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|
;
; Default mouse callbacks for the C64
;
; Ullrich von Bassewitz, 2004-03-20
;
; All functions in this module should be interrupt safe, because they may
; be called from an interrupt handler
;
.constructor initmcb
.export _mouse_def_callbacks
.import _mouse_def_pointershape
.import _mouse_def_pointercolor
.import mcb_spritememory
.import mcb_spritepointer
.include "mouse-kernel.inc"
.include "c64.inc"
.macpack generic
; Sprite definitions. The first value can be changed to adjust the number
; of the sprite used for the mouse. All others depend on this value.
MOUSE_SPR = 0 ; Sprite used for the mouse
MOUSE_SPR_MASK = $01 .shl MOUSE_SPR ; Positive mask
MOUSE_SPR_NMASK = .lobyte(.not MOUSE_SPR_MASK) ; Negative mask
VIC_SPR_X = (VIC_SPR0_X + 2*MOUSE_SPR) ; Sprite X register
VIC_SPR_Y = (VIC_SPR0_Y + 2*MOUSE_SPR) ; Sprite Y register
; --------------------------------------------------------------------------
; Initialize the mouse sprite.
.segment "ONCE"
initmcb:
; Make all RAM accessible
lda #$30
ldy $01
sei
sta $01
; Copy the mouse sprite data
ldx #64 - 1
@L0: lda _mouse_def_pointershape,x
sta mcb_spritememory,x
dex
bpl @L0
; Set the mouse sprite pointer
lda #<(mcb_spritememory / 64)
sta mcb_spritepointer + MOUSE_SPR
; Restore memory configuration
sty $01
cli
; Set the mouse sprite color
lda _mouse_def_pointercolor
sta VIC_SPR0_COLOR + MOUSE_SPR
rts
; --------------------------------------------------------------------------
; Hide the mouse pointer. Always called with interrupts disabled.
.code
hide:
lda #MOUSE_SPR_NMASK
and VIC_SPR_ENA
sta VIC_SPR_ENA
rts
; --------------------------------------------------------------------------
; Show the mouse pointer. Always called with interrupts disabled.
show:
lda #MOUSE_SPR_MASK
ora VIC_SPR_ENA
sta VIC_SPR_ENA
; Fall through
; --------------------------------------------------------------------------
; Prepare to move the mouse pointer. Always called with interrupts disabled.
prep:
; Fall through
; --------------------------------------------------------------------------
; Draw the mouse pointer. Always called with interrupts disabled.
draw:
rts
; --------------------------------------------------------------------------
; Move the mouse pointer X position to the value in a/x. Always called with
; interrupts disabled.
movex:
; Add the X correction and set the low byte. This frees A.
add #24 ; X correction
sta VIC_SPR_X
; Set the high byte
txa
adc #0
bne @L1 ; Branch if high byte not zero
lda VIC_SPR_HI_X ; Get high X bits of all sprites
and #MOUSE_SPR_NMASK ; Clear high bit for sprite
sta VIC_SPR_HI_X
rts
@L1: lda VIC_SPR_HI_X ; Get high X bits of all sprites
ora #MOUSE_SPR_MASK ; Set high bit for sprite
sta VIC_SPR_HI_X
rts
; --------------------------------------------------------------------------
; Move the mouse pointer Y position to the value in a/x. Always called with
; interrupts disabled.
movey:
add #50 ; Y correction (first visible line)
sta VIC_SPR_Y ; Set Y position
rts
; --------------------------------------------------------------------------
; Callback structure
.rodata
_mouse_def_callbacks:
.addr hide
.addr show
.addr prep
.addr draw
.addr movex
.addr movey
|
