2 ; Graphics driver for the 40x48x16 mode on the Apple II
4 ; Stefan Haubenthal <polluks@sdf.lonestar.org>
5 ; Oliver Schmidt <ol.sc@web.de>
8 .include "zeropage.inc"
10 .include "tgi-kernel.inc"
11 .include "tgi-error.inc"
14 ; ------------------------------------------------------------------------
32 ; Used for passing parameters to the driver
39 ; ------------------------------------------------------------------------
43 ; Header. Includes jump table and constants.
45 ; First part of the header is a structure that has a magic and defines the
46 ; capabilities of the driver
48 .byte $74, $67, $69 ; "tgi"
49 .byte TGI_API_VERSION ; TGI API version number
50 .word 40 ; X resolution
51 .word 48 ; Y resolution
52 .byte 16 ; Number of drawing colors
53 .byte 1 ; Number of screens available
54 .byte 8 ; System font X size
55 .byte 8 ; System font Y size
56 .word $0198 ; Aspect ratio (based on 4/3 display)
57 .byte 0 ; TGI driver flags
59 ; Next comes the jump table. With the exception of IRQ, all entries must be
60 ; valid and may point to an RTS for test versions (function not implemented).
81 .addr 0 ; IRQ entry is unused
83 ; ------------------------------------------------------------------------
87 ERROR: .res 1 ; Error code
88 MIX: .res 1 ; 4 lines of text
90 ; ------------------------------------------------------------------------
94 DEFPALETTE: .byte $00, $01, $02, $03, $04, $05, $06, $07
95 .byte $08, $09, $0A, $0B, $0C, $0D, $0E, $0F
97 TGI2COL: .byte $00, $0C, $03, $0F, $01, $09, $06, $02
98 .byte $04, $05, $07, $08, $0A, $0B, $0D, $0E
100 COL2TGI: .byte $00, $04, $07, $02, $08, $09, $06, $0A
101 .byte $0B, $05, $0C, $0D, $01, $0E, $0F, $03
105 ; ------------------------------------------------------------------------
109 ; INIT: Changes an already installed device from text mode to graphics mode.
110 ; Note that INIT/DONE may be called multiple times while the driver
111 ; is loaded, while INSTALL is only called once, so any code that is needed
112 ; to initializes variables and so on must go here. Setting palette and
113 ; clearing the screen is not needed because this is called by the graphics
115 ; The graphics kernel will never call INIT when a graphics mode is already
116 ; active, so there is no need to protect against that.
117 ; Must set an error code: YES
119 ; Switch into graphics mode
120 bit $C082 ; Switch in ROM
123 bit $C080 ; Switch in LC bank 2 for R/O
125 ; Done, reset the error code
132 ; INSTALL routine. Is called after the driver is loaded into memory. May
133 ; initialize anything that has to be done just once. Is probably empty
135 ; Must set an error code: NO
139 ; UNINSTALL routine. Is called before the driver is removed from memory. May
140 ; clean up anything done by INSTALL but is probably empty most of the time.
141 ; Must set an error code: NO
145 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
146 ; The page number is already checked to be valid by the graphics kernel.
147 ; Must set an error code: NO (will only be called if page ok)
151 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
152 ; The page number is already checked to be valid by the graphics kernel.
153 ; Must set an error code: NO (will only be called if page ok)
157 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
158 ; direction is passend in X/Y, the text direction is passed in A.
159 ; Must set an error code: NO
163 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
164 ; current text style. The text to output is given as a zero terminated
165 ; string with address in ptr3.
166 ; Must set an error code: NO
170 ; DONE: Will be called to switch the graphics device back into text mode.
171 ; The graphics kernel will never call DONE when no graphics mode is active,
172 ; so there is no need to protect against that.
173 ; Must set an error code: NO
175 bit $C082 ; Switch in ROM
178 bit $C080 ; Switch in LC bank 2 for R/O
181 ; GETERROR: Return the error code in A and clear it.
188 ; CLEAR: Clears the screen.
189 ; Must set an error code: NO
191 bit $C082 ; Switch in ROM
192 lda COLOR ; Save current drawing color
195 ldy MAXY,x ; Max Y depends on 4 lines of text
198 sta COLOR ; Restore current drawing color
199 bit $C080 ; Switch in LC bank 2 for R/O
202 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
203 ; to be in a valid range (0..maxcolor-1).
204 ; Must set an error code: NO (will only be called if color ok)
206 bit $C082 ; Switch in ROM
210 bit $C080 ; Switch in LC bank 2 for R/O
213 ; CONTROL: Platform/driver specific entry point.
214 ; Must set an error code: YES
216 ; Check data msb and code to be 0
220 ; Check data lsb to be [0..1]
224 bit $C082 ; Switch in ROM
226 ; Switch 4 lines of text
228 .assert MIXCLR + 1 = MIXSET, error
229 lda MIXCLR,x ; No BIT absolute,X available
231 ; Save current switch setting
236 ; Clear 8 lines of graphics
237 lda COLOR ; Save current drawing color
239 lda #39 ; Rightmost column
243 ldy #$00 ; Leftmost column
245 jsr HLINE ; Preserves X
247 cpx #47+1 ; Last line
250 sta COLOR ; Restore current drawing color
251 bcs :+ ; Branch always
253 ; Clear 4 lines of text
255 : bit $C080 ; Switch in LC bank 2 for R/O
257 ; Done, reset the error code
259 beq :+ ; Branch always
261 ; Done, set the error code
262 err: lda #TGI_ERR_INV_ARG
266 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
267 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
269 ; Must set an error code: YES
271 lda #TGI_ERR_INV_FUNC
275 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
276 ; set the palette should return the default palette here, so there's no
277 ; way for this function to fail.
278 ; Must set an error code: NO
282 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
283 ; drivers should return something reasonable here, even drivers that don't
284 ; support palettes, otherwise the caller has no way to determine the colors
285 ; of the (not changeable) palette.
286 ; Must set an error code: NO (all drivers must have a default palette)
292 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
293 ; color. The coordinates passed to this function are never outside the
294 ; visible screen area, so there is no need for clipping inside this function.
295 ; Must set an error code: NO
297 bit $C082 ; Switch in ROM
301 bit $C080 ; Switch in LC bank 2 for R/O
304 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
305 ; coordinates passed to this function are never outside the visible screen
306 ; area, so there is no need for clipping inside this function.
308 bit $C082 ; Switch in ROM
315 bit $C080 ; Switch in LC bank 2 for R/O
318 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
319 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
320 ; Contrary to most other functions, the graphics kernel will sort and clip
321 ; the coordinates before calling the driver, so on entry the following
322 ; conditions are valid:
325 ; (X1 >= 0) && (X1 < XRES)
326 ; (X2 >= 0) && (X2 < XRES)
327 ; (Y1 >= 0) && (Y1 < YRES)
328 ; (Y2 >= 0) && (Y2 < YRES)
329 ; Must set an error code: NO
331 bit $C082 ; Switch in ROM
338 jsr HLINE ; Preserves X
342 bit $C080 ; Switch in LC bank 2 for R/O
345 ; ------------------------------------------------------------------------
347 .include "../../tgi/tgidrv_line.inc"