Method PopulateMargin

trinity/Tr2HostBitmap.cpp:387–443

-------------------------------------------------- Description: Take the pixels in the sub-block (margin, margin)...(width-margin,height-margin) and copy their values into the border pixels to get a clamping effect. --------------------------------------------------

///   values into the border pixels to get a clamping effect.
/// --------------------------------------------------
bool Tr2HostBitmap::PopulateMargin( unsigned margin )
{
	if( !IsValid() || IsCompressed() || m_mipCount != 1 || 2 * margin >= GetWidth() || 2 * margin >= GetHeight() )
	{
		return false;
	}

	const unsigned bytesPerPixel = GetBytesPerPixel( GetFormat() );
	const unsigned bytesPerMargin = bytesPerPixel * margin;


	const unsigned width = GetWidth() - 2 * margin;
	const unsigned height = GetHeight() - 2 * margin;

	//top margin
	const char* src = GetRawData( margin, margin );
	for( unsigned i = 0; i != margin; ++i )
	{
		char* dst = GetRawData( margin, i );
		memcpy( dst, src, bytesPerPixel * width );
	}

	//bottom margin
	src = GetRawData( margin, height + margin - 1 );
	for( unsigned i = 0; i != margin; ++i )
	{
		char* dst = GetRawData( margin, height + margin + i );
		memcpy( dst, src, bytesPerPixel * width );
	}

	for( unsigned y = 0; y != height; ++y )
	{
		//left margin
		src = GetRawData( margin, y + margin );
		char* dst = GetRawData( 0, y + margin );
		for( unsigned i = 0; i != margin; ++i )
		{
			for( unsigned j = 0; j != bytesPerPixel; ++j )
			{
				dst[i * bytesPerPixel + j] = src[j];
			}
		}

		//right margin
		src += ( width - 1 ) * bytesPerPixel;
		dst += width * bytesPerPixel + bytesPerMargin;
		for( unsigned i = 0; i != margin; ++i )
		{
			for( unsigned j = 0; j != bytesPerPixel; ++j )
			{
				dst[i * bytesPerPixel + j] = src[j];
			}
		}
	}

	return true;
}