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cc65/libsrc/atari/mcbpm.s
Oliver Schmidt 419eb700b5 Renamed INITBSS to INIT and INIT to ONCE.
The way we want to use the INITBSS segment - and especially the fact that it won't have the type bss on all ROM based targets - means that the name INITBSS is misleading. After all INIT is the best name from my perspective as it serves several purposes and therefore needs a rather generic name.

Unfortunately this means that the current INIT segment needs to be renamed too. Looking for a short (ideally 4 letter) name I came up with ONCE as it contains all code (and data) accessed only once during initialization.
2016-03-06 21:27:19 +01:00

238 lines
6.0 KiB
ArmAsm

;
; P/M mouse callbacks for the Ataris
;
; Christian Groessler, 11.04.2014
;
; All functions in this module should be interrupt safe, because they may
; be called from an interrupt handler
;
.include "atari.inc"
.importzp sp
.export _mouse_pm_callbacks
.constructor pm_init, 27
.destructor pm_down
; get mouse shape data
.import mouse_pm_bits
.importzp mouse_pm_height
.importzp mouse_pm_hotspot_x
.importzp mouse_pm_hotspot_y
; P/M definitions. The MOUSE_PM_NUM value can be changed to adjust the
; number of the P/M used for the mouse. All others depend on this value.
; Valid P/M numbers are 0 to 4. When 4 is used, the missiles are used
; as a player.
.ifdef USE_PAGE6
MOUSE_PM_NUM = 2 ; P/M used for the mouse
; This cannot be changed since only player #2 uses the memory at $600.
.else
MOUSE_PM_NUM = 4 ; P/M used for the mouse
; Using player #4 (missiles) wastes the least amount of memory on the
; atari target, since top of memory is typically at $xC20, and the
; missiles use the space at $xB00-$xBFF.
; On the atarixl target this configuration (not using page 6) is not
; really satisfying since the top of memory typically lies beneath
; the ROM and there is flickering visible while the ROM is banked in.
.endif
MOUSE_PM_BASE = pm_base ; ZP location pointing to the hw area used by the selected P/M
.if MOUSE_PM_NUM = 4
MOUSE_PM_RAW = 0 ; MOUSE_PM_RAW is the hardware P/M number for MOUSE_PM_NUM
.macro set_mouse_x
; assume CF = 0
sta HPOSM3
adc #2
sta HPOSM2
adc #2
sta HPOSM1
adc #2
sta HPOSM0
.endmacro
.else
MOUSE_PM_RAW = MOUSE_PM_NUM + 1
.macro set_mouse_x
sta HPOSP0 + MOUSE_PM_NUM
.endmacro
.endif
; ------------------------------------------------------------------------
.rodata
; Callback structure
_mouse_pm_callbacks:
.addr hide
.addr show
.addr prep
.addr draw
.addr movex
.addr movey
; ------------------------------------------------------------------------
.bss
omy: .res 1 ; old Mouse Y position
colhlp: .res 1 ; helper variable to set P/M color
; ------------------------------------------------------------------------
.segment "EXTZP" : zeropage
pm_base:.res 2
; ------------------------------------------------------------------------
.code
; Hide the mouse cursor.
hide: lda #0
sta GRACTL
rts
; Show the mouse cursor.
show:
.if MOUSE_PM_NUM < 4
lda #2
.else
lda #1
.endif
sta GRACTL
jmp update_colors
prep:
draw:
rts
; Move the mouse cursor x position to the value in A/X.
movex: cpx #1
ror a
clc
adc #48
sbc #(mouse_pm_hotspot_x - 1) & $FF
set_mouse_x
jmp update_colors
; Move the mouse cursor y position to the value in A/X.
movey: clc
adc #32
sbc #(mouse_pm_hotspot_y - 1) & $FF
pha
lda omy
jsr clr_pm ; remove player at old position
jsr update_colors
pla
sta omy
;jmp set_pm ; put player to new position
; fall thru
; Set P/M data from 'mouse_pm_bits'
set_pm: tay
ldx #0
set_l: lda mouse_pm_bits,x
sta (MOUSE_PM_BASE),y
inx
iny
beq set_end
cpx #mouse_pm_height
bcc set_l
set_end:rts
; Clear (zero) P/M data
clr_pm: ldx #mouse_pm_height
tay
lda #0
clr_l: sta (MOUSE_PM_BASE),y
iny
beq clr_end
dex
bne clr_l
clr_end:rts
pm_down = hide
; this assumes a GRAPHICS 0 screen
update_colors:
lda COLOR2 ; get background color
and #$F0
sta colhlp
lda COLOR1
and #$0F
ora colhlp
.if MOUSE_PM_NUM = 4
sta PCOLR0
sta PCOLR1
sta PCOLR2
sta PCOLR3
lda #0
sta SIZEM
.else
sta PCOLR0 + MOUSE_PM_NUM
lda #0
sta SIZEP0 + MOUSE_PM_NUM
.endif
rts
; ------------------------------------------------------------------------
.segment "ONCE"
pm_init:
lda #0
.ifdef USE_PAGE6
sta MOUSE_PM_BASE
ldx #6 ; page 6
stx MOUSE_PM_BASE+1
.else
; use top of memory and lower sp accordingly
sta sp
sta MOUSE_PM_BASE
lda sp+1
and #7 ; offset within 2K
cmp #3 + MOUSE_PM_RAW + 1 ; can we use it?
bcc @decr ; no
lda sp+1
and #$F8
@set: adc #3 + MOUSE_PM_RAW - 1 ; CF is set, so adding MOUSE_PM_RAW + 3
sta MOUSE_PM_BASE+1
sta sp+1
bne @cont ; jump always
@decr: lda sp+1
and #$F8
sbc #8 - 1 ; CF is clear, subtracts 8
bcs @set ; jump always
@cont: lda #0
.endif
tay
@iniloo:sta (MOUSE_PM_BASE),y
iny
bne @iniloo
.ifndef USE_PAGE6
lda MOUSE_PM_BASE+1
and #$F8
.endif
sta PMBASE
lda #62
sta SDMCTL
lda #1
sta GPRIOR
jmp update_colors