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 CPREP: jmp $0000 ; Prepare to move the cursor
53 CDRAW: jmp $0000 ; Draw the cursor
54 CMOVEX: jmp $0000 ; Move the cursor to X coord
55 CMOVEY: jmp $0000 ; Move the cursor to Y coord
58 ;----------------------------------------------------------------------------
71 ;----------------------------------------------------------------------------
72 ; Global variables. The bounding box values are sorted so that they can be
73 ; written with the least effort in the SETBOX and GETBOX routines, so don't
79 YPos: .res 2 ; Current mouse position, Y
80 XPos: .res 2 ; Current mouse position, X
81 XMin: .res 2 ; X1 value of bounding box
82 YMin: .res 2 ; Y1 value of bounding box
83 XMax: .res 2 ; X2 value of bounding box
84 YMax: .res 2 ; Y2 value of bounding box
85 Buttons: .res 1 ; Button mask
87 ; Default values for above variables
91 ; (We use ".proc" because we want to define both a label and a scope.)
94 .word SCREEN_HEIGHT/2 ; YPos
95 .word SCREEN_WIDTH/2 ; XPos
98 .word SCREEN_WIDTH ; XMax
99 .word SCREEN_HEIGHT ; YMax
105 ;----------------------------------------------------------------------------
106 ; INSTALL routine. Is called after the driver is loaded into memory. If
107 ; possible, check if the hardware is present.
108 ; Must return an MOUSE_ERR_xx code in a/x.
112 ; Initialize variables. Just copy the default stuff over
114 ldx #.sizeof(DefVars)-1
120 ; Make sure the mouse cursor is at the default location.
129 ; Done, return zero (= MOUSE_ERR_OK)
135 ;----------------------------------------------------------------------------
136 ; UNINSTALL routine. Is called before the driver is removed from memory.
137 ; No return code required (the driver is removed from memory on return).
139 UNINSTALL = HIDE ; Hide cursor on exit
141 ;----------------------------------------------------------------------------
142 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
143 ; a counter for calls to show/hide, and the driver entry point is only called
144 ; if the mouse is currently visible and should get hidden. For most drivers,
145 ; no special action is required besides hiding the mouse cursor.
146 ; No return code required.
154 ;----------------------------------------------------------------------------
155 ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
156 ; a counter for calls to show/hide, and the driver entry point is only called
157 ; if the mouse is currently hidden and should become visible. For most drivers,
158 ; no special action is required besides enabling the mouse cursor.
159 ; No return code required.
167 ;----------------------------------------------------------------------------
168 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
169 ; from the C program, that is, a pointer to a mouse_box struct in a/x.
170 ; No checks are done if the mouse is currently inside the box, this is the job
171 ; of the caller. It is not necessary to validate the parameters, trust the
172 ; caller and save some code here. No return code required.
175 stx ptr1+1 ; Save data pointer
177 ldy #.sizeof (MOUSE_BOX)-1
189 ;----------------------------------------------------------------------------
190 ; GETBOX: Return the mouse bounding box. The parameters are passed as they
191 ; come from the C program, that is, a pointer to a mouse_box struct in a/x.
194 stx ptr1+1 ; Save data pointer
196 ldy #.sizeof (MOUSE_BOX)-1
208 ;----------------------------------------------------------------------------
209 ; MOVE: Move the mouse to a new position. The position is passed as it comes
210 ; from the C program, that is: X on the stack and Y in a/x. The C wrapper will
211 ; remove the parameter from the stack on return.
212 ; No checks are done if the new position is valid (within the bounding box or
213 ; the screen). No return code required.
228 stx YPos+1 ; New Y position
237 sta XPos ; New X position
238 jsr CMOVEX ; Move the cursor
242 plp ; Restore interrupt flag
245 ;----------------------------------------------------------------------------
246 ; BUTTONS: Return the button mask in a/x.
253 ;----------------------------------------------------------------------------
254 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
255 ; No return code required.
257 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
260 sei ; Disable interrupts
261 lda XPos ; Transfer the position
270 plp ; Restore interrupt flag
273 sta (ptr1),y ; Store last byte
277 ;----------------------------------------------------------------------------
278 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
279 ; struct pointed to by ptr1. No return code required.
281 ; We're cheating here to keep the code smaller: The first fields of the
282 ; mouse_info struct are identical to the mouse_pos struct, so we will just
283 ; call _mouse_pos to initialize the struct pointer and fill the position
288 ; Fill in the button state
291 ldy #MOUSE_INFO::BUTTONS
296 ;----------------------------------------------------------------------------
297 ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
298 ; specific data in ptr1, and the ioctl code in A.
299 ; Must return an error code in a/x.
302 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
303 ldx #>MOUSE_ERR_INV_IOCTL
306 ;----------------------------------------------------------------------------
307 ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
308 ; (so be careful). The routine MUST return carry set if the interrupt has been
309 ; 'handled' - which means that the interrupt source is gone. Otherwise it
310 ; MUST return carry clear.
315 ; Check for a pressed button and place the result into Buttons
320 lda PORTA ; get other buttons
323 and #5 ; pen button and left button are mapped to left mouse button
335 ; If we read 228 for X or Y positions, we assume the user has lifted the pen
336 ; and don't change the cursor position.
340 beq @Cont ; CF set if equal
342 cmp #228 ; CF set if equal
344 @Cont: php ; remember CF
355 ; Get cursor position
356 ; -------------------
357 ; The touch pad is read thru the paddle potentiometers. The possible
358 ; values are 1..228. Since the maximum value is less than the X
359 ; dimension we have to "stretch" this value. In order to use only
360 ; divisions by powers of two, we use the following appoximation:
362 ; 1+1/2-1/8+1/32 = 1.4062
363 ; For Y we subtract 1/8 of it to get in the YMax ballpark.
365 ; A small area in the Y dimension of the touchpad isn't used with
366 ; this approximation. The Y value is inverted, (0,0) is the bottom
367 ; left corner of the touchpad.
371 ldx PADDL0 ; get X postion
372 dex ; decrement, since it's 1-based
383 lsr a ; port value / 4
384 lsr a ; port value / 8
394 lsr a ; port value / 16
395 lsr a ; port value / 32
406 ; Limit the X coordinate to the bounding box
424 ; Move the mouse pointer to the new X pos
431 ldx PADDL1 ; get Y postion
432 dex ; decrement, since it's 1-based
436 sbc YPos ; invert value
450 ; Limit the Y coordinate to the bounding box
468 ; Move the mouse pointer to the new X pos
475 clc ; Interrupt not "handled"