EGFX · FUNCTION 23ALPHA · USE AT YOUR OWN RISK
XOR_SPRITE
Reserved: draws nothing in EGFX 0.6.
The current ROM implements this entry as an immediate return. The call is still acknowledged, but no pixels change, so do not use it to draw or to erase. For erasing, draw an opaque black frame with COMPACT_SPRITE (37), as the Breakout renderer does. Older notes describing a pre-shifted XOR renderer are out of date. The example below still runs, but its XOR call has no effect.
Parameters
| Name | Order | Description |
|---|---|---|
PX/PY | 8–11 | Sprite position. |
IMAGE | 12 | Loaded sprite image. |
BASIC example
Tested listing: companion-demo.bas.
10 MODE 1:HIMEM=&2400:PROCeginit:PROCegcompanion(5,&81,255)
20 REPEAT:PROCegbegin
30 PROCegsprite(80,80,1):PROCegsprite(160,112,3):PROCegxor(224,144,5)
40 PROCegtext("COMPANION ROM SPRITES",8,8)
50 PROCegpresent:UNTIL INKEY(0)=81
60 END
Assembly example
JSR init_egfx
JSR begin_frame
LDA #23 : JSR eg_call
JSR present_frame
RTS