; ; Driver for the Inkwell Systems 170-C and 184-C lightpens. ; ; 2013-06-03, Greg King ; .include "zeropage.inc" .include "mouse-kernel.inc" .include "c64.inc" .macpack generic .macpack cbm ; ------------------------------------------------------------------------ ; 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_EARLY_IRQ ; Callback table, set by the kernel before INSTALL is called. CHIDE: jmp $0000 ; Hide the cursor CSHOW: jmp $0000 ; Show 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 SCREEN_ZONE = YSIZE / 4 * XSIZE ; This driver is for the standard 40-column screen. SCREEN := $0400 COLOR_RAM := $D800 ;---------------------------------------------------------------------------- ; 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: 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 ; Old HW-counter values OldPenY: .res 1 .data ; Start with an average offset. XOffset: .byte 48 / 2 ; Calibration offset, for X position .rodata ; Default values for above 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 .proc Command1 scrcode "Adjust by clicking on line." .endproc .proc Command2 scrcode "Finish by clicking off box." .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. sei 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 cli ; There is a delay between when the VIC sends its signal, and when the display ; shows that signal. There is another delay between the display and when ; the lightpen says that it saw that signal. Each display and pen is different. ; Therefore, this driver must be calibrated to them. A white box is painted on ; the screen; and, a line is drawn down the middle of it. When the user clicks ; on that line, the difference between its position and where the VIC thinks ; that the pen is pointing becomes an offset that is subtracted from what the ; VIC sees. lda VIC_BG_COLOR0 ldx #6 ; Blue screen stx VIC_BG_COLOR0 pha jsr CLRSCR ldy #.sizeof (Command2) - 1 @L2: lda Command2,y sta SCREEN + SCREEN_ZONE * 2 + XSIZE * 3 + (XSIZE - .sizeof (Command2)) / 2,y lda #15 ; Light gray text sta COLOR_RAM + SCREEN_ZONE * 2 + XSIZE * 3 + (XSIZE - .sizeof (Command1)) / 2,y dey bpl @L2 ldy #.sizeof (Command1) - 1 @L1: lda Command1,y sta SCREEN + SCREEN_ZONE * 2 + XSIZE * 1 + (XSIZE - .sizeof (Command1)) / 2,y lda #15 ; Light gray text sta COLOR_RAM + SCREEN_ZONE * 2 + XSIZE * 1 + (XSIZE - .sizeof (Command1)) / 2,y dey bpl @L1 ldx #SCREEN_ZONE @L3: lda #$80 | $20 ; Reversed space screen-code sta SCREEN + SCREEN_ZONE - 1,x lda #15 ; Light gray box sta COLOR_RAM + SCREEN_ZONE - 1,x dex bnz @L3 ldy #$80 | $5d ; Reversed vertical-bar screen-code .repeat 4, L sty SCREEN + SCREEN_ZONE + (L + 1) * XSIZE + XSIZE / 2 .endrep lda VIC_SPR0_COLOR ldx #12 ; Medium gray pointer stx VIC_SPR0_COLOR pha jsr SHOW lda #<(SCREEN_HEIGHT / 4 / 2) ldx #>(SCREEN_HEIGHT / 4 / 2) jsr PutCursor ; Wait for the main button to be released. @L4: lda Buttons bnz @L4 ; Wait for the main button to be pressed. @L5: lda Buttons bze @L5 ; Find out if the pen is on or off the box. ldy YPos ldx YPos+1 txa cpy #<(YSIZE / 4 * 1 * 8) sbc #>(YSIZE / 4 * 1 * 8) bmi @L6 ; Above box txa cpy #<(YSIZE / 4 * 2 * 8) sbc #>(YSIZE / 4 * 2 * 8) bpl @L6 ; Below box ; The pen is on the box; adjust the offset. lda OldPenX sub #(XSIZE * 8 / 2 + 8/2) / 2 sta XOffset sta OldPenX ; Make IRQ update X co-ordinate jmp @L4 ; Wait for the main button to be released. @L6: lda Buttons bnz @L6 lda XOffset ; Tell test program about calibration sta $3ff pla sta VIC_SPR0_COLOR pla sta VIC_BG_COLOR0 jsr CLRSCR ; Be sure 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. jsr HIDE lda #<(SCREEN_HEIGHT / 2) ldx #>(SCREEN_HEIGHT / 2) PutCursor: sei 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 := HIDE ; Hide cursor on exit ;---------------------------------------------------------------------------- ; 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 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: ; 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 co-ordinate by the calibration offset. sub XOffset ; Calculate the new X co-ordinate (--> .AY --> .XY). ; The VIC-II register is eight bits; but, the screen co-ordinate is nine bits. ; Therefor, 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 ; 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: 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