; ; Graphics driver for the 280x192x8 mode on the Apple II ; ; Stefan Haubenthal ; Oliver Schmidt ; Based on 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 ; ------------------------------------------------------------------------ ; Zero page stuff HBASL := $26 HMASK := $30 PAGE := $E6 SCALE := $E7 ROT := $F9 ; Graphics entry points, by cbmnut (applenut??) cbmnut@hushmail.com TEXT := $F399 ; Return to text screen HGR2 := $F3D8 ; Initialize and clear hi-res page 2. HGR := $F3E2 ; Initialize and clear hi-res page 1. HCLR := $F3F2 ; Clear the current hi-res screen to black. BKGND := $F3F6 ; Clear the current hi-res screen to the ; last plotted color (from ($1C). HPOSN := $F411 ; Positions the hi-res cursor without ; plotting a point. ; Enter with (A) = Y-coordinate, and ; (Y,X) = X-coordinate. HPLOT := $F457 ; Calls HPOSN and tries to plot a dot at ; the cursor's position. If you are ; trying to plot a non-white color at ; a complementary color position, no ; dot will be plotted. HLIN := $F53A ; Draws a line from the last plotted ; point or line destination to: ; (X,A) = X-coordinate, and ; (Y) = Y-coordinate. HFIND := $F5CB ; Converts the hi-res coursor's position ; back to X- and Y-coordinates; stores ; X-coordinate at $E0,E1 and Y-coordinate ; at $E2. DRAW := $F601 ; Draws a shape. Enter with (Y,X) = the ; address of the shape table, and (A) = ; the rotation factor. Uses the current ; color. XDRAW := $F65D ; Draws a shape by inverting the existing ; color of the dots the shape draws over. ; Same entry parameters as DRAW. SETHCOL := $F6EC ; Set the hi-res color to (X), where (X) ; must be between 0 and 7. ; ------------------------------------------------------------------------ ; 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) SETPIXELCLIP TEMP := tmp3 ; icmp TEMP2 := tmp4 ; icmp XX := ptr3 ; (2) CIRCLE YY := ptr4 ; (2) CIRCLE TEMP3 := sreg ; CIRCLE TEMP4 := sreg+1 ; CIRCLE MaxO := sreg ; (overwritten by TEMP3+TEMP4, but restored from OG/OU anyway) XS := regsave ; (2) CIRCLE YS := regsave+2 ; (2) CIRCLE ; ------------------------------------------------------------------------ .segment "JUMPTABLE" ; Header. Includes jump table and constants. ; 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). .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 ; ------------------------------------------------------------------------ .bss ; Absolute variables used in the code ERROR: .res 1 ; Error code .ifdef __APPLE2ENH__ Set80: .res 1 ; Set 80 column store .endif ; Circle stuff OGora: .res 2 OUkos: .res 2 Y3: .res 2 ; ------------------------------------------------------------------------ .rodata ; Constants and tables DEFPALETTE: .byte $00, $01, $02, $03, $04, $05, $06, $07 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 ; 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: .ifdef __APPLE2ENH__ ; Save and clear 80 column store lda RD80COL sta Set80 sta CLR80COL .endif ; Switch into graphics mode bit HIRES bit MIXCLR bit TXTCLR ; Done, reset the error code lda #TGI_ERR_OK sta ERROR ; Fall through ; 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: ; Fall through ; 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 ; 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: ; Switch into text mode bit TXTSET bit LOWSCR .ifdef __APPLE2ENH__ ; Restore 80 column store lda Set80 bpl :+ sta SET80COL : bit LORES ; Limit SET80COL-HISCR to text .endif rts ; GETERROR: Return the error code in A and clear it. GETERROR: lda ERROR ldx #TGI_ERR_OK stx ERROR rts ; CLEAR: Clears the screen. ; Must set an error code: NO CLEAR: bit $C082 ; Switch in ROM jsr HCLR bit $C080 ; Switch in LC bank 2 for R/O 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: tax .assert LOWSCR + 1 = HISCR, error lda LOWSCR,x ; No BIT absolute,X available 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 :+ lda #>$4000 ; Page 2 .byte $2C ; BIT absolute : lda #>$2000 ; Page 1 sta PAGE 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: bit $C082 ; Switch in ROM tax jsr SETHCOL bit $C080 ; Switch in LC bank 2 for R/O rts ; CONTROL: Platform/driver specific entry point. ; Must set an error code: YES CONTROL: ; Fall through ; 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: ; Fall through ; 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 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 SETPIXEL: bit $C082 ; Switch in ROM ldx X1 ldy X1+1 lda Y1 jsr HPLOT bit $C080 ; Switch in LC bank 2 for R/O rts SETPIXELCLIP: lda Y1+1 bmi :+ ; y < 0 lda X1+1 bmi :+ ; x < 0 lda X1 ldx X1+1 sta ADDR stx ADDR+1 ldx #ADDR lda xres ldy xres+1 jsr icmp ; ( x < xres ) ... bcs :+ lda Y1 ldx Y1+1 sta ADDR stx ADDR+1 ldx #ADDR lda yres ldy yres+1 jsr icmp ; ... && ( y < yres ) bcc SETPIXEL : 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: bit $C082 ; Switch in ROM ldx X1 ldy X1+1 lda Y1 jsr HPOSN lda (HBASL),y and HMASK asl beq :+ ; 0 (black) lda #$03 ; 3 (white) : bcc :+ adc #$03 ; += 4 (black -> black2, white -> white2) : ldx #$00 bit $C080 ; Switch in LC bank 2 for R/O 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: bit $C082 ; Switch in ROM ldx X1 ldy X1+1 lda Y1 jsr HPOSN lda X2 ldx X2+1 ldy Y2 jsr HLIN bit $C080 ; Switch in LC bank 2 for R/O rts ; 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 : lda Y2 pha lda Y1 sta Y2 jsr LINE pla sta Y2 inc Y1 cmp Y1 bne :- 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 :+ jmp SETPIXELCLIP ; Plot as a point : sta XX ; x = r lda #$00 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) { while: ldx #YY lda XX ldy XX+1 jsr icmp bcc :+ rts ; 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 #$01 bcc :+ inx : 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 #$01 bcc :+ inx : sta OUkos stx OUkos+1 ; ++y inc YY bne :+ inc YY+1 ; 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 :++ ; --x lda XX sub #$01 sta XX bcs :+ dec XX+1 ; mo = ou } : lda OUkos ldx OUkos+1 jmp :++ ; else mo = og : lda OGora ldx OGora+1 : sta MaxO stx MaxO+1 ; } jmp while ; 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 SCALE asl ; 16 <=> 90þ asl asl asl sta ROT 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: bit $C082 ; Switch in ROM ldx X1 ldy X1+1 lda Y1 jsr HPOSN lda SHAPE+2*99 add #SHAPE sta tmp3+1 ldy #$00 : lda (ptr3),y beq :+ sub #$1F ; No controls asl ; Offset * 2 tax lda SHAPE,x add #SHAPE sta tmp1+1 tya pha ldx tmp1 ldy tmp1+1 lda ROT jsr DRAW ldx tmp3 ldy tmp3+1 lda ROT jsr DRAW pla tay iny bne :- : bit $C080 ; Switch in LC bank 2 for R/O rts ; Copies of some runtime routines abs: ; A/Y := abs (A/Y) cpy #$00 bpl :+ clc eor #$FF adc #$01 pha tya eor #$FF adc #$00 tay pla : rts icmp: ; Compare A/Y to zp,X sta TEMP ; TEMP/TEMP2 - arg2 sty TEMP2 lda $00,x pha lda $01,x tay pla tax tya ; X/A - arg1 (a = high) sub TEMP2 bne :++ cpx TEMP beq :+ adc #$FF ora #$01 : rts : bvc :+ eor #$FF ora #$01 : rts