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 CPREP: jmp $0000 ; Prepare to move the cursor
54 CDRAW: jmp $0000 ; Draw the cursor
55 CMOVEX: jmp $0000 ; Move the cursor to X coord
56 CMOVEY: jmp $0000 ; Move the cursor to Y coord
59 ;----------------------------------------------------------------------------
72 ;----------------------------------------------------------------------------
73 ; Global variables. The bounding box values are sorted so that they can be
74 ; written with the least effort in the SETBOX and GETBOX routines, so don't
80 YPos: .res 2 ; Current mouse position, Y
81 XPos: .res 2 ; Current mouse position, X
82 XMin: .res 2 ; X1 value of bounding box
83 YMin: .res 2 ; Y1 value of bounding box
84 XMax: .res 2 ; X2 value of bounding box
85 YMax: .res 2 ; Y2 value of bounding box
86 Buttons: .res 1 ; Button mask
89 Temp: .res 1 ; Temporary value used in the int handler
91 ; Default values for above 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 ; XMax
103 .word SCREEN_HEIGHT ; YMax
109 ;----------------------------------------------------------------------------
110 ; INSTALL routine. Is called after the driver is loaded into memory. If
111 ; possible, check if the hardware is present.
112 ; Must return an MOUSE_ERR_xx code in a/x.
116 ; Initialize variables. Just copy the default stuff over
118 ldx #.sizeof(DefVars)-1
124 ; Make sure the mouse cursor is at the default location.
133 ; Done, return zero (= MOUSE_ERR_OK)
139 ;----------------------------------------------------------------------------
140 ; UNINSTALL routine. Is called before the driver is removed from memory.
141 ; No return code required (the driver is removed from memory on return).
143 UNINSTALL = HIDE ; Hide cursor on exit
145 ;----------------------------------------------------------------------------
146 ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
147 ; a counter for calls to show/hide, and the driver entry point is only called
148 ; if the mouse is currently visible and should get hidden. For most drivers,
149 ; no special action is required besides hiding the mouse cursor.
150 ; No return code required.
158 ;----------------------------------------------------------------------------
159 ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
160 ; a counter for calls to show/hide, and the driver entry point is only called
161 ; if the mouse is currently hidden and should become visible. For most drivers,
162 ; no special action is required besides enabling the mouse cursor.
163 ; No return code required.
171 ;----------------------------------------------------------------------------
172 ; SETBOX: Set the mouse bounding box. The parameters are passed as they come
173 ; from the C program, that is, a pointer to a mouse_box struct in a/x.
174 ; No checks are done if the mouse is currently inside the box, this is the job
175 ; of the caller. It is not necessary to validate the parameters, trust the
176 ; caller and save some code here. No return code required.
179 stx ptr1+1 ; Save data pointer
181 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
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.
232 stx YPos+1 ; New Y position
241 sta XPos ; New X position
242 jsr CMOVEX ; Move the cursor
246 plp ; Restore interrupt flag
249 ;----------------------------------------------------------------------------
250 ; BUTTONS: Return the button mask in a/x.
257 ;----------------------------------------------------------------------------
258 ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
259 ; No return code required.
261 POS: ldy #MOUSE_POS::XCOORD ; Structure offset
264 sei ; Disable interrupts
265 lda XPos ; Transfer the position
274 plp ; Restore interrupt flag
277 sta (ptr1),y ; Store last byte
281 ;----------------------------------------------------------------------------
282 ; INFO: Returns mouse position and current button mask in the MOUSE_INFO
283 ; struct pointed to by ptr1. No return code required.
285 ; We're cheating here to keep the code smaller: The first fields of the
286 ; mouse_info struct are identical to the mouse_pos struct, so we will just
287 ; call _mouse_pos to initialize the struct pointer and fill the position
292 ; Fill in the button state
295 ldy #MOUSE_INFO::BUTTONS
300 ;----------------------------------------------------------------------------
301 ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl
302 ; specific data in ptr1, and the ioctl code in A.
303 ; Must return an error code in a/x.
306 IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioclts for now
307 ldx #>MOUSE_ERR_INV_IOCTL
310 ;----------------------------------------------------------------------------
311 ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context
312 ; (so be careful). The routine MUST return carry set if the interrupt has been
313 ; 'handled' - which means that the interrupt source is gone. Otherwise it
314 ; MUST return carry clear.
319 ; Check for a pressed button and place the result into Buttons
322 lda TRIG0 ; joystick #0 trigger
323 bne @L0 ; not pressed
327 lda PORTA ; get joystick direction bits
328 and #15 ; clear joystick #1 bits
336 lda Temp ; Read joystick #0
337 and #(JOY::LEFT | JOY::RIGHT)
340 ; We will cheat here and rely on the fact that either the left, OR the right
343 and #JOY::RIGHT ; Check RIGHT bit
347 bne @AddX ; Branch always
351 ; Calculate the new X coordinate (--> a/y)
354 tay ; Remember low byte
359 ; Limit the X coordinate to the bounding box
377 ; Move the mouse pointer to the new X pos
382 ; Calculate the Y movement vector
384 @SkipX: lda Temp ; Read joystick #0
385 and #(JOY::UP | JOY::DOWN) ; Check up/down
388 ; We will cheat here and rely on the fact that either the up, OR the down
399 ; Calculate the new Y coordinate (--> a/y)
402 tay ; Remember low byte
407 ; Limit the Y coordinate to the bounding box
425 ; Move the mouse pointer to the new X pos
433 clc ; Interrupt not "handled"