mirror of
https://github.com/cc65/cc65.git
synced 2024-07-05 06:28:57 +00:00
252 lines
8.6 KiB
ArmAsm
252 lines
8.6 KiB
ArmAsm
;
|
|
; Standard joystick driver for the Creativision.
|
|
;
|
|
; Christian Groessler, 2017-03-08
|
|
;
|
|
|
|
.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
|
|
|
|
; Symbolic names for joystick masks (similar names like the defines in joystick.h, but not related to them)
|
|
|
|
JOY_UP = $10
|
|
JOY_DOWN = $04
|
|
JOY_LEFT = $20
|
|
JOY_RIGHT = $08
|
|
JOY_FIRE = $01
|
|
JOY_FIRE2 = $02
|
|
|
|
; Joystick state masks (8 values)
|
|
|
|
.byte JOY_UP
|
|
.byte JOY_DOWN
|
|
.byte JOY_LEFT
|
|
.byte JOY_RIGHT
|
|
.byte JOY_FIRE
|
|
.byte JOY_FIRE2
|
|
.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 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 cc65 values
|
|
; fall thru...
|
|
|
|
; ------------------------------------------------------------------------
|
|
; convert: make runtime lib compatible values
|
|
; inputs:
|
|
; A - buttons
|
|
; X - direction
|
|
;
|
|
|
|
convert:
|
|
|
|
; ------
|
|
; 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? Can there be cases that just one of those bits is set?
|
|
; Until these questions have been answered, we only use the lower two
|
|
; bits and ignore the upper ones...
|
|
|
|
and #%00000011 ; button status came in in A, strip high bits
|
|
sta retval ; initialize 'retval' with button status
|
|
|
|
; ------
|
|
; direction:
|
|
; CV has a 16-direction joystick
|
|
;
|
|
; port values: (compass points)
|
|
; N - $49 - %01001001
|
|
; NNE - $48 - %01001000
|
|
; NE - $47 - %01000111
|
|
; ENE - $46 - %01000110
|
|
; E - $45 - %01000101
|
|
; ESE - $44 - %01000100
|
|
; SE - $43 - %01000011
|
|
; SSE - $42 - %01000010
|
|
; S - $41 - %01000001
|
|
; SSW - $40 - %01000000
|
|
; SW - $4F - %01001111
|
|
; WSW - $4E - %01001110
|
|
; W - $4D - %01001101
|
|
; WNW - $4C - %01001100
|
|
; NW - $4B - %01001011
|
|
; NNW - $4A - %01001010
|
|
; center - $00 - %00000000
|
|
;
|
|
; mapping to cc65 definitions (4-direction joystick with 8 possible directions thru combinations)
|
|
; N, E, S, W -> JOY_UP, JOY_RIGHT, JOY_DOWN, JOY_LEFT
|
|
; NE, SE, SW, NW -> (JOY_UP | JOY_RIGHT), (JOY_DOWN | JOY_RIGHT), (JOY_DOWN | JOY_LEFT), (JOY_UP | JOY_LEFT)
|
|
; NNE, ENE, ESE, SSE, SSW, WSW, WNW, NNW:
|
|
; toggle between straight and diagonal direction for every call, e.g.
|
|
; NNE:
|
|
; call to READJOY: return JOY_UP | JOY_RIGHT
|
|
; call to READJOY: return JOY_UP
|
|
; call to READJOY: return JOY_UP | JOY_RIGHT
|
|
; call to READJOY: return JOY_UP
|
|
; call to READJOY: return JOY_UP | JOY_RIGHT
|
|
; etc...
|
|
|
|
txa ; move direction status into A
|
|
beq done ; center position (no bits are set), nothing to do
|
|
|
|
and #$0F ; get rid of the "$40" bit
|
|
bit bit0 ; is it a "three letter" direction (NNE, ENE, etc.)?
|
|
beq special ; yes (bit #0 is zero)
|
|
|
|
lsr a ; create index into table
|
|
tax
|
|
lda dirtable,x
|
|
done: ora retval ; include "button" bits
|
|
ldx #0
|
|
rts
|
|
|
|
; NNE, ENE, ESE, SSE, SSW, WSW, WNW, NNW
|
|
|
|
special: lsr a
|
|
tax
|
|
|
|
lda toggler ; toggle the toggler
|
|
eor #$01
|
|
sta toggler
|
|
bne spec_1 ; toggler is 1, use spectable_1 entry
|
|
|
|
lda spectable_0,x ; toggler is 0, use spectable_0 entry
|
|
bne done ; jump always
|
|
|
|
spec_1: lda spectable_1,x
|
|
bne done ; jump always
|
|
|
|
; ------------------------------------------------------------------------
|
|
;
|
|
.rodata
|
|
|
|
; a mapping table of "port values" to "cc65 values"
|
|
; port value had been shifted one bit to the right (range 0..7)
|
|
dirtable: .byte JOY_DOWN ; S
|
|
.byte JOY_DOWN | JOY_RIGHT ; SE
|
|
.byte JOY_RIGHT ; E
|
|
.byte JOY_UP | JOY_RIGHT ; NE
|
|
.byte JOY_UP ; N
|
|
.byte JOY_UP | JOY_LEFT ; NW
|
|
.byte JOY_LEFT ; W
|
|
.byte JOY_DOWN | JOY_LEFT ; SW
|
|
|
|
; two "special" mapping tables for three-letter directions (NNE, etc.)
|
|
spectable_0: .byte JOY_DOWN ; SSW
|
|
.byte JOY_DOWN ; SSE
|
|
.byte JOY_RIGHT ; ESE
|
|
.byte JOY_RIGHT ; ENE
|
|
.byte JOY_RIGHT ; NNE
|
|
.byte JOY_UP ; NNW
|
|
.byte JOY_LEFT ; WNW
|
|
.byte JOY_LEFT ; WSW
|
|
|
|
spectable_1: .byte JOY_DOWN | JOY_LEFT ; SSW
|
|
.byte JOY_DOWN | JOY_RIGHT ; SSE
|
|
.byte JOY_DOWN | JOY_RIGHT ; ESE
|
|
.byte JOY_UP | JOY_RIGHT ; ENE
|
|
.byte JOY_UP | JOY_RIGHT ; NNE
|
|
.byte JOY_UP | JOY_LEFT ; NNW
|
|
.byte JOY_UP | JOY_LEFT ; WNW
|
|
.byte JOY_DOWN | JOY_LEFT ; WSW
|
|
|
|
; ------------------------------------------------------------------------
|
|
;
|
|
bit0: .byte $01
|
|
|
|
; ------------------------------------------------------------------------
|
|
;
|
|
.bss
|
|
toggler: .res 1
|
|
retval: .res 1
|
|
|
|
.end
|