mirror of
https://github.com/cc65/cc65.git
synced 2024-09-11 06:54:33 +00:00
Note that the joystick driver doesn't support combined movements (like left/up or right/down). This should be fixed.
194 lines
5.3 KiB
ArmAsm
194 lines
5.3 KiB
ArmAsm
;
|
|
; Standard joystick driver for the Creativision.
|
|
;
|
|
; Christian Groessler, 2017-02-06
|
|
;
|
|
|
|
.include "zeropage.inc"
|
|
|
|
.include "joy-kernel.inc"
|
|
.include "joy-error.inc"
|
|
.include "creativision.inc"
|
|
|
|
.macpack module
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Header. Includes jump table
|
|
|
|
module_header _creativisionstd_joy
|
|
|
|
; Driver signature
|
|
|
|
.byte $6A, $6F, $79 ; "joy"
|
|
.byte JOY_API_VERSION ; Driver API version number
|
|
|
|
; Library reference
|
|
|
|
.addr $0000
|
|
|
|
; Button state masks (8 values)
|
|
|
|
.byte $10 ; JOY_UP
|
|
.byte $04 ; JOY_DOWN
|
|
.byte $20 ; JOY_LEFT
|
|
.byte $08 ; JOY_RIGHT
|
|
.byte $01 ; JOY_FIRE (button #1)
|
|
.byte $02 ; JOY_FIRE2 (button #2)
|
|
.byte $00 ; Future expansion
|
|
.byte $00 ; Future expansion
|
|
|
|
; Jump table.
|
|
|
|
.addr INSTALL
|
|
.addr UNINSTALL
|
|
.addr COUNT
|
|
.addr READJOY
|
|
.addr 0 ; IRQ entry not used
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Constants
|
|
|
|
JOY_COUNT = 2 ; Number of joysticks we support
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Code
|
|
|
|
.code
|
|
|
|
; ------------------------------------------------------------------------
|
|
; INSTALL routine. Is called after the driver is loaded into memory. If
|
|
; possible, check if the hardware is present and determine the amount of
|
|
; memory available.
|
|
; Must return an JOY_ERR_xx code in a/x.
|
|
;
|
|
|
|
INSTALL:
|
|
lda #JOY_ERR_OK
|
|
ldx #0
|
|
; rts ; Fall through
|
|
|
|
; ------------------------------------------------------------------------
|
|
; UNINSTALL routine. Is called before the driver is removed from memory.
|
|
; Can do cleanup or whatever. Must not return anything.
|
|
;
|
|
|
|
UNINSTALL:
|
|
rts
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; COUNT: Return the total number of available joysticks in a/x.
|
|
;
|
|
|
|
COUNT:
|
|
lda #<JOY_COUNT
|
|
ldx #>JOY_COUNT
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; READ: Read a particular joystick passed in A.
|
|
;
|
|
|
|
READJOY:
|
|
and #1 ; fix joystick number
|
|
bne READJOY_1 ; read right joystick
|
|
|
|
; Read left joystick
|
|
|
|
ldx ZP_JOY0_DIR
|
|
lda ZP_JOY0_BUTTONS
|
|
jmp convert ; convert joystick state to sane cc65 values
|
|
|
|
; Read right joystick
|
|
|
|
READJOY_1:
|
|
|
|
ldx ZP_JOY1_DIR
|
|
lda ZP_JOY1_BUTTONS
|
|
lsr a
|
|
lsr a
|
|
;jmp convert ; convert joystick state to sane cc65 values
|
|
; fall thru...
|
|
|
|
; ------------------------------------------------------------------------
|
|
; convert: make runtime lib compatible values
|
|
; A - buttons
|
|
; X - direction
|
|
;
|
|
|
|
convert:
|
|
ldy #0
|
|
sty retval ; initialize return value
|
|
|
|
; ------
|
|
; buttons:
|
|
; Port values are for the left hand joystick (right hand joystick
|
|
; values were shifted to the right to be identical).
|
|
; Why are there two bits indicating a pressed trigger?
|
|
; According to the "Second book of programs for the Dick Smith Wizard"
|
|
; (pg. 88ff), the left hand fire button gives the value of
|
|
; %00010001 and the right hand button gives %00100010
|
|
; Why two bits? Am I missing something? Can there be cases that just
|
|
; one of those bits is set?
|
|
; We just test if any of those two bits is not zero...
|
|
|
|
tay
|
|
and #%00010001
|
|
beq cnv_1
|
|
|
|
inc retval ; left button pressed
|
|
|
|
cnv_1: tya
|
|
and #%00100010
|
|
beq cnv_2
|
|
|
|
lda #$02
|
|
ora retval
|
|
sta retval ; right button pressed
|
|
|
|
; ------
|
|
; direction:
|
|
cnv_2: txa
|
|
; tested with https://sourceforge.net/projects/creativisionemulator
|
|
; $49 - %01001001 - up
|
|
; $41 - %01000001 - down
|
|
; $4D - %01001101 - left
|
|
; $45 - %01000101 - right
|
|
;
|
|
; are these correct? "Second book of programs for the Dick Smith Wizard" pg. 85 says something different
|
|
; ignored for now...
|
|
; $85 - %10000101 - up + right
|
|
; $8D - %10001101 - down + left
|
|
; $89 - %10001001 - up + left
|
|
; $85 - %10000101 - down + right (emulator bug?)
|
|
|
|
bit testbit ; bit #0 set?
|
|
beq done ; no, no direction
|
|
|
|
and #%00001100 ; mask out other bits
|
|
lsr a
|
|
lsr a
|
|
tax
|
|
lda #%00000100 ; init bitmask
|
|
loop: dex
|
|
bmi done2
|
|
asl a
|
|
bne loop
|
|
|
|
done2: ora retval
|
|
rts
|
|
|
|
done: lda retval
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
;
|
|
.data
|
|
testbit:.byte $01
|
|
|
|
; ------------------------------------------------------------------------
|
|
;
|
|
.bss
|
|
retval: .res 0
|