Drawing one image onto another

I used one of these two (can't remember which) in Fairway. The image was pre-calced before the screen was shown, wasn't slow enough to notice:

' -----------------------------------------------------------------------------
' ccCopyImageRect: Copies part of an image onto another image
' by James Chamblin
' -----------------------------------------------------------------------------
Function ccCopyImageRect(Source:TImage,SX:Int,SY:Int,SWidth:Int,SHeight:Int,Dest:TImage,DX:Int,DY:Int)
	'get the pixmap for the images
	Local SourcePix:TPixmap = LockImage(Source)
	Local DestPix:TPixmap = LockImage(Dest)
	
	'find the dimentions
	Local SourceWidth:Int = PixmapWidth(SourcePix)
	Local SourceHeight:Int = PixmapHeight(SourcePix)
	Local DestWidth:Int = PixmapWidth(DestPix)
	Local DestHeight:Int = PixmapHeight(DestPix)
	
	If SX < SourceWidth And SY < SourceHeight And DX < DestWidth And DY < DestHeight 'make sure rects are on image
		If SX+SWidth > SourceWidth Then SWidth = SourceWidth - SX 'bound the coordinates to the image area
		If SY+SHeight > SourceHeight Then SHeight = SourceHeight - SY
		If DX+SWidth > DestWidth Then SWidth = DestWidth - DX 'Make sure coordinates will fit into the destination
		If DY+SHeight > DestHeight Then SHeight = DestHeight - DY
		
		'find the pitch
		Local SourcePitch:Int = PixmapPitch(SourcePix)
		Local DestPitch:Int = PixmapPitch(DestPix)
	
		'pointers To the first pixel of pixmaps
		Local SourcePtr:Byte Ptr = PixmapPixelPtr(SourcePix) + SY * SourcePitch + SX * 4
		Local DestPtr:Byte Ptr = PixmapPixelPtr(DestPix) + DY * DestPitch + DX * 4
		
		'copy pixels over one line at a time
		For Local i:Int = 1 To SHeight
			MemCopy(DestPtr,SourcePtr,SWidth*4)
			SourcePtr :+ SourcePitch
			DestPtr :+ DestPitch
		Next
	End If
	
	'unlock the buffers
	UnlockImage(Source)
	UnlockImage(Dest)
End Function

' -----------------------------------------------------------------------------
' ccCopyImageToImage: Copies one TImage to another with a variety of modes
' by Dave Munsie
' -----------------------------------------------------------------------------
Function ccCopyImageToImage(Source:TImage,SX:Int,SY:Int,SWidth:Int,SHeight:Int,Dest:TImage,DX:Int,DY:Int,flags:Int=0)
  '
  ' flags: 0 = Normal  1 = Mirror  2 = Flip  3 = Mirror and Flip
  '
  Local SourcePix:TPixmap = LockImage(Source)
  Local DestPix:TPixmap = LockImage(Dest)
  Local SourceWidth:Int = PixmapWidth(SourcePix)
  Local SourceHeight:Int = PixmapHeight(SourcePix)
  Local DestWidth:Int = PixmapWidth(DestPix)
  Local DestHeight:Int = PixmapHeight(DestPix)
  If SX < SourceWidth And SY < SourceHeight And DX < DestWidth And DY < DestHeight 
  If SX+SWidth > SourceWidth Then SWidth = SourceWidth - SX 
  If SY+SHeight > SourceHeight Then SHeight = SourceHeight - SY
  If DX+SWidth > DestWidth Then SWidth = DestWidth - DX 
  If DY+SHeight > DestHeight Then SHeight = DestHeight - DY
  Select flags
   Case 0 ' Normal
    For Local py:Int = 0 To SHeight-1 
     For Local px:Int = 0 To SWidth- 1
      WritePixel(DestPix,DX+px,DY+py,ReadPixel(SourcePix,SX+px,SY+py))
     Next 
    Next
   Case 1 ' Mirror
    For Local py:Int = 0 To SHeight-1 
     For Local px:Int = 0 To SWidth- 1
      WritePixel(DestPix,DX+px,DY+py,ReadPixel(SourcePix,(SX+(SWidth-1))-px,SY+py))
     Next
    Next
   Case 2 ' Flip
    For Local py:Int = 0 To SHeight-1 
     For Local px:Int = 0 To SWidth- 1
      WritePixel(DestPix,DX+px,DY+py,ReadPixel(SourcePix,SX+px,(SY+(SHeight-1))-py))
     Next
    Next
   Case 3 ' Mirror and Flip
    For Local py:Int = 0 To SHeight-1 
     For Local px:Int = 0 To SWidth- 1
      WritePixel(DestPix,DX+px,DY+py,ReadPixel(SourcePix,(SX+(SWidth-1))-px,(SY+(SHeight-1))-py))
     Next
    Next
  End Select
 EndIf
 UnlockImage(Source)
 UnlockImage(Dest)
End Function