PR#3
PREFIX /A2OSX.BUILD
LOMEM $A00
INC 1
AUTO 6
				.LIST OFF	
*--------------------------------------
LBUF.SetBounds1YA	
				jsr DIVMOD7YA			A=DIV, X=MOD
				sta LBUF.C1
				tay
				
				lda C1.MASK,x			
				sta LBUF.C1.MASK
				lda C1.DATA,x
				sta LBUF.C1.DATA
				rts
*--------------------------------------
LBUF.SetBounds2YA
				jsr DIVMOD7YA			A=DIV, X=MOD
				sta LBUF.C2
				tay
				
				cmp LBUF.C1				C1=C2, go combine in C1
				beq .1
				
				lda C2.MASK,x			
				sta LBUF.C2.MASK
				lda C2.DATA,x
				sta LBUF.C2.DATA
				rts

.1				lda C1.MASK,x
				and C2.MASK,x
				sta	LBUF.C1.MASK
				
				lda C1.DATA,x
				and C2.DATA,x
				sta LBUF.C2.DATA
				rts
*--------------------------------------
LBUF.DrawAtY	lda BASEL,y				setup line Base Ptr
				sta ZPBasePtr
				lda BASEH,y
				sta ZPBasePtr+1
				
				lda CB.Cache+S.CB.OP
				bit #S.CB.OP.RESTORE
				bne .8
				bit #S.CB.OP.SAVE
				beq .1
				
				
				lda CB.Cache+S.CB.OP
				
.1				and #$f
				tax
				jmp (J.LBUF.DrawAtY,x)
				
.8				rts				
*--------------------------------------		
LBUF.DrawAtY.XOR
				ldx LBUF.C1				x C1->C2
				
				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C1
				and LBUF.C1.MASK		clear ONLY bits starting at X1 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C1.DATA		set ONLY bits starting at X1 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen
				
				inx
				cpx LBUF.C2
				beq .2					C1=C2, go setup C2
				bcs .8					C1+1 > C2, we are done...			
				
.1				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda LBUF.DATA,x			set all bytes between C1+1 & C2-1
				sta (ZPBasePtr),y

				inx
				cpx LBUF.C2
				bne .1
				
.2				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C2
				and LBUF.C2.MASK		clear ONLY bits ending at X2 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C2.DATA		set ONLY bits ending at X2 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen	
				
.8				rts		
*--------------------------------------
LBUF.DrawAtY.SET				
				ldx LBUF.C1				x C1->C2
				
				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C1
				and LBUF.C1.MASK		clear ONLY bits starting at X1 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C1.DATA		set ONLY bits starting at X1 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen
				
				inx
				cpx LBUF.C2
				beq .2					C1=C2, go setup C2
				bcs .8					C1+1 > C2, we are done...			
				
.1				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda LBUF.DATA,x			set all bytes between C1+1 & C2-1
				sta (ZPBasePtr),y

				inx
				cpx LBUF.C2
				bne .1
				
.2				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C2
				and LBUF.C2.MASK		clear ONLY bits ending at X2 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C2.DATA		set ONLY bits ending at X2 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen
				
.8				rts
*--------------------------------------
LBUF.DrawAtY.ORA				
				ldx LBUF.C1				x C1->C2
				
				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C1
				and LBUF.C1.MASK		clear ONLY bits starting at X1 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C1.DATA		set ONLY bits starting at X1 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen
				
				inx
				cpx LBUF.C2
				beq .2					C1=C2, go setup C2
				bcs .8					C1+1 > C2, we are done...			
				
.1				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda LBUF.DATA,x			set all bytes between C1+1 & C2-1
				sta (ZPBasePtr),y

				inx
				cpx LBUF.C2
				bne .1
				
.2				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C2
				and LBUF.C2.MASK		clear ONLY bits ending at X2 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C2.DATA		set ONLY bits ending at X2 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen	
				
.8				rts
*--------------------------------------
LBUF.DrawAtY.AND				
				ldx LBUF.C1				x C1->C2
				
				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C1
				and LBUF.C1.MASK		clear ONLY bits starting at X1 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C1.DATA		set ONLY bits starting at X1 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen
				
				inx
				cpx LBUF.C2
				beq .2					C1=C2, go setup C2
				bcs .8					C1+1 > C2, we are done...			
				
.1				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda LBUF.DATA,x			set all bytes between C1+1 & C2-1
				sta (ZPBasePtr),y

				inx
				cpx LBUF.C2
				bne .1
				
.2				ldy COL.BANK,x
				sta $C000,y
				ldy COL.OFS,x
				
				lda (ZPBasePtr),y		Get C2
				and LBUF.C2.MASK		clear ONLY bits ending at X2 mod 7
				sta GBYTE
				lda LBUF.DATA,x			get DATA bits
				and LBUF.C2.DATA		set ONLY bits ending at X2 mod 7
				ora GBYTE
				sta (ZPBasePtr),y		update screen
				
.8				rts
*--------------------------------------
MAN
SAVE /A2OSX.SRC/DRV/DHGR.DRV.S.LBUF
LOAD /A2OSX.SRC/DRV/DHGR.DRV.S
ASM