2 ; Driver for a "joystick mouse".
4 ; C128 version: Ullrich von Bassewitz, 2004-04-05, 2009-09-26
5 ; Adapted to Atari: Christian Groessler, 2014-01-02
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
47 .byte MOUSE_FLAG_LATE_IRQ
49 ; Callback table, set by the kernel before INSTALL is called
51 CHIDE: jmp $0000 ; Hide the cursor
52 CSHOW: jmp $0000 ; Show the cursor
53 CMOVEX: jmp $0000 ; Move the cursor to X coord
54 CMOVEY: jmp $0000 ; Move the cursor to Y coord
57 ;----------------------------------------------------------------------------
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
87 Temp: .res 1 ; Temporary value used in the int handler
90 ; Default values for above variables
95 .word SCREEN_HEIGHT/2 ; YPos
96 .word SCREEN_WIDTH/2 ; XPos
99 .word SCREEN_WIDTH ; XMax
100 .word SCREEN_HEIGHT ; YMax
106 ;----------------------------------------------------------------------------
107 ; INSTALL routine. Is called after the driver is loaded into memory. If
108 ; possible, check if the hardware is present.
109 ; Must return an MOUSE_ERR_xx code in a/x.
113 ; Initialize variables. Just copy the default stuff over
115 ldx #.sizeof(DefVars)-1
121 ; Be sure the mouse cursor is invisible and at the default location. We
122 ; need to do that here, because our mouse interrupt handler doesn't set the
123 ; mouse position if it hasn't changed.
135 ; Done, return zero (= MOUSE_ERR_OK)
141 ;----------------------------------------------------------------------------
142 ; UNINSTALL routine. Is called before the driver is removed from memory.
143 ; No return code required (the driver is removed from memory on return).
145 UNINSTALL = HIDE ; Hide cursor on exit
147 ;----------------------------------------------------------------------------
148 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
149 ; a counter for calls to show/hide, and the driver entry point is only called
150 ; if the mouse is currently visible and should get hidden. For most drivers,
151 ; no special action is required besides hiding the mouse cursor.
152 ; 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.
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 a/x.
176 ; No checks are done if the mouse is currently inside the box, this 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 a/x.
199 stx ptr1+1 ; Save data pointer
201 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 a/x. 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
231 stx YPos+1 ; New Y position
240 sta XPos ; New X position
242 jsr CMOVEX ; Move the cursor
249 @Ret: cli ; Allow interrupts
252 ;----------------------------------------------------------------------------
253 ; BUTTONS: Return the button mask in a/x.
260 ;----------------------------------------------------------------------------
261 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
262 ; No return code required.
264 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
266 sei ; Disable interrupts
267 lda XPos ; Transfer the position
276 cli ; Enable interrupts
279 sta (ptr1),y ; Store last byte
283 ;----------------------------------------------------------------------------
284 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
285 ; struct pointed to by ptr1. No return code required.
287 ; We're cheating here to keep the code smaller: The first fields of the
288 ; mouse_info struct are identical to the mouse_pos struct, so we will just
289 ; call _mouse_pos to initialize the struct pointer and fill the position
294 ; Fill in the button state
297 ldy #MOUSE_INFO::BUTTONS
302 ;----------------------------------------------------------------------------
303 ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
304 ; specific data in ptr1, and the ioctl code in A.
305 ; Must return an error code in a/x.
308 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
309 ldx #>MOUSE_ERR_INV_IOCTL
312 ;----------------------------------------------------------------------------
313 ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
314 ; (so be careful). The routine MUST return carry set if the interrupt has been
315 ; 'handled' - which means that the interrupt source is gone. Otherwise it
316 ; MUST return carry clear.
321 ; Check for a pressed button and place the result into Buttons
324 lda TRIG0 ; joystick #0 trigger
325 bne @L0 ; not pressed
329 lda PORTA ; get joystick direction bits
330 and #15 ; clear joystick #1 bits
334 beq hlprts ; no movement, do nothing
340 lda Temp ; Read joystick #0
341 and #(JOY::LEFT | JOY::RIGHT)
344 ; We will cheat here and rely on the fact that either the left, OR the right
347 and #JOY::RIGHT ; Check RIGHT bit
351 bne @AddX ; Branch always
355 ; Calculate the new X coordinate (--> a/y)
358 tay ; Remember low byte
363 ; Limit the X coordinate to the bounding box
381 ; Move the mouse pointer to the new X pos
386 ; Calculate the Y movement vector
388 @SkipX: lda Temp ; Read joystick #0
389 and #(JOY::UP | JOY::DOWN) ; Check up/down
392 ; We will cheat here and rely on the fact that either the up, OR the down
403 ; Calculate the new Y coordinate (--> a/y)
406 tay ; Remember low byte
411 ; Limit the Y coordinate to the bounding box
429 ; Move the mouse pointer to the new X pos
441 @Done: clc ; Interrupt not "handled"