《Focus On 3D Terrain Programming》中一段代码的注释三

取自《Focus On 3D Terrain Programming》中的一段:

 //--------------------------------------------------------------
 // Name:          CIMAGE::LoadUncompressedTGA - private
 // Description:   Load an uncompressed targa (TGA)
 // Arguments:     None
 // Return Value:  A boolean variable: -true: TGA was loaded
 //                                    -false: TGA was not loaded
 //--------------------------------------------------------------
 bool CIMAGE::LoadUncompressedTGA( void )
 {
   ........
   ....
   pTGAinfo.m_uiBytesPerPixel= m_uiBPP/;
   pTGAinfo.m_uiImageSize    = ( pTGAinfo.m_uiBytesPerPixel*m_uiWidth*m_uiHeight );

   //copy the image data
   memcpy( m_ucpData, ucpFile, pTGAinfo.m_uiImageSize );

   //byte swapping ( optimized by Steve Thomas )
   for( uiCSwap=; uiCSwap<( int )pTGAinfo.m_uiImageSize; uiCSwap+=pTGAinfo.m_uiBytesPerPixel )
   {
     m_ucpData[uiCSwap]^= m_ucpData[uiCSwap+]^=m_ucpData[uiCSwap]^= m_ucpData[uiCSwap+];
   }

   //the uncompressed TGA has been successfully loaded
   return true;
 }

===============

开开眼界，把BGR转换为RGB的交换代码，过于高大上了，直接操作的硬件，可以提高一定的速度，对大图片有用。

    m_ucpData[uiCSwap]^= m_ucpData[uiCSwap+2]^=m_ucpData[uiCSwap]^= m_ucpData[uiCSwap+2];