mirror of
https://github.com/cc65/cc65.git
synced 2024-12-28 06:30:16 +00:00
397 lines
11 KiB
ArmAsm
397 lines
11 KiB
ArmAsm
;
|
|
; Graphics driver for the 320 pixels across, 240 pixels down, 256 colors mode
|
|
; on the Commander X16
|
|
;
|
|
; 2022-03-30, Greg King <gregdk@users.sf.net>
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
|
|
.include "tgi-kernel.inc"
|
|
.include "tgi-error.inc"
|
|
|
|
.include "cbm_kernal.inc"
|
|
.include "cx16.inc"
|
|
|
|
.macpack generic
|
|
.macpack module
|
|
|
|
|
|
; Macro that copies a word into a pseudo-register
|
|
|
|
.mac setReg reg, src
|
|
lda src
|
|
ldx src+1
|
|
sta gREG::reg
|
|
stx gREG::reg+1
|
|
.endmac
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table and constants.
|
|
|
|
module_header _cx320p1_tgi ; 320 pixels across, 1 pixel per byte
|
|
|
|
; First part of the header is a structure that has a signature,
|
|
; and defines the capabilities of the driver.
|
|
|
|
.byte $74, $67, $69 ; ASCII "tgi"
|
|
.byte TGI_API_VERSION ; TGI API version number
|
|
.addr $0000 ; Library reference
|
|
.word 320 ; X resolution
|
|
.word 240 ; Y resolution
|
|
.byte <$0100 ; Number of drawing colors
|
|
.byte 1 ; Number of screens available
|
|
.byte 8 ; System font X size
|
|
.byte 8 ; System font Y size
|
|
.word $0100 ; Aspect ratio (based on VGA 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
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Constant
|
|
|
|
GRAPH320 = $80
|
|
|
|
; ------------------------------------------------------------------------
|
|
; 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
|
|
|
|
; Absolute variables used in the code
|
|
|
|
.bss
|
|
|
|
; The colors are indicies into a TGI palette. The TGI palette is indicies into
|
|
; VERA's palette. Vera's palette is a table of Red, Green, and Blue levels.
|
|
; The first 16 RGB elements mimic the Commodore 64's colors.
|
|
|
|
defpalette: .res $0100
|
|
palette: .res $0100
|
|
|
|
bcolor := palette + 0 ; Background color
|
|
color: .res 1 ; Stroke and fill index
|
|
text_mode: .res 1 ; Old text mode
|
|
|
|
.data
|
|
|
|
error: .byte TGI_ERR_OK ; Error code
|
|
|
|
|
|
.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:
|
|
; Create the default palette.
|
|
|
|
ldx #$00
|
|
: txa
|
|
sta defpalette,x
|
|
inx
|
|
bnz :-
|
|
|
|
; 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
|
|
|
|
; ------------------------------------------------------------------------
|
|
; 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 initiate variables and so on must go here. Setting the palette is not
|
|
; needed because that is called by the graphics kernel later.
|
|
; The graphics kernel never will call INIT when a graphics mode already is
|
|
; active, so there is no need to protect against that.
|
|
;
|
|
; Must set an error code: YES
|
|
|
|
INIT: stz error ; #TGI_ERR_OK
|
|
|
|
; Save the current text mode.
|
|
|
|
sec
|
|
jsr SCREEN_MODE
|
|
sta text_mode
|
|
|
|
; Switch into (320 x 240 x 256) graphics mode.
|
|
|
|
lda #GRAPH320
|
|
clc
|
|
jmp SCREEN_MODE
|
|
|
|
; ------------------------------------------------------------------------
|
|
; 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:
|
|
lda text_mode
|
|
clc
|
|
jmp SCREEN_MODE
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETERROR: Return the error code in .A, and clear it.
|
|
|
|
GETERROR:
|
|
lda error
|
|
stz error
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; CONTROL: Platform-/driver-specific entry point.
|
|
;
|
|
; Must set an error code: YES
|
|
|
|
CONTROL:
|
|
lda #TGI_ERR_INV_FUNC
|
|
sta error
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; CLEAR: Clear the screen.
|
|
;
|
|
; Must set an error code: NO
|
|
|
|
CLEAR := GRAPH_CLEAR
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETVIEWPAGE: Set the visible page. Called with the new page in .A (0..n-1).
|
|
; 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:
|
|
|
|
; Fall through.
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETDRAWPAGE: Set the drawable page. Called with the new page in .A (0..n-1).
|
|
; 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
|
|
|
|
; ------------------------------------------------------------------------
|
|
; 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:
|
|
stz error ; #TGI_ERR_OK
|
|
ldy #$00
|
|
: lda (ptr1),y
|
|
sta palette,y
|
|
iny
|
|
bnz :-
|
|
|
|
lda color ; Get stroke and fill index
|
|
|
|
; Fall through.
|
|
|
|
; ------------------------------------------------------------------------
|
|
; SETCOLOR: Set the drawing color (in .A). The new color already is checked
|
|
; to be in a valid range (0..maxcolor).
|
|
;
|
|
; Must set an error code: NO (will be called only if color OK)
|
|
|
|
SETCOLOR:
|
|
tax
|
|
sta color
|
|
lda palette,x ; Set stroke and fill color
|
|
tax
|
|
ldy bcolor ; Get background color
|
|
jmp GRAPH_SET_COLORS
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETPALETTE: Return the current palette in .XA. 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 .XA. 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 changable) 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 never are outside the
|
|
; visible screen area, so there is no need for clipping inside this function.
|
|
;
|
|
; Must set an error code: NO
|
|
|
|
SETPIXEL:
|
|
jsr Point
|
|
jsr FB_CURSOR_POSITION
|
|
ldx color
|
|
lda palette,x
|
|
jmp FB_SET_PIXEL
|
|
|
|
; ------------------------------------------------------------------------
|
|
; GETPIXEL: Read the color value of a pixel, and return it in .XA. The
|
|
; co-ordinates passed to this function never are outside the visible screen
|
|
; area, so there is no need for clipping inside this function.
|
|
|
|
GETPIXEL:
|
|
jsr Point
|
|
jsr FB_CURSOR_POSITION
|
|
jsr FB_GET_PIXEL
|
|
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 Point
|
|
setReg r2, X2
|
|
setReg r3, Y2
|
|
jmp GRAPH_DRAW_LINE
|
|
|
|
; ------------------------------------------------------------------------
|
|
; 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:
|
|
; Set the starting corner.
|
|
|
|
jsr Point
|
|
|
|
; Set the width.
|
|
|
|
lda X2
|
|
sub X1
|
|
sta gREG::r2
|
|
lda X2+1
|
|
sbc X1+1
|
|
sta gREG::r2+1
|
|
|
|
; Set the height.
|
|
|
|
lda Y2
|
|
sub Y1
|
|
sta gREG::r3
|
|
lda Y2+1
|
|
sbc Y1+1
|
|
sta gREG::r3+1
|
|
|
|
; Set the corner radius.
|
|
|
|
stz gREG::r4
|
|
stz gREG::r4+1
|
|
|
|
sec ; Fill the rectangle
|
|
jmp GRAPH_DRAW_RECT
|
|
|
|
; ------------------------------------------------------------------------
|
|
; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
|
|
; directions are passed in .X and .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 address in ptr3.
|
|
;
|
|
; Must set an error code: NO
|
|
|
|
OUTTEXT:
|
|
jsr Point
|
|
|
|
ldy #$00
|
|
@next: lda (ptr3),y
|
|
bze @end
|
|
phy
|
|
jsr GRAPH_PUT_CHAR
|
|
ply
|
|
iny
|
|
bnz @next
|
|
@end: rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Point: Set the arguments for the first point of a Kernal graphics function.
|
|
|
|
Point: setReg r0, X1
|
|
setReg r1, Y1
|
|
rts
|