A2osX/LIB/LIBGUI.S.DRAW.txt

PR#3
PREFIX /A2OSX.BUILD
NEW
INC 1
AUTO 6
*--------------------------------------
Draw			>PULLW ZPCmdPtr

				lda (ZPCmdPtr)			Get Cmd

.1				tax
				cpx #S.CB.CMD.DRAWLINE
				bcc .3					Native DRV Cmd

				ldy CB.CmdLen,x
				
.2				lda (ZPCmdPtr),y		Y=Byte count-1 to cache
				sta CB.Cache,y
				dey
				bpl .2
				
				jsr Draw.Jmp
				bra .7
				
.3				>LDYA ZPCmdPtr

				jsr GoDev.YA
				
.7				lda (ZPCmdPtr)			Get Cmd
				tax
				lda CB.CmdLen,x
				sec
				adc ZPCmdPtr
				sta ZPCmdPtr
				bcc .8
				inc ZPCmdPtr+1
				
.8				lda (ZPCmdPtr)			Get Cmd
				bne .1
				
				clc								
				rts
				
Draw.Jmp		jmp (J.Cmds,x)				
*--------------------------------------
* In: Control Block in CB.Cache
*  CMD
*  OP
*  MODE
*  COLOR
*  X1
*  Y1
*  X2
*  Y2
*--------------------------------------
DrawLine		lda CB.Cache+S.CB.X2
				sec
				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...

				lda #S.CB.CMD.VLINE
				sta CB.Cache+S.CB.CMD
				jmp GoDev				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
				lda CB.Cache+S.CB.Y1
				ldx CB.Cache+S.CB.Y2
				stx CB.Cache+S.CB.Y1
				sta CB.Cache+S.CB.Y2

				>NOT16 DX				swap X1/X2, Y1/Y2, set DX=-DX (DX positive)

.2				lda #1
				sta	IY

				lda CB.Cache+S.CB.Y2
				sec
				sbc CB.Cache+S.CB.Y1
				sta DY
				
*				lda CB.Cache+S.CB.Y2+1
				lda #0
*				sbc CB.Cache+S.CB.Y1+1
				sbc #0
				sta DY+1				DY = Y2 - Y1		
				
				bmi .3					DY < 0 ...
				
				ora DY
				bne .4
				
				lda #S.CB.CMD.HLINE
				sta CB.Cache+S.CB.CMD
				jmp GoDev				DY=0 : HLIN X1,X2 At Y1
				
.3				>NOT16 DY				set DY=-DY
				lda #$ff
				sta IY					set IY=-1

.4				lda #S.CB.CMD.SETPIXEL
				sta CB.Cache+S.CB.CMD
				jsr GoDev
				
				lda DX
				sec
				sbc DY
				tax
				
				lda DX+1
*				sbc DY+1
				sbc #0
				bmi DrawLine.IncY		DY is greater than DX, we will increase on Y axis
				
				txa
				beq DrawLine.IncXY		DX=DY, go inc X & Y
				
				jmp DrawLine.IncX		DY is lower than DX, we will increase on X axis

DrawLine.IncXY	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				lda CB.Cache+S.CB.Y1	Y1=Y1+IY
				clc
				adc IY
				sta CB.Cache+S.CB.Y1
				
				jsr GoDev
				bra .1
				
.8				rts
				
DrawLine.IncY	lda DY
				eor #$ff
				sta Counter
				lda DY+1
				eor #$ff
				sta Counter+1

				lda DX					IE=2*DX
				asl
				sta IE
				pha
				
				lda DX+1
				rol
				sta IE+1
				tax

				pla						D=IE-DY
				sec
				sbc DY
				sta D
				
				txa
				sbc DY+1
				sta D+1
				
				lda DX					INE=2*(DX-DY)
				sec
				sbc DY
				pha
				
				lda DX+1
				sbc DY+1
				tax
				
				pla
				
				asl
				sta INE
				txa
				rol
				sta INE+1
				
.1				inc Counter
				bne .2
				inc Counter+1
				beq .8

.2				lda D+1					IF D < 0 ...
				bmi .4
				
				lda D					D > 0 : D=D+INE
				clc
				adc INE
				sta D
				lda D+1
				adc INE+1
				sta D+1
				
				inc CB.Cache+S.CB.X1	X1=X1+1
				bne .5
				inc CB.Cache+S.CB.X1+1
				
				bra .5				

.4				lda D					D > 0 : D=D+IE
				clc
				adc IE
				sta D
				lda D+1
				adc IE+1
				sta D+1
				
.5				lda CB.Cache+S.CB.Y1	Y1=Y1+IY
				clc
				adc IY
				sta CB.Cache+S.CB.Y1
				
				jsr GoDev
				bra .1
				
.8				rts

DrawLine.IncX	lda DX
				eor #$ff
				sta Counter
				lda DX+1
				eor #$ff
				sta Counter+1			
				
				lda DY					IE=2*DY
				asl
				sta IE
				pha
				
*				lda DY+1
				lda #0
				rol
				sta IE+1
				tax
				
				pla						D=IE-DX
				sec
				sbc DX
				sta D
				
				txa
				sbc DX+1
				sta D+1
				
				lda DY					INE=2*(DY-DX)
				sec
				sbc DX
				pha
				
*				lda DY+1
				lda #0
				sbc DX+1
				tax
				
				pla
				asl
				sta INE
				txa
				rol
				sta INE+1
				
.1				inc Counter
				bne .2
				inc Counter+1
				beq .8

.2				lda D+1					ID D < 0 ....
				bmi .4
				
				lda D					D > 0 : D=D+INE
				clc
				adc INE
				sta D
				lda D+1
				adc INE+1
				sta D+1
				
				lda CB.Cache+S.CB.Y1	Y1=Y1+IY
				clc
				adc IY
				sta CB.Cache+S.CB.Y1
				
				bra .5				

.4				lda D					D < 0 : D=D+IE
				clc
				adc IE
				sta D
				lda D+1k
				adc IE+1
				sta D+1
				
.5				inc CB.Cache+S.CB.X1	X1=X1+1
				bne .6
				inc CB.Cache+S.CB.X1+1
				
.6				jsr GoDev
				bra .1
				
.8				rts
*--------------------------------------
MAN
SAVE /A2OSX.SRC/LIB/LIBGUI.S.DRAW
LOAD /A2OSX.SRC/LIB/LIBGUI.S
ASM