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39 lines
1004 B
ArmAsm
39 lines
1004 B
ArmAsm
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; Ullrich von Bassewitz, 2003-04-13
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;
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; void cclearxy (unsigned char x, unsigned char y, unsigned char length);
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; void cclear (unsigned char length);
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;
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.export _cclearxy, _cclear
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.import setscrptr
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.import rvs
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.import popax
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.importzp ptr2
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.include "atmos.inc"
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_cclearxy:
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pha ; Save the length
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jsr popax ; Get X and Y
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sta CURS_Y ; Store Y
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stx CURS_X ; Store X
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pla ; Restore the length and run into _cclear
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_cclear:
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tax ; Is the length zero?
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beq @L9 ; Jump if done
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jsr setscrptr ; Set ptr2 to screen, won't use X
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lda #' '
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ora rvs
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@L1: sta (ptr2),y ; Write one char
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iny ; Next char
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bne @L2
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inc ptr2+1 ; Bump high byte of screen pointer
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@L2: dex
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bne @L1
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@L9: rts
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