SphericalHarmonics.java

/*******************************************************************************
 * 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.environment;

import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.utils.GdxRuntimeException;

public class SphericalHarmonics {
	// <kalle_h> last term is no x*x * y*y but x*x - y*y
	private final static float coeff[] = {0.282095f, 0.488603f, 0.488603f, 0.488603f, 1.092548f, 1.092548f, 1.092548f, 0.315392f,
		0.546274f};

	private final static float clamp (final float v) {
		return v < 0f ? 0f : (v > 1f ? 1f : v);
	}

	public final float data[];

	public SphericalHarmonics () {
		data = new float[9 * 3];
	}

	public SphericalHarmonics (final float copyFrom[]) {
		if (copyFrom.length != (9 * 3)) throw new GdxRuntimeException("Incorrect array size");
		data = copyFrom.clone();
	}

	public SphericalHarmonics set (final float values[]) {
		for (int i = 0; i < data.length; i++)
			data[i] = values[i];
		return this;
	}

	public SphericalHarmonics set (final AmbientCubemap other) {
		return set(other.data);
	}

	public SphericalHarmonics set (final Color color) {
		return set(color.r, color.g, color.b);
	}

	public SphericalHarmonics set (float r, float g, float b) {
		for (int idx = 0; idx < data.length;) {
			data[idx++] = r;
			data[idx++] = g;
			data[idx++] = b;
		}
		return this;
	}
}