-- Love2d Mesh

-- init
function love.load()
  -- get window width and height
  wdw_w, wdw_h = love.graphics.getDimensions()

  img = love.graphics.newImage("uvcheckermap01-512.png")

  bx, by = wdw_w / 2, wdw_h / 2
  v = {
    {
      -- top left
      -- x, y, u, v, r, g, b
      bx - 50, by - 200, 0.0, 0.0, 1.0, 1.0, 1.0
    },
    {
      -- top right
      -- x, y, u, v, e, g, b
      bx + 50, by -200, 1.0, 0.0, 1.0, 1.0, 1.0
    },
    {
      -- bottom left
      -- x, y, u, v, e, g, b
      bx - 300, by + 200, 0.0, 1.0, 1.0, 1.0, 1.0
    },
    {
      -- bottom right
      -- x, y, u, v, e, g, b
      bx + 300, by + 200, 1.0, 1.0, 1.0, 1.0, 1.0
    },
  }

  mesh = love.graphics.newMesh(v, "strip")
  mesh:setTexture(img)

  ang = 0
end

-- update
function love.update(dt)
  ang = ang + 180 * dt
  local d = 150 + 100 * math.sin(math.rad(ang))

  if true then
    local i = 1
    -- mesh:setVertex(index, x, y, u, v, r, g, b, a)
    mesh:setVertex(i, (bx - d), v[i][2], v[i][3], v[i][4], v[i][5], v[i][6], v[i][7], v[i][8])

    i = 2
    mesh:setVertex(i, (bx + d), v[i][2], v[i][3], v[i][4], v[i][5], v[i][6], v[i][7], v[i][8])
  else
    v[1][1] = bx - d
    v[2][1] = bx + d
    -- mesh:setVertex(index, table)
    mesh:setVertex(1, v[1])
    mesh:setVertex(2, v[2])
  end
end

-- draw
function love.draw()
  -- fill BG color
  love.graphics.setColor(0.1, 0.2, 0.4)
  love.graphics.rectangle("fill", 0, 0, wdw_w, wdw_h)

  -- draw mesh
  love.graphics.setColor(1, 1, 1)
  love.graphics.draw(mesh, 0, 0)

  -- print FPS
  love.graphics.setColor(1, 1, 1)
  love.graphics.print("FPS: "..tostring(love.timer.getFPS()), 10, 10)
end

function love.keypressed(key, isrepeat)
  -- ESC to exit
  if key == "escape" then
    love.event.quit()
  end
end