OS_SpriteOp 65
OS SWI Calls
» OS_SpriteOp
» OS_SpriteOp 65 – Tile Sprite Scaled
OS_SpriteOp 65 – Tile Sprite Scaled
(SWI &2E)
| Entry | |
|---|---|
| R0 | 65 (Reason code) + Area value |
| R1 | Unused/Sprite area (as defined by area value in R0) |
| R2 | Sprite name/pointer (as defined by area value in R0) |
| R3 | X coordinate |
| R4 | Y coordinate |
| R5 | Flags |
| R6 | Pointer to scaling factors, or 0 for 1:1 scaling |
| R7 | Pointer to pixel translation table / Colour Mapping Descriptor, or 0 for no translation |
| Exit | |
|---|---|
| All registers preserved | |
Use
This call paints multiple copies of a scaled sprite to the screen, tiling them in order to completely fill the current graphics window.
Compared to calling OS_SpriteOp 52 or OS_SpriteOp 34 in a loop, this call has greater scope for hardware acceleration to be used, and is therefore the preferred method for drawing tiled sprites.
Notes
Coordinates are in OS units, and specify the bottom-left corner of one of the tiles. Whether the coordinates specify a point inside or outside the graphics window is irrelevant, as the tiled area is effectively infinite, with the graphics window cropping it to a finite area.
This call is a tiled version of OS_SpriteOp 52, and therefore supports all the features of that call.
See also
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