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cc65/libsrc/cbm510/mcbdefault.s
Greg King a0d986faf8 Fixed the horizontal movement of the mouse pointer on platforms with the VIC-II display chip.
ca65's logical (Boolean) NOT operator was used where bitwise NOT should be used.  The effect was that all sprites were shifted to the left side of a screen when the mouse sprite was put on the left side.
2020-11-27 21:22:22 -05:00

171 lines
4.5 KiB
ArmAsm

;
; Default mouse callbacks for the CBM510 (P128)
;
; 2004-03-20, Ullrich von Bassewitz2
; 2013-06-25, Greg King
;
; All functions in this module should be interrupt-safe because they might
; be called from an interrupt handler.
;
.constructor initmcb
.export _mouse_def_callbacks
.import _mouse_def_pointershape
.import _mouse_def_pointercolor
.import vic:zp
.include "mouse-kernel.inc"
.include "cbm510.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 that value.
MOUSE_SPR = 0 ; Sprite used for the mouse
MOUSE_SPR_MEM = $F400 ; Memory location
MOUSE_SPR_MASK = $01 .shl MOUSE_SPR ; Positive mask
MOUSE_SPR_NMASK = .lobyte(.bitnot 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:
; Copy the mouse sprite data
ldx #64 - 1
@L0: lda _mouse_def_pointershape,x
sta MOUSE_SPR_MEM,x
dex
bpl @L0
; Set the mouse sprite pointer
lda #<(MOUSE_SPR_MEM / 64)
sta $F3F8 + MOUSE_SPR
; Set the mouse sprite color
ldx IndReg
lda #15
sta IndReg
lda _mouse_def_pointercolor
ldy #VIC_SPR0_COLOR + MOUSE_SPR
sta (vic),y
stx IndReg
rts
; --------------------------------------------------------------------------
; Hide the mouse pointer. Always called with interrupts disabled.
.code
hide:
ldy #15
sty IndReg
ldy #VIC_SPR_ENA
lda (vic),y
and #MOUSE_SPR_NMASK
sta (vic),y
ldy ExecReg
sty IndReg
rts
; --------------------------------------------------------------------------
; Show the mouse pointer. Always called with interrupts disabled.
show:
ldy #15
sty IndReg
ldy #VIC_SPR_ENA
lda (vic),y
ora #MOUSE_SPR_MASK
sta (vic),y
ldy ExecReg
sty IndReg
; 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 .XA. Always called with
; interrupts disabled.
movex:
ldy #15
sty IndReg
; Add the x correction; and, set the low byte. That frees .A.
add #<24 ; x correction
ldy #VIC_SPR_X
sta (vic),y
; Set the high byte
ldy #VIC_SPR_HI_X
txa
adc #>24
bnz @L1 ; Branch if high byte not zero
lda (vic),y ; Get high x bits of all sprites
and #MOUSE_SPR_NMASK ; Clear high bit for sprite
sta (vic),y
@L0: ldy ExecReg
sty IndReg
rts
@L1: lda (vic),y ; Get high x bits of all sprites
ora #MOUSE_SPR_MASK ; Set high bit for sprite
sta (vic),y
bnz @L0 ; Branch always
; --------------------------------------------------------------------------
; Move the mouse pointer y position to the value in .XA. Always called with
; interrupts disabled.
movey:
ldy #15
sty IndReg
add #50 ; y correction (first visible line)
ldy #VIC_SPR_Y
sta (vic),y ; Set y position
ldy ExecReg
sty IndReg
rts
; --------------------------------------------------------------------------
; Callback structure
.rodata
_mouse_def_callbacks:
.addr hide
.addr show
.addr prep
.addr draw
.addr movex
.addr movey