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Code optimizations (by Stefan Haubenthal and me).

git-svn-id: svn://svn.cc65.org/cc65/trunk@3906 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
uz 2009-01-06 17:49:29 +00:00
parent 368e881288
commit 8c8e0b131f

View File

@ -6,46 +6,46 @@
; Stefan Haubenthal, 2004-10-05 ; Stefan Haubenthal, 2004-10-05
; ;
.include "zeropage.inc" .include "zeropage.inc"
.include "joy-kernel.inc" .include "joy-kernel.inc"
.include "joy-error.inc" .include "joy-error.inc"
.include "nes.inc" .include "nes.inc"
; ------------------------------------------------------------------------ ; ------------------------------------------------------------------------
; Header. Includes jump table ; Header. Includes jump table
.segment "JUMPTABLE" .segment "JUMPTABLE"
; Driver signature ; Driver signature
.byte $6A, $6F, $79 ; "joy" .byte $6A, $6F, $79 ; "joy"
.byte JOY_API_VERSION ; Driver API version number .byte JOY_API_VERSION ; Driver API version number
; Button state masks (8 values) ; Button state masks (8 values)
.byte $08 ; JOY_UP .byte $10 ; JOY_UP
.byte $04 ; JOY_DOWN .byte $20 ; JOY_DOWN
.byte $02 ; JOY_LEFT .byte $40 ; JOY_LEFT
.byte $01 ; JOY_RIGHT .byte $80 ; JOY_RIGHT
.byte $80 ; JOY_FIRE (A) .byte $01 ; JOY_FIRE (A)
.byte $40 ; JOY_FIRE2 (B) .byte $02 ; JOY_FIRE2 (B)
.byte $20 ; JOY_FIRE3 (Select) .byte $04 ; (Select)
.byte $10 ; JOY_FIRE4 (Start) .byte $08 ; (Start)
; Jump table. ; Jump table.
.addr INSTALL .addr INSTALL
.addr UNINSTALL .addr UNINSTALL
.addr COUNT .addr COUNT
.addr READJOY .addr READJOY
.addr 0 ; IRQ entry unused .addr 0 ; IRQ entry unused
; ------------------------------------------------------------------------ ; ------------------------------------------------------------------------
; Constants ; Constants
JOY_COUNT = 2 ; Number of joysticks we support JOY_COUNT = 2 ; Number of joysticks we support
.code .code
@ -58,9 +58,9 @@ JOY_COUNT = 2 ; Number of joysticks we support
; ;
INSTALL: INSTALL:
lda #JOY_ERR_OK lda #JOY_ERR_OK
ldx #0 ldx #0
; rts ; Run into UNINSTALL instead ; rts ; Run into UNINSTALL instead
; ------------------------------------------------------------------------ ; ------------------------------------------------------------------------
; UNINSTALL routine. Is called before the driver is removed from memory. ; UNINSTALL routine. Is called before the driver is removed from memory.
@ -68,7 +68,7 @@ INSTALL:
; ;
UNINSTALL: UNINSTALL:
rts rts
; ------------------------------------------------------------------------ ; ------------------------------------------------------------------------
@ -76,37 +76,32 @@ UNINSTALL:
; ;
COUNT: COUNT:
lda #JOY_COUNT lda #JOY_COUNT
ldx #0 ldx #0
rts rts
; ------------------------------------------------------------------------ ; ------------------------------------------------------------------------
; READ: Read a particular joystick passed in A. ; READ: Read a particular joystick passed in A.
; ;
READJOY: READJOY:
and #$01 ; Fix joystick number and #$01 ; Fix joystick number
tay ; Joystick number (0,1) into Y tay ; Joystick number (0,1) into Y
lda #1
sta APU_PAD1,y
lda #0
sta APU_PAD1,y
; Read joystick ; Read joystick
lda #1 ldx #8
sta APU_PAD1,y @Loop: lda APU_PAD1,y
lda #0 ror a
sta APU_PAD1,y ror tmp1
sta tmp1 dex
bne @Loop
ldx #8 lda tmp1
@L1: asl tmp1 ; ldx #$00 ; X implicitly fixed
lda APU_PAD1,y rts
and #$01
beq @L2
lda tmp1
ora #$01
sta tmp1
@L2: dex
bne @L1
lda tmp1
; ldx #$00 ; fix X
rts