2 ; Driver for a "joystick mouse".
4 ; Ullrich von Bassewitz, 2004-04-05, 2009-09-26
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 ;----------------------------------------------------------------------------
70 ;----------------------------------------------------------------------------
71 ; Global variables. The bounding box values are sorted so that they can be
72 ; written with the least effort in the SETBOX and GETBOX routines, so don't
78 YPos: .res 2 ; Current mouse position, Y
79 XPos: .res 2 ; Current mouse position, X
80 XMin: .res 2 ; X1 value of bounding box
81 YMin: .res 2 ; Y1 value of bounding box
82 XMax: .res 2 ; X2 value of bounding box
83 YMax: .res 2 ; Y2 value of bounding box
84 Buttons: .res 1 ; Button mask
86 ; Temporary value used in the int handler
92 ; Default values for below variables
93 ; (We use ".proc" because we want to define both a label and a scope.)
96 .word SCREEN_HEIGHT/2 ; YPos
97 .word SCREEN_WIDTH/2 ; XPos
100 .word SCREEN_WIDTH ; XMax
101 .word SCREEN_HEIGHT ; YMax
107 ;----------------------------------------------------------------------------
108 ; INSTALL routine. Is called after the driver is loaded into memory. If
109 ; possible, check if the hardware is present.
110 ; Must return an MOUSE_ERR_xx code in a/x.
114 ; Initialize variables. Just copy the default stuff over
116 ldx #.sizeof(DefVars)-1
122 ; Be sure the mouse cursor is invisible and at the default location. We
123 ; need to do that here, because our mouse interrupt handler doesn't set the
124 ; mouse position if it hasn't changed.
136 ; Done, return zero (= MOUSE_ERR_OK)
142 ;----------------------------------------------------------------------------
143 ; UNINSTALL routine. Is called before the driver is removed from memory.
144 ; No return code required (the driver is removed from memory on return).
146 UNINSTALL = HIDE ; Hide cursor on exit
148 ;----------------------------------------------------------------------------
149 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
150 ; a counter for calls to show/hide, and the driver entry point is only called
151 ; if the mouse is currently visible and should get hidden. For most drivers,
152 ; no special action is required besides hiding the mouse cursor.
153 ; 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.
172 ;----------------------------------------------------------------------------
173 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
174 ; from the C program, that is, a pointer to a mouse_box struct in a/x.
175 ; No checks are done if the mouse is currently inside the box, this is the job
176 ; of the caller. It is not necessary to validate the parameters, trust the
177 ; caller and save some code here. No return code required.
180 stx ptr1+1 ; Save data pointer
182 ldy #.sizeof (MOUSE_BOX)-1
193 ;----------------------------------------------------------------------------
194 ; GETBOX: Return the mouse bounding box. The parameters are passed as they
195 ; come from the C program, that is, a pointer to a mouse_box struct in a/x.
198 stx ptr1+1 ; Save data pointer
200 ldy #.sizeof (MOUSE_BOX)-1
211 ;----------------------------------------------------------------------------
212 ; MOVE: Move the mouse to a new position. The position is passed as it comes
213 ; from the C program, that is: X on the stack and Y in a/x. The C wrapper will
214 ; remove the parameter from the stack on return.
215 ; No checks are done if the new position is valid (within the bounding box or
216 ; the screen). No return code required.
219 MOVE: sei ; No interrupts
222 stx YPos+1 ; New Y position
231 sta XPos ; New X position
233 jsr CMOVEX ; Move the cursor
235 cli ; Allow interrupts
238 ;----------------------------------------------------------------------------
239 ; BUTTONS: Return the button mask in a/x.
246 ;----------------------------------------------------------------------------
247 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
248 ; No return code required.
250 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
252 sei ; Disable interrupts
253 lda XPos ; Transfer the position
262 cli ; Enable interrupts
265 sta (ptr1),y ; Store last byte
269 ;----------------------------------------------------------------------------
270 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
271 ; struct pointed to by ptr1. No return code required.
273 ; We're cheating here to keep the code smaller: The first fields of the
274 ; mouse_info struct are identical to the mouse_pos struct, so we will just
275 ; call _mouse_pos to initialize the struct pointer and fill the position
280 ; Fill in the button state
283 ldy #MOUSE_INFO::BUTTONS
288 ;----------------------------------------------------------------------------
289 ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
290 ; specific data in ptr1, and the ioctl code in A.
291 ; Must return an error code in a/x.
294 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
295 ldx #>MOUSE_ERR_INV_IOCTL
298 ;----------------------------------------------------------------------------
299 ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
300 ; (so be careful). The routine MUST return carry set if the interrupt has been
301 ; 'handled' - which means that the interrupt source is gone. Otherwise it
302 ; MUST return carry clear.
307 lda CIA1_PRB ; Read joystick #0
309 eor #$1F ; Make all bits active high
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"