Code 14c - Images

--# Main
-- Code 14c - Images

-- Bruce Elliott
-- May 2013

-- Coroutine draw multiple images to screen

supportedOrientations(LANDSCAPE_RIGHT)
displayMode(FULLSCREEN)

function setup()

    print("Coroutine Example")
    useTouch = false

    obj = coroutine.create(object)
    coroutine.resume(obj)
    -- Remove comment to draw an object
    -- each time screen is touched--
    -- useTouch = true
end

-- This function gets called once every frame
function draw()

    -- This sets the line thickness
    strokeWidth(2)

    if useTouch == true then
        -- wait
    else
        drawObject()
    end

    -- Do your drawing here

end

function object()
    -- img contains the nodes of an object
    -- to be drawn on the screen
    img ={}

    -- scale is used to change the length of img
    -- lines
    scale = 0
    while scale < 50 do
        -- img can have 2 to 15 nodes
        -- two nodes are used to draw a line
        n = math.random(2, 15)
        for i = 1, n do
            img[i] = buildNode(scale)
        end

        -- Move nodes on screen attempt
        -- to get even distribution for objects
        deltaX = math.random(1, WIDTH)
        deltaY = math.random(1, HEIGHT)

        -- Adjust nodes so they are on screen
        -- using math.min and WIDTH or HEIGHT
        -- This method simply forces nodes onto
        -- the screen which changes original
        -- image shape. Better might be to move
        -- all nodes enough so they are all on the
        -- screen and the image shape is maintained.

        for i = 1, n do
            img[i].x = math.min(img[i].x + deltaX, WIDTH)
            img[i].y = math.min(img[i].y + deltaY, HEIGHT)
        end

        -- stop coroutine and wait for drawObject
        -- to resume it
        coroutine.yield(n, img)

        -- Increment scale (length of img lines)
        scale = scale + 1

    end

end

function drawObject()
    -- resume the coroutine return:
    --    status - coroutine active
    --    drawN - number of nodes in object
    --    thisObj - table of node values

    -- "Done" will display in upper left corner after all
    -- objects have been drawn
    status, drawN, thisObj = coroutine.resume(obj)

    -- Set line color for this image
    setStroke()

    -- Determine if coroutine is active
    if status ~= false and thisObj ~= nil then
        -- Draw all but the last line in an object
        for i = 1, drawN - 1 do
            line(thisObj[i].x, thisObj[i].y, thisObj[i+1].x, thisObj[i+1].y)
        end
        -- Draw last line fron last node to first node
        line(thisObj[drawN].x, thisObj[drawN].y, thisObj[1].x, thisObj[1].y)
    else
        text("Done", 70, HEIGHT -50)
    end
end

function setStroke()
    -- Determine a random color for an
    -- object lines
    strokeRed = math.random(0, 255)
    strokeGreen = math.random(0, 255)
    strokeBlue = math.random(0, 255)
    stroke(strokeRed, strokeGreen, strokeBlue, 255)
end

function buildNode(scale)
    -- Create a node as a vec2
    p = vec2()

    -- Random x, y values
    p.x, p.y = getRan()

    -- Add scale to x, y
    p.x = p.x + scale
    p.y = p.y + scale
 --   print("node", p.x, p.y)

    -- return the node
    return p
end

function getRan()
    -- This determines the base x and y position
    -- of the object used by buildNode
    x = math.random(10,150)
    y = math.random(10,150)

    -- Return x, y
    return x, y
end

function touched(touch)
    if touch.state == ENDED and useTouch == true then
        drawObject()
    end
end