节点接口（Node）

节点脚本可用于渲染形状、图像、文本、画板等。

脚本化节点可附加在任意 Node 上，并在宿主节点本地变换空间（local transform space）渲染。

更多信息见：Node Scripts

方法（Methods）

init

节点创建时调用一次。初始化成功返回 true。

-- Define the script's data and inputs.
type MyNode = {}

-- Called once when the script initializes.
function init(self: MyNode, context: Context): boolean
  return true
end

-- Return a factory function that Rive uses to build the Node instance.
return function(): Node<MyNode>
  return {
    init = init
  }
end

advance

可选逐帧更新。返回 true 则继续接收 advance。

-- Define the script's data and inputs.
type MyNode = {}

-- Called every frame to advance the simulation.
-- 'seconds' is the elapsed time since the previous frame.
function advance(self: MyNode, seconds: number): boolean
  return false
end

-- Return a factory function that Rive uses to build the Node instance.
return function(): Node<MyNode>
  return {
    advance = advance,
  }
end

update

输入值变化时调用。

-- Define the script's data and inputs.
type MyNode = {}

-- Called when any input value changes.
function update(self: MyNode)
  print('An script input value has changed.')
end

-- Return a factory function that Rive uses to build the Node instance.
return function(): Node<MyNode>
  return {
    update = update,
  }
end

draw

使用 渲染器（Renderer） 绘制内容。

-- Define the script's data and inputs.
type MyNode = {}

-- Called every frame (after advance) to render the content.
function draw(self: MyNode, renderer: Renderer) end

-- Return a factory function that Rive uses to build the Node instance.
return function(): Node<MyNode>
  return {
    draw = draw,
  }
end

pointerDown

指针按下处理。

function handlePointerDown(self: MyGame, event: PointerEvent)
  print('Pointer Position: ', event.position.x, event.position.y)

  event:hit()
end

return function(): Node<MyGame>
    return {
        init = init,
        advance = advance,
        draw = draw,
        pointerDown = handlePointerDown,
    }
end

pointerMove

指针移动处理。

function handlePointerMove(self: MyGame, event: PointerEvent)
  print('Pointer Position: ', event.position.x, event.position.y)

  event:hit()
end

return function(): Node<MyGame>
    return {
        init = init,
        advance = advance,
        draw = draw,
        pointerMove = handlePointerMove,
    }
end

pointerUp

指针抬起处理。

function handlePointerUp(self: MyGame, event: PointerEvent)
  print('Pointer Position: ', event.position.x, event.position.y)

  event:hit()
end

return function(): Node<MyGame>
    return {
        init = init,
        advance = advance,
        draw = draw,
        pointerUp = handlePointerUp,
    }
end

pointerExit

指针离开处理。

function handlePointerExit(self: MyGame, event: PointerEvent)
  print('Pointer Position: ', event.position.x, event.position.y)

  event:hit()
end

return function(): Node<MyGame>
    return {
        init = init,
        advance = advance,
        draw = draw,
        pointerExit = handlePointerExit,
    }
end