/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.graphics.g3d.particles.influencers;

import com.badlogic.gdx.graphics.g3d.particles.ParallelArray.FloatChannel;
import com.badlogic.gdx.graphics.g3d.particles.ParallelArray.ObjectChannel;
import com.badlogic.gdx.graphics.g3d.particles.ParticleChannels;
import com.badlogic.gdx.graphics.g3d.particles.ParticleController;
import com.badlogic.gdx.utils.GdxRuntimeException;

/** It's an {@link Influencer} which updates the simulation of particles containing a {@link ParticleController}. Must be the last
 * influencer to be updated, so it has to be placed at the end of the influencers list when creating a {@link ParticleController}.
 * @author Inferno */
public class ParticleControllerFinalizerInfluencer extends Influencer {
	FloatChannel positionChannel, scaleChannel, rotationChannel;
	ObjectChannel<ParticleController> controllerChannel;
	boolean hasScale, hasRotation;

	public ParticleControllerFinalizerInfluencer () {
	}

	@Override
	public void init () {
		controllerChannel = controller.particles.getChannel(ParticleChannels.ParticleController);
		if (controllerChannel == null)
			throw new GdxRuntimeException(
				"ParticleController channel not found, specify an influencer which will allocate it please.");
		scaleChannel = controller.particles.getChannel(ParticleChannels.Scale);
		rotationChannel = controller.particles.getChannel(ParticleChannels.Rotation3D);
		hasScale = scaleChannel != null;
		hasRotation = rotationChannel != null;
	}

	@Override
	public void allocateChannels () {
		positionChannel = controller.particles.addChannel(ParticleChannels.Position);
	}

	@Override
	public void update () {
		for (int i = 0, positionOffset = 0, c = controller.particles.size; i < c; ++i, positionOffset += positionChannel.strideSize) {
			ParticleController particleController = controllerChannel.data[i];
			float scale = hasScale ? scaleChannel.data[i] : 1;
			float qx = 0, qy = 0, qz = 0, qw = 1;
			if (hasRotation) {
				int rotationOffset = i * rotationChannel.strideSize;
				qx = rotationChannel.data[rotationOffset + ParticleChannels.XOffset];
				qy = rotationChannel.data[rotationOffset + ParticleChannels.YOffset];
				qz = rotationChannel.data[rotationOffset + ParticleChannels.ZOffset];
				qw = rotationChannel.data[rotationOffset + ParticleChannels.WOffset];
			}
			particleController.setTransform(positionChannel.data[positionOffset + ParticleChannels.XOffset],
				positionChannel.data[positionOffset + ParticleChannels.YOffset], positionChannel.data[positionOffset
					+ ParticleChannels.ZOffset], qx, qy, qz, qw, scale);
			particleController.update();
		}
	}

	@Override
	public ParticleControllerFinalizerInfluencer copy () {
		return new ParticleControllerFinalizerInfluencer();
	}
}