; ; Driver for a "joystick mouse". ; ; Ullrich von Bassewitz, 2004-04-05, 2009-09-26 ; .include "zeropage.inc" .include "mouse-kernel.inc" .include "c128.inc" .macpack generic ; ------------------------------------------------------------------------ ; Header. Includes jump table .segment "JUMPTABLE" HEADER: ; Driver signature .byte $6d, $6f, $75 ; "mou" .byte MOUSE_API_VERSION ; Mouse driver API version number ; Jump table. .addr INSTALL .addr UNINSTALL .addr HIDE .addr SHOW .addr SETBOX .addr GETBOX .addr MOVE .addr BUTTONS .addr POS .addr INFO .addr IOCTL .addr IRQ ; Mouse driver flags .byte MOUSE_FLAG_LATE_IRQ ; Callback table, set by the kernel before INSTALL is called CHIDE: jmp $0000 ; Hide the cursor CSHOW: jmp $0000 ; Show the cursor CMOVEX: jmp $0000 ; Move the cursor to X coord CMOVEY: jmp $0000 ; Move the cursor to Y coord ;---------------------------------------------------------------------------- ; Constants SCREEN_HEIGHT = 200 SCREEN_WIDTH = 320 .enum JOY UP = $01 DOWN = $02 LEFT = $04 RIGHT = $08 FIRE = $10 .endenum ;---------------------------------------------------------------------------- ; Global variables. The bounding box values are sorted so that they can be ; written with the least effort in the SETBOX and GETBOX routines, so don't ; reorder them. .bss Vars: YPos: .res 2 ; Current mouse position, Y XPos: .res 2 ; Current mouse position, X XMin: .res 2 ; X1 value of bounding box YMin: .res 2 ; Y1 value of bounding box XMax: .res 2 ; X2 value of bounding box YMax: .res 2 ; Y2 value of bounding box Buttons: .res 1 ; Button mask ; Temporary value used in the int handler Temp: .res 1 ; Default values for above variables .rodata .proc DefVars .word SCREEN_HEIGHT/2 ; YPos .word SCREEN_WIDTH/2 ; XPos .word 0 ; XMin .word 0 ; YMin .word SCREEN_WIDTH ; XMax .word SCREEN_HEIGHT ; YMax .byte 0 ; Buttons .endproc .code ;---------------------------------------------------------------------------- ; INSTALL routine. Is called after the driver is loaded into memory. If ; possible, check if the hardware is present. ; Must return an MOUSE_ERR_xx code in a/x. INSTALL: ; Initialize variables. Just copy the default stuff over ldx #.sizeof(DefVars)-1 @L1: lda DefVars,x sta Vars,x dex bpl @L1 ; Be sure the mouse cursor is invisible and at the default location. We ; need to do that here, because our mouse interrupt handler doesn't set the ; mouse position if it hasn't changed. sei jsr CHIDE lda XPos ldx XPos+1 jsr CMOVEX lda YPos ldx YPos+1 jsr CMOVEY cli ; Done, return zero (= MOUSE_ERR_OK) ldx #$00 txa rts ;---------------------------------------------------------------------------- ; UNINSTALL routine. Is called before the driver is removed from memory. ; No return code required (the driver is removed from memory on return). UNINSTALL = HIDE ; Hide cursor on exit ;---------------------------------------------------------------------------- ; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages ; a counter for calls to show/hide, and the driver entry point is only called ; if the mouse is currently visible and should get hidden. For most drivers, ; no special action is required besides hiding the mouse cursor. ; No return code required. HIDE: sei jsr CHIDE cli rts ;---------------------------------------------------------------------------- ; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages ; a counter for calls to show/hide, and the driver entry point is only called ; if the mouse is currently hidden and should become visible. For most drivers, ; no special action is required besides enabling the mouse cursor. ; No return code required. SHOW: sei jsr CSHOW cli rts ;---------------------------------------------------------------------------- ; SETBOX: Set the mouse bounding box. The parameters are passed as they come ; from the C program, that is, a pointer to a mouse_box struct in a/x. ; No checks are done if the mouse is currently inside the box, this is the job ; of the caller. It is not necessary to validate the parameters, trust the ; caller and save some code here. No return code required. SETBOX: sta ptr1 stx ptr1+1 ; Save data pointer ldy #.sizeof (MOUSE_BOX)-1 sei @L1: lda (ptr1),y sta XMin,y dey bpl @L1 cli rts ;---------------------------------------------------------------------------- ; GETBOX: Return the mouse bounding box. The parameters are passed as they ; come from the C program, that is, a pointer to a mouse_box struct in a/x. GETBOX: sta ptr1 stx ptr1+1 ; Save data pointer ldy #.sizeof (MOUSE_BOX)-1 sei @L1: lda XMin,y sta (ptr1),y dey bpl @L1 cli rts ;---------------------------------------------------------------------------- ; MOVE: Move the mouse to a new position. The position is passed as it comes ; from the C program, that is: X on the stack and Y in a/x. The C wrapper will ; remove the parameter from the stack on return. ; No checks are done if the new position is valid (within the bounding box or ; the screen). No return code required. ; MOVE: sei ; No interrupts sta YPos stx YPos+1 ; New Y position jsr CMOVEY ; Set it ldy #$01 lda (sp),y sta XPos+1 tax dey lda (sp),y sta XPos ; New X position jsr CMOVEX ; Move the cursor cli ; Allow interrupts rts ;---------------------------------------------------------------------------- ; BUTTONS: Return the button mask in a/x. BUTTONS: lda Buttons ldx #$00 rts ;---------------------------------------------------------------------------- ; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1. ; No return code required. POS: ldy #MOUSE_POS::XCOORD ; Structure offset sei ; Disable interrupts lda XPos ; Transfer the position sta (ptr1),y lda XPos+1 iny sta (ptr1),y lda YPos iny sta (ptr1),y lda YPos+1 cli ; Enable interrupts iny sta (ptr1),y ; Store last byte rts ; Done ;---------------------------------------------------------------------------- ; INFO: Returns mouse position and current button mask in the MOUSE_INFO ; struct pointed to by ptr1. No return code required. ; ; We're cheating here to keep the code smaller: The first fields of the ; mouse_info struct are identical to the mouse_pos struct, so we will just ; call _mouse_pos to initialize the struct pointer and fill the position ; fields. INFO: jsr POS ; Fill in the button state lda Buttons ldy #MOUSE_INFO::BUTTONS sta (ptr1),y rts ;---------------------------------------------------------------------------- ; IOCTL: Driver defined entry point. The wrapper will pass a pointer to ioctl ; specific data in ptr1, and the ioctl code in A. ; Must return an error code in a/x. ; IOCTL: lda #MOUSE_ERR_INV_IOCTL rts ;---------------------------------------------------------------------------- ; IRQ: Irq handler entry point. Called as a subroutine but in IRQ context ; (so be careful). The routine MUST return carry set if the interrupt has been ; 'handled' - which means that the interrupt source is gone. Otherwise it ; MUST return carry clear. ; IRQ: lda #$7F sta CIA1_PRA lda CIA1_PRB ; Read joystick #0 and #$1F eor #$1F ; Make all bits active high sta Temp ; Check for a pressed button and place the result into Buttons ldx #$00 ; Assume no button pressed and #JOY::FIRE ; Check fire button beq @L0 ; Jump if not pressed ldx #MOUSE_BTN_LEFT ; Left (only) button is pressed @L0: stx Buttons ; Check left/right lda Temp ; Read joystick #0 and #(JOY::LEFT | JOY::RIGHT) beq @SkipX ; ; We will cheat here and rely on the fact that either the left, OR the right ; bit can be active and #JOY::RIGHT ; Check RIGHT bit bne @Right lda #$FF tax bne @AddX ; Branch always @Right: lda #$01 ldx #$00 ; Calculate the new X coordinate (--> a/y) @AddX: add XPos tay ; Remember low byte txa adc XPos+1 tax ; Limit the X coordinate to the bounding box cpy XMin sbc XMin+1 bpl @L1 ldy XMin ldx XMin+1 jmp @L2 @L1: txa cpy XMax sbc XMax+1 bmi @L2 ldy XMax ldx XMax+1 @L2: sty XPos stx XPos+1 ; Move the mouse pointer to the new X pos tya jsr CMOVEX ; Calculate the Y movement vector @SkipX: lda Temp ; Read joystick #0 and #(JOY::UP | JOY::DOWN) ; Check up/down beq @SkipY ; ; We will cheat here and rely on the fact that either the up, OR the down ; bit can be active lsr a ; Check UP bit bcc @Down lda #$FF tax bne @AddY @Down: lda #$01 ldx #$00 ; Calculate the new Y coordinate (--> a/y) @AddY: add YPos tay ; Remember low byte txa adc YPos+1 tax ; Limit the Y coordinate to the bounding box cpy YMin sbc YMin+1 bpl @L3 ldy YMin ldx YMin+1 jmp @L4 @L3: txa cpy YMax sbc YMax+1 bmi @L4 ldy YMax ldx YMax+1 @L4: sty YPos stx YPos+1 ; Move the mouse pointer to the new X pos tya jsr CMOVEY ; Done @SkipY: clc ; Interrupt not "handled" rts