/*******************************************************************************
 * Breakout Cave Survey Visualizer
 *
 * Copyright (C) 2014 James Edwards
 *
 * jedwards8 at fastmail dot fm
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *******************************************************************************/
package org.andork.jogl.awt.anim;

import org.andork.awt.anim.Animation;
import org.andork.jogl.JoglViewSettings;
import org.andork.math3d.Orbiter;
import org.andork.math3d.Vecmath;
import org.andork.util.Reparam;

import com.jogamp.opengl.GLAutoDrawable;

public class RandomViewOrbitAnimation implements Animation {

	JoglViewSettings viewSettings;

	GLAutoDrawable drawable;
	final float[] v = Vecmath.newMat4f();

	Orbiter orbiter = new Orbiter();

	int period;

	int tiltPeriod;
	float panRate;

	float minTilt;
	float maxTilt;
	float startTilt = Float.NaN;

	float endTilt = Float.NaN;
	float tiltParam;

	public RandomViewOrbitAnimation(GLAutoDrawable drawable, JoglViewSettings viewSettings, float[] center,
			float panRate, float minTilt, float maxTilt,
			int period, int tiltPeriod) {
		if (period <= 0) {
			throw new IllegalArgumentException("period must be > 0");
		}
		this.viewSettings = viewSettings;
		this.drawable = drawable;
		orbiter.setCenter(center);
		this.panRate = panRate;
		this.minTilt = minTilt;
		this.maxTilt = maxTilt;
		this.period = period;
		this.tiltPeriod = tiltPeriod;
	}

	@Override
	public long animate(long animTime) {
		tiltParam += Math.PI * 2 * animTime / tiltPeriod;

		viewSettings.getViewXform(v);

		float currentTilt = orbiter.getTilt(v);
		if (Float.isNaN(startTilt)) {
			if (currentTilt < minTilt) {
				startTilt = currentTilt;
				endTilt = maxTilt;
			} else if (currentTilt > maxTilt) {
				startTilt = minTilt;
				endTilt = maxTilt;
			} else {
				startTilt = minTilt;
				endTilt = maxTilt;
			}
		}

		if (tiltParam >= Math.PI) {
			startTilt = minTilt;
			endTilt = maxTilt;
		}

		float nextTilt = Reparam.linear((float) Math.cos(tiltParam), 1, -1, startTilt, endTilt);

		orbiter.orbit(v, panRate * animTime / period, nextTilt - currentTilt, v);

		orbiter.orbit(v, panRate * animTime / period, 0, v);

		viewSettings.setViewXform(v);

		drawable.display();

		return period;
	}
}