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cc65/libsrc/cbm510/mou/cbm510-joy.s
Oliver Schmidt 4065cb1983 Harmonized interface between mouse drivers and callbacks.
The Apple2 doesn't have sprites so the Apple2 mouse callbacks place a special character on the text screen to indicate the mouse position. In order to support the necessary character removing and redrawing the Apple2 mouse driver called the Apple2 mouse callbacks in an "unusual way". So far so (sort of) good.

However the upcoming Atari mouse driver aims to support both "sprite-type" mouse callbacks as well as "text-char-type" mouse callbacks. Therefore the interface between mouse drivers and callbacks needs to be extended to allow the mouse callbacks to hide their different types from the mouse driver.

The nature of this change can be seen best by looking at the Apple2 file modifications. The CBM drivers and callbacks (at least the current ones) don't benefit from this change.
2014-01-15 22:47:59 +01:00

451 lines
12 KiB
ArmAsm

;
; Driver for a "joystick mouse".
;
; 2009-09-26, Ullrich von Bassewitz
; 2013-09-05, Greg King
;
.include "zeropage.inc"
.include "../extzp.inc"
.include "mouse-kernel.inc"
.include "cbm510.inc"
.macpack generic
; ------------------------------------------------------------------------
; Header. Includes jump table
.segment "JUMPTABLE"
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
CDRAW: jmp $0000 ; Draw the cursor
CMOVE: jmp $0000 ; Prepare to move 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 #>0
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 CMOVE
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 #<-1
tax
bnz @AddX ; Branch always
@Right: lda #<1
ldx #>1
; 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 #<-1
tax
bnz @AddY
@Down: lda #<1
ldx #>1
; 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