A2osX/DRV/DHGR.DRV.S.PIX.txt

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PR#3
PREFIX /A2OSX.BUILD
LOMEM $A00
INC 1
AUTO 6
.LIST OFF
*--------------------------------------
* SETPIXEL
* 1 : OP (XOR,SET,ORA)
* 2 : Mode
* 3 : Color
* 4 : SrcX1
* 6 : SrcY1
*--------------------------------------
SETPIXEL lda CB.Cache+S.CB.MODE
bit #S.CB.MODE.C16
bne SETPIXEL.C16
SETPIXEL.MONO >LDYA CB.Cache+S.CB.X1
jsr DIVMOD7YA
tay
lda COL.OFS,y
phy
ldy CB.Cache+S.CB.Y1
clc
adc BASEL,y
sta ZPBasePtr
lda BASEH,y
sta ZPBasePtr+1
ply
lda COL.BANK,y
tay
sta $C000,y Select proper BANK
lda CB.Cache+S.CB.OP
* cmp #S.CB.OP.XOR
beq SETPIXEL.MONO.XOR
lda CB.Cache+S.CB.COLOR
bne SETPIXEL.MONO.WHITE
SETPIXEL.MONO.BLACK
lda (ZPBasePtr)
and Mono.NMasks,x
sta (ZPBasePtr)
rts
SETPIXEL.MONO.WHITE
lda (ZPBasePtr)
ora Mono.Masks,x
sta (ZPBasePtr)
rts
SETPIXEL.MONO.XOR
lda (ZPBasePtr)
eor Mono.Masks,x
sta (ZPBasePtr)
rts
SETPIXEL.C16 lda CB.Cache+S.CB.X1
lsr CB.Cache+S.CB.X1+1 divide by 4
ror
lsr CB.Cache+S.CB.X1+1
ror
tay Y=X/4 (range 0->139)
lda DIV7.0,y A=X/4/7 (range 0->19)
asl times 2 (range 0->38)
ldx CB.Cache+S.CB.Y1
* clc
adc BASEL,x setup line Base Ptr (cc by asl)
sta ZPBasePtr ZPBasePtr now point to first of...
lda BASEH,x
sta ZPBasePtr+1 ...the 4 columns
lda MOD7.0,y get MOD
asl times 4 to compute index in MASK tables
asl
tax set in X for Masks,NMasks
lda CB.Cache+S.CB.COLOR
asl times 4 to compute index in PIXELS table
asl
tay
lda Color.Masks,x bits in 1st byte to light?
beq .10
and Color.Pixels,y apply color
sta GBYTE
sta SETPAGE2
lda (ZPBasePtr)
and Color.NMasks,x reset existing pixel,
ora GBYTE
sta (ZPBasePtr)
.10 inx
iny
lda Color.Masks,x
beq .11
and Color.Pixels,y apply color
sta GBYTE
sta CLRPAGE2
lda (ZPBasePtr)
and Color.NMasks,x reset existing pixel,
ora GBYTE
sta (ZPBasePtr)
.11 inc ZPBasePtr
inx
iny
lda Color.Masks,x
beq .12
and Color.Pixels,y apply color
sta GBYTE
sta SETPAGE2
lda (ZPBasePtr)
and Color.NMasks,x reset existing pixel,
ora GBYTE
sta (ZPBasePtr)
.12 inx
iny
lda Color.Masks,x
beq .13
and Color.Pixels,y apply color
sta GBYTE
sta CLRPAGE2
lda (ZPBasePtr)
and Color.NMasks,x reset existing pixel,
ora GBYTE
sta (ZPBasePtr)
.13 rts
*--------------------------------------
* GETPIXEL
*--------------------------------------
GETPIXEL rts
*--------------------------------------
MAN
SAVE /A2OSX.SRC/DRV/DHGR.DRV.S.PIX
LOAD /A2OSX.SRC/DRV/DHGR.DRV.S
ASM