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 CPREP: jmp $0000 ; Prepare to move the cursor
56 CDRAW: jmp $0000 ; Draw the cursor
57 CMOVEX: jmp $0000 ; Move the cursor to x co-ord.
58 CMOVEY: jmp $0000 ; Move the cursor to y co-ord.
61 ;----------------------------------------------------------------------------
64 SCREEN_HEIGHT = YSIZE * 8
65 SCREEN_WIDTH = XSIZE * 8
75 ;----------------------------------------------------------------------------
76 ; Global variables. The bounding box values are sorted so that they can be
77 ; written with the least effort in the SETBOX and GETBOX routines; so, don't
83 YPos: .res 2 ; Current mouse position, y
84 XPos: .res 2 ; Current mouse position, x
85 XMin: .res 2 ; X1 value of bounding box
86 YMin: .res 2 ; Y1 value of bounding box
87 XMax: .res 2 ; X2 value of bounding box
88 YMax: .res 2 ; Y2 value of bounding box
90 ; Temporary value used in the interrupt handler
96 ; Default values for above variables
97 ; (We use ".proc" because we want to define both a label and a scope.)
100 .word SCREEN_HEIGHT / 2 ; YPos
101 .word SCREEN_WIDTH / 2 ; XPos
104 .word SCREEN_WIDTH - 1 ; XMax
105 .word SCREEN_HEIGHT - 1 ; YMax
110 ;----------------------------------------------------------------------------
111 ; INSTALL routine. Is called after the driver is loaded into memory. If
112 ; possible, check if the hardware is present.
113 ; Must return a MOUSE_ERR_xx code in .XA.
117 ; Initiate variables; just copy the default stuff over.
119 ldx #.sizeof(DefVars) - 1
125 ; Be sure the mouse cursor is invisible and at the default location. We
126 ; need to do that here because our mouse interrupt handler doesn't set the
127 ; mouse position if it hasn't changed.
145 ;----------------------------------------------------------------------------
146 ; UNINSTALL routine. Is called before the driver is removed from memory.
147 ; No return code required (the driver is removed from memory, on return).
149 UNINSTALL := HIDE ; Hide cursor, on exit
151 ;----------------------------------------------------------------------------
152 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
153 ; a counter for calls to show/hide; and, the driver entry point is called only
154 ; if the mouse currently is visible and should get hidden. For most drivers,
155 ; no special action is required besides hiding the mouse cursor.
156 ; No return code required.
163 ;----------------------------------------------------------------------------
164 ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
165 ; a counter for calls to show/hide; and, the driver entry point is called only
166 ; if the mouse currently is hidden and should become visible. For most drivers,
167 ; no special action is required besides enabling the mouse cursor.
168 ; No return code required.
175 ;----------------------------------------------------------------------------
176 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
177 ; from the C program, that is, a pointer to a mouse_box struct in .XA.
178 ; No checks are done if the mouse currently is inside the box; that is the job
179 ; of the caller. It is not necessary to validate the parameters; trust the
180 ; caller, and save some code here. No return code required.
183 stx ptr1+1 ; Save data pointer
185 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 .XA.
201 stx ptr1+1 ; Save data pointer
203 ldy #.sizeof (MOUSE_BOX) - 1
212 ;----------------------------------------------------------------------------
213 ; MOVE: Move the mouse to a new position. The position is passed as it comes
214 ; from the C program, that is: x on the stack and y in .XA. The C wrapper will
215 ; remove the parameter from the stack, on return.
216 ; No checks are done if the new position is valid (within the bounding box or
217 ; the screen). No return code required.
220 MOVE: sei ; No interrupts
222 jsr MoveY ; Set new y position
230 jsr MoveX ; Move the pointer
232 cli ; Allow interrupts
235 ;----------------------------------------------------------------------------
236 ; BUTTONS: Return the button mask in .XA.
237 ; Joystick 2's fire button is the left mouse button.
238 ; Joystick 1's fire button is the right mouse button.
241 ldx #15 ; Switch to the system bank
244 ; Get the fire-button bits
249 ; Switch back to the execution bank.
254 ; Joystick 2, fire button is in bit 7.
255 ; Joystick 1, fire button is in bit 6.
258 asl a ; Move bits 7,6 to bits 1,0
261 adc #%00001110 ; Move bit 1 to bit 4
262 and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
264 ; Bits go up when buttons go down.
266 eor #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
270 ;----------------------------------------------------------------------------
271 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
272 ; struct pointed to by ptr1. No return code required.
274 ; We're cheating here to keep the code smaller: The first fields of the
275 ; mouse_info struct are identical to the mouse_pos struct; so, we just will
276 ; use _mouse_pos to fill the position fields.
280 ; Fill in the button state.
282 ldy #MOUSE_INFO::BUTTONS
285 ; jmp POS ; Fall through
287 ;----------------------------------------------------------------------------
288 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
289 ; No return code required.
291 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
293 sei ; Disable interrupts
294 lda XPos ; Transfer the position
303 cli ; Enable interrupts
306 sta (ptr1),y ; Store last byte
310 ;----------------------------------------------------------------------------
311 ; IOCTL: Driver-defined entry point. The wrapper will pass a pointer to ioctl-
312 ; specific data in ptr1, and the ioctl code in .A.
313 ; Must return an error code in .XA.
316 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioctls, for now
317 ldx #>MOUSE_ERR_INV_IOCTL
320 ;----------------------------------------------------------------------------
321 ; IRQ: Irq.-handler entry point. Called as a subroutine, but in the IRQ context
322 ; (so, be careful). The routine MUST return carry set if the interrupt has been
323 ; 'handled' -- which means that the interrupt source is gone. Otherwise, it
324 ; MUST return carry clear.
329 ldy #15 ; Switch to the system bank
332 ; Get the direction bits.
335 lda (cia2),y ; Read joystick inputs
337 ; Switch back to the execution bank.
342 ; Joystick 2, directions in bits 7-4.
343 ; Mask the relevant bits.
346 eor #$F0 ; All bits are inverted
351 and #(JOY::LEFT | JOY::RIGHT) << 4
354 ; We will cheat here, and rely on the fact that either the left OR the right
357 and #JOY::RIGHT << 4 ; Check RIGHT bit
361 bnz @AddX ; Branch always
365 ; Calculate the new x co-ordinate (--> .YA).
368 tay ; Remember low byte
373 ; Limit the x co-ordinate to the bounding box.
391 ; Calculate the y movement vector.
393 @SkipX: lda Temp ; Get joystick again
394 and #(JOY::UP | JOY::DOWN) << 4 ; Check up/down
397 ; We will cheat here, and rely on the fact that either the up OR the down
400 and #JOY::UP << 4 ; Check UP bit
408 ; Calculate the new y co-ordinate (--> .YA).
411 tay ; Remember low byte
416 ; Limit the y co-ordinate to the bounding box.
437 clc ; Interrupt not "handled"
440 ; Move the mouse pointer to the new x pos.
446 ; Move the mouse pointer to the new y pos.