import GUI in "%oot/lib/GUI"
var iWindow : int := Window.Open ("offscreenonly, graphics:640;480, nocursor, noecho ")

type obstacle :
    record
        x : int
        y : int
    end record

var iDotX : int := 320
var iDotY : int := 240
var iM, iB : real
var iX, iY, iButton : int
var iSpeed : int := 5
var bCollision : boolean := false

var aiBlockers : array 1 .. 10 of obstacle
for i : 1 .. 10
    randint (aiBlockers (i).x, 10, 630)
    randint (aiBlockers (i).y, 10, 470)
end for

procedure CheckAndMove (iValue, iIncrement, iDir : int, bIsX : boolean)

    var bCollision : boolean := false

    for i : 1 .. 10
        if bIsX = true then
            if sqrt ((iDotX + (iDir * iIncrement) - aiBlockers (i).x) ** 2 + (iDotY - aiBlockers (i).y) ** 2) < 20 then
                bCollision := true
            end if
        else
            if sqrt ((iDotX - aiBlockers (i).x) ** 2 + (iDotY + (iDir * iIncrement) - aiBlockers (i).y) ** 2) < 20 then
                bCollision := true
            end if
        end if
    end for

    if bCollision = true then
    else
        if bIsX = true then
            iDotX += iDir * iIncrement           
            iDotY := round ((iM * iDotX) + iB)
        else
            iDotY += iDir * iIncrement
            iDotX := round ((iDotY - iB) / iM)
        end if
    end if

end CheckAndMove

procedure Display

    delay (10)
    GUI.SetBackgroundColour (7)
    drawfilloval (iDotX, iDotY, 10, 10, 1)
    for i : 1 .. 10
        drawfilloval (aiBlockers (i).x, aiBlockers (i).y, 10, 10, 4)
    end for

    Window.Update (iWindow)

end Display

loop

    Display

    mousewhere (iX, iY, iButton)

    %  If Dot's location is the same as mouse then do nothing.  If Dot's path has a slope of 0 then this just moves it up the
    % line.  Otherwise this calculates slope.
    if iX = iDotX and iY = iDotY then
    elsif iX = iDotX then
        if iY > iDotY then
            iDotY += iSpeed
        else
            iDotY -= iSpeed
        end if
    elsif iY = iDotY then
        if iX > iDotX then
            iDotX += iSpeed
        else
            iDotX -= iSpeed
        end if
    else
        iM := (iY - iDotY) / (iX - iDotX)
        iB := iDotY - (iM * iDotX)
    end if

    %  This determines whether to move the Dot primarily along the X or Y axis and then calculate the other coordinate.
    if iDotX < iX and iDotY < iY then
        if iX - iDotX < iY - iDotY then
            CheckAndMove (iDotY, iSpeed, 1, false)
            %iDotY += iSpeed
            %iDotX := round ((iDotY - iB) / iM)
        else
            CheckAndMove (iDotX, iSpeed, 1, true)
            %iDotX += iSpeed
            %iDotY := round ((iM * iDotX) + iB)
        end if
    elsif iDotX < iX and iDotY > iY then
        if iX - iDotX < iDotY - iY then
            CheckAndMove (iDotY, iSpeed, -1, false)
            %iDotY -= iSpeed
            %iDotX := round ((iDotY - iB) / iM)
        else
            CheckAndMove (iDotX, iSpeed, 1, true)
            %iDotX += iSpeed
            %iDotY := round ((iM * iDotX) + iB)
        end if
    elsif iDotX > iX and iDotY < iY then
        if iDotX - iX < iY - iDotY then
            CheckAndMove (iDotY, iSpeed, 1, false)
            %iDotY += iSpeed
            %iDotX := round ((iDotY - iB) / iM)
        else
            CheckAndMove (iDotX, iSpeed, -1, true)
            %iDotX -= iSpeed
            %iDotY := round ((iM * iDotX) + iB)
        end if
    elsif iDotX > iX and iDotY > iY then
        if iDotX - iX < iDotY - iY then
            CheckAndMove (iDotY, iSpeed, -1, false)
            %iDotY -= iSpeed
            %iDotX := round ((iDotY - iB) / iM)
        else
            CheckAndMove (iDotX, iSpeed, -1, true)
            %iDotX -= iSpeed
            %iDotY := round ((iM * iDotX) + iB)
        end if
    else
    end if

    %  Moves Dot to mouse location if closer than 5 to avoid jumping when mouse isn't moving.
    if sqrt ((iY - iDotY) ** 2 + (iX - iDotX) ** 2) < iSpeed then
        iDotX := iX
        iDotY := iY
    end if

    exit when hasch
    exit when buttonmoved ("down")

end loop

Window.Close (iWindow)