; ; Graphics driver for the 228x200x3 palette mode on the Atmos ; ; Stefan Haubenthal ; 2014-09-10, Greg King ; .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 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 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