--

-- ////\\\\

-- ////\\\\ TUTORIAL

-- ////\\\\ PART 3

-- \\\\////

-- \\\\//// INTERACTION

-- \\\\////

--

local viewport = { width = 128, height = 64 }

local focus = { x = 0, y = 0 }

-- Main

function init()

-- Render Style

screen.level(15)

screen.aa(0)

screen.line_width(1)

-- Center focus

reset()

-- Render

redraw()

end

function reset()

print('reset')

focus.x = viewport.width/2

focus.y = viewport.height/2

end

-- Interactions

function key(id,state)

print('key',id,state)

reset()

redraw()

end

function enc(id,delta)

print('enc',id,delta)

if id == 2 then

focus.x = clamp(focus.x + delta,6,123)

elseif id == 3 then

focus.y = clamp(focus.y + delta,6,59)

end

redraw()

end

-- Render

function draw_frame()

screen.rect(1, 1, viewport.width-1, viewport.height-1)

screen.stroke()

end

function draw_crosshair()

screen.move(focus.x,focus.y - 4)

screen.line(focus.x,focus.y - 2)

screen.move(focus.x - 4,focus.y)

screen.line(focus.x - 2,focus.y)

screen.move(focus.x,focus.y + 3)

screen.line(focus.x,focus.y + 1)

screen.move(focus.x + 3,focus.y)

screen.line(focus.x + 1,focus.y)

screen.stroke()

end

function draw_position()

screen.move(5,viewport.height - (8 * 1))

screen.text(math.floor(focus.x)..','..math.floor(focus.y))

end

function redraw()

screen.clear()

draw_frame()

draw_crosshair()

draw_position()

screen.update()

end

-- Utils

function clamp(val,min,max)

return val < min and min or val > max and max or val

end