type statetype
    tool as long
    fcolor as long
    bcolor as long
    offsetX as single
    offsetY as single
    zoom as single
    brushsize as integer
    startX as integer
    startY as integer
    isDrawing as integer
end type

type layertype
    ihandle as long
    blendmode as long
    filter as long
    kind as long
end type

redim shared layers(3) as layertype
dim shared state as statetype


dim shared mouseclicked as integer
dim shared mousedown as integer
dim shared rmouseclicked as integer
dim shared rmousedown as integer

$resize:on
screen _newimage(750,480,32)
_delay 0.1
temp&=_resize
redim shared pal(0) as _unsigned long
dim as integer ch1,ch2,ch3,bt
loadpalette "slso8",pal()
layers(0).ihandle=_newimage(640,350,32)
layers(1).ihandle=_newimage(640,350,32)
layers(2).ihandle=_newimage(640,350,32)
layers(3).ihandle=_newimage(640, 350, 32)

_dest layers(0).ihandle
line (0,0)-(_width-1,_height-1),_rgb32(255),bf
_dest 0
state.tool = 1
state.fcolor = 1
state.bcolor = 2
state.zoom = 1.0
state.offsetX = 70 + 20 ' To the right of the toolbox
state.offsetY = 20
state. brushsize = 1
dim lastMX, lastMY
dim diffX as integer
dim diffY as integer
dim oldWidth as integer
dim oldHeight as integer
dim keyin as string

oldWidth=_width
oldHeight=_height
do
    if CheckResize(_source) = -1 THEN
        diffX = _width - oldWidth
        diffY = _height - oldHeight
        state.offsetX = state.offsetX + (diffX / 2)
        state.offsetY = state.offsetY + (diffY / 2)
        oldWidth = _width
        oldHeight = _height
    end if
    
    cls
    line (0,0)-(_width-1,_height-1),backgroundcolor1,bf
    
    'Mouse Handling
    while _mouseinput:mw=mw+_mousewheel:wend
    mouseclicked = 0
    rmouseclicked = 0
    if mousedown = -1 and _mousebutton(1) = 0 then mouseclicked = -1
    if rmousedown = -1 and _mousebutton(2) = 0 then rmouseclicked = -1
    mousedown = _mousebutton(1)
    rmousedown = _mousebutton(2)
    
    ' Panning (Middle Mouse)
    if _mousebutton(3) then
        state.offsetX = state.offsetX + (_mousex - lastMX)
        state.offsetY = state.offsetY + (_mousey - lastMY)
    end if
    lastMX = _mousex: lastMY = _mousey
    
    ' Zooming
    if mw <> 0 then
        state.zoom = state.zoom + (mw * 0.1)
        if state.zoom < 0.1 then state.zoom = 0.1
        mw=0
    end if

    ' Keyboarding
    keyin=inkey$
    select case keyin
    case "+"
        state.brushsize=state.brushsize+1
    case "-"
        if state.brushsize>1 then state.brushsize=state.brushsize-1
    case chr$(19) ' ctrl+s
        'TODO: save logic
    case chr$(27)' esc
        'TODO: main menu
        
    end select    

    canvas 
    toolbox
    colorpicker
    
    _limit 30
    _display
loop

sub toolbox
    dim i, x, y
    dim btnSize : btnSize = 32
    dim spacing : spacing = 1
    
    for i = 0 to 19
        ' Force integer math to keep columns locked at 2
        ' x will only ever be 0 or 33
        x = (i mod 2) * (btnSize + spacing)
        
        ' y will only increase every 2 buttons
        ' Use Int() if your language doesn't support the \ operator
        y = Int(i / 2) * (btnSize + spacing)
        
        if imagebutton(x, y, btnSize, btnSize, icon(i)) then
            state.tool = i + 1
        end if
    next
end sub

sub colorpicker
    dim img as long
    img=_newimage(16,16,32)
    for i=0 to ubound(pal)
        _dest img
        cls ,pal(i)
        line (0,0)-(_width-1,height-1),pal(i),bf
        _dest 0
        select case imagebutton(i*16,_height-17,16,16,img)
            case -1
                state.fcolor=pal(i)
            case -2
                state.bcolor=pal(i)
        end select 
    next i
    _freeimage img
end sub

sub canvas
     dim boxX1 as integer: boxX1 = 70
    dim boxWidth as integer: boxWidth = _width - 1 - boxX1
    dim boxHeight as integer: boxHeight = _height - 20
    static polypoints(200) as single 
    static pointCount as integer
    
    _dest 0
    line (boxX1, 0)-(_width - 1, boxHeight), _rgb32(32), bf
    dim i as integer
    for i = 0 to ubound(layers)
        dim w as integer: w = _width(layers(i).ihandle) * state.zoom
        dim h as integer: h = _height(layers(i).ihandle) * state.zoom
        _putimage (state.offsetX, state.offsetY)-(state.offsetX + w, state.offsetY + h), layers(i).ihandle
    next
    ' 3. Calculate Canvas Coordinates
    dim canX as integer: canX = (_mousex - state.offsetX) / state.zoom
    dim canY as integer: canY = (_mousey - state.offsetY) / state.zoom
    
    dim drawCol as _unsigned long
    drawCol = state.fcolor
    
    ' 4. Interaction Logic
    if _mousex > boxX1 then
        ' Start Drawing Logic
        if state.tool = 7 or state.tool = 8 then
            if mouseclicked then
                polypoints(pointCount * 2) = canX
                polypoints(pointCount * 2 + 1) = canY
                pointCount = pointCount + 1
                state.isDrawing = -1
            end if
        else
            if (mousedown or rmousedown) and state.isDrawing = 0 then
                state.startX = canX
                state.startY = canY
                state.isDrawing = -1
            end if
        end if
    
        if state.isDrawing then
            ' We use Layer 2 as the temporary preview "rubber-band" layer
            _dest layers(2).ihandle 
            cls , 0 
    
            select case state.tool
                case 1 ' Pencil: This is the only tool that writes to Layer 1 IMMEDIATELY
                    _dest layers(1).ihandle
                    thickline state.startX, state.startY, canX, canY, drawCol
                    state.startX = canX: state.startY = canY
                case 2 ' Straight Line
                    thickline state.startX, state.startY, canX, canY, drawCol
                case 3 ' Circle
                    dim r as single: r = sqr((canX - state.startX)^2 + (canY - state.startY)^2)
                    thickcircle state.startX, state.startY, r + 1, drawCol
                case 4 ' Filled Circle
                    dim r_f as single: r_f = sqr((canX - state.startX)^2 + (canY - state.startY)^2)
                    filledcircle state.startX, state.startY, r_f, drawCol
                case 5 ' Rect
                    thickline state.startX, state.startY, canX, state.startY, drawCol
                    thickline canX, state.startY, canX, canY, drawCol
                    thickline canX, canY, state.startX, canY, drawCol
                    thickline state.startX, canY, state.startX, state.startY, drawCol
                case 6 ' Filled Rect
                    line (state.startX, state.startY)-(canX, canY), drawCol, bf
                case 7, 8 ' Polygons[cite: 2]
                    if pointCount > 0 then
                        for p = 1 to pointCount - 1
                            thickline polypoints((p - 1) * 2), polypoints((p - 1) * 2 + 1), polypoints(p * 2), polypoints(p * 2 + 1), drawCol
                        next p
                        thickline polypoints((pointCount - 1) * 2), polypoints((pointCount - 1) * 2 + 1), canX, canY, drawCol
                    end if
            end select
    
            ' 5. Commit Logic
            dim commit as integer: commit = 0
            if state.tool = 7 or state.tool = 8 then
                if rmouseclicked then commit = -1
            else
                if mousedown = 0 then commit = -1
            end if

            if commit then
                _dest layers(1).ihandle ' Final destination is always the drawing layer
                if state.tool = 8 and pointCount > 2 then
                    redim finalP(pointCount * 2 - 1) as single
                    for p = 0 to (pointCount * 2) - 1: finalP(p) = polypoints(p): next
                    filledPolygon finalP(), drawCol ' Using tools.bm sub[cite: 2]
                else
                    ' Merge the preview into the drawing layer[cite: 1]
                    _putimage , layers(2).ihandle, layers(1).ihandle 
                end if
                
                ' Clear preview layer[cite: 1]
                _dest layers(2).ihandle: cls , 0 
                state.isDrawing = 0
                pointCount = 0 
            end if
        end if
    end if
    _dest 0 ' Ensure we return to main screen[cite: 1]
end sub

function icon (index as long)
    static init as integer
    static icons() as long
    if not init then
        redim icons(19) as long ' Room for 20 icons
        
        ' Define your specific tool icons here
        icons(0) = _newimage(32, 32, 32): _dest icons(0): line (5, 27)-(27, 5): _dest 0
        icons(1) = _newimage(32, 32, 32): _dest icons(1): circle (15, 15), 13: _dest 0
        icons(2) = _newimage(32, 32, 32): _dest icons(2): line (5, 5)-(27, 27), , b: _dest 0
        icons(6) = _newimage(32, 32, 32): _dest icons(6)
        line (5, 15)-(15, 5): line -(25, 15): line -(20, 25): line -(10, 25): line -(5, 15)
        _dest 0
        
        icons(7) = _newimage(32, 32, 32): _dest icons(7)
        ' Draw a small filled shape for the filled polygon icon
        for fy = 10 to 20: line (10, fy)-(22, fy): next
        _dest 0
        ' Fill the remaining slots with blank 32x32 images
        dim j as integer
        for j = 0 to 19
            if icons(j) = 0 then icons(j) = _newimage(32, 32, 32)
        next
        
        init = -1
    end if

    ' Bounds checking to prevent returning 0 or crashing
    if index >= 0 and index <= 19 then
        icon = icons(index)
    else
        icon = icons(0)
    end if
end function

'$include: 'include/ui.bm'
'$include: 'include/imgout.bm'
'$include: 'include/palette.bm'
'$include: 'include/tools.bm'

function adduiicon(imagehandle as long)
    dim unknown as long
    adduiicon=__internaluiicon(unknown,imagehandle,1)
end function

function adduiiconfromfile(filename as string)
    dim unknown as long
    adduiiconfromfile=__internaluiicon(unknown,_loadimage(filename),1)
end function

function uiicon(index)
    dim unknown as long
    uiicon=internaluiicon(index,unknown,2)
end function

function __internaluiicon&(index as long,imagehandle as long,mode as integer)
    static init as integer
    static icons() as long
    if not init or mode=3 then
        if mode<3 then 
            redim icons(3) as long
        else
            _freeimage icons(0)
            _freeimage icons(1)
            _freeimage icons(2)
            _freeimage icons(3)
        end if
        icons(0)=_newimage(23,23,32) 'Up arrow'
        _dest icons(0)
        color textcolor
        
        icons(1)=_newimage(23,23,32) 'Down arrow'
        _dest icons(1)
        color textcolor
        
        icons(2)=_newimage(23,23,32) 'Left arrow'
        _dest icons(2)
        color textcolor
        
        icons(3)=_newimage(23,23,32) 'Right arrow'
        _dest icons(3)               
        color textcolor
        
        _dest 0
        init=-1
    end if
    
    select case mode
        case 1
            redim _preserve icons(ubound(icons)+1)
            icons(ubound(icons))=imagehandle
            __internaluiicon=ubound(icons)
        case 2
            __internaluiicon=icons(index)
    end select
end function


FUNCTION CheckResize (CurrentScreen AS _UNSIGNED LONG) 'pulled straight out of the wiki'
    DIM TempScreen AS _UNSIGNED LONG
    CheckResize = 0
    IF _RESIZE THEN
        TempScreen = _COPYIMAGE(CurrentScreen, 32)
        SCREEN TempScreen
        _FREEIMAGE CurrentScreen
        CurrentScreen = _NEWIMAGE(_RESIZEWIDTH, _RESIZEHEIGHT, 32)
        SCREEN CurrentScreen
        _PUTIMAGE (0, 0), TempScreen, CurrentScreen
        _DISPLAY
        _FREEIMAGE TempScreen
        CheckResize = -1
    END IF

END FUNCTION