bundles/core/org.eclipse.apogy.core.environment.earth.surface.ui/src-gen-custom/org/eclipse/apogy/core/environment/earth/surface/ui/impl/EarthSurfaceUIUtilitiesCustomImpl.java

/*******************************************************************************
 * Copyright (c) 2018 Agence spatiale canadienne / Canadian Space Agency 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Pierre Allard,
 *     Regent L'Archeveque - initial API and implementation
 *     
 * SPDX-License-Identifier: EPL-1.0
 *******************************************************************************/
package org.eclipse.apogy.core.environment.earth.surface.ui.impl;

import javax.vecmath.Color3f;

import org.eclipse.apogy.core.environment.earth.surface.AtmosphereUtils;

public class EarthSurfaceUIUtilitiesCustomImpl extends EarthSurfaceUIUtilitiesImpl {

	public static final double LOWER_SUN_ALTITUDE_FOR_TRANSPARENCY = Math.toRadians(-5.0);
	public static final double LOWER_SUN_ALTITUDE_TRANSPARENCY = 1.0;
	public static final double UPPER_SUN_ALTITUDE_FOR_TRANSPARENCY = Math.toRadians(0.0);
	public static final double UPPER_SUN_ALTITUDE_TRANSPARENCY = 0.0;

	public static final Color3f DAY_SKY_COLOR = new Color3f(0, 0, 1);
	public static final Color3f SUNSET_SKY_COLOR = new Color3f(((float) 201 / 255), 0, 1);

	@Override
	public Color3f getSunLightColor(double sunAltitude) {
		Color3f color;
		if (sunAltitude >= 0) {
			// Applies extinction of green and blue.
			double colorExtinctionFactor = 1.0 - Math.exp(-sunAltitude / 0.053);
			color = new Color3f(1, (float) colorExtinctionFactor, (float) colorExtinctionFactor);

			// Applies atmosphere extinction.
			double sunIntensity = AtmosphereUtils.INSTANCE.getDirectSunIntensity(sunAltitude, 0.0);
			double sunMaximumIntensity = AtmosphereUtils.INSTANCE.getDirectSunIntensity(Math.toRadians(90), 0.0);
			float extinction = (float) (sunIntensity / sunMaximumIntensity);

			color.scale(extinction);
		} else {
			color = new Color3f(0, 0, 0);
		}

		// System.out.println("Sun Light Color : " + color);

		return color;
	}

	@Override
	public double getSkyTransparency(double sunAltitude) {
		double transparency = 0.0;

		if (sunAltitude < LOWER_SUN_ALTITUDE_FOR_TRANSPARENCY) {
			transparency = LOWER_SUN_ALTITUDE_TRANSPARENCY;
		} else if ((sunAltitude >= LOWER_SUN_ALTITUDE_FOR_TRANSPARENCY)
				&& (sunAltitude < UPPER_SUN_ALTITUDE_FOR_TRANSPARENCY)) {
			transparency = (sunAltitude - LOWER_SUN_ALTITUDE_FOR_TRANSPARENCY) * UPPER_SUN_ALTITUDE_TRANSPARENCY
					+ (UPPER_SUN_ALTITUDE_FOR_TRANSPARENCY - sunAltitude) * LOWER_SUN_ALTITUDE_TRANSPARENCY;

			transparency = transparency / (UPPER_SUN_ALTITUDE_FOR_TRANSPARENCY - LOWER_SUN_ALTITUDE_FOR_TRANSPARENCY);
		} else {
			transparency = UPPER_SUN_ALTITUDE_TRANSPARENCY;
		}

		return transparency;
	}

	@Override
	public Color3f getSkyColor(double sunAltitude) {
		Color3f color = new Color3f();

		double max = Math.toRadians(10);
		double min = Math.toRadians(0);
		if (sunAltitude < max) {
			if (sunAltitude > min) {
				float t = (float) ((sunAltitude - min) / (max - min));
				color.interpolate(SUNSET_SKY_COLOR, DAY_SKY_COLOR, t);
			} else {
				color = SUNSET_SKY_COLOR;
			}
		} else {
			color = DAY_SKY_COLOR;
		}

		return color;
	}

} // EnvironmentUIUtilitiesImpl