cc65/libsrc/geos-common/conio/cclear.s

;
; Maciej 'YTM/Elysium' Witkowiak
;
; 06.03.2002

; void cclearxy (unsigned char x, unsigned char y, unsigned char length);
; void cclear (unsigned char length);

	    .include "jumptab.inc"
	    .include "geossym.inc"

    	    .export		_cclearxy, _cclear
	    .import		popa, _gotoxy, fixcursor
	    .importzp		cursor_x, cursor_y, cursor_c

_cclearxy:
       	pha	    		; Save the length
	jsr	popa		; Get y
       	jsr    	_gotoxy		; Call this one, will pop params
	pla			; Restore the length

_cclear:
   	cmp	#0		; Is the length zero?
   	beq	L9  		; Jump if done
	tax
	lda	cursor_x	; left start
	sta	r3L
	lda	cursor_x+1
	sta	r3L+1
	lda	cursor_y	; level
	sta	r2L
	clc
	adc	#8
	sta	r2H
	txa			; right end
	clc
	adc	cursor_c
	sta	cursor_c
	sta	r4L
	ldx	#r4
	ldy 	#3
	jsr 	DShiftLeft
	lda	curPattern	; store current pattern
	pha
	lda	#0		; set pattern to clear
	jsr	SetPattern
	jsr	Rectangle
	pla
	jsr	SetPattern	; restore pattern
	jsr	fixcursor
L9:	rts