/*******************************************************************************
 * 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.tests;

import java.util.Comparator;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.tests.utils.GdxTest;
import com.badlogic.gdx.utils.Array;

/** Demonstrates how to do simple z-sorting of sprites
 * @author mzechner */
public class SortedSpriteTest extends GdxTest {
	/** Sprite based class that adds a z-coordinate for depth sorting. Note that allt he constructors were auto-generated in Eclipse
	 * (alt + shift + s, c).
	 * @author mzechner */
	public class MySprite extends Sprite {
		public float z;

		public MySprite () {
			super();
		}

		public MySprite (Sprite sprite) {
			super(sprite);
		}

		public MySprite (Texture texture, int srcX, int srcY, int srcWidth, int srcHeight) {
			super(texture, srcX, srcY, srcWidth, srcHeight);
		}

		public MySprite (Texture texture, int srcWidth, int srcHeight) {
			super(texture, srcWidth, srcHeight);
		}

		public MySprite (Texture texture) {
			super(texture);
		}

		public MySprite (TextureRegion region, int srcX, int srcY, int srcWidth, int srcHeight) {
			super(region, srcX, srcY, srcWidth, srcHeight);
		}

		public MySprite (TextureRegion region) {
			super(region);
		}
	}

	/** Comparator used for sorting, sorts in ascending order (biggset z to smallest z).
	 * @author mzechner */
	public class MySpriteComparator implements Comparator<MySprite> {
		@Override
		public int compare (MySprite sprite1, MySprite sprite2) {
			return (sprite2.z - sprite1.z) > 0 ? 1 : -1;
		}
	}

	/** spritebatch used for rendering **/
	SpriteBatch batch;
	/** the texture used by the sprites **/
	Texture texture;
	/** array of sprites **/
	Array<MySprite> sprites = new Array<MySprite>();
	/** a comparator, we keep it around so the GC shuts up **/
	MySpriteComparator comparator = new MySpriteComparator();

	@Override
	public void create () {
		// create the SpriteBatch
		batch = new SpriteBatch();

		// load a texture, usually you dispose of this
		// eventually.
		texture = new Texture("data/badlogicsmall.jpg");

		// create 100 sprites, tinted red, from dark to light.
		// red color component is also used as z-value so we
		// can see that the sorting works.
		for (int i = 0; i < 100; i++) {
			// create the sprite and set a random position
			MySprite sprite = new MySprite(texture);
			sprite.setPosition(MathUtils.random() * Gdx.graphics.getWidth(), MathUtils.random() * Gdx.graphics.getHeight());

			// create a random z coordinate in the range 0-1
			sprite.z = MathUtils.random();

			// set the tinting color to the z coordinate as well
			// for visual inspection
			sprite.setColor(sprite.z, 0, 0, 1);

			// add the sprite to the array
			sprites.add(sprite);
		}
	}

	@Override
	public void render () {
		Gdx.gl.glClearColor(0.2f, 0.2f, 0.2f, 1);
		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

		// sort the sprites (not necessary if we know
		// the are already sorted).
		sprites.sort(comparator);

		// draw the sprites
		batch.begin();
		for (MySprite sprite : sprites) {
			sprite.draw(batch);
		}
		batch.end();
	}

	@Override
	public void dispose () {
		batch.dispose();
		texture.dispose();
	}
}