;
; Driver for the Inkwell Systems 170-C and 184-C lightpens.
;
-; 2013-06-03, Greg King
+; 2013-07-01, Greg King
;
.include "zeropage.inc"
.include "c64.inc"
.macpack generic
- .macpack cbm
; ------------------------------------------------------------------------
; Header. Includes jump table.
; Library reference
- .addr $0000
+LIBREF: .addr $0000
; Jump table
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
-SCREEN_ZONE = YSIZE / 4 * XSIZE
-
-; This driver is for the standard 40-column screen.
-
-SCREEN := $0400
-COLOR_RAM := $D800
+SCREEN_HEIGHT = YSIZE * 8
;----------------------------------------------------------------------------
; 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:
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
+OldPenX: .res 1 ; Previous HW-counter values
OldPenY: .res 1
.data
-; Start with an average offset.
+; Default Inkwell calibration.
+; The first number is the width of the left border;
+; the second number is the actual calibration value.
-XOffset: .byte 48 / 2 ; Calibration offset, for X position
-
-.rodata
+XOffset: .byte (24 + 24) / 2 ; x-offset
-; 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
+; Jump to a function that puts a new calibration value into XOffset.
+Calibrate: jmp $0000
.code
; Initiate variables. Just copy the default stuff over.
- sei
ldx #.sizeof (DefVars) - 1
@L0: lda DefVars,x
sta Vars,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
+; Call a calibration function through the library-reference.
-; 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
+ 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 the lightpen cursor is invisible and at the default location.
+; 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.
- jsr HIDE
+@L1: sei
+ jsr CHIDE
lda #<(SCREEN_HEIGHT / 2)
ldx #>(SCREEN_HEIGHT / 2)
-PutCursor:
- sei
jsr MoveY
lda #<(SCREEN_WIDTH / 2)
ldx #>(SCREEN_WIDTH / 2)
; MUST return carry clear.
;
-IRQ:
+IRQ: jsr CPREP
; Record the state of the buttons.
; Try to avoid crosstalk between the keyboard and the lightpen.
beq @SkipX
sta OldPenX
-; Adjust the co-ordinate by the calibration offset.
+; Adjust the value by the calibration offset.
sub XOffset
-; Calculate the new X co-ordinate (--> .AY --> .XY).
+; Calculate the new X co-ordinate.
; 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;
+; 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
+ tax ; Remember high byte
; Limit the X co-ordinate to the bounding box.
; Done
-@SkipX: clc ; Interrupt not "handled"
+@SkipX: jsr CDRAW
+ clc ; Interrupt not "handled"
rts
; Move the lightpen pointer to the new Y pos.
projects / cc65 / blobdiff