Swap bits between common bitmap and obscured ClipRect
Source position: layers.pas line 114
procedure SwapBitsRastPortClipRect( |
rp: pRastPort; |
cr: pClipRect |
); |
rp |
|
pointer to rastport |
cr |
|
pointer to cliprect to swap bits with |
Support routine useful for those that need to do some operations not done by the layer library. Allows programmer to swap the contents of a small BitMap with a subsection of the display. This is accomplished without using extra memory. The bits in the display RastPort are exchanged with the bits in the ClipRect's BitMap.
Note: the ClipRect structures which the layer library allocates are actually a little bigger than those described in the graphics/clip.h include file. So be warned that it is not a good idea to have instances of cliprects in your code.
Attention
Because the blit operation started by this function is done asynchronously, it is imperative that a WaitBlit() be performed before releasing or using the processor to modify any of the associated structures.