bundles/core/org.eclipse.apogy.core.environment.ui.jme3/src/org/eclipse/apogy/core/environment/ui/jme3/EnvironmentUIJME3Utilities.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.ui.jme3;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.apogy.common.topology.ui.jme3.JME3Utilities;

import com.jme3.math.Vector3f;
import com.jme3.scene.Mesh;
import com.jme3.util.BufferUtils;

public class EnvironmentUIJME3Utilities {
	/**
	 * Creates a Mesh representing a grid in the XY plane.
	 * 
	 * @param gridSize  The size of the grid squares.
	 * @param planeSize The overall size of the grid.
	 * @return The Mesh.
	 */
	public static Mesh createGrid(float gridSize, float planeSize) {
		float planeHalfSize = planeSize / 2.0f;

		List<Vector3f> verticesList = new ArrayList<Vector3f>();
		List<Integer> indexesList = new ArrayList<Integer>();

		// Lines in the Y direction
		float x = 0;
		while (x <= planeHalfSize) {
			Vector3f p1 = new Vector3f(x, -planeHalfSize, 0);
			Vector3f p2 = new Vector3f(x, planeHalfSize, 0);

			verticesList.add(p1);
			verticesList.add(p2);

			indexesList.add(verticesList.indexOf(p1));
			indexesList.add(verticesList.indexOf(p2));

			x += gridSize;
		}

		x = 0.0f;
		while (x >= -planeHalfSize) {
			Vector3f p1 = new Vector3f(x, -planeHalfSize, 0);
			Vector3f p2 = new Vector3f(x, planeHalfSize, 0);

			verticesList.add(p1);
			verticesList.add(p2);

			indexesList.add(verticesList.indexOf(p1));
			indexesList.add(verticesList.indexOf(p2));

			x -= gridSize;
		}

		// Lines in the X direction
		float y = 0;
		while (y <= planeHalfSize) {
			Vector3f p1 = new Vector3f(-planeHalfSize, y, 0);
			Vector3f p2 = new Vector3f(planeHalfSize, y, 0);

			verticesList.add(p1);
			verticesList.add(p2);

			indexesList.add(verticesList.indexOf(p1));
			indexesList.add(verticesList.indexOf(p2));

			y += gridSize;
		}

		y = 0;
		while (y >= -planeHalfSize) {
			Vector3f p1 = new Vector3f(-planeHalfSize, y, 0);
			Vector3f p2 = new Vector3f(planeHalfSize, y, 0);

			verticesList.add(p1);
			verticesList.add(p2);

			indexesList.add(verticesList.indexOf(p1));
			indexesList.add(verticesList.indexOf(p2));

			y -= gridSize;
		}

		Mesh mesh = new Mesh();
		mesh.setMode(Mesh.Mode.Lines);
		mesh.setBuffer(com.jme3.scene.VertexBuffer.Type.Position, 3,
				BufferUtils.createFloatBuffer(JME3Utilities.convertToFloatArray(verticesList)));
		mesh.setBuffer(com.jme3.scene.VertexBuffer.Type.Index, 2,
				BufferUtils.createIntBuffer(JME3Utilities.convertToIntArray(indexesList)));
		mesh.updateBound();
		mesh.updateCounts();

		return mesh;
	}

	/**
	 * Creates a square plane in the XY plane centered at the origin.
	 * 
	 * @param planeSize The overall size of the plane.
	 * @return The plane mesh.
	 */
	public static Mesh createPlane(float planeSize) {
		float planeHalfSize = planeSize / 2.0f;

		List<Vector3f> verticesList = new ArrayList<Vector3f>();
		List<Integer> indexesList = new ArrayList<Integer>();

		Vector3f p0 = new Vector3f(-planeHalfSize, -planeHalfSize, 0);
		Vector3f p1 = new Vector3f(planeHalfSize, -planeHalfSize, 0);
		Vector3f p2 = new Vector3f(planeHalfSize, planeHalfSize, 0);
		Vector3f p3 = new Vector3f(-planeHalfSize, planeHalfSize, 0);

		verticesList.add(p0);
		verticesList.add(p1);
		verticesList.add(p2);
		verticesList.add(p3);

		indexesList.add(new Integer(0));
		indexesList.add(new Integer(1));
		indexesList.add(new Integer(2));

		indexesList.add(new Integer(0));
		indexesList.add(new Integer(2));
		indexesList.add(new Integer(3));

		Mesh mesh = new Mesh();
		mesh.setBuffer(com.jme3.scene.VertexBuffer.Type.Position, 3,
				BufferUtils.createFloatBuffer(JME3Utilities.convertToFloatArray(verticesList)));
		mesh.setBuffer(com.jme3.scene.VertexBuffer.Type.Index, 2,
				BufferUtils.createIntBuffer(JME3Utilities.convertToIntArray(indexesList)));
		mesh.updateBound();
		mesh.updateCounts();

		return mesh;
	}
}