Editing Bit blit (section)

=== Technique ===

When preparing the sprite, the colors are very important. The ''mask'' pixels are 0 (black) wherever the corresponding sprite pixel is to be displayed, and 1 (white) wherever the background needs to be preserved. The ''sprite'' must be 0 (black) anywhere where it is supposed to be transparent, but note that black can be used in the non-transparent regions.

In the first blit, the ''mask'' is blitted onto the ''background'' using the raster operator ''[[bitwise operation#AND|AND]]''. Because any value ANDed with 0 equals 0, and any value ANDed with 1 is unchanged, black areas are created where the actual sprites will appear, while leaving the rest of the background alone.

{| class="wikitable"
|-
! Result of the first blit
|-
|align="center"| [[Image:XBlit_and.png|none]]
|}

In the second blit, the ''sprite'' is blitted onto the newly altered background using the raster operator of ''[[bitwise operation#OR|OR]]''. Because any value ORed with 0 is unchanged, the background is unaffected and the black areas are filled with the actual sprite image.

{| class="wikitable"
|-
! Final result
|-
|align="center"| [[Image:XBlit_final.png|none]]
|}

It is also possible to achieve the same effect using a sprite with a white background and a [[white-on-black]] mask. In this case, the mask would be ORed first, and the sprite ANDed next.