PR#3
PREFIX /A2OSX.BUILD
NEW
INC 1
AUTO 6
				.LIST OFF	
				.OP	65C02
				.OR	$2000
				.TF /A2OSX.BUILD/LIB/LIBGFX.O
*--------------------------------------
				.INB /A2OSX.BUILD/INC/MACROS.I
				.INB /A2OSX.BUILD/INC/A2OSX.I
				.INB /A2OSX.BUILD/INC/LIBGFX.I
*--------------------------------------
				.MA SWAP16
				lda ]1
				ldx ]2
				stx ]1
				sta ]2
				lda ]1+1
				ldx ]2+1
				stx ]1+1
				sta ]2+1
				.EM
				.MA NOT16
				sec
				lda #0
				sbc ]1
				sta ]1
				lda #0
				sbc ]1+1
				sta ]1+1
				.EM
*--------------------------------------
ZPCBPtr			.EQ ZPLIB
ZPDCPtr			.EQ ZPLIB+2
*--------------------------------------
*			File Header (16 Bytes)
*--------------------------------------
CS.START		cld
				jmp (.1,x)
				.DA #$61				6502,Level 1 (65c02)
				.DA #1					BIN Layout Version 1
				.DA 0
				.DA CS.END-CS.START
				.DA 0
				.DA 0
				.DA 0
*--------------------------------------
* Relocation Table
*--------------------------------------
.1				.DA LIB.LOAD
				.DA LIB.UNLOAD
				.DA InitGFXA
				.DA CloseGFX
				.DA InitCursor
				.DA SetCursorYA
				.DA HideCursor
				.DA ShowCursor
				.DA DrawLine
L.CB.Cache		.DA CB.Cache
				.DA 0
*--------------------------------------
LIB.LOAD
LIB.UNLOAD		clc
				rts
*--------------------------------------
InitGFXA		sta hDev
				>SYSCALL GetDevByIDA
				>STYA GoDevGFX.1+1

				clc
				rts			
*--------------------------------------
CloseGFX
				stz hDev
				sec
				rts
*--------------------------------------
InitCursor
*--------------------------------------
SetCursorYA
*--------------------------------------
HideCursor
*--------------------------------------
ShowCursor

				clc
				rts
*--------------------------------------
* In: Control Block
*  hDC
*  OP
*  MODE
*  COLOR
*  X1
*  Y1
*  X2
*  Y2
*--------------------------------------
DrawLine		ldy #S.CB.Y2+1
				jsr GetCB
				
				sec

				lda CB.Cache+S.CB.X2
				sbc CB.Cache+S.CB.X1
				sta DX
				
				lda CB.Cache+S.CB.X2+1
				sbc CB.Cache+S.CB.X1+1
				sta DX+1				DX% = X2% - X1%
				
				bmi .1					DX < 0....
				
				ora DX
				bne .2					DX > 0...
				
				ldx #DEVMGR.GFX.VLINE
				jmp GoDevGFX			DX=0 : VLIN Y1,Y2 At X1
				
.1				>SWAP16 CB.Cache+S.CB.X1,CB.Cache+S.CB.X2
				>SWAP16 CB.Cache+S.CB.Y1,CB.Cache+S.CB.Y2
				>NOT16 DX				swap X1/X2, Y1/Y2, set DX=-DX

.2				stz	IY

				sec

				lda CB.Cache+S.CB.Y2
				sbc CB.Cache+S.CB.Y1
				sta DY
				
				lda CB.Cache+S.CB.Y2+1
				sbc CB.Cache+S.CB.Y1+1
				sta DY+1				DY% = Y2% - Y1%		
				
				bmi .3					DY < 0 ...
				
				ora DY
				bne .4
				
				ldx #DEVMGR.GFX.HLINE
				jmp GoDevGFX			DY=0 : HLIN X1,X2 At Y1
				
.3				>NOT16 DY				set DY=-DY
				dec IY

.4				ldx #DEVMGR.GFX.SETPIXEL
				jsr GoDevGFX
				
				sec
				lda DX
				sbc DY
				sta DXY
				
				lda DX+1
				sbc DY+1
				sta DXY+1
				bmi DrawLine.IncY		DY is greater than DX, we will increase on Y axis
				
				ora DXY
				bne DrawLine.IncX		DY is lower than DX, we will increase on X axis

DrawLine.XY		lda DX					DX=DY
				eor #$ff
				sta Counter
				lda DX+1
				eor #$ff
				sta Counter+1

.1				inc Counter
				bne .2
				inc Counter+1
				beq .8
				
.2				inc CB.Cache+S.CB.X1
				bne .3
				inc CB.Cache+S.CB.X1+1
				
.3				bit IY
				bmi .4
				
				inc CB.Cache+S.CB.Y1
				bne .5
				inc CB.Cache+S.CB.Y1+1
				bra .5
				
.4				sec
				lda CB.Cache+S.CB.Y1
				sbc #1
				sta CB.Cache+S.CB.Y1
				bcs .5
				
				dec CB.Cache+S.CB.Y1+1
				
.5				ldx #DEVMGR.GFX.SETPIXEL
				jsr GoDevGFX
				bra .1
				
.8				rts
				
DrawLine.IncY	lda DY
				eor #$ff
				sta Counter
				lda DY+1
				eor #$ff
				sta Counter+1

				rts

DrawLine.IncX	lda DX
				eor #$ff
				sta Counter
				lda DX+1
				eor #$ff
				sta Counter+1			
				
				rts
*--------------------------------------
GetCB			>PULLW ZPCBPtr
				
.1				lda (ZPCBPtr),y			Y=Byte count to cache
				sta CB.Cache,y
				dey
				bpl .1
				rts
*--------------------------------------
GoDevGFX		>LDYA L.CB.Cache
GoDevGFX.1		jmp $ffff
*--------------------------------------
CS.END
hDev			.BS 1
*--------------------------------------
DX				.BS 2
DY				.BS 2
IY				.BS 1
DXY				.BS 2
Counter			.BS 2
*--------------------------------------
CB.Cache		.BS S.CB
*--------------------------------------
CUR.Arrow		.DA #0
				.DA #0
CUR.Arrow.DATA	.DA	%00000001.000000000
				.DA %00000011.000000000
				.DA %00000101.000000000
				.DA %00001001.000000000
				.DA %00010001.000000000
				.DA %00100011.000000000
				.DA %01110101.000000000
				.DA %00011000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
CUR.Arrow.MASK	.DA	%00000000.000000000
				.DA	%00000000.000000000
				.DA	%00000010.000000000
				.DA	%00000110.000000000
				.DA	%00001110.000000000
				.DA	%00011100.000000000
				.DA	%00001000.000000000
				.DA	%00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
				.DA %00000000.000000000
*--------------------------------------
PAT.Arrow		.DA #S.BM.F.BBP1
				.DA #1					RowBytes
				.DA 7					W
				.DA 8					H
				.DA 0
*--------------------------------------
MAN
SAVE /A2OSX.SRC/LIB/LIBGFX.S
ASM