Added a standard mouse driver to the cx16 library.

libsrc/cx16/mcbdefault.s

@@ -0,0 +1,65 @@
+;
+; Default mouse callbacks for the CX16
+;
+; 2019-11-09, Greg King
+;
+; All functions in this module should be interrupt safe
+; because they might be called from an interrupt handler.
+;
+
+        .export         _mouse_def_callbacks
+
+        .include        "cbm_kernal.inc"
+        .include        "cx16.inc"
+
+; --------------------------------------------------------------------------
+; Hide the mouse pointer. Always called with interrupts disabled.
+
+.code
+
+hide:   ldx     #$00            ; Don't change sprite's scale
+        lda     #$00            ; Disable sprite
+        jmp     MOUSE
+
+; --------------------------------------------------------------------------
+; Show the mouse pointer. Always called with interrupts disabled.
+
+show:   ldx     #$00
+        lda     #<-$01          ; Enable sprite
+        jmp     MOUSE
+
+; --------------------------------------------------------------------------
+; Prepare to move the mouse pointer. Always called with interrupts disabled.
+
+prep:   ; Fall through
+
+; --------------------------------------------------------------------------
+; Draw the mouse pointer. Always called with interrupts disabled.
+
+draw:   ; Fall through
+
+; --------------------------------------------------------------------------
+; Move the mouse pointer X position to the value in .XA .  Always called with
+; interrupts disabled.
+
+movex:                          ; Already set by drivers
+        ; Fall through
+
+; --------------------------------------------------------------------------
+; Move the mouse pointer Y position to the value in .XA .  Always called with
+; interrupts disabled.
+
+movey:  rts                     ; Already set by drivers
+
+; --------------------------------------------------------------------------
+; Callback structure
+
+.rodata
+
+_mouse_def_callbacks:
+        .addr   hide
+        .addr   show
+        .addr   prep
+        .addr   draw
+        .addr   movex
+        .addr   movey