smooth_2d.h

//	Copyright (c) 2019 Lawnjelly

//	Permission is hereby granted, free of charge, to any person obtaining a copy
//	of this software and associated documentation files (the "Software"), to deal
//	in the Software without restriction, including without limitation the rights
//	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//	copies of the Software, and to permit persons to whom the Software is
//	furnished to do so, subject to the following conditions:

//	The above copyright notice and this permission notice shall be included in all
//	copies or substantial portions of the Software.

//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//	SOFTWARE.

#ifndef SMOOTH2D_H
#define SMOOTH2D_H

/**
	@author lawnjelly <lawnjelly@gmail.com>
*/

#include "scene/2d/node_2d.h"

// Smooth node allows fixed timestep interpolation without having to write any code.
// It requires a proxy node (which is moved on physics tick), e.g. a rigid body or manually moved node2d..
// and instead of having MeshInstance as a child of this, you add Smooth node to another part of the scene graph,
// make the MeshInstance a child of the smooth node, then choose the proxy as the target for the smooth node.

// Note that in the special case of manually moving the proxy to a completely new location, you should call
// 'teleport' on the smooth node after setting the proxy node transform. This will ensure that the current AND
// previous transform records are reset, so it moves instantaneously.

class Smooth2D : public Node2D {
	GDCLASS(Smooth2D, Node2D);

	// custom
	class STransform {
	public:
		Point2 pos;
		float angle;
		Size2 scale;
	};

	Point2 m_ptTranslateDiff;

#define SMOOTHNODE Node2D
#include "smooth_header.inl"
#undef SMOOTHNODE

	// specific
public:
	Smooth2D();

private:
	float LerpAngle(float from, float to, float weight) const;
	float ShortAngleDist(float from, float to) const;
};

VARIANT_ENUM_CAST(Smooth2D::eMode);

#endif