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Meteors added :)

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Pecusx
2023-09-03 15:47:45 +02:00
parent d716e02e12
commit f701ef3227
8 changed files with 103 additions and 7 deletions
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Atari/gr_basics.asm
+30
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@@ -161,6 +161,36 @@ ClearPlot
rts
.endp
; -----------------------------------------
.proc ExPlot ;ExPlot (EplotX, EplotY)
; EOR plot:
; Inverts color of a pixel
; Note: No coordinate control!!!
; With off-screen coordinates, it can damage main program.
; -----------------------------------------
; let's calculate coordinates from xdraw and ydraw
;xbyte = xbyte/8
lda EplotX+1
lsr
lda EplotX
ror ;just one bit over 256. Max screenwidth = 512!!!
lsr
lsr
sta EplotByte
;---
ldx EplotY
ldy linetableL,x
lda linetableH,x
sta EplotByte+1
ldx EplotX ; optimization (256 bytes long bittable)
lda (EplotByte),y
eor bittable1_long,x
sta (EplotByte),y
rts
.endp
; -----------------------------------------
.proc point_plot
; -----------------------------------------