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 .addr $0000 ; Library reference
51 .word 40 ; X resolution
52 .word 48 ; Y resolution
53 .byte 16 ; Number of drawing colors
54 .byte 1 ; Number of screens available
55 .byte 8 ; System font X size
56 .byte 8 ; System font Y size
57 .word $0198 ; Aspect ratio (based on 4/3 display)
58 .byte 0 ; TGI driver flags
60 ; Next comes the jump table. With the exception of IRQ, all entries must be
61 ; valid and may point to an RTS for test versions (function not implemented).
82 .addr 0 ; IRQ entry is unused
84 ; ------------------------------------------------------------------------
88 ERROR: .res 1 ; Error code
89 MIX: .res 1 ; 4 lines of text
91 ; ------------------------------------------------------------------------
95 DEFPALETTE: .byte $00, $01, $02, $03, $04, $05, $06, $07
96 .byte $08, $09, $0A, $0B, $0C, $0D, $0E, $0F
98 TGI2COL: .byte $00, $0C, $03, $0F, $01, $09, $06, $02
99 .byte $04, $05, $07, $08, $0A, $0B, $0D, $0E
101 COL2TGI: .byte $00, $04, $07, $02, $08, $09, $06, $0A
102 .byte $0B, $05, $0C, $0D, $01, $0E, $0F, $03
106 ; ------------------------------------------------------------------------
110 ; INIT: Changes an already installed device from text mode to graphics mode.
111 ; Note that INIT/DONE may be called multiple times while the driver
112 ; is loaded, while INSTALL is only called once, so any code that is needed
113 ; to initializes variables and so on must go here. Setting palette and
114 ; clearing the screen is not needed because this is called by the graphics
116 ; The graphics kernel will never call INIT when a graphics mode is already
117 ; active, so there is no need to protect against that.
118 ; Must set an error code: YES
120 ; Switch into graphics mode
121 bit $C082 ; Switch in ROM
124 bit $C080 ; Switch in LC bank 2 for R/O
126 ; Done, reset the error code
133 ; INSTALL routine. Is called after the driver is loaded into memory. May
134 ; initialize anything that has to be done just once. Is probably empty
136 ; Must set an error code: NO
140 ; UNINSTALL routine. Is called before the driver is removed from memory. May
141 ; clean up anything done by INSTALL but is probably empty most of the time.
142 ; Must set an error code: NO
146 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
147 ; The page number is already checked to be valid by the graphics kernel.
148 ; Must set an error code: NO (will only be called if page ok)
152 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
153 ; The page number is already checked to be valid by the graphics kernel.
154 ; Must set an error code: NO (will only be called if page ok)
158 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
159 ; direction is passend in X/Y, the text direction is passed in A.
160 ; Must set an error code: NO
164 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
165 ; current text style. The text to output is given as a zero terminated
166 ; string with address in ptr3.
167 ; Must set an error code: NO
171 ; DONE: Will be called to switch the graphics device back into text mode.
172 ; The graphics kernel will never call DONE when no graphics mode is active,
173 ; so there is no need to protect against that.
174 ; Must set an error code: NO
176 bit $C082 ; Switch in ROM
179 bit $C080 ; Switch in LC bank 2 for R/O
182 ; GETERROR: Return the error code in A and clear it.
189 ; CLEAR: Clears the screen.
190 ; Must set an error code: NO
192 bit $C082 ; Switch in ROM
193 lda COLOR ; Save current drawing color
196 ldy MAXY,x ; Max Y depends on 4 lines of text
199 sta COLOR ; Restore current drawing color
200 bit $C080 ; Switch in LC bank 2 for R/O
203 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
204 ; to be in a valid range (0..maxcolor-1).
205 ; Must set an error code: NO (will only be called if color ok)
207 bit $C082 ; Switch in ROM
211 bit $C080 ; Switch in LC bank 2 for R/O
214 ; CONTROL: Platform/driver specific entry point.
215 ; Must set an error code: YES
217 ; Check data msb and code to be 0
221 ; Check data lsb to be [0..1]
225 bit $C082 ; Switch in ROM
227 ; Switch 4 lines of text
229 .assert MIXCLR + 1 = MIXSET, error
230 lda MIXCLR,x ; No BIT absolute,X available
232 ; Save current switch setting
237 ; Clear 8 lines of graphics
238 lda COLOR ; Save current drawing color
240 lda #39 ; Rightmost column
244 ldy #$00 ; Leftmost column
246 jsr HLINE ; Preserves X
248 cpx #47+1 ; Last line
251 sta COLOR ; Restore current drawing color
252 bcs :+ ; Branch always
254 ; Clear 4 lines of text
256 : bit $C080 ; Switch in LC bank 2 for R/O
258 ; Done, reset the error code
260 beq :+ ; Branch always
262 ; Done, set the error code
263 err: lda #TGI_ERR_INV_ARG
267 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
268 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
270 ; Must set an error code: YES
272 lda #TGI_ERR_INV_FUNC
276 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
277 ; set the palette should return the default palette here, so there's no
278 ; way for this function to fail.
279 ; Must set an error code: NO
283 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
284 ; drivers should return something reasonable here, even drivers that don't
285 ; support palettes, otherwise the caller has no way to determine the colors
286 ; of the (not changeable) palette.
287 ; Must set an error code: NO (all drivers must have a default palette)
293 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
294 ; color. The coordinates passed to this function are never outside the
295 ; visible screen area, so there is no need for clipping inside this function.
296 ; Must set an error code: NO
298 bit $C082 ; Switch in ROM
302 bit $C080 ; Switch in LC bank 2 for R/O
305 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
306 ; coordinates passed to this function are never outside the visible screen
307 ; area, so there is no need for clipping inside this function.
309 bit $C082 ; Switch in ROM
316 bit $C080 ; Switch in LC bank 2 for R/O
319 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
320 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
321 ; Contrary to most other functions, the graphics kernel will sort and clip
322 ; the coordinates before calling the driver, so on entry the following
323 ; conditions are valid:
326 ; (X1 >= 0) && (X1 < XRES)
327 ; (X2 >= 0) && (X2 < XRES)
328 ; (Y1 >= 0) && (Y1 < YRES)
329 ; (Y2 >= 0) && (Y2 < YRES)
330 ; Must set an error code: NO
332 bit $C082 ; Switch in ROM
339 jsr HLINE ; Preserves X
343 bit $C080 ; Switch in LC bank 2 for R/O
346 ; ------------------------------------------------------------------------
348 .include "../../tgi/tgidrv_line.inc"