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cc65/libsrc/c128/mou/c128-inkwell.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

461 lines
13 KiB
ArmAsm

;
; Driver for the Inkwell Systems 170-C and 184-C lightpens.
;
; 2013-07-01, Greg King
;
.include "zeropage.inc"
.include "mouse-kernel.inc"
.include "c128.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
LIBREF: .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_EARLY_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
; This driver is for the 40-column screen.
XSIZE = 40
YSIZE = 25
SCREEN_WIDTH = XSIZE * 8
SCREEN_HEIGHT = YSIZE * 8
;----------------------------------------------------------------------------
; 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.
.rodata
; Default values for below variables
; (We use ".proc" because we want to define both a label and a scope.)
.proc DefVars
.word 0 ; XMin
.word 0 ; YMin
.word SCREEN_WIDTH - 1 ; XMax
.word SCREEN_HEIGHT - 1 ; YMax
.byte %00000000 ; Buttons
.endproc
.bss
Vars:
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
Buttons: .res 1 ; Button status bits
XPos: .res 2 ; Current lightpen position, X
YPos: .res 2 ; Current lightpen position, Y
OldPenX: .res 1 ; Previous HW-counter values
OldPenY: .res 1
INIT_save: .res 1
.data
; Default Inkwell calibration.
; The first number is the width of the left border;
; the second number is the actual calibration value.
XOffset: .byte (24 + 24) / 2 ; x-offset
; Jump to a function that puts a new calibration value into XOffset.
Calibrate: jmp $0000
.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:
; Disable the BASIC interpreter's interrupt-driven sprite-motion code.
; That allows direct access to the VIC-IIe's sprite registers.
lda INIT_STATUS
sta INIT_save
lda #%11000000
sta INIT_STATUS
; Initiate variables. Just copy the default stuff over.
ldx #.sizeof (DefVars) - 1
@L0: lda DefVars,x
sta Vars,x
dex
bpl @L0
ldx VIC_LPEN_X
ldy VIC_LPEN_Y
stx OldPenX
sty OldPenY
; Call a calibration function through the library-reference.
lda LIBREF
ldx LIBREF+1
sta ptr1 ; Point to mouse_adjuster
stx ptr1+1
ldy #1
lda (ptr1),y
bze @L1 ; Don't call pointer if it's NULL
sta Calibrate+2 ; Point to function
dey
lda (ptr1),y
sta Calibrate+1
lda #<XOffset ; Function will set this variable
ldx #>XOffset
jsr Calibrate
; Be sure that the lightpen cursor is invisible and at the default location.
; It needs to be done here because the lightpen interrupt handler doesn't
; set the lightpen position if it hasn't changed.
@L1: sei
jsr CHIDE
lda #<(SCREEN_HEIGHT / 2)
ldx #>(SCREEN_HEIGHT / 2)
jsr MoveY
lda #<(SCREEN_WIDTH / 2)
ldx #>(SCREEN_WIDTH / 2)
jsr MoveX
cli
; Done, return zero.
lda #MOUSE_ERR_OK
tax
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:
jsr HIDE ; Hide cursor on exit
lda INIT_save
sta INIT_STATUS
rts
;----------------------------------------------------------------------------
; HIDE routine. Is called to hide the lightpen pointer. The mouse kernel manages
; a counter for calls to show/hide, and the driver entry point is called only
; if the mouse is currently visible, and should get hidden. For most drivers,
; no special action is required besides hiding the lightpen cursor.
; No return code required.
HIDE: sei
jsr CHIDE
cli
rts
;----------------------------------------------------------------------------
; SHOW routine. Is called to show the lightpen pointer. The mouse kernel manages
; a counter for calls to show/hide, and the driver entry point is called only
; if the mouse is currently hidden, and should become visible. For most drivers,
; no special action is required besides enabling the lightpen cursor.
; No return code required.
SHOW: sei
jsr CSHOW
cli
rts
;----------------------------------------------------------------------------
; SETBOX: Set the lightpen 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 lightpen is currently 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 lightpen 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
ldy #$01
lda (sp),y
tax
dey
lda (sp),y
jsr MoveX ; Move the cursor
cli ; Allow interrupts
rts
;----------------------------------------------------------------------------
; BUTTONS: Return the button mask in .XA.
BUTTONS:
lda Buttons
ldx #>0
; Make the lightpen buttons look like a 1351 mouse.
asl a
asl SID_ADConv2 ; PotY
rol a
eor #MOUSE_BTN_RIGHT
and #MOUSE_BTN_LEFT | MOUSE_BTN_RIGHT
rts
;----------------------------------------------------------------------------
; POS: Return the lightpen 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
;----------------------------------------------------------------------------
; INFO: Returns lightpen 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'll just
; call _mouse_pos to initiate the struct pointer, and fill the position
; fields.
INFO: jsr POS
; Fill in the button state
jsr BUTTONS ; Will not touch ptr1
ldy #MOUSE_INFO::BUTTONS
sta (ptr1),y
rts
;----------------------------------------------------------------------------
; 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.
;
IRQ: jsr CMOVE
; Record the state of the buttons.
; Try to avoid crosstalk between the keyboard and the lightpen.
ldy #%00000000 ; Set ports A and B to input
sty CIA1_DDRB
sty CIA1_DDRA ; Keyboard won't look like buttons
lda CIA1_PRB ; Read Control-Port 1
dec CIA1_DDRA ; Set port A back to output
eor #%11111111 ; Bit goes up when button goes down
sta Buttons
bze @L0
lda #%11101111 ; (Don't change bit that feeds VIC-II)
sta CIA1_DDRB ; Buttons won't look like keyboard
sty CIA1_PRB ; Set "all keys pushed"
; Read the VIC-II lightpen registers.
@L0: lda VIC_LPEN_Y
cmp OldPenY
; Skip processing if nothing has changed.
beq @SkipY
sta OldPenY
; Subtract the height of the top border, so that the lightpen co-ordinate
; will match the TGI co-ordinate.
sub #50
tay ; Remember low byte
ldx #>0
; Limit the Y co-ordinate to the bounding box.
txa
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
@SkipY: lda VIC_LPEN_X
cmp OldPenX
; Skip processing if nothing has changed.
beq @SkipX
sta OldPenX
; Adjust the value by the calibration offset.
sub XOffset
; Calculate the new X co-ordinate.
; The VIC-II register is eight bits; but, the screen co-ordinate is nine bits.
; Therefore, the VIC-II number is doubled. Then, it points to every other pixel;
; but, it can reach across the screen.
asl a
tay ; Remember low byte
lda #>0
rol a
tax ; Remember high byte
; 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
; Done
@SkipX: jsr CDRAW
clc ; Interrupt not "handled"
rts
; Move the lightpen pointer to the new Y pos.
MoveY: sta YPos
stx YPos+1
jmp CMOVEY
; Move the lightpen pointer to the new X pos.
MoveX: sta XPos
stx XPos+1
jmp CMOVEX