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cc65/libsrc/geos/devel/geos-tgi.s
cuz 9b24bbc85c Removed the HORLINE entry point 
git-svn-id: svn://svn.cc65.org/cc65/trunk@2652 b7a2c559-68d2-44c3-8de9-860c34a00d81
2003-11-12 16:40:54 +00:00

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;
; Graphics driver for the 320x200x2 or 640x200x2 mode on GEOS 64/128
; Maciej 'YTM/Elysium' Witkowiak <ytm@elysium.pl>
; 28-31.12.2002
.include "zeropage.inc"
.include "tgi-kernel.inc"
.include "tgi-mode.inc"
.include "tgi-error.inc"
.include "../inc/const.inc"
.include "../inc/jumptab.inc"
.include "../inc/geossym.inc"
.include "../inc/geossym2.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 320 ; 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).
.word INSTALL
.word UNINSTALL
.word INIT
.word DONE
.word GETERROR
.word CONTROL
.word CLEAR
.word SETVIEWPAGE
.word SETDRAWPAGE
.word SETCOLOR
.word SETPALETTE
.word GETPALETTE
.word GETDEFPALETTE
.word SETPIXEL
.word GETPIXEL
.word LINE
.word BAR
.word CIRCLE
.word TEXTSTYLE
.word OUTTEXT
; ------------------------------------------------------------------------
; 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
TEMP = tmp3
TEMP2 = tmp4
TEMP3 = sreg
TEMP4 = sreg+1
; 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 (64k VDC only)
ERROR: .res 1 ; Error code
PALETTE: .res 2 ; The current palette
BITMASK: .res 1 ; $00 = clear, $01 = set pixels
OLDCOLOR: .res 1 ; colors before entering gfx mode
; Line routine stuff (combined with CIRCLE to save space)
OGora: .res 2
OUkos: .res 2
Y3: .res 2
; 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
; 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, $07
; colors BROWN and GRAY3 are wrong
.code
; ------------------------------------------------------------------------
; INSTALL routine. Is called after the driver is loaded into memory. May
; initialize anything that has to be done just once. Is probably empty
; most of the time.
;
; Must set an error code: NO
;
INSTALL:
lda version ; if GEOS 1.0...
and #$f0
cmp #$10
beq @L40
lda c128Flag ; at least GEOS 2.0, but we're on C128?
bpl @L40
lda graphMode ; GEOS 2.0, C128, but is 80 column screen enabled?
bmi @L80
@L40: rts ; leave default values for 40 column screen
; check for VDC version and update register $19 value
@L80:
lda #<640
ldx #>640
sta xres
stx xres+1
; 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:
ldx #$01
stx BITMASK ; solid black as pattern
lda #1
jsr SetPattern
lda #ST_WR_FORE ; write only on foreground
sta dispBufferOn
lda graphMode
bmi @L80
; Remember current color value (40 columns)
lda screencolors
sta OLDCOLOR
jmp @L99
; Remember current color value (80 columns)
@L80: lda scr80colors
sta OLDCOLOR
@L99: lda #0
jsr SETVIEWPAGE ; switch into viewpage 0
; 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:
lda #0
jsr SETVIEWPAGE ; switch into viewpage 0
lda graphMode
bmi @L80
lda OLDCOLOR
sta screencolors ; restore color for 40 columns
ldx #0
@L1: sta COLOR_MATRIX,x
sta COLOR_MATRIX+$0100,x
sta COLOR_MATRIX+$0200,x
sta COLOR_MATRIX+1000-256,x
inx
bne @L1
rts
@L80: lda OLDCOLOR ; restore color for 80 columns
ldx #VDC_COLORS
jmp VDCWriteReg
; ------------------------------------------------------------------------
; 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 curPattern
pha
lda #0
jsr SetPattern
ldx #0
stx r3L
stx r3H
stx r2L
lda #199
sta r2H
lda graphMode
bpl @L40
lda #>639 ; 80 columns
ldx #<639
bne @L99
@L40: lda #>319 ; 40 columns
ldx #<319
@L99: sta r4H
stx r4L
jsr Rectangle
pla
sta curPattern
rts
; ------------------------------------------------------------------------
; 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:
ldx graphMode
bmi @L80
rts
@L80: 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:
ldx graphMode
bmi @L80
rts
@L80: 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 #1
@L1: sta BITMASK
jmp SetPattern ; need to have either 0 or 1
; ------------------------------------------------------------------------
; 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:
jsr GETERROR ; clear error (if any)
ldy #PALETTESIZE - 1
@L1: lda (ptr1),y ; Copy the palette
and #$0F ; Make a valid color
sta PALETTE,y
dey
bpl @L1
; Put colors from palette into screen
lda graphMode
bmi @L80
lda PALETTE+1 ; foreground
asl a
asl a
asl a
asl a
ora PALETTE ; background
ldx #0
@L2: sta COLOR_MATRIX,x
sta COLOR_MATRIX+$0100,x
sta COLOR_MATRIX+$0200,x
sta COLOR_MATRIX+1000-256,x
inx
bne @L2
rts
@L80: 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
jmp VDCWriteReg
; ------------------------------------------------------------------------
; 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:
lda X1
ldx X1+1
ldy Y1
sta r3L
stx r3H
sty r11L
sec
lda BITMASK ; set or clear C flag
bne @L1
clc
@L1: lda #0
jmp DrawPoint
; ------------------------------------------------------------------------
; 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:
lda X1
ldx X1+1
ldy Y1
sta r3L
stx r3H
sty r11L
jsr TestPoint
ldx #0
bcc @L1
inx
@L1: txa
ldx #0
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:
lda X1
ldx X1+1
ldy Y1
sta r3L
stx r3H
sty r11L
lda X2
ldx X2+1
ldy Y2
sta r4L
stx r4H
sty r11H
sec
lda BITMASK ; set or clear C flag
bne @L1
clc
@L1: lda #0
jmp DrawLine
; ------------------------------------------------------------------------
; 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:
lda X1
ldx X1+1
ldy Y1
sta r3L
stx r3H
sty r2L
lda X2
ldx X2+1
ldy Y2
sta r4L
stx r4H
sty r2H
jmp Rectangle
; ------------------------------------------------------------------------
; 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:
lda TEXTDIR
; cmp #TGI_TEXT_HORIZONTAL ; this is equal 0
bne @vertical
lda X1 ; horizontal text output
ldx X1+1
ldy Y1
sta r11L
stx r11H
sty r1H
lda ptr3
ldx ptr3+1
sta r0L
stx r0H
jmp PutString
@vertical:
lda X1 ; vertical text output
ldx X1+1
ldy Y1
sta r11L
stx r11H
sty r1H
ldy #0
lda (ptr3),y
beq @end
jsr PutChar
inc ptr3
bne @L1
inc ptr3+1
@L1: lda Y1
clc
adc #8
sta Y1
bne @vertical
@end: rts
;-------------
; copies of some runtime routines
abs:
; a/y := abs(a/y)
dey
iny
bpl @L1
; negay
clc
eor #$ff
adc #1
pha
tya
eor #$ff
adc #0
tay
pla
@L1: 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
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