--- /dev/null
+;
+; Graphics driver for the 280x192x6 mode on the Apple II
+;
+; Stefan Haubenthal <polluks@sdf.lonestar.org>
+; Based on Stephen L. Judd's GRLIB code and
+; Maciej Witkowiak's circle routine
+;
+
+ .include "zeropage.inc"
+
+ .include "tgi-kernel.inc"
+ .include "tgi-mode.inc"
+ .include "tgi-error.inc"
+ .include "apple2.inc"
+
+ .macpack generic
+
+; ------------------------------------------------------------------------
+; 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 280 ; X resolution
+yres: .word 192 ; Y resolution
+ .byte 8 ; Number of drawing colors
+ .byte 2 ; 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
+
+ERROR: .res 1 ; Error code
+
+; Line routine stuff (combined with CIRCLE to save space)
+
+OGora: .res 2
+OUkos: .res 2
+Y3: .res 2
+
+; Text output stuff
+TEXTMAGX = $E7
+TEXTMAGY = $E7
+TEXTDIR = $F9
+
+; Constants and tables
+
+.rodata
+
+DEFPALETTE: .byte $00, $05, $04, $01, $00, $08, $06, $01; 6 unique colors
+PALETTESIZE = * - DEFPALETTE
+
+SHAPE: .byte $64,$01,$d0,$00,$d5,$00,$da,$00,$e0,$00,$ef,$00,$fe,$00,$0c,$01
+ .byte $19,$01,$1d,$01,$25,$01,$2d,$01,$3d,$01,$46,$01,$4b,$01,$52,$01
+ .byte $56,$01,$60,$01,$70,$01,$77,$01,$83,$01,$8e,$01,$9a,$01,$a7,$01
+ .byte $b6,$01,$bf,$01,$ce,$01,$dd,$01,$e2,$01,$e7,$01,$f9,$01,$03,$02
+ .byte $15,$02,$1f,$02,$32,$02,$42,$02,$52,$02,$5e,$02,$6c,$02,$79,$02
+ .byte $85,$02,$91,$02,$a1,$02,$a9,$02,$b2,$02,$bf,$02,$c5,$02,$d5,$02
+ .byte $e5,$02,$f4,$02,$00,$03,$10,$03,$1f,$03,$2d,$03,$35,$03,$44,$03
+ .byte $53,$03,$63,$03,$71,$03,$7b,$03,$85,$03,$91,$03,$97,$03,$a3,$03
+ .byte $b6,$03,$bf,$03,$c3,$03,$cf,$03,$dc,$03,$e4,$03,$f3,$03,$00,$04
+ .byte $0a,$04,$19,$04,$25,$04,$2a,$04,$32,$04,$3c,$04,$43,$04,$50,$04
+ .byte $5a,$04,$66,$04,$72,$04,$7e,$04,$87,$04,$94,$04,$9c,$04,$a8,$04
+ .byte $b4,$04,$c1,$04,$cc,$04,$db,$04,$e6,$04,$ee,$04,$f3,$04,$fb,$04
+ .byte $04,$05,$1a,$05,$1f,$05,$24,$05,$29,$05,$22,$01,$00,$00,$00,$00
+ .byte $09,$89,$92,$92,$00,$36,$36,$16,$0e,$00,$0d,$fe,$6e,$96,$52,$00
+ .byte $69,$fe,$17,$2d,$2d,$1e,$1f,$17,$2d,$2d,$1e,$1f,$6e,$4e,$00,$09
+ .byte $8d,$3f,$bf,$0d,$15,$3f,$0e,$0d,$1e,$3f,$77,$71,$09,$00,$6d,$11
+ .byte $df,$77,$09,$1e,$17,$4d,$3a,$df,$4e,$29,$0e,$00,$a9,$1f,$6e,$1e
+ .byte $17,$0d,$0d,$1e,$df,$0e,$6d,$0e,$00,$36,$96,$52,$00,$09,$1e,$17
+ .byte $36,$15,$0e,$0e,$00,$15,$0e,$36,$1e,$17,$4e,$01,$00,$09,$8d,$1f
+ .byte $1f,$0e,$2d,$1e,$17,$2d,$15,$1f,$1f,$4e,$4e,$01,$00,$89,$6e,$3a
+ .byte $3f,$77,$31,$56,$09,$00,$92,$8a,$f6,$0d,$00,$52,$89,$3f,$b7,$52
+ .byte $49,$00,$92,$92,$0e,$00,$49,$11,$17,$1e,$17,$1e,$56,$49,$01,$00
+ .byte $29,$ad,$df,$33,$4d,$35,$1f,$1f,$2e,$4d,$fe,$1b,$0e,$2d,$4e,$00
+ .byte $31,$77,$36,$be,$2d,$0e,$00,$29,$ad,$df,$73,$49,$1e,$bf,$1e,$2e
+ .byte $2d,$75,$00,$2d,$2d,$be,$3e,$4e,$fe,$1b,$0e,$2d,$4e,$00,$49,$3e
+ .byte $17,$0d,$fe,$33,$2d,$2d,$1e,$76,$01,$00,$2d,$2d,$de,$1b,$2e,$2d
+ .byte $15,$36,$df,$73,$2d,$4e,$00,$09,$2d,$de,$bb,$4d,$3a,$3f,$6e,$09
+ .byte $fe,$1b,$0e,$2d,$4e,$00,$2d,$2d,$be,$1e,$17,$36,$4e,$09,$00,$29
+ .byte $ad,$df,$33,$4d,$f1,$3f,$17,$4d,$31,$df,$73,$2d,$4e,$00,$29,$ad
+ .byte $df,$33,$4d,$31,$3f,$77,$09,$1e,$df,$2a,$75,$09,$00,$12,$16,$96
+ .byte $01,$00,$52,$b2,$f6,$0d,$00,$49,$3e,$17,$2d,$2d,$35,$3f,$3f,$3f
+ .byte $0e,$2d,$2d,$f5,$1b,$77,$4e,$09,$00,$12,$2d,$2d,$de,$9b,$2d,$2d
+ .byte $96,$01,$00,$49,$15,$ff,$13,$2d,$2d,$ad,$3f,$3f,$3f,$2e,$2d,$2d
+ .byte $1e,$37,$4e,$09,$00,$29,$ad,$df,$73,$09,$1e,$b6,$4e,$01,$00,$09
+ .byte $2d,$3e,$37,$2d,$3e,$ff,$2a,$2d,$2d,$f5,$3f,$3f,$0e,$2d,$1e,$4d
+ .byte $01,$00,$09,$15,$1f,$17,$4d,$31,$df,$33,$2d,$2d,$fe,$1b,$6e,$09
+ .byte $0e,$00,$2d,$ad,$df,$33,$4d,$f1,$3f,$37,$4d,$31,$df,$33,$2d,$75
+ .byte $01,$00,$29,$ad,$df,$33,$36,$4d,$11,$df,$73,$2d,$4e,$00,$2d,$ad
+ .byte $df,$6e,$31,$df,$6e,$31,$df,$17,$2d,$75,$01,$00,$2d,$2d,$de,$1b
+ .byte $6e,$11,$3f,$37,$36,$2d,$2d,$0e,$00,$2d,$2d,$de,$1b,$6e,$11,$3f
+ .byte $37,$36,$4e,$49,$00,$29,$ad,$df,$33,$36,$4d,$35,$df,$73,$2d,$75
+ .byte $00,$4d,$31,$df,$33,$4d,$31,$3f,$3f,$6e,$09,$fe,$1b,$6e,$09,$0e
+ .byte $00,$2d,$1e,$36,$36,$17,$2d,$0e,$00,$49,$31,$36,$36,$df,$73,$2d
+ .byte $4e,$00,$4d,$f1,$df,$6e,$1e,$37,$0d,$15,$df,$6e,$09,$0e,$00,$36
+ .byte $36,$36,$2d,$75,$00,$4d,$31,$ff,$37,$0d,$0d,$fe,$1f,$6e,$09,$fe
+ .byte $1b,$6e,$09,$0e,$00,$4d,$31,$df,$33,$6d,$31,$1f,$1f,$6e,$29,$fe
+ .byte $1b,$6e,$09,$0e,$00,$29,$ad,$df,$33,$4d,$31,$df,$33,$4d,$31,$df
+ .byte $73,$2d,$4e,$00,$2d,$ad,$df,$33,$4d,$f1,$3f,$37,$36,$4e,$49,$00
+ .byte $29,$ad,$df,$33,$4d,$31,$df,$33,$0d,$0d,$1e,$df,$0e,$6d,$0e,$00
+ .byte $2d,$ad,$df,$33,$4d,$f1,$3f,$37,$0d,$15,$df,$6e,$09,$0e,$00,$29
+ .byte $ad,$df,$33,$4d,$3a,$77,$09,$fe,$1b,$0e,$2d,$4e,$00,$2d,$2d,$de
+ .byte $36,$36,$76,$09,$00,$4d,$31,$df,$33,$4d,$31,$df,$33,$4d,$31,$df
+ .byte $73,$2d,$4e,$00,$4d,$31,$df,$33,$4d,$31,$df,$33,$4d,$f1,$1f,$0e
+ .byte $4e,$01,$00,$4d,$31,$df,$33,$4d,$31,$1f,$1f,$6e,$0d,$3e,$1f,$37
+ .byte $4d,$71,$00,$4d,$31,$df,$73,$0d,$1e,$17,$0d,$15,$df,$33,$4d,$71
+ .byte $00,$4d,$31,$df,$73,$0d,$1e,$36,$76,$09,$00,$2d,$2d,$be,$1e,$17
+ .byte $1e,$2e,$2d,$75,$00,$2d,$2d,$de,$3b,$2e,$3e,$2e,$3e,$2e,$2d,$75
+ .byte $00,$72,$15,$0e,$15,$56,$00,$2d,$2d,$3e,$2e,$3e,$2e,$3e,$df,$2a
+ .byte $2d,$75,$00,$49,$15,$3f,$17,$2d,$2d,$15,$3f,$3f,$3f,$4e,$2d,$3e
+ .byte $37,$2d,$3e,$6f,$49,$00,$92,$92,$49,$11,$3f,$3f,$4d,$09,$00,$76
+ .byte $96,$52,$00,$52,$2d,$35,$df,$33,$4d,$31,$ff,$73,$6d,$0e,$00,$36
+ .byte $2d,$ad,$df,$33,$4d,$31,$df,$33,$2d,$75,$01,$00,$52,$2d,$de,$33
+ .byte $76,$2d,$0e,$00,$49,$31,$df,$2a,$2d,$fe,$1b,$6e,$09,$fe,$1b,$0e
+ .byte $2d,$75,$00,$52,$2d,$15,$df,$33,$2d,$2d,$de,$1b,$0e,$2d,$75,$00
+ .byte $09,$f5,$33,$8d,$3f,$77,$36,$4e,$01,$00,$52,$2d,$35,$df,$33,$4d
+ .byte $31,$3f,$77,$09,$1e,$3f,$4d,$01,$00,$36,$2d,$ad,$df,$33,$4d,$31
+ .byte $df,$33,$4d,$71,$00,$16,$36,$36,$0e,$00,$09,$9e,$35,$36,$f6,$6f
+ .byte $01,$00,$36,$4d,$1e,$1f,$2e,$15,$1f,$6e,$71,$00,$35,$36,$36,$17
+ .byte $2d,$0e,$00,$12,$2d,$ad,$1f,$1f,$6e,$0d,$fe,$1f,$6e,$0d,$0e,$00
+ .byte $12,$2d,$15,$df,$6e,$31,$df,$6e,$71,$00,$52,$2d,$15,$df,$33,$4d
+ .byte $31,$df,$73,$2d,$4e,$00,$12,$2d,$ad,$df,$33,$4d,$f1,$3f,$37,$6e
+ .byte $49,$00,$52,$2d,$35,$df,$33,$4d,$31,$3f,$77,$09,$2e,$00,$12,$0d
+ .byte $ad,$df,$37,$36,$4e,$49,$00,$52,$2d,$f5,$db,$0e,$2d,$15,$df,$13
+ .byte $2d,$75,$01,$00,$31,$17,$2d,$f5,$33,$76,$75,$00,$12,$4d,$31,$df
+ .byte $33,$4d,$31,$ff,$73,$6d,$0e,$00,$12,$4d,$31,$df,$33,$4d,$f1,$1f
+ .byte $0e,$4e,$01,$00,$12,$4d,$31,$df,$33,$0d,$0d,$fe,$1f,$0e,$0d,$4e
+ .byte $00,$12,$4d,$f1,$1f,$0e,$15,$1f,$17,$4d,$71,$00,$12,$4d,$31,$df
+ .byte $33,$4d,$31,$3f,$77,$09,$1e,$3f,$4d,$01,$00,$12,$2d,$2d,$1e,$17
+ .byte $1e,$17,$2d,$2d,$0e,$00,$09,$f5,$33,$1e,$0e,$76,$75,$00,$36,$36
+ .byte $36,$2e,$00,$ad,$ae,$17,$fe,$2a,$4e,$01,$00,$69,$11,$1f,$1f,$4e
+ .byte $b1,$92,$09,$00,$2d,$2d,$35,$3f,$3f,$37,$2d,$2d,$35,$3f,$3f,$37
+ .byte $2d,$2d,$35,$3f,$3f,$37,$2d,$2d,$75,$00,$40,$c0,$40,$18,$00,$40
+ .byte $c0,$40,$43,$00,$40,$c0,$40,$08,$00,$19,$00,$00
+
+.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:
+
+
+; ------------------------------------------------------------------------
+; 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:
+
+; Switch into graphics mode
+
+ jsr HGR
+ lda MIXOFF
+
+; 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 = TEXT
+
+; ------------------------------------------------------------------------
+; 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 = HCLR
+
+; ------------------------------------------------------------------------
+; 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:
+ tax
+ beq @L1
+ lda PG2ON
+ rts
+@L1: lda PG2OFF
+ rts
+
+; ------------------------------------------------------------------------
+; 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:
+ tax
+ beq @L1
+ jmp HGR2
+@L1: jmp HGR
+
+; ------------------------------------------------------------------------
+; 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
+ jmp SETHCOL
+
+; ------------------------------------------------------------------------
+; 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:
+ lda #TGI_ERR_INV_FUNC
+ 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:
+
+; ------------------------------------------------------------------------
+; 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:
+ ldx X1
+ ldy X1+1
+ lda Y1
+ jmp HPLOT
+
+; ------------------------------------------------------------------------
+; 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 #TGI_ERR_INV_FUNC
+ sta ERROR
+ 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:
+ ldx X1
+ ldy X1+1
+ lda Y1
+ jsr HPOSN
+ lda X2
+ ldx X2+1
+ ldy Y2
+ jmp HLIN
+
+; ------------------------------------------------------------------------
+; 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
+@L1: lda Y2
+ pha
+ lda Y1
+ sta Y2
+ jsr LINE
+ pla
+ sta Y2
+ inc Y1
+ cmp Y1
+ bne @L1
+ rts
+
+; ------------------------------------------------------------------------
+; 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
+ add XX
+ sta X1
+ lda XS+1
+ adc XX+1
+ sta X1+1 ; x1 = xs+x
+ lda YS
+ add 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
+ sub 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
+ sub 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
+ add YY
+ sta X1
+ lda XS+1
+ adc YY+1
+ sta X1+1 ; x1 = xs+y
+ lda YS
+ add 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
+ sub 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
+ sub 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
+ add YY
+ tay
+ txa
+ adc YY+1
+ tax
+ tya
+ add YY
+ tay
+ txa
+ adc YY+1
+ tax
+ tya
+ add #1
+ bcc @L0143
+ inx
+@L0143: sta OGora
+ stx OGora+1
+ ; ou = og-x-x+1
+ sub XX
+ tay
+ txa
+ sbc XX+1
+ tax
+ tya
+ sub XX
+ tay
+ txa
+ sbc XX+1
+ tax
+ tya
+ add #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;
+ lda XX
+ sub #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
+ asl ; 16 <=> 90°
+ asl
+ asl
+ asl
+ 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:
+ ldx X1
+ ldy X1+1
+ lda Y1
+ jsr HPOSN
+ lda SHAPE+2*99
+ add #<SHAPE
+ sta tmp3
+ lda SHAPE+2*99+1
+ adc #>SHAPE
+ sta tmp3+1
+
+ ldy #0
+@L1: lda (ptr3),y
+ beq @end
+ sub #31 ; no controls
+ asl ; offset*2
+ tax
+ lda SHAPE,x
+ add #<SHAPE
+ sta tmp1
+ lda SHAPE+1,x
+ adc #>SHAPE
+ sta tmp1+1
+ tya
+ pha
+ ldx tmp1
+ ldy tmp1+1
+ lda TEXTDIR
+ jsr DRAW
+ ldx tmp3
+ ldy tmp3+1
+ lda TEXTDIR
+ jsr DRAW
+ pla
+ tay
+ iny
+ bne @L1
+@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 $1,x
+ tay
+ pla
+ tax
+ tya ; x/a - arg1 (a=high)
+
+ sub TEMP2
+ bne @L4
+ cpx TEMP
+ beq @L3
+ adc #$ff
+ ora #$01
+@L3: rts
+@L4: bvc @L3
+ eor #$ff
+ ora #$01
+ rts
projects / cc65 / commitdiff