2 ; Graphics driver for the 280x192x8 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"
16 ; ------------------------------------------------------------------------
26 ; Graphics entry points, by cbmnut (applenut??) cbmnut@hushmail.com
28 TEXT := $F399 ; Return to text screen
29 HGR2 := $F3D8 ; Initialize and clear hi-res page 2.
30 HGR := $F3E2 ; Initialize and clear hi-res page 1.
31 HCLR := $F3F2 ; Clear the current hi-res screen to black.
32 BKGND := $F3F6 ; Clear the current hi-res screen to the
33 ; last plotted color (from ($1C).
34 HPOSN := $F411 ; Positions the hi-res cursor without
36 ; Enter with (A) = Y-coordinate, and
37 ; (Y,X) = X-coordinate.
38 HPLOT := $F457 ; Calls HPOSN and tries to plot a dot at
39 ; the cursor's position. If you are
40 ; trying to plot a non-white color at
41 ; a complementary color position, no
42 ; dot will be plotted.
43 HLIN := $F53A ; Draws a line from the last plotted
44 ; point or line destination to:
45 ; (X,A) = X-coordinate, and
47 HFIND := $F5CB ; Converts the hi-res coursor's position
48 ; back to X- and Y-coordinates; stores
49 ; X-coordinate at $E0,E1 and Y-coordinate
51 DRAW := $F601 ; Draws a shape. Enter with (Y,X) = the
52 ; address of the shape table, and (A) =
53 ; the rotation factor. Uses the current
55 XDRAW := $F65D ; Draws a shape by inverting the existing
56 ; color of the dots the shape draws over.
57 ; Same entry parameters as DRAW.
58 SETHCOL := $F6EC ; Set the hi-res color to (X), where (X)
59 ; must be between 0 and 7.
61 ; ------------------------------------------------------------------------
63 ; Variables mapped to the zero page segment variables. Some of these are
64 ; used for passing parameters to the driver.
71 ; ------------------------------------------------------------------------
74 module_header _a2e_hi_tgi
76 module_header _a2_hi_tgi
79 ; Header. Includes jump table and constants.
81 ; First part of the header is a structure that has a magic and defines the
82 ; capabilities of the driver
84 .byte $74, $67, $69 ; "tgi"
85 .byte TGI_API_VERSION ; TGI API version number
86 .addr $0000 ; Library reference
87 .word 280 ; X resolution
88 .word 192 ; Y resolution
89 .byte 8 ; Number of drawing colors
90 pages: .byte 2 ; Number of screens available
91 .byte 7 ; System font X size
92 .byte 8 ; System font Y size
93 .word $00EA ; Aspect ratio (based on 4/3 display)
94 .byte 0 ; TGI driver flags
96 ; Next comes the jump table. With the exception of IRQ, all entries must be
97 ; valid and may point to an RTS for test versions (function not implemented).
119 ; ------------------------------------------------------------------------
123 ; Absolute variables used in the code
125 ERROR: .res 1 ; Error code
127 ; ------------------------------------------------------------------------
131 ; Constants and tables
133 DEFPALETTE: .byte $00, $01, $02, $03, $04, $05, $06, $07
136 ; Beagle Bros Shape Mechanic font F.ASCII.SMALL
137 ; modified to exactly reproduce the text glyphs
140 ; ------------------------------------------------------------------------
144 ; INSTALL routine. Is called after the driver is loaded into memory. May
145 ; initialize anything that has to be done just once. Is probably empty
147 ; Must set an error code: NO
150 ; No page switching if 80 column store is enabled
159 ; UNINSTALL routine. Is called before the driver is removed from memory. May
160 ; clean up anything done by INSTALL but is probably empty most of the time.
161 ; Must set an error code: NO
165 ; INIT: Changes an already installed device from text mode to graphics mode.
166 ; Note that INIT/DONE may be called multiple times while the driver
167 ; is loaded, while INSTALL is only called once, so any code that is needed
168 ; to initializes variables and so on must go here. Setting palette and
169 ; clearing the screen is not needed because this is called by the graphics
171 ; The graphics kernel will never call INIT when a graphics mode is already
172 ; active, so there is no need to protect against that.
173 ; Must set an error code: YES
175 ; Switch into graphics mode
180 ; Beagle Bros Shape Mechanic fonts don't
181 ; scale well so use fixed scaling factor
185 ; Done, reset the error code
190 ; DONE: Will be called to switch the graphics device back into text mode.
191 ; The graphics kernel will never call DONE when no graphics mode is active,
192 ; so there is no need to protect against that.
193 ; Must set an error code: NO
195 ; Switch into text mode
200 ; Limit SET80COL-HISCR to text
204 ; Reset the text window top
209 ; GETERROR: Return the error code in A and clear it.
216 ; CONTROL: Platform/driver specific entry point.
217 ; Must set an error code: YES
219 ; Check data msb and code to be 0
223 ; Check data lsb to be [0..1]
228 ; Set text window top
234 ; Switch 4 lines of text
235 .assert MIXCLR + 1 = MIXSET, error
236 lda MIXCLR,x ; No BIT absolute,X available
238 ; Done, reset the error code
240 beq :+ ; Branch always
242 ; Done, set the error code
243 err: lda #TGI_ERR_INV_ARG
247 ; CLEAR: Clears the screen.
248 ; Must set an error code: NO
250 bit $C082 ; Switch in ROM
252 bit $C080 ; Switch in LC bank 2 for R/O
255 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
256 ; The page number is already checked to be valid by the graphics kernel.
257 ; Must set an error code: NO (will only be called if page ok)
260 .assert LOWSCR + 1 = HISCR, error
261 lda LOWSCR,x ; No BIT absolute,X available
264 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
265 ; The page number is already checked to be valid by the graphics kernel.
266 ; Must set an error code: NO (will only be called if page ok)
271 .byte $2C ; BIT absolute
272 : lda #>$2000 ; Page 1
276 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
277 ; to be in a valid range (0..maxcolor-1).
278 ; Must set an error code: NO (will only be called if color ok)
280 bit $C082 ; Switch in ROM
283 bit $C080 ; Switch in LC bank 2 for R/O
286 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
287 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
289 ; Must set an error code: YES
291 lda #TGI_ERR_INV_FUNC
295 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
296 ; set the palette should return the default palette here, so there's no
297 ; way for this function to fail.
298 ; Must set an error code: NO
302 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
303 ; drivers should return something reasonable here, even drivers that don't
304 ; support palettes, otherwise the caller has no way to determine the colors
305 ; of the (not changeable) palette.
306 ; Must set an error code: NO (all drivers must have a default palette)
312 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
313 ; color. The coordinates passed to this function are never outside the
314 ; visible screen area, so there is no need for clipping inside this function.
315 ; Must set an error code: NO
317 bit $C082 ; Switch in ROM
322 bit $C080 ; Switch in LC bank 2 for R/O
325 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
326 ; coordinates passed to this function are never outside the visible screen
327 ; area, so there is no need for clipping inside this function.
329 bit $C082 ; Switch in ROM
340 adc #$03 ; += 4 (black -> black2, white -> white2)
342 bit $C080 ; Switch in LC bank 2 for R/O
345 ; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
346 ; X2/Y2 = ptr3/ptr4 using the current drawing color.
347 ; Must set an error code: NO
349 bit $C082 ; Switch in ROM
358 bit $C080 ; Switch in LC bank 2 for R/O
361 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
362 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
363 ; Contrary to most other functions, the graphics kernel will sort and clip
364 ; the coordinates before calling the driver, so on entry the following
365 ; conditions are valid:
368 ; (X1 >= 0) && (X1 < XRES)
369 ; (X2 >= 0) && (X2 < XRES)
370 ; (Y1 >= 0) && (Y1 < YRES)
371 ; (Y2 >= 0) && (Y2 < YRES)
372 ; Must set an error code: NO
387 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
388 ; direction is passend in X/Y, the text direction is passed in A.
389 ; Must set an error code: NO
391 cmp #TGI_TEXT_VERTICAL
397 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
398 ; current text style. The text to output is given as a zero terminated
399 ; string with address in ptr3.
400 ; Must set an error code: NO
402 bit $C082 ; Switch in ROM
407 beq :+ ; Not horizontal
415 bne :+ ; Not vertical
420 lda FONT+2*99 ; "connection char"
423 lda FONT+2*99+1 ; "connection char"
429 sty tmp1 ; Save string index
431 sbc #$1F ; No control chars
442 jsr DRAW ; Draw char from string
446 jsr DRAW ; Draw "connection char"
447 ldy tmp1 ; Restore string index
449 bne :- ; Branch always
450 : bit $C080 ; Switch in LC bank 2 for R/O