2 ; Mouse driver for Atari Touch Tablet
4 ; Christian Groessler, 2014-01-05
7 .include "zeropage.inc"
8 .include "mouse-kernel.inc"
13 ; ------------------------------------------------------------------------
14 ; Header. Includes jump table
22 .byte $6d, $6f, $75 ; "mou"
23 .byte MOUSE_API_VERSION ; Mouse driver API version number
46 .byte MOUSE_FLAG_LATE_IRQ
48 ; Callback table, set by the kernel before INSTALL is called
50 CHIDE: jmp $0000 ; Hide the cursor
51 CSHOW: jmp $0000 ; Show the cursor
52 CMOVEX: jmp $0000 ; Move the cursor to X coord
53 CMOVEY: jmp $0000 ; Move the cursor to Y coord
56 ;----------------------------------------------------------------------------
69 ;----------------------------------------------------------------------------
70 ; Global variables. The bounding box values are sorted so that they can be
71 ; written with the least effort in the SETBOX and GETBOX routines, so don't
77 YPos: .res 2 ; Current mouse position, Y
78 XPos: .res 2 ; Current mouse position, X
79 XMin: .res 2 ; X1 value of bounding box
80 YMin: .res 2 ; Y1 value of bounding box
81 XMax: .res 2 ; X2 value of bounding box
82 YMax: .res 2 ; Y2 value of bounding box
83 Buttons: .res 1 ; Button mask
88 ; Default values for above variables
93 .word SCREEN_HEIGHT/2 ; YPos
94 .word SCREEN_WIDTH/2 ; XPos
97 .word SCREEN_WIDTH ; XMax
98 .word SCREEN_HEIGHT ; YMax
104 ;----------------------------------------------------------------------------
105 ; INSTALL routine. Is called after the driver is loaded into memory. If
106 ; possible, check if the hardware is present.
107 ; Must return an MOUSE_ERR_xx code in a/x.
111 ; Initialize variables. Just copy the default stuff over
113 ldx #.sizeof(DefVars)-1
119 ; Be sure the mouse cursor is invisible and at the default location. We
120 ; need to do that here, because our mouse interrupt handler doesn't set the
121 ; mouse position if it hasn't changed.
134 ; Done, return zero (= MOUSE_ERR_OK)
140 ;----------------------------------------------------------------------------
141 ; UNINSTALL routine. Is called before the driver is removed from memory.
142 ; No return code required (the driver is removed from memory on return).
144 UNINSTALL = HIDE ; Hide cursor on exit
146 ;----------------------------------------------------------------------------
147 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
148 ; a counter for calls to show/hide, and the driver entry point is only called
149 ; if the mouse is currently visible and should get hidden. For most drivers,
150 ; no special action is required besides hiding the mouse cursor.
151 ; No return code required.
160 ;----------------------------------------------------------------------------
161 ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
162 ; a counter for calls to show/hide, and the driver entry point is only called
163 ; if the mouse is currently hidden and should become visible. For most drivers,
164 ; no special action is required besides enabling the mouse cursor.
165 ; No return code required.
174 ;----------------------------------------------------------------------------
175 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
176 ; from the C program, that is, a pointer to a mouse_box struct in a/x.
177 ; No checks are done if the mouse is currently inside the box, this is the job
178 ; of the caller. It is not necessary to validate the parameters, trust the
179 ; caller and save some code here. No return code required.
182 stx ptr1+1 ; Save data pointer
184 ldy #.sizeof (MOUSE_BOX)-1
196 ;----------------------------------------------------------------------------
197 ; GETBOX: Return the mouse bounding box. The parameters are passed as they
198 ; come from the C program, that is, a pointer to a mouse_box struct in a/x.
201 stx ptr1+1 ; Save data pointer
203 ldy #.sizeof (MOUSE_BOX)-1
215 ;----------------------------------------------------------------------------
216 ; MOVE: Move the mouse to a new position. The position is passed as it comes
217 ; from the C program, that is: X on the stack and Y in a/x. The C wrapper will
218 ; remove the parameter from the stack on return.
219 ; No checks are done if the new position is valid (within the bounding box or
220 ; the screen). No return code required.
237 stx YPos+1 ; New Y position
246 sta XPos ; New X position
248 jsr CMOVEX ; Move the cursor
255 @Ret: plp ; Restore interrupt flag
258 ;----------------------------------------------------------------------------
259 ; BUTTONS: Return the button mask in a/x.
266 ;----------------------------------------------------------------------------
267 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
268 ; No return code required.
270 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
273 sei ; Disable interrupts
274 lda XPos ; Transfer the position
283 plp ; Restore interrupt flag
286 sta (ptr1),y ; Store last byte
290 ;----------------------------------------------------------------------------
291 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
292 ; struct pointed to by ptr1. No return code required.
294 ; We're cheating here to keep the code smaller: The first fields of the
295 ; mouse_info struct are identical to the mouse_pos struct, so we will just
296 ; call _mouse_pos to initialize the struct pointer and fill the position
301 ; Fill in the button state
304 ldy #MOUSE_INFO::BUTTONS
309 ;----------------------------------------------------------------------------
310 ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
311 ; specific data in ptr1, and the ioctl code in A.
312 ; Must return an error code in a/x.
315 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
316 ldx #>MOUSE_ERR_INV_IOCTL
319 ;----------------------------------------------------------------------------
320 ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
321 ; (so be careful). The routine MUST return carry set if the interrupt has been
322 ; 'handled' - which means that the interrupt source is gone. Otherwise it
323 ; MUST return carry clear.
328 ; Check for a pressed button and place the result into Buttons
335 lda PORTA ; get other buttons
338 and #5 ; pen button and left button are mapped to left mouse button
350 ; If we read 228 for X or Y positions, we assume the user has lifted the pen
351 ; and don't change the cursor position.
365 ; Get cursor position
366 ; -------------------
367 ; The touch pad is read thru the paddle potentiometers. The possible
368 ; values are 1..228. Since the maximum value is less than the X
369 ; dimension we have to "stretch" this value. In order to use only
370 ; divisions by powers of two, we use the following appoximation:
372 ; 1+1/2-1/8+1/32 = 1.4062
373 ; For Y we subtract 1/8 of it to get in the YMax ballpark.
375 ; A small area in the Y dimension of the touchpad isn't used with
376 ; this approximation. The Y value is inverted, (0,0) is the bottom
377 ; left corner of the touchpad.
381 @L03: ldx PADDL0 ; get X postion
382 dex ; decrement, since it's 1-based
393 lsr a ; port value / 4
394 lsr a ; port value / 8
404 lsr a ; port value / 16
405 lsr a ; port value / 32
416 ; Limit the X coordinate to the bounding box
434 ; Move the mouse pointer to the new X pos
441 ldx PADDL1 ; get Y postion
442 dex ; decrement, since it's 1-based
446 sbc YPos ; invert value
460 ; Limit the Y coordinate to the bounding box
478 ; Move the mouse pointer to the new X pos
487 @Done: clc ; Interrupt not "handled"