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cc65/libsrc/apple2/apple2-280-192-8.s
cuz feae688346 Oliver Schmidt updated the graphics drivers and part of the C library for the
Apple machines.


git-svn-id: svn://svn.cc65.org/cc65/trunk@3816 b7a2c559-68d2-44c3-8de9-860c34a00d81
2008-03-16 09:37:22 +00:00

774 lines
20 KiB
ArmAsm
Raw Blame History

;
; Graphics driver for the 280x192x8 mode on the Apple II
;
; Stefan Haubenthal <polluks@sdf.lonestar.org>
; Oliver Schmidt <ol.sc@web.de>
; 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
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
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 <=> 90<39>
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
lda SHAPE+2*99+1
adc #>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
lda SHAPE+1,x
adc #>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