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cc65/libsrc/cbm510/mou/cbm510-joy.s

453 lines
12 KiB
ArmAsm

;
; Driver for a "joystick mouse".
;
; 2009-09-26, Ullrich von Bassewitz
; 2014-09-10, Greg King
;
.include "zeropage.inc"
.include "../extzp.inc"
.include "mouse-kernel.inc"
.include "cbm510.inc"
.macpack generic
.macpack module
; ------------------------------------------------------------------------
; Header. Includes jump table
module_header _cbm510_joy_mou
HEADER:
; Driver signature
.byte $6d, $6f, $75 ; ASCII "mou"
.byte MOUSE_API_VERSION ; Mouse driver API version number
; Library reference
.addr $0000
; Jump table
.addr INSTALL
.addr UNINSTALL
.addr HIDE
.addr SHOW
.addr SETBOX
.addr GETBOX
.addr MOVE
.addr BUTTONS
.addr POS
.addr INFO
.addr IOCTL
.addr IRQ
; Mouse driver flags
.byte MOUSE_FLAG_LATE_IRQ
; Callback table, set by the kernel before INSTALL is called.
CHIDE: jmp $0000 ; Hide the cursor
CSHOW: jmp $0000 ; Show the cursor
CPREP: jmp $0000 ; Prepare to move the cursor
CDRAW: jmp $0000 ; Draw the cursor
CMOVEX: jmp $0000 ; Move the cursor to x co-ord.
CMOVEY: jmp $0000 ; Move the cursor to y co-ord.
;----------------------------------------------------------------------------
; Constants
SCREEN_HEIGHT = YSIZE * 8
SCREEN_WIDTH = XSIZE * 8
.scope JOY
UP = %00000001
DOWN = %00000010
LEFT = %00000100
RIGHT = %00001000
FIRE = %00010000
.endscope
;----------------------------------------------------------------------------
; Global variables. The bounding box values are sorted so that they can be
; written with the least effort in the SETBOX and GETBOX routines; so, don't
; re-order them.
.bss
Vars:
YPos: .res 2 ; Current mouse position, y
XPos: .res 2 ; Current mouse position, x
XMin: .res 2 ; X1 value of bounding box
YMin: .res 2 ; Y1 value of bounding box
XMax: .res 2 ; X2 value of bounding box
YMax: .res 2 ; Y2 value of bounding box
; Temporary value used in the interrupt handler
Temp: .res 1
.rodata
; Default values for above variables
; (We use ".proc" because we want to define both a label and a scope.)
.proc DefVars
.word SCREEN_HEIGHT / 2 ; YPos
.word SCREEN_WIDTH / 2 ; XPos
.word 0 ; XMin
.word 0 ; YMin
.word SCREEN_WIDTH - 1 ; XMax
.word SCREEN_HEIGHT - 1 ; YMax
.endproc
.code
;----------------------------------------------------------------------------
; INSTALL routine. Is called after the driver is loaded into memory. If
; possible, check if the hardware is present.
; Must return a MOUSE_ERR_xx code in .XA.
INSTALL:
; Initiate variables; just copy the default stuff over.
ldx #.sizeof(DefVars) - 1
@L1: lda DefVars,x
sta Vars,x
dex
bpl @L1
; Be sure the mouse cursor is invisible and at the default location. We
; need to do that here because our mouse interrupt handler doesn't set the
; mouse position if it hasn't changed.
sei
jsr CHIDE
lda XPos
ldx XPos+1
jsr CMOVEX
lda YPos
ldx YPos+1
jsr CMOVEY
cli
; Done, return zero.
ldx #>MOUSE_ERR_OK
txa
rts
;----------------------------------------------------------------------------
; UNINSTALL routine. Is called before the driver is removed from memory.
; No return code required (the driver is removed from memory, on return).
UNINSTALL := HIDE ; Hide cursor, on exit
;----------------------------------------------------------------------------
; HIDE routine. Is called to hide the mouse pointer. The mouse kernel manages
; a counter for calls to show/hide; and, the driver entry point is called only
; if the mouse currently is visible and should get hidden. For most drivers,
; no special action is required besides hiding the mouse cursor.
; No return code required.
HIDE: sei
jsr CHIDE
cli
rts
;----------------------------------------------------------------------------
; SHOW routine. Is called to show the mouse pointer. The mouse kernel manages
; a counter for calls to show/hide; and, the driver entry point is called only
; if the mouse currently is hidden and should become visible. For most drivers,
; no special action is required besides enabling the mouse cursor.
; No return code required.
SHOW: sei
jsr CSHOW
cli
rts
;----------------------------------------------------------------------------
; SETBOX: Set the mouse bounding box. The parameters are passed as they come
; from the C program, that is, a pointer to a mouse_box struct in .XA.
; No checks are done if the mouse currently is inside the box; that is the job
; of the caller. It is not necessary to validate the parameters; trust the
; caller, and save some code here. No return code required.
SETBOX: sta ptr1
stx ptr1+1 ; Save data pointer
ldy #.sizeof (MOUSE_BOX) - 1
sei
@L1: lda (ptr1),y
sta XMin,y
dey
bpl @L1
cli
rts
;----------------------------------------------------------------------------
; GETBOX: Return the mouse bounding box. The parameters are passed as they
; come from the C program, that is, a pointer to a mouse_box struct in .XA.
GETBOX: sta ptr1
stx ptr1+1 ; Save data pointer
ldy #.sizeof (MOUSE_BOX) - 1
@L1: lda XMin,y
sta (ptr1),y
dey
bpl @L1
rts
;----------------------------------------------------------------------------
; MOVE: Move the mouse to a new position. The position is passed as it comes
; from the C program, that is: x on the stack and y in .XA. The C wrapper will
; remove the parameter from the stack, on return.
; No checks are done if the new position is valid (within the bounding box or
; the screen). No return code required.
;
MOVE: sei ; No interrupts
jsr MoveY ; Set new y position
ldy #1
lda (sp),y
sta XPos+1
tax
dey
lda (sp),y
jsr MoveX ; Move the pointer
cli ; Allow interrupts
rts
;----------------------------------------------------------------------------
; BUTTONS: Return the button mask in .XA.
; Joystick 2's fire button is the left mouse button.
; Joystick 1's fire button is the right mouse button.
BUTTONS:
ldx #15 ; Switch to the system bank
stx IndReg
; Get the fire-button bits
ldy #CIA::PRA
lda (cia2),y
; Switch back to the execution bank.
ldy ExecReg
sty IndReg
; Joystick 2, fire button is in bit 7.
; Joystick 1, fire button is in bit 6.
and #%11000000
asl a ; Move bits 7,6 to bits 1,0
rol a
rol a
adc #%00001110 ; Move bit 1 to bit 4
and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
; Bits go up when buttons go down.
eor #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
ldx #>$0000
rts
;----------------------------------------------------------------------------
; INFO: Returns mouse position and current button mask in the MOUSE_INFO
; struct pointed to by ptr1. No return code required.
;
; We're cheating here to keep the code smaller: The first fields of the
; mouse_info struct are identical to the mouse_pos struct; so, we just will
; use _mouse_pos to fill the position fields.
INFO: jsr BUTTONS
; Fill in the button state.
ldy #MOUSE_INFO::BUTTONS
sta (ptr1),y
; jmp POS ; Fall through
;----------------------------------------------------------------------------
; POS: Return the mouse position in the MOUSE_POS struct pointed to by ptr1.
; No return code required.
POS: ldy #MOUSE_POS::XCOORD ; Structure offset
sei ; Disable interrupts
lda XPos ; Transfer the position
sta (ptr1),y
lda XPos+1
iny
sta (ptr1),y
lda YPos
iny
sta (ptr1),y
lda YPos+1
cli ; Enable interrupts
iny
sta (ptr1),y ; Store last byte
rts ; Done
;----------------------------------------------------------------------------
; IOCTL: Driver-defined entry point. The wrapper will pass a pointer to ioctl-
; specific data in ptr1, and the ioctl code in .A.
; Must return an error code in .XA.
;
IOCTL: lda #<MOUSE_ERR_INV_IOCTL ; We don't support ioctls, for now
ldx #>MOUSE_ERR_INV_IOCTL
rts
;----------------------------------------------------------------------------
; IRQ: Irq.-handler entry point. Called as a subroutine, but in the IRQ context
; (so, be careful). The routine MUST return carry set if the interrupt has been
; 'handled' -- which means that the interrupt source is gone. Otherwise, it
; MUST return carry clear.
; Reads joystick 2.
;
IRQ: jsr CPREP
ldy #15 ; Switch to the system bank
sty IndReg
; Get the direction bits.
ldy #CIA::PRB
lda (cia2),y ; Read joystick inputs
; Switch back to the execution bank.
ldy ExecReg
sty IndReg
; Joystick 2, directions in bits 7-4.
; Mask the relevant bits.
and #$F0
eor #$F0 ; All bits are inverted
sta Temp
; Check left/right.
and #(JOY::LEFT | JOY::RIGHT) << 4
bze @SkipX
; We will cheat here, and rely on the fact that either the left OR the right
; bit can be active.
and #JOY::RIGHT << 4 ; Check RIGHT bit
bnz @Right
lda #<-$0001
tax
bnz @AddX ; Branch always
@Right: lda #<$0001
ldx #>$0001
; Calculate the new x co-ordinate (--> .YA).
@AddX: add XPos
tay ; Remember low byte
txa
adc XPos+1
tax
; Limit the x co-ordinate to the bounding box.
cpy XMin
sbc XMin+1
bpl @L1
ldy XMin
ldx XMin+1
jmp @L2
@L1: txa
cpy XMax
sbc XMax+1
bmi @L2
ldy XMax
ldx XMax+1
@L2: tya
jsr MoveX
; Calculate the y movement vector.
@SkipX: lda Temp ; Get joystick again
and #(JOY::UP | JOY::DOWN) << 4 ; Check up/down
bze @SkipY
; We will cheat here, and rely on the fact that either the up OR the down
; bit can be active.
and #JOY::UP << 4 ; Check UP bit
bze @Down
lda #<-$0001
tax
bnz @AddY
@Down: lda #<$0001
ldx #>$0001
; Calculate the new y co-ordinate (--> .YA).
@AddY: add YPos
tay ; Remember low byte
txa
adc YPos+1
tax
; Limit the y co-ordinate to the bounding box.
cpy YMin
sbc YMin+1
bpl @L3
ldy YMin
ldx YMin+1
jmp @L4
@L3: txa
cpy YMax
sbc YMax+1
bmi @L4
ldy YMax
ldx YMax+1
@L4: tya
jsr MoveY
; Done
@SkipY: jsr CDRAW
clc ; Interrupt not "handled"
rts
; Move the mouse pointer to the new x pos.
MoveX: sta XPos
stx XPos+1
jmp CMOVEX
; Move the mouse pointer to the new y pos.
MoveY: sta YPos
stx YPos+1
jmp CMOVEY