WeeGUI/applesoft.s

1118 lines
22 KiB
ArmAsm

;
; applesoft.s
; Applesoft API via the & extension point
;
; Created by Quinn Dunki on 8/15/14.
; Copyright (c) 2014 One Girl, One Laptop Productions. All rights reserved.
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Applesoft ROM entry points and constants
;
LINNUML = $0050 ; Scratch pad for calculating line numbers (LSB)
LINNUMH = $0051 ; Scratch pad for calculating line numbers (MSB)
CURLINL = $0075 ; Current line number (LSB)
CURLINH = $0076 ; Current line number (MSB)
CHRGET = $00b1 ; Advances text point and gets character in A
CHRGOT = $00b7 ; Returns character at text pointer in A
TXTPTRL = $00b8 ; Current location in BASIC listing (LSB)
TXTPTRH = $00b9 ; Current location in BASIC listing (MSB)
VARPNT = $0083 ; Return value for PTRGET
FAC = $009d ; Floating point accumulator
AMPVECTOR = $03f5 ; Ampersand entry vector
ERROR = $d412 ; Reports error in X
NEWSTT = $d7d2 ; Advance to next Applesoft statement
GOTO = $d93e ; Entry point of Applesoft GOTO
LINGET = $da0c ; Read a line number (16-bit integer) into LINNUM
FRMNUM = $dd67 ; Evaluate an expression as a number and store in FAC
CHKCOM = $debe ; Validates current character is a ',', then gets it
SYNCHR = $dec0 ; Validates current character is what's in A
AYINT = $e10c ; Convert FAC to 8-bit signed integer
GETBYT = $e6f8 ; Gets an integer at text pointer, stores in X
GETNUM = $e746 ; Gets an 8-bit, stores it X, skips past a comma
PTRGET = $dfe3 ; Finds the Applesoft variable in memory at text pointer
TOKEN_GOSUB = $b0 ; Applesoft's token for GOSUB
TOKEN_HOME = $97 ; Applesoft's token for HOME
TOKEN_PRINT = $ba ; Applesoft's token for PRINT
TOKEN_MINUS = $c9 ; Applesoft's token for a minus sign
TOKEN_DRAW = $94 ; Applesoft's token for DRAW
TOKEN_PLOT = $8d ; Applesoft's token for PLOT
TOKEN_GET = $be ; Applesoft's token for GET
ERR_UNDEFINEDFUNC = 224
ERR_SYNTAX = 16
ERR_ENDOFDATA = 5
ERR_TOOLONG = 176
MAXCMDLEN = 6
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGInitApplesoft
; Sets up Applesoft API
;
WGInitApplesoft:
pha
lda #$4c ; Patch in our jump vector for &
sta AMPVECTOR
lda #<WGAmpersand
sta AMPVECTOR+1
lda #>WGAmpersand
sta AMPVECTOR+2
pla
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand
; The entry point from Applesoft. Applesoft text pointer
; will be positioned two after the '&', and accumulator will
; contain first character after the '&'
; Side effects: Clobbers S0
;
WGAmpersand:
tsx ; Start by caching a valid stack state to return to Applesoft,
stx WG_STACKPTR ; in case we need to do so in a hurry
sta SCRATCH0
SAVE_AXY
SAVE_ZPP
ldy #0
ldx SCRATCH0
WGAmpersand_parseLoop:
txa
beq WGAmpersand_matchStart ; Check for end-of-statement (CHRGET handles : and EOL)
cmp #'('
beq WGAmpersand_matchStart
sta WGAmpersandCommandBuffer,y
jsr CHRGET
tax
iny
cpy #MAXCMDLEN+1
bne WGAmpersand_parseLoop
WGAmpersand_parseFail:
ldx #ERR_UNDEFINEDFUNC
jsr ERROR
bra WGAmpersand_done
WGAmpersand_matchStart:
lda #0
sta WGAmpersandCommandBuffer,y ; Null terminate the buffer for matching
ldy #0
ldx #0 ; Command buffer now contains our API call
phx ; We stash the current command number on the stack
WGAmpersand_matchLoop:
lda WGAmpersandCommandBuffer,y
beq WGAmpersand_matchPossible
cmp WGAmpersandCommandTable,x
bne WGAmpersand_matchNext ; Not this one
iny
inx
bra WGAmpersand_matchLoop
WGAmpersand_matchPossible:
lda WGAmpersandCommandTable,x
beq WGAmpersand_matchFound ; Got one!
WGAmpersand_matchNext:
pla ; Advance index to next commmand in table
inc
pha
asl
asl
asl
tax
cpx #WGAmpersandCommandTableEnd-WGAmpersandCommandTable
beq WGAmpersand_matchFail ; Hit the end of the table
ldy #0
bra WGAmpersand_matchLoop
WGAmpersand_matchFound:
pla ; This is now the matching command number
inc
asl
asl
asl
tay
lda WGAmpersandCommandTable-2,y ; Prepare an indirect JSR to our command
sta WGAmpersand_commandJSR+1 ; Self-modifying code!
lda WGAmpersandCommandTable-1,y
sta WGAmpersand_commandJSR+2
; Self-modifying code!
WGAmpersand_commandJSR:
jsr WGAmpersand_done ; Address here overwritten with command
bra WGAmpersand_done
WGAmpersand_matchFail:
pla ; We left command number on the stack while matching
ldx #ERR_UNDEFINEDFUNC
jsr ERROR
WGAmpersand_done:
RESTORE_ZPP
RESTORE_AXY
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersandBeginArguments
; Begins reading an ampersand argument list
; Side effects: Clobbers all registers
WGAmpersandBeginArguments:
pha
lda #'('
jsr SYNCHR ; Expect opening parenthesis
pla
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersandNextArgument
; Prepares for the next argument in the list
; Side effects: Clobbers all registers
WGAmpersandNextArgument:
jsr CHRGOT
jsr CHKCOM ; Verify parameter separator
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersandEndArguments
; Finishes reading an ampersand argument list
; Side effects: Clobbers all registers
WGAmpersandEndArguments:
pha
lda #')'
jsr SYNCHR ; Expect closing parenthesis
pla
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersandIntArgument
; Reads an integer argument for the current command
; OUT A : The argument
; Side effects: Clobbers all registers
WGAmpersandIntArgument:
jsr CHRGOT
cmp #TOKEN_MINUS
beq WGAmpersandIntArgument_signed
jsr GETBYT
txa
rts
WGAmpersandIntArgument_signed:
jsr CHRGET
jsr GETBYT
txa
eor #$ff
inc
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersandAddrArgument
; Reads a 16-bit pointer (or integer) argument for the current command
; OUT X : The argument (LSB)
; OUT Y : The argument (MSB)
; Side effects: Clobbers all registers
WGAmpersandAddrArgument:
jsr CHRGOT
jsr LINGET
ldx LINNUML
ldy LINNUMH
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersandStrArgument
; Reads a string argument for the current command in PARAM0/1.
; This string is copied into privately allocated memory.
; OUT X : Pointer to a stored copy of the string (LSB)
; OUT Y : Pointer to a stored copy of the string (MSB)
; Side effects: Clobbers P0/P1 and all registers
WGAmpersandStrArgument:
lda #'"'
jsr SYNCHR ; Expect opening quote
lda TXTPTRL ; Allocate for, and copy the string at TXTPTR
sta PARAM0
lda TXTPTRH
sta PARAM1
lda #'"' ; Specify quote as our terminator
jsr WGStoreStr
WGAmpersandStrArgument_loop:
jsr CHRGET ; Consume the string for Applesoft
beq WGAmpersandStrArgument_done
cmp #'"' ; Check for closing quote
bne WGAmpersandStrArgument_loop
WGAmpersandStrArgument_done:
lda #'"'
jsr SYNCHR ; Expect closing quote
ldx PARAM0
ldy PARAM1
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersandTempStrArgument
; Reads a string argument for the current command in PARAM0/1.
; This string is pointed to IN PLACE, and NOT copied.
; OUT X : Pointer to a stored copy of the string (LSB)
; OUT Y : Pointer to a stored copy of the string (MSB)
; OUT A : String length
; Side effects: Clobbers P0/P1 and all registers
WGAmpersandTempStrArgument:
lda #'"'
jsr SYNCHR ; Expect opening quote
lda TXTPTRL ; Grab current TXTPTR
sta PARAM0
lda TXTPTRH
sta PARAM1
WGAmpersandTempStrArgument_loop:
jsr CHRGET ; Consume the string for Applesoft
beq WGAmpersandTempStrArgument_done
cmp #'"' ; Check for closing quote
bne WGAmpersandTempStrArgument_loop
WGAmpersandTempStrArgument_done:
lda #'"'
jsr SYNCHR ; Expect closing quote
; Compute the 8-bit distance TXTPTR moved. Note that we can't simply
; count in the above loop, because CHRGET will skip ahead unpredictable
; amounts
sec
lda TXTPTRL
sbc PARAM0
dec
ldx PARAM0 ; Return results
ldy PARAM1
; pla
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Ampersand API entry points
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_HOME
; Clears the screen
; &HOME
WGAmpersand_HOME:
jsr WGClearScreen
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_DESK
; Render the desktop
; &DESK
WGAmpersand_DESK:
jsr WGDesktop
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_WINDW
; Create a view
; &WINDW(id,style,x,y,width,height,canvas width,canvas height)
WGAmpersand_WINDW:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+0
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
ora #VIEW_STYLE_APPLESOFT ; Flag this as an Applesoft-created view
sta WGAmpersandCommandBuffer+1
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+2
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+3
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+4
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+5
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+6
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+7
jsr WGAmpersandEndArguments
CALL16 WGCreateView,WGAmpersandCommandBuffer
jsr WGEraseViewContents
jsr WGPaintView
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_CHKBX
; Create a checkbox
; &CHKBX(id,x,y,"title")
WGAmpersand_CHKBX:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+0
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+1
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+2
jsr WGAmpersandNextArgument
jsr WGAmpersandStrArgument
stx WGAmpersandCommandBuffer+3
sty WGAmpersandCommandBuffer+4
jsr WGAmpersandEndArguments
CALL16 WGCreateCheckbox,WGAmpersandCommandBuffer
LDY_ACTIVEVIEW ; Flag this as an Applesoft-created view
lda #VIEW_STYLE_APPLESOFT
ora WG_VIEWRECORDS+4,y
sta WG_VIEWRECORDS+4,y
jsr WGPaintView
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_BUTTN
; Create a button
; &BUTTN(id,x,y,width,lineNum,"title")
WGAmpersand_BUTTN:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+0
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+1
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+2
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WGAmpersandCommandBuffer+3
jsr WGAmpersandNextArgument
jsr WGAmpersandAddrArgument
stx WGAmpersandCommandBuffer+4
sty WGAmpersandCommandBuffer+5
jsr WGAmpersandNextArgument
jsr WGAmpersandStrArgument
stx WGAmpersandCommandBuffer+6
sty WGAmpersandCommandBuffer+7
jsr WGAmpersandEndArguments
CALL16 WGCreateButton,WGAmpersandCommandBuffer
LDY_ACTIVEVIEW ; Flag this as an Applesoft-created view
lda #VIEW_STYLE_APPLESOFT
ora WG_VIEWRECORDS+4,y
sta WG_VIEWRECORDS+4,y
jsr WGPaintView
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_SEL
; Select a view
; &SEL(id)
WGAmpersand_SEL:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
jsr WGSelectView
jsr WGAmpersandEndArguments
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_FOC
; Focuses selected view
; &FOC
WGAmpersand_FOC:
jsr WGViewFocus
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_FOCN
; Focuses next view
; &FOCN
WGAmpersand_FOCN:
jsr WGViewFocusNext
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_FOCP
; Focuses previous view
; &FOCP
WGAmpersand_FOCP:
jsr WGViewFocusPrev
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_ACT
; Takes action on focused view
; &ACT
WGAmpersand_ACT:
jsr WGViewFocusAction
jsr WGBottomCursor
lda WG_GOSUB
bne WGAmpersand_ACTGosub
rts
WGAmpersand_ACTGosub:
jmp WGGosub ; No coming back from an Applesoft GOSUB!
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_STACT
; Sets the callback for the selected view
; &STACT(lineNum)
WGAmpersand_STACT:
jsr WGAmpersandBeginArguments
jsr WGAmpersandAddrArgument
stx PARAM0
sty PARAM1
jsr WGAmpersandEndArguments
jsr WGViewSetAction
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_TITLE
; Sets the title for the selected view
; &TITLE("title")
WGAmpersand_TITLE:
jsr WGAmpersandBeginArguments
jsr WGAmpersandStrArgument
stx PARAM0
sty PARAM1
jsr WGAmpersandEndArguments
jsr WGViewSetTitle
jsr WGPaintView
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_CURSR
; Sets the cursor position in selected viewspace
; &CURSR(x,y)
WGAmpersand_CURSR:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
sta PARAM0
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta PARAM1
jsr WGAmpersandEndArguments
jsr WGSetCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_PRINT
; Prints a string in the selected view at the local cursor
; &PRINT("string")
WGAmpersand_PRINT:
jsr WGAmpersandBeginArguments
jsr WGAmpersandTempStrArgument
stx PARAM0
sty PARAM1
pha
jsr WGAmpersandEndArguments
; We're pointing to the string directly in the Applesoft
; source, so we need to NULL-terminate it for printing. In
; order to avoid copying the whole thing, we'll do something
; kinda dirty here.
pla
tay
lda (PARAM0),y ; Cache the byte at the end of the string
pha
lda #0
sta (PARAM0),y ; Null-terminate the string in-place
jsr WGPrint
pla
sta (PARAM0),y ; Put original byte back
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_SCR
; Sets scroll position of selected view
; &SCR(x,y)
WGAmpersand_SCR:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
pha
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
pha
jsr WGAmpersandEndArguments
pla
jsr WGScrollY
pla
jsr WGScrollX
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_SCRBY
; Adjusts scroll position of selected view by a delta
; &SCRBY(x,y)
WGAmpersand_SCRBY:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
pha
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
pha
jsr WGAmpersandEndArguments
pla
jsr WGScrollYBy
pla
jsr WGScrollXBy
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_GOSUB
; A custom gosub, because we can. Only for testing at the moment
; &GOSUB
WGAmpersand_GOSUB:
lda #$e8
sta PARAM0
lda #$03
sta PARAM1
jmp WGGosub
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_ERASE
; Erases the contents of the selected view
; &ERASE
WGAmpersand_ERASE:
jsr WGEraseViewContents
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_NRML
; Sets text mode to normal
; &NRML
WGAmpersand_NRML:
lda #CHAR_NORMAL
sta INVERSE
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_IVER
; Sets text mode to inverse
; &INVR
WGAmpersand_INVR:
lda #CHAR_INVERSE
sta INVERSE
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_FILL
; Fills a rectangle with a character
; &FILL(x,y,width,height,char)
WGAmpersand_FILL:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
sta PARAM0
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta PARAM1
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta PARAM2
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta PARAM3
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
ora #$80 ; Convert to Apple format
pha
jsr WGAmpersandEndArguments
ply
jsr WGFillRect
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_DRAW
; Strokes a rectangle with a character
; &DRAW(x,y,width,height)
WGAmpersand_DRAW:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
sta PARAM0
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta PARAM1
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta PARAM2
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta PARAM3
jsr WGAmpersandEndArguments
jsr WGStrokeRect
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_PNT
; Repaints the selected view
; &PNT
WGAmpersand_PNT:
jsr WGPaintView
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_PNTA
; Repaints all views
; &PNTA
WGAmpersand_PNTA:
jsr WGViewPaintAll
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_PLOT
; Plots a single character (in Apple format)
; &PLOT(x,y,value)
WGAmpersand_PLOT:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
sta WG_CURSORX
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
sta WG_CURSORY
jsr WGAmpersandNextArgument
jsr WGAmpersandIntArgument
pha
jsr WGAmpersandEndArguments
pla
jsr WGPlot
jsr WGBottomCursor
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_MOUSE
; Enable or disable the mouse
; &MOUSE(enable)
WGAmpersand_MOUSE:
jsr WGAmpersandBeginArguments
jsr WGAmpersandIntArgument
pha
jsr WGAmpersandEndArguments
pla
beq WGAmpersand_MOUSEoff
jsr WGEnableMouse
rts
WGAmpersand_MOUSEoff:
jsr WGDisableMouse
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_PDACT
; Performs any pending view action
; &PDACT
WGAmpersand_PDACT:
lda WG_PENDINGACTIONVIEW
bmi WGAmpersand_PDACTdone
jsr WGPendingViewAction
jsr WGBottomCursor
WGAmpersand_PDACTdone:
lda WG_GOSUB
bne WGAmpersand_PDACTGosub
rts
WGAmpersand_PDACTGosub:
jmp WGGosub ; No coming back from an Applesoft GOSUB!
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGAmpersand_GET
; A non-blocking version of Applesoft GET. Returns 0 if no key
; is pending
; &GET(A$)
WGAmpersand_GET:
jsr WGAmpersandBeginArguments
jsr PTRGET
lda KBD
bpl WGAmpersand_GETnone ; No key pending
sta KBDSTRB ; Clear strobe and high bit
and #%01111111
bra WGAmpersand_GETstore
WGAmpersand_GETnone:
lda #0
WGAmpersand_GETstore:
ldy #0
sta WG_KEYBUFFER ; Store the key
lda #1 ; Create an Applesoft string record in the
sta (VARPNT),y ; variable's location
iny
lda #<WG_KEYBUFFER
sta (VARPNT),y
iny
lda #>WG_KEYBUFFER
sta (VARPNT),y
jsr WGAmpersandEndArguments
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGBottomCursor
; Leave the cursor state in a place that Applesoft is happy with
;
WGBottomCursor:
SAVE_AY
lda #0
sta CH
sta OURCH
lda #23
sta CV
sta OURCV
lda TEXTLINES_H+23
sta BASH
lda TEXTLINES_L+23
sta BASL
RESTORE_AY
rts
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; WGGosub
; Performs an Applesoft GOSUB to a line number
; PARAM0: Line number (LSB)
; PARAM1: Line number (MSB)
;
WGGosub:
lda #0
sta WG_GOSUB ; Clear the flag
; Can't come back from what we're about to do, so cleanup from the
; original Ampersand entry point now! This is some seriously voodoo
; shit we're gonna pull here.
ldx WG_STACKPTR
txs
; Fake an Applesoft GOSUB by pushing the same stuff it would do
lda TXTPTRH
pha
lda TXTPTRL
pha
lda CURLINH
pha
lda CURLINL
pha
lda #TOKEN_GOSUB
pha
; Here's the tricky bit- we jump into Applesoft's GOTO
; just after the part where it reads the line number. This
; allows us to piggy back on the hard work of finding the
; line number in the Applesoft source code, and storing
; it in the TXTPTR (thus performing the jump portion of
; a GOSUB). Since GOSUB normally falls through into GOTO,
; by faking the setup portion of the GOSUB, then leaving
; the state as GOTO expects it, we can fake the entire
; process to GOSUB to a line number we specify
lda PARAM0
sta LINNUML
lda PARAM1
sta LINNUMH
jsr GOTO+3
; The goto has pointed the interpreter at the subroutine,
; so now advance to the next statement to continue executing.
; We'll never regain control, which is why we had to clean
; up from the ampersand entry before we got here.
jmp NEWSTT
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Applesoft API state
;
WGAmpersandCommandBuffer:
.byte 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
.byte 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
WGAmpersandCommandBufferEnd:
.byte 0 ; Make sure this last byte is always kept as a terminator
WG_STACKPTR: ; A place to save the stack pointer for tricky Applesoft manipulation
.byte 0
WG_KEYBUFFER: ; A phony string buffer for non-blocking GET
.byte 0
; Jump table for ampersand commands.
; Each row is 8 bytes (5 for name, NULL terminator, 2 for address)
;
; Note the strange constants in place of some strings- this is because
; all text is tokenized before we receive it, so reserved words may
; be compressed
;
WGAmpersandCommandTable:
.byte TOKEN_HOME,0,0,0,0,0
.addr WGAmpersand_HOME
.byte "DESK",0,0
.addr WGAmpersand_DESK
.byte "WINDW",0
.addr WGAmpersand_WINDW
.byte "CHKBX",0
.addr WGAmpersand_CHKBX
.byte "BUTTN",0
.addr WGAmpersand_BUTTN
.byte "SEL",0,0,0
.addr WGAmpersand_SEL
.byte "FOC",0,0,0
.addr WGAmpersand_FOC
.byte "FOCN",0,0
.addr WGAmpersand_FOCN
.byte "FOCP",0,0
.addr WGAmpersand_FOCP
.byte "ACT",0,0,0
.addr WGAmpersand_ACT
.byte "STACT",0
.addr WGAmpersand_STACT
.byte "TITLE",0
.addr WGAmpersand_TITLE
.byte "CURSR",0
.addr WGAmpersand_CURSR
.byte "SCR",0,0,0
.addr WGAmpersand_SCR
.byte "SCRBY",0
.addr WGAmpersand_SCRBY
.byte "ERASE",0
.addr WGAmpersand_ERASE
.byte TOKEN_PRINT,0,0,0,0,0
.addr WGAmpersand_PRINT
.byte "NRML",0,0
.addr WGAmpersand_NRML
.byte "INVR",0,0
.addr WGAmpersand_INVR
.byte "FILL",0,0
.addr WGAmpersand_FILL
.byte TOKEN_DRAW,0,0,0,0,0
.addr WGAmpersand_DRAW
.byte "PNT",0,0,0
.addr WGAmpersand_PNT
.byte "PNTA",0,0
.addr WGAmpersand_PNTA
.byte TOKEN_PLOT,0,0,0,0,0
.addr WGAmpersand_PLOT
.byte "MOUSE",0
.addr WGAmpersand_MOUSE
.byte "PDACT",0
.addr WGAmpersand_PDACT
.byte TOKEN_GET,0,0,0,0,0
.addr WGAmpersand_GET
;.byte TOKEN_GOSUB,0,0,0,0,0,0,0,0,0,0,0,0,0 ; For internal testing of the procedural gosub
;.addr WGAmpersand_GOSUB
WGAmpersandCommandTableEnd: