straightedge.geom.vision.VisionData Maven / Gradle / Ivy

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Includes 2 main parts: - Path finding through 2D polygons using the A star algorithm and navigation-mesh generation Field of vision / shadows / line of sight / lighting. The basic polygon and point classes are the KPolygon and KPoint. KPolygon contains a list of KPoints for vertices as well as a center (centroid), area, and radius (circular bound or distance from center to furthest point). KPolygon was born out of the need for a more game-oriented and flexible polygon class than the Path2D class in the standard Java library. KPolygon implements java.awt.geom.Shape so it can be easily drawn and filled by Java2D's Graphics2D object. - This API provides path-finding and field-of-vision. For other complex geometric operations such as buffering (fattening and shrinking) and constructive area geometry (intersections and unions) it is recommended to use the excellent Java Topology Suite (JTS). The standard Java2D library also provides the Area class which can be used for some constructive area geometry operations. Note that there is a utility class PolygonConverter that can quickly convert KPolygons to JTS polygons and vice versa.

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/*
 * Copyright (c) 2008, Keith Woodward
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of Keith Woodward nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */
package straightedge.geom.vision;

import straightedge.geom.*;
import java.util.*;

public class VisionData{
	// The inputs to the VisionFinder.calc method
	public KPoint eye;
	public KPolygon boundaryPolygon;

	// The last calculated results of the VisionFinder.calc method
	public ArrayList visiblePoints;
	public KPolygon visiblePolygon;

	// These are some variables that can be re-used to prevent excess garbage for the garbage collector.
	// Note that these values can be re-used when the eye and the boundaryPolygon are
	// translated by the same coordinates.
	// Otherwise these variables need to be re-initialised by calling reset()
	// before this VisionData is passed to the VisibilityFinder.calc method.
	public int[] boundaryPolygonXIndicators;
	public int[] boundaryPolygonYIndicators;
	public double maxEyeToBoundaryPolygonPointDist = -1;
	public double minEyeToBoundaryPolygonPointDist = Double.MAX_VALUE;
	public double maxEyeToBoundaryPolygonPointDistSq = -1;
	public double minEyeToBoundaryPolygonPointDistSq = Double.MAX_VALUE;
	//public double[] boundaryPolygonPointAngles;

	protected VisionData(){
	}

	public VisionData(KPoint eye, KPolygon boundaryPolygon){
		reset(eye, boundaryPolygon);
	}
	public void reset(KPoint eye, KPolygon boundaryPolygon){
		this.eye = eye;
		this.boundaryPolygon = boundaryPolygon;
		visiblePoints = null;
		visiblePolygon = null;

		ArrayList boundaryPolygonPoints = boundaryPolygon.getPoints();
//		if (boundaryPolygonPointAngles == null || boundaryPolygonPointAngles.length != boundaryPolygonPoints.size()){
//			boundaryPolygonPointAngles = new double[boundaryPolygonPoints.size()];
//		}
		//sightPolygonPointToEyeDists = new float[points.size()];
		for (int i = 0; i < boundaryPolygonPoints.size(); i++){
			int iPlus = (i+1 >= boundaryPolygonPoints.size() ? 0 : i+1);
			double distSq = eye.distanceSq(boundaryPolygonPoints.get(i));
			//sightPolygonPointToEyeDists[i] = dist;
			if (distSq > maxEyeToBoundaryPolygonPointDistSq){
				maxEyeToBoundaryPolygonPointDistSq = distSq;
			}
			double ptSegDistSq = eye.ptSegDistSq(boundaryPolygonPoints.get(i), boundaryPolygonPoints.get(iPlus));
			if (ptSegDistSq < minEyeToBoundaryPolygonPointDistSq){
				minEyeToBoundaryPolygonPointDistSq = ptSegDistSq;
			}
			//boundaryPolygonPointAngles[i] = eye.findAngle(boundaryPolygonPoints.get(i));
		}
		maxEyeToBoundaryPolygonPointDist = Math.sqrt(maxEyeToBoundaryPolygonPointDistSq);
		minEyeToBoundaryPolygonPointDist = Math.sqrt(minEyeToBoundaryPolygonPointDistSq);
		if (boundaryPolygonXIndicators == null || boundaryPolygonXIndicators.length != boundaryPolygonPoints.size()){
			boundaryPolygonXIndicators = new int[boundaryPolygonPoints.size()];
		}
		if (boundaryPolygonYIndicators == null || boundaryPolygonYIndicators.length != boundaryPolygonPoints.size()){
			boundaryPolygonYIndicators = new int[boundaryPolygonPoints.size()];
		}
	}

	public void reset(){
		reset(eye, boundaryPolygon);
	}

	public KPolygon getBoundaryPolygon() {
		return boundaryPolygon;
	}

	public KPoint getEye() {
		return eye;
	}

	public ArrayList getVisiblePoints() {
		return visiblePoints;
	}

	public KPolygon getVisiblePolygon() {
		return visiblePolygon;
	}

	public ArrayList getVisibleOccluders(){
		// Add any occluders that are visible into a list by searching for them in the VisionData's VisiblePoints.
		ArrayList visibleOccluders = new ArrayList();
		for (int i = 0; i < visiblePoints.size(); i++){
			VisiblePoint vp = visiblePoints.get(i);
			if (vp.getType() == VisiblePoint.OCCLUDER){
				VPOccluder vpo = (VPOccluder)vp;
				Occluder occluder = vpo.getOccluder();
				if (visibleOccluders.contains(occluder) == false){
					visibleOccluders.add(occluder);
				}
			}else if (vp.getType() == VisiblePoint.OCCLUDER_OCCLUDER_INTERSECTION){
				VPOccluderOccluderIntersection vpo = (VPOccluderOccluderIntersection)vp;
				Occluder occluder = vpo.getOccluder();
				if (visibleOccluders.contains(occluder) == false){
					visibleOccluders.add(occluder);
				}
				Occluder occluder2 = vpo.getOccluder2();
				if (visibleOccluders.contains(occluder2) == false){
					visibleOccluders.add(occluder2);
				}
			}else if (vp.getType() == VisiblePoint.OCCLUDER_BOUNDARY_INTERSECTION){
				VPOccluderBoundaryIntersection vpo = (VPOccluderBoundaryIntersection)vp;
				Occluder occluder = vpo.getOccluder();
				if (visibleOccluders.contains(occluder) == false){
					visibleOccluders.add(occluder);
				}
			}else if (vp.getType() == VisiblePoint.SHADOW_ON_OCCLUDER){
				VPShadowOnOccluder vpo = (VPShadowOnOccluder)vp;
				Occluder occluder = vpo.getOccluder();
				if (visibleOccluders.contains(occluder) == false){
					visibleOccluders.add(occluder);
				}
			}
		}
		return visibleOccluders;
	}
}