renderd7/external/tween-engine/include/TweenEngine/TweenAccessor.h
2021-07-23 13:58:16 +00:00

104 lines
3.4 KiB
C++

//
// TweenAccessor.h
//
// This code is derived from Universal Tween Engine
// Licensed under Apache License 2.0 - http://www.apache.org/licenses/LICENSE-2.0
//
/**
* The TweenAccessor interface lets you interpolate any attribute from any
* object. Just implement it as you want and register it to the engine by
* calling {@link Tween#registerAccessor}.
* <p/>
*
* <h2>Example</h2>
*
* The following code snippet presents an example of implementation for tweening
* a Particle class. This Particle class is supposed to only define a position
* with an "x" and an "y" fields, and their associated getters and setters.
* <p/>
*
* <pre> {@code
* public class ParticleAccessor implements TweenAccessor<Particle> {
* public static final int X = 1;
* public static final int Y = 2;
* public static final int XY = 3;
*
* public int getValues(Particle target, int tweenType, float[] returnValues) {
* switch (tweenType) {
* case X: returnValues[0] = target.getX(); return 1;
* case Y: returnValues[0] = target.getY(); return 1;
* case XY:
* returnValues[0] = target.getX();
* returnValues[1] = target.getY();
* return 2;
* default: assert false; return 0;
* }
* }
*
* public void setValues(Particle target, int tweenType, float[] newValues) {
* switch (tweenType) {
* case X: target.setX(newValues[0]); break;
* case Y: target.setY(newValues[1]); break;
* case XY:
* target.setX(newValues[0]);
* target.setY(newValues[1]);
* break;
* default: assert false; break;
* }
* }
* }
* }</pre>
*
* Once done, you only need to register this TweenAccessor once to be able to
* use it for every Particle objects in your application:
* <p/>
*
* <pre> {@code
* Tween.registerAccessor(Particle.class, new ParticleAccessor());
* }</pre>
*
* And that's all, the Tween Engine can no work with all your particles!
*
* @author Aurelien Ribon | http://www.aurelienribon.com/
*/
#ifndef __TweenAccessor__
#define __TweenAccessor__
namespace TweenEngine
{
template<class T>
class TweenAccessor
{
public:
virtual ~TweenAccessor() {}
/**
* Gets one or many values from the target object associated to the
* given tween type. It is used by the Tween Engine to determine starting
* values.
*
* @param target The target object of the tween.
* @param tweenType An integer representing the tween type.
* @param returnValues An array which should be modified by this method.
* @return The count of modified slots from the returnValues array.
*/
virtual int getValues(T& target, int tweenType, float *returnValues) = 0;
/**
* This method is called by the Tween Engine each time a running tween
* associated with the current target object has been updated.
*
* @param target The target object of the tween.
* @param tweenType An integer representing the tween type.
* @param newValues The new values determined by the Tween Engine.
*/
virtual void setValues(T& target, int tweenType, float *newValues) = 0;
};
}
#endif /* defined(__TweenAccessor__) */