eu.mihosoft.vrl.v3d.Node Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jcsg Show documentation
Show all versions of jcsg Show documentation
Java implementation of BSP based CSG (Constructive Solid Geometry)
/**
* Node.java
*
* Copyright 2014-2014 Michael Hoffer . 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.
*
* THIS SOFTWARE IS PROVIDED BY Michael Hoffer "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 Michael Hoffer 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.
*
* The views and conclusions contained in the software and documentation are
* those of the authors and should not be interpreted as representing official
* policies, either expressed or implied, of Michael Hoffer
* .
*/
package eu.mihosoft.vrl.v3d;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Holds a node in a BSP tree. A BSP tree is built from a collection of polygons
* by picking a polygon to split along. That polygon (and all other coplanar
* polygons) are added directly to that node and the other polygons are added to
* the front and/or back subtrees. This is not a leafy BSP tree since there is
* no distinction between internal and leaf nodes.
*/
final class Node {
/**
* Polygons.
*/
private List polygons;
/**
* Plane used for BSP.
*/
private Plane plane;
/**
* Polygons in front of the plane.
*/
private Node front;
/**
* Polygons in back of the plane.
*/
private Node back;
/**
* Constructor.
*
* Creates a BSP node consisting of the specified polygons.
*
* @param polygons polygons
*/
public Node(List polygons) {
this.polygons = new ArrayList<>();
if (polygons != null) {
this.build(polygons);
}
}
/**
* Constructor. Creates a node without polygons.
*/
public Node() {
this(null);
}
@Override
public Node clone() {
Node node = new Node();
node.plane = this.plane == null ? null : this.plane.clone();
node.front = this.front == null ? null : this.front.clone();
node.back = this.back == null ? null : this.back.clone();
// node.polygons = new ArrayList<>();
// polygons.parallelStream().forEach((Polygon p) -> {
// node.polygons.add(p.clone());
// });
Stream polygonStream;
if (polygons.size() > 200) {
polygonStream = polygons.parallelStream();
} else {
polygonStream = polygons.stream();
}
node.polygons = polygonStream.
map(p -> p.clone()).collect(Collectors.toList());
return node;
}
/**
* Converts solid space to empty space and vice verca.
*/
public void invert() {
Stream polygonStream;
if (polygons.size() > 200) {
polygonStream = polygons.parallelStream();
} else {
polygonStream = polygons.stream();
}
polygonStream.forEach((polygon) -> {
polygon.flip();
});
if (this.plane == null && !polygons.isEmpty()) {
this.plane = polygons.get(0).plane.clone();
} else if (this.plane == null && polygons.isEmpty()) {
throw new RuntimeException("Please fix me! I don't know what to do?");
}
this.plane.flip();
if (this.front != null) {
this.front.invert();
}
if (this.back != null) {
this.back.invert();
}
Node temp = this.front;
this.front = this.back;
this.back = temp;
}
/**
* Recursively removes all polygons in the {@link polygons} list that are
* contained within this BSP tree.
*
* Note: polygons are splitted if necessary.
*
* @param polygons the polygons to clip
*
* @return the cliped list of polygons
*/
private List clipPolygons(List polygons) {
if (this.plane == null) {
return new ArrayList<>(polygons);
}
List frontP = new ArrayList<>();
List backP = new ArrayList<>();
for (Polygon polygon : polygons) {
this.plane.splitPolygon(polygon, frontP, backP, frontP, backP);
}
if (this.front != null) {
frontP = this.front.clipPolygons(frontP);
}
if (this.back != null) {
backP = this.back.clipPolygons(backP);
} else {
backP = new ArrayList<>(0);
}
frontP.addAll(backP);
return frontP;
}
// Remove all polygons in this BSP tree that are inside the other BSP tree
// `bsp`.
/**
* Removes all polygons in this BSP tree that are inside the specified BSP
* tree ({@code bsp}).
*
* Note: polygons are splitted if necessary.
*
* @param bsp bsp that shall be used for clipping
*/
public void clipTo(Node bsp) {
this.polygons = bsp.clipPolygons(this.polygons);
if (this.front != null) {
this.front.clipTo(bsp);
}
if (this.back != null) {
this.back.clipTo(bsp);
}
}
/**
* Returns a list of all polygons in this BSP tree.
*
* @return a list of all polygons in this BSP tree
*/
public List allPolygons() {
List localPolygons = new ArrayList<>(this.polygons);
if (this.front != null) {
localPolygons.addAll(this.front.allPolygons());
// polygons = Utils.concat(polygons, this.front.allPolygons());
}
if (this.back != null) {
// polygons = Utils.concat(polygons, this.back.allPolygons());
localPolygons.addAll(this.back.allPolygons());
}
return localPolygons;
}
/**
* Build a BSP tree out of {@code polygons}. When called on an existing
* tree, the new polygons are filtered down to the bottom of the tree and
* become new nodes there. Each set of polygons is partitioned using the
* first polygon (no heuristic is used to pick a good split).
*
* @param polygons polygons used to build the BSP
*/
public final void build(List polygons) {
if (polygons.isEmpty()) return;
if (this.plane == null) {
this.plane = polygons.get(0).plane.clone();
}
List frontP = new ArrayList<>();
List backP = new ArrayList<>();
// parellel version does not work here
polygons.forEach((polygon) -> {
this.plane.splitPolygon(
polygon, this.polygons, this.polygons, frontP, backP);
});
if (frontP.size() > 0) {
if (this.front == null) {
this.front = new Node();
}
this.front.build(frontP);
}
if (backP.size() > 0) {
if (this.back == null) {
this.back = new Node();
}
this.back.build(backP);
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy