2 ; Graphics driver for the 240x200x2 monochrome mode on the Atmos
4 ; Stefan Haubenthal <polluks@sdf.lonestar.org>
5 ; 2012-08-11, Greg King <greg.king5@verizon.net>
8 .include "zeropage.inc"
10 .include "tgi-kernel.inc"
11 .include "tgi-error.inc"
16 XSIZE = 6 ; System font width
17 YSIZE = 8 ; System font height
19 ; ------------------------------------------------------------------------
20 ; Header. Includes jump table and constants.
24 ; First part of the header is a structure that has a magic and defines the
25 ; capabilities of the driver
27 .byte $74, $67, $69 ; "tgi"
28 .byte TGI_API_VERSION ; TGI API version number
29 .word 240 ; X resolution
30 .word 200 ; Y resolution
31 .byte 2 ; Number of drawing colors
32 .byte 1 ; Number of screens available
33 .byte XSIZE ; System font X size
34 .byte YSIZE ; System font Y size
35 .word $011C ; Aspect ratio (based on 4/3 display)
36 .byte 0 ; TGI driver flags
38 ; Next comes the jump table. Currently all entries must be valid and may point
39 ; to an RTS for test versions (function not implemented).
60 .addr 0 ; IRQ entry is unused
62 ; ------------------------------------------------------------------------
65 ; Variables mapped to the zero page segment variables. Some of these are
66 ; used for passing parameters to the driver.
73 ; Absolute variables used in the code
77 ERROR: .res 1 ; Error code
78 MODE: .res 1 ; Graphics mode
80 ; Constants and tables
96 DEFPALETTE: .byte 0, 1
100 ; ------------------------------------------------------------------------
101 ; INSTALL routine. Is called after the driver is loaded into memory. May
102 ; initialize anything that has to be done just once. Is probably empty
105 ; Must set an error code: NO
110 ; ------------------------------------------------------------------------
111 ; UNINSTALL routine. Is called before the driver is removed from memory. May
112 ; clean up anything done by INSTALL but is probably empty most of the time.
114 ; Must set an error code: NO
120 ; ------------------------------------------------------------------------
121 ; INIT: Changes an already installed device from text mode to graphics
123 ; Note that INIT/DONE may be called multiple times while the driver
124 ; is loaded, while INSTALL is only called once, so any code that is needed
125 ; to initializes variables and so on must go here. Setting palette and
126 ; clearing the screen is not needed because this is called by the graphics
128 ; The graphics kernel will never call INIT when a graphics mode is already
129 ; active, so there is no need to protect against that.
131 ; Must set an error code: YES
136 ; Switch into graphics mode
140 ; Done, reset the error code
146 ; ------------------------------------------------------------------------
147 ; DONE: Will be called to switch the graphics device back into text mode.
148 ; The graphics kernel will never call DONE when no graphics mode is active,
149 ; so there is no need to protect against that.
151 ; Must set an error code: NO
156 ; ------------------------------------------------------------------------
157 ; GETERROR: Return the error code in A and clear it.
165 ; ------------------------------------------------------------------------
166 ; CONTROL: Platform/driver specific entry point.
168 ; Must set an error code: YES
177 ; ------------------------------------------------------------------------
178 ; CLEAR: Clears the screen.
180 ; Must set an error code: NO
185 ; ------------------------------------------------------------------------
186 ; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
187 ; The page number is already checked to be valid by the graphics kernel.
189 ; Must set an error code: NO (will only be called if page ok)
194 ; ------------------------------------------------------------------------
195 ; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
196 ; The page number is already checked to be valid by the graphics kernel.
198 ; Must set an error code: NO (will only be called if page ok)
204 ; ------------------------------------------------------------------------
205 ; SETCOLOR: Set the drawing color (in A). The new color is already checked
206 ; to be in a valid range (0..maxcolor-1).
208 ; Must set an error code: NO (will only be called if color ok)
215 ; ------------------------------------------------------------------------
216 ; SETPALETTE: Set the palette (not available with all drivers/hardware).
217 ; A pointer to the palette is passed in ptr1. Must set an error if palettes
220 ; Must set an error code: YES
224 lda #TGI_ERR_INV_FUNC ; This resolution has no palette
228 ; ------------------------------------------------------------------------
229 ; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
230 ; set the palette should return the default palette here, so there's no
231 ; way for this function to fail.
233 ; Must set an error code: NO
238 ; ------------------------------------------------------------------------
239 ; GETDEFPALETTE: Return the default palette for the driver in A/X. All
240 ; drivers should return something reasonable here, even drivers that don't
241 ; support palettes, otherwise the caller has no way to determine the colors
242 ; of the (not changeable) palette.
244 ; Must set an error code: NO (all drivers must have a default palette)
252 ; ------------------------------------------------------------------------
253 ; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
254 ; color. The coordinates passed to this function are never outside the
255 ; visible screen area, so there is no need for clipping inside this function.
257 ; Must set an error code: NO
273 ; ------------------------------------------------------------------------
274 ; GETPIXEL: Read the color value of a pixel and return it in A/X. The
275 ; coordinates passed to this function are never outside the visible screen
276 ; area, so there is no need for clipping inside this function.
292 ; ------------------------------------------------------------------------
293 ; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
294 ; X2/Y2 = ptr3/ptr4 using the current drawing color.
296 ; Must set an error code: NO
319 ; ------------------------------------------------------------------------
320 ; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
321 ; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
322 ; Contrary to most other functions, the graphics kernel will sort and clip
323 ; the coordinates before calling the driver, so on entry the following
324 ; conditions are valid:
327 ; (X1 >= 0) && (X1 < XRES)
328 ; (X2 >= 0) && (X2 < XRES)
329 ; (Y1 >= 0) && (Y1 < YRES)
330 ; (Y2 >= 0) && (Y2 < YRES)
332 ; Must set an error code: NO
349 ; ------------------------------------------------------------------------
350 ; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
351 ; direction is passend in X/Y, the text direction is passed in A.
353 ; Must set an error code: NO
360 ; ------------------------------------------------------------------------
361 ; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
362 ; current text style. The text to output is given as a zero terminated
363 ; string with address in ptr3.
365 ; Must set an error code: NO
372 lda #3 ; (Move graphics cursor; don't draw)