2 ; Driver for a "joystick mouse".
4 ; Ullrich von Bassewitz, 2004-03-29, 2009-09-26
5 ; 2010-02-08, Greg King
8 .include "zeropage.inc"
9 .include "mouse-kernel.inc"
14 ; ------------------------------------------------------------------------
15 ; Header. Includes jump table
23 .byte $6d, $6f, $75 ; "mou"
24 .byte MOUSE_API_VERSION ; Mouse driver API version number
43 .byte MOUSE_FLAG_LATE_IRQ
45 ; Callback table, set by the kernel before INSTALL is called
47 CHIDE: jmp $0000 ; Hide the cursor
48 CSHOW: jmp $0000 ; Show the cursor
49 CMOVEX: jmp $0000 ; Move the cursor to X coord
50 CMOVEY: jmp $0000 ; Move the cursor to Y coord
53 ;----------------------------------------------------------------------------
67 ;----------------------------------------------------------------------------
68 ; Global variables. The bounding box values are sorted so that they can be
69 ; written with the least effort in the SETBOX and GETBOX routines, so don't
75 YPos: .res 2 ; Current mouse position, Y
76 XPos: .res 2 ; Current mouse position, X
77 XMin: .res 2 ; X1 value of bounding box
78 YMin: .res 2 ; Y1 value of bounding box
79 XMax: .res 2 ; X2 value of bounding box
80 YMax: .res 2 ; Y2 value of bounding box
81 Buttons: .res 1 ; Button mask
83 ; Temporary value used in the int handler
87 ; Default values for above variables
92 .word SCREEN_HEIGHT/2 ; YPos
93 .word SCREEN_WIDTH/2 ; XPos
96 .word SCREEN_WIDTH ; XMax
97 .word SCREEN_HEIGHT ; YMax
103 ;----------------------------------------------------------------------------
104 ; INSTALL routine. Is called after the driver is loaded into memory. If
105 ; possible, check if the hardware is present.
106 ; Must return an MOUSE_ERR_xx code in a/x.
110 ; Initialize variables. Just copy the default stuff over
112 ldx #.sizeof(DefVars)-1
118 ; Be sure the mouse cursor is invisible and at the default location. We
119 ; need to do that here, because our mouse interrupt handler doesn't set the
120 ; mouse position if it hasn't changed.
132 ; Done, return zero (= MOUSE_ERR_OK)
138 ;----------------------------------------------------------------------------
139 ; UNINSTALL routine. Is called before the driver is removed from memory.
140 ; No return code required (the driver is removed from memory on return).
142 UNINSTALL = HIDE ; Hide cursor on exit
144 ;----------------------------------------------------------------------------
145 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
146 ; a counter for calls to show/hide, and the driver entry point is only called
147 ; if the mouse is currently visible and should get hidden. For most drivers,
148 ; no special action is required besides hiding the mouse cursor.
149 ; No return code required.
156 ;----------------------------------------------------------------------------
157 ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
158 ; a counter for calls to show/hide, and the driver entry point is only called
159 ; if the mouse is currently hidden and should become visible. For most drivers,
160 ; no special action is required besides enabling the mouse cursor.
161 ; No return code required.
168 ;----------------------------------------------------------------------------
169 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
170 ; from the C program, that is, a pointer to a mouse_box struct in a/x.
171 ; No checks are done if the mouse is currently inside the box, this is the job
172 ; of the caller. It is not necessary to validate the parameters, trust the
173 ; caller and save some code here. No return code required.
176 stx ptr1+1 ; Save data pointer
178 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
205 ;----------------------------------------------------------------------------
206 ; MOVE: Move the mouse to a new position. The position is passed as it comes
207 ; from the C program, that is: X on the stack and Y in a/x. The C wrapper will
208 ; remove the parameter from the stack on return.
209 ; No checks are done if the new position is valid (within the bounding box or
210 ; the screen). No return code required.
213 MOVE: sei ; No interrupts
216 stx YPos+1 ; New Y position
225 sta XPos ; New X position
227 jsr CMOVEX ; Move the cursor
229 cli ; Allow interrupts
232 ;----------------------------------------------------------------------------
233 ; BUTTONS: Return the button mask in a/x.
240 ;----------------------------------------------------------------------------
241 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
242 ; No return code required.
244 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
246 sei ; Disable interrupts
247 lda XPos ; Transfer the position
256 cli ; Enable interrupts
259 sta (ptr1),y ; Store last byte
263 ;----------------------------------------------------------------------------
264 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
265 ; struct pointed to by ptr1. No return code required.
267 ; We're cheating here to keep the code smaller: The first fields of the
268 ; mouse_info struct are identical to the mouse_pos struct, so we will just
269 ; call _mouse_pos to initialize the struct pointer and fill the position
274 ; Fill in the button state
277 ldy #MOUSE_INFO::BUTTONS
282 ;----------------------------------------------------------------------------
283 ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
284 ; specific data in ptr1, and the ioctl code in A.
285 ; Must return an error code in a/x.
288 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
289 ldx #>MOUSE_ERR_INV_IOCTL
292 ;----------------------------------------------------------------------------
293 ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
294 ; (so be careful). The routine MUST return carry set if the interrupt has been
295 ; 'handled' - which means that the interrupt source is gone. Otherwise it
296 ; MUST return carry clear.
299 ; Avoid crosstalk between the keyboard and a joystick.
301 IRQ: ldy #%00000000 ; Set ports A and B to input
303 sty CIA1_DDRA ; Keyboard won't look like joystick
304 lda CIA1_PRB ; Read Control-Port 1
305 dec CIA1_DDRA ; Set port A back to output
306 eor #%11111111 ; Bit goes up when switch goes down
308 dec CIA1_DDRB ; Joystick won't look like keyboard
309 sty CIA1_PRB ; Set "all keys pushed"
312 ; Check for a pressed button and place the result into Buttons
314 ldx #$00 ; Assume no button pressed
315 and #JOY::FIRE ; Check fire button
316 beq @L0 ; Jump if not pressed
317 ldx #MOUSE_BTN_LEFT ; Left (only) button is pressed
322 lda Temp ; Read joystick #0
323 and #(JOY::LEFT | JOY::RIGHT)
326 ; We will cheat here and rely on the fact that either the left, OR the right
329 and #JOY::RIGHT ; Check RIGHT bit
333 bne @AddX ; Branch always
337 ; Calculate the new X coordinate (--> a/y)
340 tay ; Remember low byte
345 ; Limit the X coordinate to the bounding box
363 ; Move the mouse pointer to the new X pos
368 ; Calculate the Y movement vector
370 @SkipX: lda Temp ; Read joystick #0
371 and #(JOY::UP | JOY::DOWN) ; Check up/down
374 ; We will cheat here and rely on the fact that either the up, OR the down
385 ; Calculate the new Y coordinate (--> a/y)
388 tay ; Remember low byte
393 ; Limit the Y coordinate to the bounding box
411 ; Move the mouse pointer to the new X pos
418 @SkipY: clc ; Interrupt not handled