2 ; Driver for a "joystick mouse".
4 ; 2009-09-26, Ullrich von Bassewitz
5 ; 2013-09-05, Greg King
8 .include "zeropage.inc"
9 .include "../extzp.inc"
11 .include "mouse-kernel.inc"
16 ; ------------------------------------------------------------------------
17 ; Header. Includes jump table
25 .byte $6d, $6f, $75 ; ASCII "mou"
26 .byte MOUSE_API_VERSION ; Mouse driver API version number
49 .byte MOUSE_FLAG_LATE_IRQ
51 ; Callback table, set by the kernel before INSTALL is called.
53 CHIDE: jmp $0000 ; Hide the cursor
54 CSHOW: jmp $0000 ; Show the cursor
55 CMOVEX: jmp $0000 ; Move the cursor to x co-ord.
56 CMOVEY: jmp $0000 ; Move the cursor to y co-ord.
59 ;----------------------------------------------------------------------------
62 SCREEN_HEIGHT = YSIZE * 8
63 SCREEN_WIDTH = XSIZE * 8
73 ;----------------------------------------------------------------------------
74 ; Global variables. The bounding box values are sorted so that they can be
75 ; written with the least effort in the SETBOX and GETBOX routines; so, don't
81 YPos: .res 2 ; Current mouse position, y
82 XPos: .res 2 ; Current mouse position, x
83 XMin: .res 2 ; X1 value of bounding box
84 YMin: .res 2 ; Y1 value of bounding box
85 XMax: .res 2 ; X2 value of bounding box
86 YMax: .res 2 ; Y2 value of bounding box
88 ; Temporary value used in the interrupt handler
94 ; Default values for below variables
95 ; (We use ".proc" because we want to define both a label and a scope.)
98 .word SCREEN_HEIGHT / 2 ; YPos
99 .word SCREEN_WIDTH / 2 ; XPos
102 .word SCREEN_WIDTH - 1 ; XMax
103 .word SCREEN_HEIGHT - 1 ; YMax
108 ;----------------------------------------------------------------------------
109 ; INSTALL routine. Is called after the driver is loaded into memory. If
110 ; possible, check if the hardware is present.
111 ; Must return a MOUSE_ERR_xx code in .XA.
115 ; Initiate variables; just copy the default stuff over.
117 ldx #.sizeof(DefVars) - 1
123 ; Be sure the mouse cursor is invisible and at the default location. We
124 ; need to do that here because our mouse interrupt handler doesn't set the
125 ; mouse position if it hasn't changed.
143 ;----------------------------------------------------------------------------
144 ; UNINSTALL routine. Is called before the driver is removed from memory.
145 ; No return code required (the driver is removed from memory, on return).
147 UNINSTALL := HIDE ; Hide cursor, on exit
149 ;----------------------------------------------------------------------------
150 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
151 ; a counter for calls to show/hide; and, the driver entry point is called only
152 ; if the mouse currently is visible and should get hidden. For most drivers,
153 ; no special action is required besides hiding the mouse cursor.
154 ; No return code required.
161 ;----------------------------------------------------------------------------
162 ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
163 ; a counter for calls to show/hide; and, the driver entry point is called only
164 ; if the mouse currently is hidden and should become visible. For most drivers,
165 ; no special action is required besides enabling the mouse cursor.
166 ; No return code required.
173 ;----------------------------------------------------------------------------
174 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
175 ; from the C program, that is, a pointer to a mouse_box struct in .XA.
176 ; No checks are done if the mouse currently is inside the box; that is the job
177 ; of the caller. It is not necessary to validate the parameters; trust the
178 ; caller, and save some code here. No return code required.
181 stx ptr1+1 ; Save data pointer
183 ldy #.sizeof (MOUSE_BOX) - 1
194 ;----------------------------------------------------------------------------
195 ; GETBOX: Return the mouse bounding box. The parameters are passed as they
196 ; come from the C program, that is, a pointer to a mouse_box struct in .XA.
199 stx ptr1+1 ; Save data pointer
201 ldy #.sizeof (MOUSE_BOX) - 1
210 ;----------------------------------------------------------------------------
211 ; MOVE: Move the mouse to a new position. The position is passed as it comes
212 ; from the C program, that is: x on the stack and y in .XA. The C wrapper will
213 ; remove the parameter from the stack, on return.
214 ; No checks are done if the new position is valid (within the bounding box or
215 ; the screen). No return code required.
218 MOVE: sei ; No interrupts
220 jsr MoveY ; Set new y position
228 jsr MoveX ; Move the pointer
230 cli ; Allow interrupts
233 ;----------------------------------------------------------------------------
234 ; BUTTONS: Return the button mask in .XA.
235 ; Joystick 2's fire button is the left mouse button.
236 ; Joystick 1's fire button is the right mouse button.
239 ldx #15 ; Switch to the system bank
242 ; Get the fire-button bits
247 ; Switch back to the execution bank.
252 ; Joystick 2, fire button is in bit 7.
253 ; Joystick 1, fire button is in bit 6.
256 asl a ; Move bits 7,6 to bits 1,0
259 adc #%00001110 ; Move bit 1 to bit 4
260 and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
262 ; Bits go up when buttons go down.
264 eor #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
268 ;----------------------------------------------------------------------------
269 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
270 ; struct pointed to by ptr1. No return code required.
272 ; We're cheating here to keep the code smaller: The first fields of the
273 ; mouse_info struct are identical to the mouse_pos struct; so, we just will
274 ; use _mouse_pos to fill the position fields.
278 ; Fill in the button state.
280 ldy #MOUSE_INFO::BUTTONS
283 ; jmp POS ; Fall through
285 ;----------------------------------------------------------------------------
286 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
287 ; No return code required.
289 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
291 sei ; Disable interrupts
292 lda XPos ; Transfer the position
301 cli ; Enable interrupts
304 sta (ptr1),y ; Store last byte
308 ;----------------------------------------------------------------------------
309 ; IOCTL: Driver-defined entry point. The wrapper will pass a pointer to ioctl-
310 ; specific data in ptr1, and the ioctl code in .A.
311 ; Must return an error code in .XA.
314 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioctls, for now
315 ldx #>MOUSE_ERR_INV_IOCTL
318 ;----------------------------------------------------------------------------
319 ; IRQ: Irq.-handler entry point. Called as a subroutine, but in the IRQ context
320 ; (so, be careful). The routine MUST return carry set if the interrupt has been
321 ; 'handled' -- which means that the interrupt source is gone. Otherwise, it
322 ; MUST return carry clear.
326 IRQ: ldy #15 ; Switch to the system bank
329 ; Get the direction bits.
332 lda (cia2),y ; Read joystick inputs
334 ; Switch back to the execution bank.
339 ; Joystick 2, directions in bits 7-4.
340 ; Mask the relevant bits.
343 eor #$F0 ; All bits are inverted
348 and #(JOY::LEFT | JOY::RIGHT) << 4
351 ; We will cheat here, and rely on the fact that either the left OR the right
354 and #JOY::RIGHT << 4 ; Check RIGHT bit
358 bnz @AddX ; Branch always
362 ; Calculate the new x co-ordinate (--> .YA).
365 tay ; Remember low byte
370 ; Limit the x co-ordinate to the bounding box.
388 ; Calculate the y movement vector.
390 @SkipX: lda Temp ; Get joystick again
391 and #(JOY::UP | JOY::DOWN) << 4 ; Check up/down
394 ; We will cheat here, and rely on the fact that either the up OR the down
397 and #JOY::UP << 4 ; Check UP bit
405 ; Calculate the new y co-ordinate (--> .YA).
408 tay ; Remember low byte
413 ; Limit the y co-ordinate to the bounding box.
433 @SkipY: clc ; Interrupt not handled
436 ; Move the mouse pointer to the new x pos.
442 ; Move the mouse pointer to the new y pos.