First attemp at scrolling text

2026-09-12 04:12:00 +00:00 · 2016-03-31 13:36:24 +11:00
parent 160b78f30a
commit f7d6840c3c
15 changed files with 1020 additions and 0 deletions
@@ -0,0 +1,86 @@
+	include "includes.i"
+
+	xdef BlitFillColor
+	xdef BlitScroll
+
+;;       A(mask) B(bob)  C(bg)   D(dest)
+;;       -       -       -       - 
+;;       0       0       0       0 
+;;       0       0       1       1 
+;;       0       1       0       0 
+;;       0       1       1       1 
+;;       1       0       0       0 
+;;       1       0       1       0 
+;;       1       1       0       1 
+;;       1       1       1       1
+	
+BlitFillColor:
+	;; kills a0,d2,d3,d5,d5
+	;; a0 - bitplane
+	;; d0 - color#
+	;; d1 - height
+	;; d2 - ypos
+
+	;; 	movem.l	d2-d5/a0,-(sp)
+	mulu.w	#BITPLANE_WIDTH_BYTES*SCREEN_BIT_DEPTH,d2
+	add.l	d2,a0
+	move.b	#0,d3				; bitplane #
+.loop:
+	move.w	d1,d4		
+	btst	d3,d0				; is the color's bit set in this plane?
+	beq	.zero
+	move.w	#BLIT_DEST|$FF,d5		; yes ? all ones
+	bra	.doblit
+.zero
+	move.w	#BLIT_DEST|$0,d5			; no ? all zeros
+.doblit
+	WaitBlitter
+
+	move.w	#0,BLTCON1(A6)
+	move.w  d5,BLTCON0(A6)
+	move.w 	#BITPLANE_WIDTH_BYTES*(SCREEN_BIT_DEPTH-1),BLTDMOD(a6)
+	move.l 	a0,BLTDPTH(a6) 
+
+	lsl.w	#6,d4	
+	ori.w	#BITPLANE_WIDTH_WORDS,d4
+        move.w	d4,BLTSIZE(a6)
+	add.b	#1,d3
+	add.w	#BITPLANE_WIDTH_BYTES,a0
+	cmp.b	#SCREEN_BIT_DEPTH,d3 		; all planes for a single line done ?	
+	bne	.loop				; no ? do the next plane
+
+	;; movem.l (sp)+,d2-d5/a0
+	rts
+
+
+
+BlitScroll:
+	;; kills a0,d1,d2
+	;; a0 - bitplane
+	;; d1 - height
+	;; d2 - ypos
+
+	;; 	movem.l	d2-d5/a0,-(sp)
+	add.l	d1,d2	;point to end of data for ascending mode
+	mulu.w	#BITPLANE_WIDTH_BYTES*SCREEN_BIT_DEPTH,d2
+	add.l	d2,a0
+
+	WaitBlitter
+
+	move.w	#$2,BLTCON1(a6)
+	move.w  #$1000|BLIT_SRCA|BLIT_DEST|$f0,BLTCON0(a6)
+	move.w 	#-2,BLTAMOD(a6)
+	move.w 	#-2,BLTDMOD(a6)
+	move.l 	a0,BLTAPTH(a6) 	
+	move.l 	a0,BLTDPTH(a6)
+	move.w	#$0000,BLTAFWM(a6)
+	move.w	#$ffff,BLTALWM(a6)	
+	
+	mulu.w	#SCREEN_BIT_DEPTH,d1
+	lsl.w	#6,d1	
+	ori.w	#BITPLANE_WIDTH_WORDS+1,d1
+        move.w	d1,BLTSIZE(a6)
+
+	;; movem.l (sp)+,d2-d5/a0
+	rts
+