) + ( uint32_t(bytes[2]) << 16 ) + ( uint32_t(bytes[1]) << 8 ) + uint32_t(bytes[0]);
}

void ImageReader::readScanlines( void* bits, int pitch, int /*w*/, int /*h*/, SurfaceFormat fmt,
	const void* pal, SurfaceFormat palfmt )
{
	// make sure we have big enough scanline buffer,
	// but use dynamic allocation only if absolutely necessary
	if ( m_scanlinebuffer.size() < m_pitch )
	{
		m_scanlinebuffer.resize( m_pitch );
	}
	uint8_t* scanlinebuffer = m_scanlinebuffer.begin();

	// read pixels
#ifdef OPTIMIZE
	assert( fmt.type() == m_fmt.type() );
	int j1 = m_height - 1;
	uint8_t* dst = reinterpret_cast<uint8_t*>(bits) + j1*pitch;
#endif

	for ( int j = 0 ; j < m_height ; j++ )
	{
#ifdef OPTIMIZE
		m_in->read( dst, m_pitch );
		dst -= pitch;

#else // non-OPTIMIZE

		switch ( m_filefmt )
		{
		case FILEFORMAT_BMP:
		case FILEFORMAT_TGA:
			readFully( m_in, scanlinebuffer, m_pitch );
			break;
		//case FILEFORMAT_JPG:
		//	readScanline_jpg( scanlinebuffer );
		//	break;
		default:
			INTERNAL_ERROR(); // throwError( IOException( Format("Unsupported image file format while reading {0}", m_in->toString()) ) );
		}

		int j1 = j;
		if ( m_bottomUp )
			j1 = m_height - j - 1;
		uint8_t* dst = reinterpret_cast<uint8_t*>(bits) + j1*pitch;

		fmt.copyPixels( dst, palfmt, pal, m_fmt, scanlinebuffer, m_palfmt, &m_colormap[0][0], m_width );
#endif
	}
}


} // img