;
-; Graphics driver for the 320x200x2 or 640x200x2 mode on GEOS 64/128
-; Maciej 'YTM/Elysium' Witkowiak <ytm@elysium.pl>
-; 28-31.12.2002
-;
-; - not tested OutText
-; - not tested on VDC
-; - erratic Circle when needs to clip
+; Graphics driver for the 320x200x2 and 640x200x2 modes on GEOS 64/128
+; 2010-08-17, Maciej 'YTM/Elysium' Witkowiak <ytm@elysium.pl>
+; 2010-08-18, Greg King
.include "zeropage.inc"
.include "tgi-kernel.inc"
- .include "tgi-mode.inc"
.include "tgi-error.inc"
.include "../inc/const.inc"
; ------------------------------------------------------------------------
; Constants
-VDC_ADDR_REG = $D600 ; VDC address
-VDC_DATA_REG = $D601 ; VDC data
+VDC_ADDR_REG := $D600 ; VDC address
+VDC_DATA_REG := $D601 ; VDC data
VDC_DSP_HI = 12 ; registers used
VDC_DSP_LO = 13
.segment "JUMPTABLE"
-; First part of the header is a structure that has a magic and defines the
-; capabilities of the driver
+; First part of the header is a structure that has a magic signature,
+; and defines the capabilities of the driver.
.byte $74, $67, $69 ; "tgi"
- .byte $00 ; TGI version number
+ .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). A future version may
-; allow for emulation: In this case the vector will be zero. Emulation means
-; that the graphics kernel will emulate the function by using lower level
-; primitives - for example ploting a line by using calls to SETPIXEL.
-
- .word INSTALL
- .word DEINSTALL
- .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 HORLINE
- .word LINE
- .word BAR
- .word CIRCLE
- .word TEXTSTYLE
- .word OUTTEXT
+ .word $100 ; Aspect ratio: 1.0
+
+; Next comes the jump table. With the exception of IRQ, 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 TEXTSTYLE
+ .addr OUTTEXT
+ .addr 0 ; IRQ entry is unused
; ------------------------------------------------------------------------
; Data.
-; Variables mapped to the zero page segment variables. Some of these are
+; 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
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
jmp VDCSetSourceAddr
; ------------------------------------------------------------------------
-; DEINSTALL routine. Is called before the driver is removed from memory. May
+; 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
;
-DEINSTALL:
+UNINSTALL:
rts
; ------------------------------------------------------------------------
; INIT: Changes an already installed device from text mode to graphics
-; mode. The number of the graphics mode is passed to the function in A.
+; 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
;
INIT:
- ; ignore passed parameter
ldx #$01
stx BITMASK ; solid black as pattern
lda #1
; 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: YES
+; Must set an error code: NO
;
DONE:
; Must set an error code: NO
;
-CLEAR:
+CLEAR:
lda curPattern
pha
lda #0
SETCOLOR:
tax
beq @L1
- inx
-@L1: stx BITMASK
- txa ; need to have either 0 or 1
- jmp SetPattern
+ lda #1
+@L1: sta BITMASK
+ jmp SetPattern ; need to have either 0 or 1
; ------------------------------------------------------------------------
; SETPALETTE: Set the palette (not available with all drivers/hardware).
;
SETPALETTE:
+ jsr GETERROR ; clear error (if any)
+
ldy #PALETTESIZE - 1
@L1: lda (ptr1),y ; Copy the palette
and #$0F ; Make a valid color
jmp VDCWriteReg
; ------------------------------------------------------------------------
-; GETPALETTE: Return the current palette in A/X. Must return NULL and set an
-; error if palettes are not supported.
+; 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: YES
+; Must set an error code: NO
;
GETPALETTE:
rts
; ------------------------------------------------------------------------
-; GETDEFPALETTE: Return the default palette for the driver in A/X. Must
-; return NULL and set an error of palettes are not supported.
+; 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: YES
+; Must set an error code: NO (all drivers must have a default palette)
;
GETDEFPALETTE:
; Must set an error code: NO
;
-SETPIXELCLIP:
- lda Y1+1
- bmi @finito ; y<0
- lda X1+1
- bmi @finito ; x<0
- lda xres
- ldx xres+1
- sta ADDR
- stx ADDR+1
- ldx #ADDR
- lda X1
- ldy X1+1
- jsr icmp ; if (xres<x1)
- bcs @cont ; !(xres<x1)
-@finito:rts
-@cont: lda yres
- ldx yres+1
- sta ADDR
- stx ADDR+1
- ldx #ADDR
- lda Y1
- ldy Y1+1
- jsr icmp ; if (yres<y1)
- bcc @finito
-
SETPIXEL:
lda X1
ldx X1+1
ldx #0
rts
-; ------------------------------------------------------------------------
-; HORLINE: Draw a horizontal line from X1/Y to X2/Y, where X1 = ptr1,
-; Y = ptr2 and X2 = ptr3, using the current drawing color.
-;
-; This is a special line drawing entry used when the line is know to be
-; horizontal, for example by the BAR emulation routine. If the driver does
-; not have special code for horizontal lines, it may just copy Y to Y2 and
-; proceed with the generic line drawing code.
-;
-; Note: Line coordinates will always be sorted (Y1 <= X2) and clipped.
-;
-; Must set an error code: NO
-;
-
-HORLINE:
- lda X1
- ldx X1+1
- ldy Y1
- sta r3L
- stx r3H
- sty r11L
- lda X2
- ldx X2+1
- sta r4L
- stx r4H
- lda BITMASK
- beq @L1
- lda #%11111111 ; pattern
-@L1: jmp HorizontalLine
-
; ------------------------------------------------------------------------
; 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.
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.
;
OUTTEXT:
- lda X1
+ 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 r0H
jmp PutString
-;-------------
-; copies of some runtime routines
-
-abs:
- ; a/y := abs(a/y)
- dey
- iny
- bpl @L1
- ; negay
+@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
- 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
+ adc #8
+ sta Y1
+ bne @vertical
+@end: rts
;-------------
; VDC helpers
projects / cc65 / blobdiff