2 ; Graphics driver for the 320x200x2 and 640x200x2 modes on GEOS 64/128
3 ; 2010-08-17, Maciej 'YTM/Elysium' Witkowiak <ytm@elysium.pl>
4 ; 2010-08-18, Greg King
6 .include "zeropage.inc"
8 .include "tgi-kernel.inc"
9 .include "tgi-error.inc"
11 .include "../inc/const.inc"
12 .include "../inc/jumptab.inc"
13 .include "../inc/geossym.inc"
14 .include "../inc/geossym2.inc"
18 ; ------------------------------------------------------------------------
21 VDC_ADDR_REG := $D600 ; VDC address
22 VDC_DATA_REG := $D601 ; VDC data
24 VDC_DSP_HI = 12 ; registers used
35 ; ------------------------------------------------------------------------
36 ; Header. Includes jump table and constants.
40 ; First part of the header is a structure that has a magic signature,
41 ; and defines the capabilities of the driver.
43 .byte $74, $67, $69 ; "tgi"
44 .byte TGI_API_VERSION ; TGI API version number
45 xres: .word 320 ; X resolution
46 yres: .word 200 ; Y resolution
47 .byte 2 ; Number of drawing colors
48 pages: .byte 1 ; Number of screens available
49 .byte 8 ; System font X size
50 .byte 8 ; System font Y size
51 .word $100 ; Aspect ratio: 1.0
53 ; Next comes the jump table. With the exception of IRQ, all entries must be
54 ; valid, and may point to an RTS for test versions (function not implemented).
75 .addr 0 ; IRQ entry is unused
77 ; ------------------------------------------------------------------------
80 ; Variables mapped to the zero-page segment variables. Some of these are
81 ; used for passing parameters to the driver.
88 ; Absolute variables used in the code
92 SCRBASE: .res 1 ; High byte of screen base (64k VDC only)
94 ERROR: .res 1 ; Error code
95 PALETTE: .res 2 ; The current palette
97 BITMASK: .res 1 ; $00 = clear, $01 = set pixels
99 OLDCOLOR: .res 1 ; colors before entering gfx mode
106 ; Constants and tables
110 DEFPALETTE: .byte $00, $0f ; White on black
111 PALETTESIZE = * - DEFPALETTE
113 ; color translation table (indexed by VIC color)
114 COLTRANS: .byte $00, $0f, $08, $06, $0a, $04, $02, $0c
115 .byte $0d, $0b, $09, $01, $0e, $05, $03, $07
116 ; colors BROWN and GRAY3 are wrong
120 ; ------------------------------------------------------------------------
121 ; INSTALL routine. Is called after the driver is loaded into memory. May
122 ; initialize anything that has to be done just once. Is probably empty
125 ; Must set an error code: NO
129 lda version ; if GEOS 1.0...
133 lda c128Flag ; at least GEOS 2.0, but we're on C128?
135 lda graphMode ; GEOS 2.0, C128, but is 80 column screen enabled?
137 @L40: rts ; leave default values for 40 column screen
139 ; check for VDC version and update register $19 value
147 ; update number of available screens
149 ldx #VDC_CSET ; determine size of RAM...
153 jsr VDCWriteReg ; turn on 64k
155 jsr settestadr1 ; save original value of test byte
159 lda #$55 ; write $55 here
161 jsr test64k ; read it here and there
162 lda #$aa ; write $aa here
164 jsr test64k ; read it here and there
168 jsr VDCWriteByte ; restore original value of test byte
170 lda ptr1 ; do bytes match?
179 jsr VDCWriteReg ; restore 16/64k flag
180 jmp @endok ; and leave default values for 16k
187 sta SCRBASE ; draw page 0 as default
197 jsr VDCWriteByte ; write $55
199 jsr VDCReadByte ; read here
202 jsr VDCReadByte ; and there
211 ldy #$02 ; test page 2 (here)
214 ldy #$42 ; or page 64+2 (there)
218 ; ------------------------------------------------------------------------
219 ; UNINSTALL routine. Is called before the driver is removed from memory. May
220 ; clean up anything done by INSTALL but is probably empty most of the time.
222 ; Must set an error code: NO
229 ; ------------------------------------------------------------------------
230 ; INIT: Changes an already installed device from text mode to graphics
232 ; Note that INIT/DONE may be called multiple times while the driver
233 ; is loaded, while INSTALL is only called once, so any code that is needed
234 ; to initializes variables and so on must go here. Setting palette and
235 ; clearing the screen is not needed because this is called by the graphics
237 ; The graphics kernel will never call INIT when a graphics mode is already
238 ; active, so there is no need to protect against that.
240 ; Must set an error code: YES
245 stx BITMASK ; solid black as pattern
248 lda #ST_WR_FORE ; write only on foreground
254 ; Remember current color value (40 columns)
259 ; Remember current color value (80 columns)
260 @L80: lda scr80colors
263 jsr SETVIEWPAGE ; switch into viewpage 0
265 ; Done, reset the error code
271 ; ------------------------------------------------------------------------
272 ; DONE: Will be called to switch the graphics device back into text mode.
273 ; The graphics kernel will never call DONE when no graphics mode is active,
274 ; so there is no need to protect against that.
276 ; Must set an error code: NO
281 jsr SETVIEWPAGE ; switch into viewpage 0
287 sta screencolors ; restore color for 40 columns
289 @L1: sta COLOR_MATRIX,x
290 sta COLOR_MATRIX+$0100,x
291 sta COLOR_MATRIX+$0200,x
292 sta COLOR_MATRIX+1000-256,x
297 @L80: lda OLDCOLOR ; restore color for 80 columns
301 ; ------------------------------------------------------------------------
302 ; GETERROR: Return the error code in A and clear it.
310 ; ------------------------------------------------------------------------
311 ; CONTROL: Platform/driver specific entry point.
313 ; Must set an error code: YES
317 lda #TGI_ERR_INV_FUNC
321 ; ------------------------------------------------------------------------
322 ; CLEAR: Clears the screen.
324 ; Must set an error code: NO
340 lda #>639 ; 80 columns
343 @L40: lda #>319 ; 40 columns
352 ; ------------------------------------------------------------------------
353 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
354 ; The page number is already checked to be valid by the graphics kernel.
356 ; Must set an error code: NO (will only be called if page ok)
370 ; ------------------------------------------------------------------------
371 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
372 ; The page number is already checked to be valid by the graphics kernel.
374 ; Must set an error code: NO (will only be called if page ok)
388 ; ------------------------------------------------------------------------
389 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
390 ; to be in a valid range (0..maxcolor-1).
392 ; Must set an error code: NO (will only be called if color ok)
400 jmp SetPattern ; need to have either 0 or 1
402 ; ------------------------------------------------------------------------
403 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
404 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
407 ; Must set an error code: YES
411 jsr GETERROR ; clear error (if any)
414 @L1: lda (ptr1),y ; Copy the palette
415 and #$0F ; Make a valid color
420 ; Put colors from palette into screen
425 lda PALETTE+1 ; foreground
430 ora PALETTE ; background
432 @L2: sta COLOR_MATRIX,x
433 sta COLOR_MATRIX+$0100,x
434 sta COLOR_MATRIX+$0200,x
435 sta COLOR_MATRIX+1000-256,x
440 @L80: ldy PALETTE+1 ; Foreground color
446 ldy PALETTE ; Background color
452 ; ------------------------------------------------------------------------
453 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
454 ; set the palette should return the default palette here, so there's no
455 ; way for this function to fail.
457 ; Must set an error code: NO
465 ; ------------------------------------------------------------------------
466 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
467 ; drivers should return something reasonable here, even drivers that don't
468 ; support palettes, otherwise the caller has no way to determine the colors
469 ; of the (not changeable) palette.
471 ; Must set an error code: NO (all drivers must have a default palette)
479 ; ------------------------------------------------------------------------
480 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
481 ; color. The coordinates passed to this function are never outside the
482 ; visible screen area, so there is no need for clipping inside this function.
484 ; Must set an error code: NO
495 lda BITMASK ; set or clear C flag
501 ; ------------------------------------------------------------------------
502 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
503 ; coordinates passed to this function are never outside the visible screen
504 ; area, so there is no need for clipping inside this function.
522 ; ------------------------------------------------------------------------
523 ; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
524 ; X2/Y2 = ptr3/ptr4 using the current drawing color.
526 ; Must set an error code: NO
543 lda BITMASK ; set or clear C flag
549 ; ------------------------------------------------------------------------
550 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
551 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
552 ; Contrary to most other functions, the graphics kernel will sort and clip
553 ; the coordinates before calling the driver, so on entry the following
554 ; conditions are valid:
557 ; (X1 >= 0) && (X1 < XRES)
558 ; (X2 >= 0) && (X2 < XRES)
559 ; (Y1 >= 0) && (Y1 < YRES)
560 ; (Y2 >= 0) && (Y2 < YRES)
562 ; Must set an error code: NO
580 ; ------------------------------------------------------------------------
581 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
582 ; direction is passend in X/Y, the text direction is passed in A.
584 ; Must set an error code: NO
594 ; ------------------------------------------------------------------------
595 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
596 ; current text style. The text to output is given as a zero terminated
597 ; string with address in ptr3.
599 ; Must set an error code: NO
604 ; cmp #TGI_TEXT_HORIZONTAL ; this is equal 0
607 lda X1 ; horizontal text output
620 lda X1 ; vertical text output
656 @L0: bit VDC_ADDR_REG
665 @L0: bit VDC_ADDR_REG