mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 00:29:31 +00:00
1278 lines
23 KiB
ArmAsm
1278 lines
23 KiB
ArmAsm
;
|
|
; Graphics driver for the 640x200x2 mode on the C128 VDC
|
|
; Maciej 'YTM/Elysium' Witkowiak <ytm@elysium.pl>
|
|
; 23.12.2002
|
|
; 2004-04-04, Greg King
|
|
;
|
|
; NOTES:
|
|
; For any smart monkey that will try to optimize this: PLEASE do tests on
|
|
; real VDC, not only VICE.
|
|
;
|
|
; Only DONE routine contains C128-mode specific stuff, everything else will
|
|
; work in C64-mode of C128 (C64 needs full VDC init then).
|
|
;
|
|
; With special initialization and CALC we can get 320x200 double-pixel mode.
|
|
;
|
|
; Color translation values for BROWN and GRAY3 are obviously wrong, they
|
|
; could be replaced by equiv. of ORANGE and GRAY2 but this would give only
|
|
; 14 of 16 colors available.
|
|
;
|
|
; Register 25 ($19) is said to require different value for VDC v1, but I
|
|
; couldn't find what it should be.
|
|
|
|
.include "zeropage.inc"
|
|
|
|
.include "tgi-kernel.inc"
|
|
.include "tgi-mode.inc"
|
|
.include "tgi-error.inc"
|
|
|
|
|
|
.macpack generic
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Constants
|
|
|
|
VDC_ADDR_REG = $D600 ; VDC address
|
|
VDC_DATA_REG = $D601 ; VDC data
|
|
|
|
VDC_DSP_HI = 12 ; registers used
|
|
VDC_DSP_LO = 13
|
|
VDC_DATA_HI = 18
|
|
VDC_DATA_LO = 19
|
|
VDC_VSCROLL = 24
|
|
VDC_HSCROLL = 25
|
|
VDC_COLORS = 26
|
|
VDC_CSET = 28
|
|
VDC_COUNT = 30
|
|
VDC_DATA = 31
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table and constants.
|
|
|
|
.segment "JUMPTABLE"
|
|
|
|
; First part of the header is a structure that has a magic and defines the
|
|
; capabilities of the driver
|
|
|
|
.byte $74, $67, $69 ; "tgi"
|
|
.byte TGI_API_VERSION ; TGI API version number
|
|
xres: .word 640 ; X resolution
|
|
yres: .word 200 ; Y resolution
|
|
.byte 2 ; Number of drawing colors
|
|
pages: .byte 1 ; Number of screens available
|
|
.byte 8 ; System font X size
|
|
.byte 8 ; System font Y size
|
|
.res 4, $00 ; Reserved for future extensions
|
|
|
|
; Next comes the jump table. Currently all entries must be valid and may point
|
|
; to an RTS for test versions (function not implemented).
|
|
|
|
.addr INSTALL
|
|
.addr UNINSTALL
|
|
.addr INIT
|
|
.addr DONE
|
|
.addr GETERROR
|
|
.addr CONTROL
|
|
.addr CLEAR
|
|
.addr SETVIEWPAGE
|
|
.addr SETDRAWPAGE
|
|
.addr SETCOLOR
|
|
.addr SETPALETTE
|
|
.addr GETPALETTE
|
|
.addr GETDEFPALETTE
|
|
.addr SETPIXEL
|
|
.addr GETPIXEL
|
|
.addr LINE
|
|
.addr BAR
|
|
.addr CIRCLE
|
|
.addr TEXTSTYLE
|
|
.addr OUTTEXT
|
|
.addr 0 ; IRQ entry is unused
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Data.
|
|
|
|
; Variables mapped to the zero page segment variables. Some of these are
|
|
; used for passing parameters to the driver.
|
|
|
|
X1 = ptr1
|
|
Y1 = ptr2
|
|
X2 = ptr3
|
|
Y2 = ptr4
|
|
RADIUS = tmp1
|
|
|
|
ADDR = tmp1 ; (2) CALC
|
|
TEMP = tmp3 ; CALC icmp
|
|
TEMP2 = tmp4 ; icmp
|
|
TEMP3 = sreg ; LINE
|
|
TEMP4 = sreg+1 ; LINE
|
|
|
|
; Line routine stuff (must be on zpage)
|
|
PB = ptr3 ; (2) LINE
|
|
UB = ptr4 ; (2) LINE
|
|
ERR = regsave ; (2) LINE
|
|
NX = regsave+2 ; (2) LINE
|
|
; Circle stuff
|
|
XX = ptr3 ; (2) CIRCLE
|
|
YY = ptr4 ; (2) CIRCLE
|
|
MaxO = sreg ; (overwritten by TEMP3+TEMP4, but restored from OG/OU anyway)
|
|
XS = regsave ; (2) CIRCLE
|
|
YS = regsave+2 ; (2) CIRCLE
|
|
|
|
; Absolute variables used in the code
|
|
|
|
.bss
|
|
|
|
SCRBASE: .res 1 ; High byte of screen base
|
|
|
|
ERROR: .res 1 ; Error code
|
|
PALETTE: .res 2 ; The current palette
|
|
|
|
BITMASK: .res 1 ; $00 = clear, $FF = set pixels
|
|
|
|
OLDCOLOR: .res 1 ; colors before entering gfx mode
|
|
|
|
; Line routine stuff (combined with CIRCLE to save space)
|
|
|
|
OGora:
|
|
COUNT: .res 2
|
|
OUkos:
|
|
NY: .res 2
|
|
Y3:
|
|
DX: .res 1
|
|
DY: .res 1
|
|
AX: .res 1
|
|
AY: .res 1
|
|
|
|
; Text output stuff
|
|
TEXTMAGX: .res 1
|
|
TEXTMAGY: .res 1
|
|
TEXTDIR: .res 1
|
|
|
|
; Constants and tables
|
|
|
|
.rodata
|
|
|
|
DEFPALETTE: .byte $00, $0f ; White on black
|
|
PALETTESIZE = * - DEFPALETTE
|
|
|
|
BITTAB: .byte $80,$40,$20,$10,$08,$04,$02,$01
|
|
|
|
BITMASKL: .byte %11111111, %01111111, %00111111, %00011111
|
|
.byte %00001111, %00000111, %00000011, %00000001
|
|
|
|
BITMASKR: .byte %10000000, %11000000, %11100000, %11110000
|
|
.byte %11111000, %11111100, %11111110, %11111111
|
|
|
|
; color translation table (indexed by VIC color)
|
|
COLTRANS: .byte $00, $0f, $08, $06, $0a, $04, $02, $0c
|
|
.byte $0d, $0b, $09, $01, $0e, $05, $03, $07
|
|
; colors BROWN and GRAY3 are wrong
|
|
|
|
; VDC initialization table (reg),(val),...,$ff
|
|
InitVDCTab:
|
|
.byte VDC_DSP_HI, 0 ; viewpage 0 as default
|
|
.byte VDC_DSP_LO, 0
|
|
.byte VDC_HSCROLL, $87
|
|
.byte $ff
|
|
|
|
SCN80CLR: .byte 27,88,147,27,88,0
|
|
|
|
.code
|
|
|
|
; ------------------------------------------------------------------------
|
|
; INSTALL routine. Is called after the driver is loaded into memory. May
|
|
; initialize anything that has to be done just once. Is probably empty
|
|
; most of the time.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
INSTALL:
|
|
; check for VDC version and update register $19 value
|
|
|
|
; check for VDC ram size and update number of available screens
|
|
|
|
ldx #VDC_CSET ; determine size of RAM...
|
|
jsr VDCReadReg
|
|
sta tmp1
|
|
ora #%00010000
|
|
jsr VDCWriteReg ; turn on 64k
|
|
|
|
jsr settestadr1 ; save original value of test byte
|
|
jsr VDCReadByte
|
|
sta tmp2
|
|
|
|
lda #$55 ; write $55 here
|
|
ldy #ptr1
|
|
jsr test64k ; read it here and there
|
|
lda #$aa ; write $aa here
|
|
ldy #ptr2
|
|
jsr test64k ; read it here and there
|
|
|
|
jsr settestadr1
|
|
lda tmp2
|
|
jsr VDCWriteByte ; restore original value of test byte
|
|
|
|
lda ptr1 ; do bytes match?
|
|
cmp ptr1+1
|
|
bne @have64k
|
|
lda ptr2
|
|
cmp ptr2+1
|
|
bne @have64k
|
|
|
|
ldx #VDC_CSET
|
|
lda tmp1
|
|
jsr VDCWriteReg ; restore 16/64k flag
|
|
jmp @endok ; and leave default values for 16k
|
|
|
|
@have64k:
|
|
lda #4
|
|
sta pages
|
|
@endok:
|
|
lda #0
|
|
sta SCRBASE ; draw page 0 as default
|
|
rts
|
|
|
|
test64k:
|
|
sta tmp1
|
|
sty ptr3
|
|
lda #0
|
|
sta ptr3+1
|
|
jsr settestadr1
|
|
lda tmp1
|
|
jsr VDCWriteByte ; write $55
|
|
jsr settestadr1
|
|
jsr VDCReadByte ; read here
|
|
pha
|
|
jsr settestadr2
|
|
jsr VDCReadByte ; and there
|
|
ldy #1
|
|
sta (ptr3),y
|
|
pla
|
|
dey
|
|
sta (ptr3),y
|
|
rts
|
|
|
|
settestadr1:
|
|
ldy #$02 ; test page 2 (here)
|
|
.byte $2c
|
|
settestadr2:
|
|
ldy #$42 ; or page 64+2 (there)
|
|
lda #0
|
|
jmp VDCSetSourceAddr
|
|
|
|
; ------------------------------------------------------------------------
|
|
; UNINSTALL routine. Is called before the driver is removed from memory. May
|
|
; clean up anything done by INSTALL but is probably empty most of the time.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
UNINSTALL:
|
|
rts
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; INIT: Changes an already installed device from text mode to graphics
|
|
; mode.
|
|
; Note that INIT/DONE may be called multiple times while the driver
|
|
; is loaded, while INSTALL is only called once, so any code that is needed
|
|
; to initializes variables and so on must go here. Setting palette and
|
|
; clearing the screen is not needed because this is called by the graphics
|
|
; kernel later.
|
|
; The graphics kernel will never call INIT when a graphics mode is already
|
|
; active, so there is no need to protect against that.
|
|
;
|
|
; Must set an error code: YES
|
|
;
|
|
|
|
INIT:
|
|
|
|
; Initialize variables
|
|
|
|
@L1: ldx #$FF
|
|
stx BITMASK
|
|
|
|
; Remeber current color value
|
|
ldx #VDC_COLORS
|
|
jsr VDCReadReg
|
|
sta OLDCOLOR
|
|
|
|
; Switch into graphics mode (set view page 0)
|
|
|
|
ldy #0
|
|
@L2: ldx InitVDCTab,y
|
|
bmi @L3
|
|
iny
|
|
lda InitVDCTab,y
|
|
jsr VDCWriteReg
|
|
iny
|
|
bne @L2
|
|
@L3:
|
|
|
|
; Done, reset the error code
|
|
|
|
lda #TGI_ERR_OK
|
|
sta ERROR
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; DONE: Will be called to switch the graphics device back into text mode.
|
|
; The graphics kernel will never call DONE when no graphics mode is active,
|
|
; so there is no need to protect against that.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
DONE:
|
|
; This part is C128-mode specific
|
|
jsr $e179 ; reload character set and setup VDC
|
|
jsr $ff62
|
|
lda $d7 ; in 80-columns?
|
|
bne @L01
|
|
@L0: lda SCN80CLR,y
|
|
beq @L1
|
|
jsr $ffd2 ; print \xe,clr,\xe
|
|
iny
|
|
bne @L0
|
|
@L01: lda #147
|
|
jsr $ffd2 ; print clr
|
|
@L1: lda #0 ; restore view page
|
|
ldx #VDC_DSP_HI
|
|
jsr VDCWriteReg
|
|
lda OLDCOLOR
|
|
ldx #VDC_COLORS
|
|
jsr VDCWriteReg ; restore color (background)
|
|
lda #$47
|
|
ldx #VDC_HSCROLL
|
|
jmp VDCWriteReg ; switch to text screen
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETERROR: Return the error code in A and clear it.
|
|
|
|
GETERROR:
|
|
ldx #TGI_ERR_OK
|
|
lda ERROR
|
|
stx ERROR
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; CONTROL: Platform/driver specific entry point.
|
|
;
|
|
; Must set an error code: YES
|
|
;
|
|
|
|
CONTROL:
|
|
lda #TGI_ERR_INV_FUNC
|
|
sta ERROR
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; CLEAR: Clears the screen.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
CLEAR:
|
|
lda #0
|
|
ldy SCRBASE
|
|
jsr VDCSetSourceAddr
|
|
lda #0
|
|
ldx #VDC_VSCROLL
|
|
jsr VDCWriteReg ; set fill mode
|
|
lda #0
|
|
jsr VDCWriteByte ; put 1rst byte (fill value)
|
|
ldy #62 ; 62 times
|
|
lda #0 ; 256 bytes
|
|
ldx #VDC_COUNT
|
|
@L1: jsr VDCWriteReg
|
|
dey
|
|
bne @L1
|
|
lda #127
|
|
jmp VDCWriteReg ; 1+62*256+127=16000=(640*256)/8
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
|
|
; The page number is already checked to be valid by the graphics kernel.
|
|
;
|
|
; Must set an error code: NO (will only be called if page ok)
|
|
;
|
|
|
|
SETVIEWPAGE:
|
|
clc
|
|
ror
|
|
ror
|
|
ror
|
|
ldx #VDC_DSP_HI
|
|
jmp VDCWriteReg
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
|
|
; The page number is already checked to be valid by the graphics kernel.
|
|
;
|
|
; Must set an error code: NO (will only be called if page ok)
|
|
;
|
|
|
|
SETDRAWPAGE:
|
|
clc
|
|
ror
|
|
ror
|
|
ror
|
|
sta SCRBASE
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETCOLOR: Set the drawing color (in A). The new color is already checked
|
|
; to be in a valid range (0..maxcolor-1).
|
|
;
|
|
; Must set an error code: NO (will only be called if color ok)
|
|
;
|
|
|
|
SETCOLOR:
|
|
tax
|
|
beq @L1
|
|
lda #$FF
|
|
@L1: sta BITMASK
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETPALETTE: Set the palette (not available with all drivers/hardware).
|
|
; A pointer to the palette is passed in ptr1. Must set an error if palettes
|
|
; are not supported
|
|
;
|
|
; Must set an error code: YES
|
|
;
|
|
|
|
SETPALETTE:
|
|
ldy #PALETTESIZE - 1
|
|
@L1: lda (ptr1),y ; Copy the palette
|
|
and #$0F ; Make a valid color
|
|
sta PALETTE,y
|
|
dey
|
|
bpl @L1
|
|
|
|
; Get the color entries from the palette
|
|
|
|
ldy PALETTE+1 ; Foreground color
|
|
lda COLTRANS,y
|
|
asl a
|
|
asl a
|
|
asl a
|
|
asl a
|
|
ldy PALETTE ; Background color
|
|
ora COLTRANS,y
|
|
|
|
ldx #VDC_COLORS
|
|
jsr VDCWriteReg ; Clear error code
|
|
lda #TGI_ERR_OK
|
|
sta ERROR
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
|
|
; set the palette should return the default palette here, so there's no
|
|
; way for this function to fail.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
GETPALETTE:
|
|
lda #<PALETTE
|
|
ldx #>PALETTE
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETDEFPALETTE: Return the default palette for the driver in A/X. All
|
|
; drivers should return something reasonable here, even drivers that don't
|
|
; support palettes, otherwise the caller has no way to determine the colors
|
|
; of the (not changeable) palette.
|
|
;
|
|
; Must set an error code: NO (all drivers must have a default palette)
|
|
;
|
|
|
|
GETDEFPALETTE:
|
|
lda #<DEFPALETTE
|
|
ldx #>DEFPALETTE
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
|
|
; color. The coordinates passed to this function are never outside the
|
|
; visible screen area, so there is no need for clipping inside this function.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
SETPIXELCLIP:
|
|
lda Y1+1
|
|
bmi @finito ; y<0
|
|
lda X1+1
|
|
bmi @finito ; x<0
|
|
lda X1
|
|
ldx X1+1
|
|
sta ADDR
|
|
stx ADDR+1
|
|
ldx #ADDR
|
|
lda xres
|
|
ldy xres+1
|
|
jsr icmp ; ( x < xres ) ...
|
|
bcs @finito
|
|
lda Y1
|
|
ldx Y1+1
|
|
sta ADDR
|
|
stx ADDR+1
|
|
ldx #ADDR
|
|
lda yres
|
|
ldy yres+1
|
|
jsr icmp ; ... && ( y < yres )
|
|
bcc SETPIXEL
|
|
@finito:rts
|
|
|
|
SETPIXEL:
|
|
jsr CALC ; Calculate coordinates
|
|
|
|
stx TEMP
|
|
lda ADDR
|
|
ldy ADDR+1
|
|
jsr VDCSetSourceAddr
|
|
jsr VDCReadByte
|
|
ldx TEMP
|
|
|
|
sta TEMP
|
|
eor BITMASK
|
|
and BITTAB,X
|
|
eor TEMP
|
|
pha
|
|
lda ADDR
|
|
ldy ADDR+1
|
|
jsr VDCSetSourceAddr
|
|
pla
|
|
jsr VDCWriteByte
|
|
|
|
@L9: rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETPIXEL: Read the color value of a pixel and return it in A/X. The
|
|
; coordinates passed to this function are never outside the visible screen
|
|
; area, so there is no need for clipping inside this function.
|
|
|
|
|
|
GETPIXEL:
|
|
jsr CALC ; Calculate coordinates
|
|
|
|
stx TEMP ; preserve X
|
|
lda ADDR
|
|
ldy ADDR+1
|
|
jsr VDCSetSourceAddr
|
|
jsr VDCReadByte
|
|
ldx TEMP
|
|
|
|
ldy #$00
|
|
and BITTAB,X
|
|
beq @L1
|
|
iny
|
|
|
|
@L1: tya ; Get color value into A
|
|
ldx #$00 ; Clear high byte
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
|
|
; X2/Y2 = ptr3/ptr4 using the current drawing color.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
LINE:
|
|
; nx = abs(x2 - x1)
|
|
lda X2
|
|
sec
|
|
sbc X1
|
|
sta NX
|
|
lda X2+1
|
|
sbc X1+1
|
|
tay
|
|
lda NX
|
|
jsr abs
|
|
sta NX
|
|
sty NX+1
|
|
; ny = abs(y2 - y1)
|
|
lda Y2
|
|
sec
|
|
sbc Y1
|
|
sta NY
|
|
lda Y2+1
|
|
sbc Y1+1
|
|
tay
|
|
lda NY
|
|
jsr abs
|
|
sta NY
|
|
sty NY+1
|
|
; if (x2>=x1)
|
|
ldx #X2
|
|
lda X1
|
|
ldy X1+1
|
|
jsr icmp
|
|
bcc @L0243
|
|
; dx = 1;
|
|
lda #1
|
|
bne @L0244
|
|
; else
|
|
; dx = -1;
|
|
@L0243: lda #$ff
|
|
@L0244: sta DX
|
|
; if (y2>=y1)
|
|
ldx #Y2
|
|
lda Y1
|
|
ldy Y1+1
|
|
jsr icmp
|
|
bcc @L024A
|
|
; dy = 1;
|
|
lda #1
|
|
bne @L024B
|
|
; else
|
|
; dy = -1;
|
|
@L024A: lda #$ff
|
|
@L024B: sta DY
|
|
; err = ax = ay = 0;
|
|
lda #0
|
|
sta ERR
|
|
sta ERR+1
|
|
sta AX
|
|
sta AY
|
|
|
|
; if (nx<ny) {
|
|
ldx #NX
|
|
lda NY
|
|
ldy NY+1
|
|
jsr icmp
|
|
bcs @L0255
|
|
; nx <-> ny
|
|
lda NX
|
|
ldx NY
|
|
sta NY
|
|
stx NX
|
|
lda NX+1
|
|
ldx NY+1
|
|
sta NY+1
|
|
stx NX+1
|
|
; ax = dx
|
|
lda DX
|
|
sta AX
|
|
; ay = dy
|
|
lda DY
|
|
sta AY
|
|
; dx = dy = 0;
|
|
lda #0
|
|
sta DX
|
|
sta DY
|
|
; ny = - ny;
|
|
@L0255: lda NY
|
|
ldy NY+1
|
|
jsr neg
|
|
sta NY
|
|
sty NY+1
|
|
; for (count=nx;count>0;--count) {
|
|
lda NX
|
|
ldx NX+1
|
|
sta COUNT
|
|
stx COUNT+1
|
|
@L0166: lda COUNT ; count>0
|
|
ora COUNT+1
|
|
bne @L0167
|
|
rts
|
|
; setpixel(X1,Y1)
|
|
@L0167: jsr SETPIXELCLIP
|
|
; pb = err + ny
|
|
lda ERR
|
|
clc
|
|
adc NY
|
|
sta PB
|
|
lda ERR+1
|
|
adc NY+1
|
|
sta PB+1
|
|
tax
|
|
; ub = pb + nx
|
|
lda PB
|
|
clc
|
|
adc NX
|
|
sta UB
|
|
txa
|
|
adc NX+1
|
|
sta UB+1
|
|
; x1 = x1 + dx
|
|
ldx #0
|
|
lda DX
|
|
bpl @L027B
|
|
dex
|
|
@L027B: clc
|
|
adc X1
|
|
sta X1
|
|
txa
|
|
adc X1+1
|
|
sta X1+1
|
|
; y1 = y1 + ay
|
|
ldx #0
|
|
lda AY
|
|
bpl @L027E
|
|
dex
|
|
@L027E: clc
|
|
adc Y1
|
|
sta Y1
|
|
txa
|
|
adc Y1+1
|
|
sta Y1+1
|
|
; if (abs(pb)<abs(ub)) {
|
|
lda PB
|
|
ldy PB+1
|
|
jsr abs
|
|
sta TEMP3
|
|
sty TEMP4
|
|
lda UB
|
|
ldy UB+1
|
|
jsr abs
|
|
ldx #TEMP3
|
|
jsr icmp
|
|
bpl @L027F
|
|
; err = pb
|
|
lda PB
|
|
ldx PB+1
|
|
jmp @L0312
|
|
; } else { x1 = x1 + ax
|
|
@L027F:
|
|
ldx #0
|
|
lda AX
|
|
bpl @L0288
|
|
dex
|
|
@L0288: clc
|
|
adc X1
|
|
sta X1
|
|
txa
|
|
adc X1+1
|
|
sta X1+1
|
|
; y1 = y1 + dy
|
|
ldx #0
|
|
lda DY
|
|
bpl @L028B
|
|
dex
|
|
@L028B: clc
|
|
adc Y1
|
|
sta Y1
|
|
txa
|
|
adc Y1+1
|
|
sta Y1+1
|
|
; err = ub }
|
|
lda UB
|
|
ldx UB+1
|
|
@L0312:
|
|
sta ERR
|
|
stx ERR+1
|
|
; } (--count)
|
|
sec
|
|
lda COUNT
|
|
sbc #1
|
|
sta COUNT
|
|
bcc @L0260
|
|
jmp @L0166
|
|
@L0260: dec COUNT+1
|
|
jmp @L0166
|
|
|
|
; ------------------------------------------------------------------------
|
|
; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
|
|
; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
|
|
; Contrary to most other functions, the graphics kernel will sort and clip
|
|
; the coordinates before calling the driver, so on entry the following
|
|
; conditions are valid:
|
|
; X1 <= X2
|
|
; Y1 <= Y2
|
|
; (X1 >= 0) && (X1 < XRES)
|
|
; (X2 >= 0) && (X2 < XRES)
|
|
; (Y1 >= 0) && (Y1 < YRES)
|
|
; (Y2 >= 0) && (Y2 < YRES)
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
BAR:
|
|
inc Y2
|
|
bne HORLINE
|
|
inc Y2+1
|
|
|
|
; Original code for a horizontal line
|
|
|
|
HORLINE:
|
|
lda X1
|
|
pha
|
|
lda X1+1
|
|
pha
|
|
jsr CALC ; get data for LEFT
|
|
lda BITMASKL,x ; remember left address and bitmask
|
|
pha
|
|
lda ADDR
|
|
pha
|
|
lda ADDR+1
|
|
pha
|
|
|
|
lda X2
|
|
sta X1
|
|
lda X2+1
|
|
sta X1+1
|
|
jsr CALC ; get data for RIGHT
|
|
lda BITMASKR,x
|
|
sta TEMP3
|
|
|
|
pla ; recall data for LEFT
|
|
sta X1+1
|
|
pla
|
|
sta X1 ; put left address into X1
|
|
pla
|
|
|
|
cmp #%11111111 ; if left bit <> 0
|
|
beq @L1
|
|
sta TEMP2 ; do left byte only...
|
|
lda X1
|
|
ldy X1+1
|
|
jsr VDCSetSourceAddr
|
|
jsr VDCReadByte
|
|
sta TEMP
|
|
eor BITMASK
|
|
and TEMP2
|
|
eor TEMP
|
|
pha
|
|
lda X1
|
|
ldy X1+1
|
|
jsr VDCSetSourceAddr
|
|
pla
|
|
jsr VDCWriteByte
|
|
inc X1 ; ... and proceed
|
|
bne @L1
|
|
inc X1+1
|
|
|
|
; do right byte (if Y2=0 ++ADDR and skip)
|
|
@L1: lda TEMP3
|
|
cmp #%11111111 ; if right bit <> 7
|
|
bne @L11
|
|
inc ADDR ; right bit = 7 - the next one is the last
|
|
bne @L10
|
|
inc ADDR+1
|
|
@L10: bne @L2
|
|
|
|
@L11: lda ADDR ; do right byte only...
|
|
ldy ADDR+1
|
|
jsr VDCSetSourceAddr
|
|
jsr VDCReadByte
|
|
sta TEMP
|
|
eor BITMASK
|
|
and TEMP3
|
|
eor TEMP
|
|
pha
|
|
lda ADDR
|
|
ldy ADDR+1
|
|
jsr VDCSetSourceAddr
|
|
pla
|
|
jsr VDCWriteByte
|
|
|
|
@L2: ; do the fill in the middle
|
|
lda ADDR ; calculate offset in full bytes
|
|
sec
|
|
sbc X1
|
|
beq @L3 ; if equal - there are no more bytes
|
|
sta ADDR
|
|
|
|
lda X1 ; setup for the left side
|
|
ldy X1+1
|
|
jsr VDCSetSourceAddr
|
|
lda BITMASK ; get color
|
|
jsr VDCWriteByte ; put 1st value
|
|
ldx ADDR
|
|
dex
|
|
beq @L3 ; 1 byte already written
|
|
|
|
stx ADDR ; if there are more bytes - fill them...
|
|
ldx #VDC_VSCROLL
|
|
lda #0
|
|
jsr VDCWriteReg ; setup for fill
|
|
ldx #VDC_COUNT
|
|
lda ADDR
|
|
jsr VDCWriteReg ; ... fill them NOW!
|
|
|
|
@L3: pla
|
|
sta X1+1
|
|
pla
|
|
sta X1
|
|
|
|
; End of horizontal line code
|
|
|
|
inc Y1
|
|
bne @L4
|
|
inc Y1+1
|
|
@L4: lda Y1
|
|
cmp Y2
|
|
bne @L5
|
|
lda Y1+1
|
|
cmp Y2+1
|
|
bne @L5
|
|
rts
|
|
|
|
@L5: jmp HORLINE
|
|
|
|
; ------------------------------------------------------------------------
|
|
; CIRCLE: Draw a circle around the center X1/Y1 (= ptr1/ptr2) with the
|
|
; radius in tmp1 and the current drawing color.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
CIRCLE:
|
|
lda RADIUS
|
|
bne @L1
|
|
jmp SETPIXELCLIP ; Plot as a point
|
|
|
|
@L1: sta XX
|
|
; x = r;
|
|
lda #0
|
|
sta XX+1
|
|
sta YY
|
|
sta YY+1
|
|
sta MaxO
|
|
sta MaxO+1
|
|
; y =0; mo=0;
|
|
lda X1
|
|
ldx X1+1
|
|
sta XS
|
|
stx XS+1
|
|
lda Y1
|
|
ldx Y1+1
|
|
sta YS
|
|
stx YS+1 ; XS/YS to remember the center
|
|
|
|
; while (y<x) {
|
|
@L013B: ldx #YY
|
|
lda XX
|
|
ldy XX+1
|
|
jsr icmp
|
|
bcc @L12
|
|
rts
|
|
@L12: ; plot points in 8 slices...
|
|
lda XS
|
|
clc
|
|
adc XX
|
|
sta X1
|
|
lda XS+1
|
|
adc XX+1
|
|
sta X1+1 ; x1 = xs+x
|
|
lda YS
|
|
clc
|
|
adc YY
|
|
sta Y1
|
|
pha
|
|
lda YS+1
|
|
adc YY+1
|
|
sta Y1+1 ; (stack)=ys+y, y1=(stack)
|
|
pha
|
|
jsr SETPIXELCLIP ; plot(xs+x,ys+y)
|
|
lda YS
|
|
sec
|
|
sbc YY
|
|
sta Y1
|
|
sta Y3
|
|
lda YS+1
|
|
sbc YY+1
|
|
sta Y1+1 ; y3 = y1 = ys-y
|
|
sta Y3+1
|
|
jsr SETPIXELCLIP ; plot(xs+x,ys-y)
|
|
pla
|
|
sta Y1+1
|
|
pla
|
|
sta Y1 ; y1 = ys+y
|
|
lda XS
|
|
sec
|
|
sbc XX
|
|
sta X1
|
|
lda XS+1
|
|
sbc XX+1
|
|
sta X1+1
|
|
jsr SETPIXELCLIP ; plot (xs-x,ys+y)
|
|
lda Y3
|
|
sta Y1
|
|
lda Y3+1
|
|
sta Y1+1
|
|
jsr SETPIXELCLIP ; plot (xs-x,ys-y)
|
|
|
|
lda XS
|
|
clc
|
|
adc YY
|
|
sta X1
|
|
lda XS+1
|
|
adc YY+1
|
|
sta X1+1 ; x1 = xs+y
|
|
lda YS
|
|
clc
|
|
adc XX
|
|
sta Y1
|
|
pha
|
|
lda YS+1
|
|
adc XX+1
|
|
sta Y1+1 ; (stack)=ys+x, y1=(stack)
|
|
pha
|
|
jsr SETPIXELCLIP ; plot(xs+y,ys+x)
|
|
lda YS
|
|
sec
|
|
sbc XX
|
|
sta Y1
|
|
sta Y3
|
|
lda YS+1
|
|
sbc XX+1
|
|
sta Y1+1 ; y3 = y1 = ys-x
|
|
sta Y3+1
|
|
jsr SETPIXELCLIP ; plot(xs+y,ys-x)
|
|
pla
|
|
sta Y1+1
|
|
pla
|
|
sta Y1 ; y1 = ys+x(stack)
|
|
lda XS
|
|
sec
|
|
sbc YY
|
|
sta X1
|
|
lda XS+1
|
|
sbc YY+1
|
|
sta X1+1
|
|
jsr SETPIXELCLIP ; plot (xs-y,ys+x)
|
|
lda Y3
|
|
sta Y1
|
|
lda Y3+1
|
|
sta Y1+1
|
|
jsr SETPIXELCLIP ; plot (xs-y,ys-x)
|
|
|
|
; og = mo+y+y+1
|
|
lda MaxO
|
|
ldx MaxO+1
|
|
clc
|
|
adc YY
|
|
tay
|
|
txa
|
|
adc YY+1
|
|
tax
|
|
tya
|
|
clc
|
|
adc YY
|
|
tay
|
|
txa
|
|
adc YY+1
|
|
tax
|
|
tya
|
|
clc
|
|
adc #1
|
|
bcc @L0143
|
|
inx
|
|
@L0143: sta OGora
|
|
stx OGora+1
|
|
; ou = og-x-x+1
|
|
sec
|
|
sbc XX
|
|
tay
|
|
txa
|
|
sbc XX+1
|
|
tax
|
|
tya
|
|
sec
|
|
sbc XX
|
|
tay
|
|
txa
|
|
sbc XX+1
|
|
tax
|
|
tya
|
|
clc
|
|
adc #1
|
|
bcc @L0146
|
|
inx
|
|
@L0146: sta OUkos
|
|
stx OUkos+1
|
|
; ++y
|
|
inc YY
|
|
bne @L0148
|
|
inc YY+1
|
|
@L0148: ; if (abs(ou)<abs(og))
|
|
lda OUkos
|
|
ldy OUkos+1
|
|
jsr abs
|
|
sta TEMP3
|
|
sty TEMP4
|
|
lda OGora
|
|
ldy OGora+1
|
|
jsr abs
|
|
ldx #TEMP3
|
|
jsr icmp
|
|
bpl @L0149
|
|
; { --x;
|
|
sec
|
|
lda XX
|
|
sbc #1
|
|
sta XX
|
|
bcs @L014E
|
|
dec XX+1
|
|
@L014E: ; mo = ou; }
|
|
lda OUkos
|
|
ldx OUkos+1
|
|
jmp @L014G
|
|
; else { mo = og }
|
|
@L0149: lda OGora
|
|
ldx OGora+1
|
|
@L014G: sta MaxO
|
|
stx MaxO+1
|
|
; }
|
|
jmp @L013B
|
|
|
|
; ------------------------------------------------------------------------
|
|
; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
|
|
; direction is passend in X/Y, the text direction is passed in A.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
TEXTSTYLE:
|
|
stx TEXTMAGX
|
|
sty TEXTMAGY
|
|
sta TEXTDIR
|
|
rts
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
|
|
; current text style. The text to output is given as a zero terminated
|
|
; string with address in ptr3.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
OUTTEXT:
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Calculate all variables to plot the pixel at X1/Y1.
|
|
;------------------------
|
|
;< X1,Y1 - pixel
|
|
;> ADDR - address of card
|
|
;> X - bit number (X1 & 7)
|
|
CALC:
|
|
lda Y1+1
|
|
sta ADDR+1
|
|
lda Y1
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1 ; Y*4
|
|
clc
|
|
adc Y1
|
|
sta ADDR
|
|
lda Y1+1
|
|
adc ADDR+1
|
|
sta ADDR+1 ; Y*4+Y=Y*5
|
|
lda ADDR
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1
|
|
sta ADDR ; Y*5*16=Y*80
|
|
lda X1+1
|
|
sta TEMP
|
|
lda X1
|
|
lsr TEMP
|
|
ror
|
|
lsr TEMP
|
|
ror
|
|
lsr TEMP
|
|
ror
|
|
clc
|
|
adc ADDR
|
|
sta ADDR
|
|
lda ADDR+1 ; ADDR = Y*80+x/8
|
|
adc TEMP
|
|
sta ADDR+1
|
|
lda ADDR+1
|
|
adc SCRBASE
|
|
sta ADDR+1
|
|
lda X1
|
|
and #7
|
|
tax
|
|
rts
|
|
|
|
;-------------
|
|
; copies of some runtime routines
|
|
|
|
abs:
|
|
; a/y := abs(a/y)
|
|
cpy #$00
|
|
bpl absend
|
|
; negay
|
|
neg: eor #$ff
|
|
add #1
|
|
pha
|
|
tya
|
|
eor #$ff
|
|
adc #0
|
|
tay
|
|
pla
|
|
absend: rts
|
|
|
|
icmp:
|
|
; compare a/y to zp,x
|
|
sta TEMP ; TEMP/TEMP2 - arg2
|
|
sty TEMP2
|
|
lda $0,x
|
|
pha
|
|
lda $1,x
|
|
tay
|
|
pla
|
|
tax
|
|
tya ; x/a - arg1 (a=high)
|
|
|
|
sec
|
|
sbc TEMP2
|
|
bne @L4
|
|
cpx TEMP
|
|
beq @L3
|
|
adc #$ff
|
|
ora #$01
|
|
@L3: rts
|
|
@L4: bvc @L3
|
|
eor #$ff
|
|
ora #$01
|
|
rts
|
|
|
|
;-------------
|
|
; VDC helpers
|
|
|
|
VDCSetSourceAddr:
|
|
pha
|
|
tya
|
|
ldx #VDC_DATA_HI
|
|
jsr VDCWriteReg
|
|
pla
|
|
ldx #VDC_DATA_LO
|
|
bne VDCWriteReg
|
|
|
|
VDCReadByte:
|
|
ldx #VDC_DATA
|
|
VDCReadReg:
|
|
stx VDC_ADDR_REG
|
|
@L0: bit VDC_ADDR_REG
|
|
bpl @L0
|
|
lda VDC_DATA_REG
|
|
rts
|
|
|
|
VDCWriteByte:
|
|
ldx #VDC_DATA
|
|
VDCWriteReg:
|
|
stx VDC_ADDR_REG
|
|
@L0: bit VDC_ADDR_REG
|
|
bpl @L0
|
|
sta VDC_DATA_REG
|
|
rts
|
|
|