void CGame::DrawTiles()
{
	int CurrentTile; 
	int StartTileX, StartTileY, EndTileX, EndTileY;
	int OffsetX, OffsetY;
		
	// compute starting map indices by dividing position by size of cell
	StartTileX = m_WorldX / 32;
	StartTileY = m_WorldY / 32;

	// compute end of map rectangle for best cast i.e. aligned on 32x32 boundary
	EndTileX = StartTileX + VIEWPORTSIZE_X - 1;
	EndTileY = StartTileY + VIEWPORTSIZE_Y - 1;
	
	// now compute number of pixels in x,y we are within the tile, i.e
	// how much is scrolled off the edge?
	OffsetX = -(m_WorldX % 32);
	OffsetY = -(m_WorldY % 32);

	// adjust end_map_x,y for offsets
	if (OffsetX)
		EndTileX++;

	if (OffsetY)
		EndTileY++;

	// set starting position of first upper lh texture
	SDL_Rect src, dest;
	dest.x = OffsetX;
	dest.y = OffsetY;
	src.w = 32;
	src.h = 32;

	for (int i = StartTileY; i < EndTileY; i++)
	{
		for (int j = StartTileX; j < EndTileX; j++)
		{
			CurrentTile = m_Levels[m_CurrentLevel].m_MapData[j];
			src.x = CurrentTile * 32;
			src.y = 0;
			
			SDL_BlitSurface(m_Tilesets[m_CurrentTileset],&src,m_Screen,&dest);

			// update tile position
			dest.x += 32;
		}

		// reset x postion, update y
		dest.x = OffsetX;
		dest.y += 32;
	}
}

	EndTileX = StartTileX + VIEWPORTSIZE_X;	EndTileY = StartTileY + VIEWPORTSIZE_Y;