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cc65/libsrc/nes/cclear.s
Oliver Schmidt 13482984ca Introduced internal gotoxy that pops both parameters.
About all CONIO functions offering a <...>xy variant call
  popa
  _gotoxy

By providing an internal gotoxy variant that starts with a popa all those CONIO function can be shortened by 3 bytes. As soon as program calls more than one CONIO function this means an overall code size reduction.
2016-06-05 14:58:38 +02:00

30 lines
794 B
ArmAsm

;
; Ullrich von Bassewitz, 08.08.1998
;
; void cclearxy (unsigned char x, unsigned char y, unsigned char length);
; void cclear (unsigned char length);
;
.export _cclearxy, _cclear
.import gotoxy, cputdirect
.importzp tmp1
_cclearxy:
pha ; Save the length
jsr gotoxy ; Call this one, will pop params
pla ; Restore the length and run into _cclear
_cclear:
cmp #0 ; Is the length zero?
beq L9 ; Jump if done
sta tmp1
L1: lda #$20 ; Blank - screen code
jsr cputdirect ; Direct output
dec tmp1
bne L1
L9: rts