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cc65/libsrc/atmos/tgi/atmos-228-200-3.s
2023-02-26 20:03:41 +01:00

415 lines
11 KiB
ArmAsm

;
; Graphics driver for the 228x200x3 palette mode on the Atmos
;
; Stefan Haubenthal <polluks@sdf.lonestar.org>
; 2014-09-10, Greg King <gregdk@users.sf.net>
;
.include "zeropage.inc"
.include "tgi-kernel.inc"
.include "tgi-error.inc"
.include "atmos.inc"
.macpack generic
.macpack module
XSIZE = 6 ; System font width
YSIZE = 8 ; System font height
; ------------------------------------------------------------------------
; Header. Includes jump table and constants.
module_header _atmos_228_200_3_tgi
; The first part of the header is a structure that has a signature,
; and defines the capabilities of the driver.
.byte "tgi"
.byte TGI_API_VERSION ; TGI API version number
.addr $0000 ; Library reference
.word 228 ; x resolution
.word 200 ; y resolution
.byte 3 ; Number of drawing colors
.byte 1 ; Number of screens available
.byte XSIZE ; System font x size
.byte YSIZE ; System font y size
.word $011C ; Aspect ratio (based on 4/3 display)
.byte 0 ; TGI driver flags
; 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 TEXTSTYLE
.addr OUTTEXT
; ------------------------------------------------------------------------
; Data.
; Variables mapped to the zero-page segment variables. These are
; used for passing parameters to the driver.
X1 := ptr1
Y1 := ptr2
X2 := ptr3
Y2 := ptr4
; Absolute variables used in the code
.bss
ERROR: .res 1 ; Error code
MODE: .res 1 ; Graphics mode
PALETTE: .res 2
; Constant table
.rodata
; Default colors: black background, white foreground
; (The third "color" actually flips a pixel
; between the foreground and background colors.)
;
DEFPALETTE: .byte 0, 1
.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 called only once. So, any code that is needed
; to initialize variables and so on must go here. Setting palette and
; clearing the screen are not needed because they are called by the graphics
; kernel later.
; The graphics kernel never will 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 HIRES
; Done, reset the error code.
; ------------------------------------------------------------------------
; GETERROR: Return the error code in A, and clear it.
GETERROR:
ldx #TGI_ERR_OK
lda ERROR
stx ERROR
; ------------------------------------------------------------------------
; 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 probably is 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 never will 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
; ------------------------------------------------------------------------
; CONTROL: Platform-/driver-specific entry point.
;
; Must set an error code: YES
;
CONTROL:
sta PATTERN
lda #TGI_ERR_OK
sta ERROR
rts
; ------------------------------------------------------------------------
; CLEAR: Clears the screen.
;
; Must set an error code: NO
;
CLEAR := HIRES
; ------------------------------------------------------------------------
; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
; The page number already is checked to be valid, by the graphics kernel.
;
; Must set an error code: NO (will be called only if page OK)
;
SETVIEWPAGE:
; ------------------------------------------------------------------------
; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
; The page number already is checked to be valid, by the graphics kernel.
;
; Must set an error code: NO (will be called only if page OK)
;
SETDRAWPAGE:
rts
; ------------------------------------------------------------------------
; SETCOLOR: Set the drawing color (in A). The new color already is checked
; to be in a valid range (0..maxcolor-1).
;
; Must set an error code: NO (will be called only if color OK)
;
SETCOLOR:
sta MODE
rts
; ------------------------------------------------------------------------
; 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:
ldy #0
jsr flipcolor
sty PARAM1+1
jsr PAPER
ldy #1
jsr flipcolor
.assert TGI_ERR_OK = 0, error
dey
sty ERROR
sty PARAM1+1
jmp INK
flipcolor:
lda (ptr1),y
sta PALETTE,y
cmp #1
beq @flip
cmp #7
bne @keep
@flip: eor #1 ^ 7
@keep: sta PARAM1
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:
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 co-ordinates 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:
lda Y1
sta PARAM2
lda MODE
mymode: sta PARAM3
lda X1
add #2 * XSIZE ; Skip screen attribute columns
sta PARAM1
lda #>$0000
sta PARAM1+1
sta PARAM2+1
sta PARAM3+1
jmp CURSET
; ------------------------------------------------------------------------
; GETPIXEL: Read the color value of a pixel, and return it in A/X. The
; co-ordinates passed to this function are never outside the visible screen
; area, so there is no need for clipping inside this function.
GETPIXEL:
lda X1
sta PARAM1
lda Y1
sta PARAM2
lda #>$0000
sta PARAM1+1
sta PARAM2+1
jsr POINT
lda PARAM1
and #%00000001
ldx #>$0000
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:
jsr SETPIXEL
lda X2
sub X1
sta PARAM1
lda X2+1
sbc X1+1
sta PARAM1+1
lda Y2
sub Y1
sta PARAM2
lda Y2+1
sbc Y1+1
sta PARAM2+1
lda MODE
sta PARAM3
ldx #>$0000
stx PARAM3+1
jmp DRAW
; ------------------------------------------------------------------------
; 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 co-ordinates 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
; ------------------------------------------------------------------------
; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in the x
; and y directions is passed in X/Y, the text direction is passed in A.
;
; Must set an error code: NO
;
TEXTSTYLE:
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 its address in ptr3.
;
; Must set an error code: NO
;
OUTTEXT:
lda Y1
sub #(YSIZE - 1)
sta PARAM2
lda #3 ; (Move graphics cursor; don't draw)
jsr mymode
ldy #0
@next: lda (ptr3),y
beq @end
sta PARAM1
lda #0
sta PARAM2
sta PARAM1+1
sta PARAM2+1
sta PARAM3+1
lda MODE
sta PARAM3
tya
pha
jsr CHAR
lda #XSIZE
sta PARAM1
lda #0
sta PARAM2
sta PARAM1+1
sta PARAM2+1
sta PARAM3+1
lda #3
sta PARAM3
jsr CURMOV
pla
tay
iny
bne @next
@end: rts