/*******************************************************************************
 * 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.values;

import com.badlogic.gdx.assets.AssetDescriptor;
import com.badlogic.gdx.assets.AssetManager;
import com.badlogic.gdx.graphics.Mesh;
import com.badlogic.gdx.graphics.VertexAttributes.Usage;
import com.badlogic.gdx.graphics.g3d.Model;
import com.badlogic.gdx.graphics.g3d.particles.ResourceData;
import com.badlogic.gdx.graphics.g3d.particles.ResourceData.SaveData;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.math.Vector3;
import com.badlogic.gdx.utils.GdxRuntimeException;

/** The base class of all the {@link ParticleValue} values which spawn a particle on a mesh shape.
 * @author Inferno */
public abstract class MeshSpawnShapeValue extends SpawnShapeValue {
	public static class Triangle {
		float x1, y1, z1, x2, y2, z2, x3, y3, z3;

		public Triangle (float x1, float y1, float z1, float x2, float y2, float z2, float x3, float y3, float z3) {
			this.x1 = x1;
			this.y1 = y1;
			this.z1 = z1;
			this.x2 = x2;
			this.y2 = y2;
			this.z2 = z2;
			this.x3 = x3;
			this.y3 = y3;
			this.z3 = z3;
		}

		public static Vector3 pick (float x1, float y1, float z1, float x2, float y2, float z2, float x3, float y3, float z3,
			Vector3 vector) {
			float a = MathUtils.random(), b = MathUtils.random();
			return vector.set(x1 + a * (x2 - x1) + b * (x3 - x1), y1 + a * (y2 - y1) + b * (y3 - y1), z1 + a * (z2 - z1) + b
				* (z3 - z1));
		}

		public Vector3 pick (Vector3 vector) {
			float a = MathUtils.random(), b = MathUtils.random();
			return vector.set(x1 + a * (x2 - x1) + b * (x3 - x1), y1 + a * (y2 - y1) + b * (y3 - y1), z1 + a * (z2 - z1) + b
				* (z3 - z1));
		}
	}

	protected Mesh mesh;
	/** the model this mesh belongs to. It can be null, but this means the mesh will not be able to be serialized correctly. */
	protected Model model;

	public MeshSpawnShapeValue (MeshSpawnShapeValue value) {
		super(value);
	}

	public MeshSpawnShapeValue () {
	}

	@Override
	public void load (ParticleValue value) {
		super.load(value);
		MeshSpawnShapeValue spawnShapeValue = (MeshSpawnShapeValue)value;
		setMesh(spawnShapeValue.mesh, spawnShapeValue.model);
	}

	public void setMesh (Mesh mesh, Model model) {
		if (mesh.getVertexAttribute(Usage.Position) == null)
			throw new GdxRuntimeException("Mesh vertices must have Usage.Position");
		this.model = model;
		this.mesh = mesh;
	}

	public void setMesh (Mesh mesh) {
		this.setMesh(mesh, null);
	}

	@Override
	public void save (AssetManager manager, ResourceData data) {
		if (model != null) {
			SaveData saveData = data.createSaveData();
			saveData.saveAsset(manager.getAssetFileName(model), Model.class);
			saveData.save("index", model.meshes.indexOf(mesh, true));
		}
	}

	@Override
	public void load (AssetManager manager, ResourceData data) {
		SaveData saveData = data.getSaveData();
		AssetDescriptor descriptor = saveData.loadAsset();
		if (descriptor != null) {
			Model model = (Model)manager.get(descriptor);
			setMesh(model.meshes.get((Integer)saveData.load("index")), model);
		}
	}

}