com.almasb.fxgl.physics.HitBox Maven / Gradle / Ivy
/*
* FXGL - JavaFX Game Library. The MIT License (MIT).
* Copyright (c) AlmasB ([email protected]).
* See LICENSE for details.
*/
package com.almasb.fxgl.physics;
import com.almasb.fxgl.entity.components.TransformComponent;
import com.almasb.fxgl.physics.box2d.collision.shapes.ShapeType;
import javafx.beans.binding.Bindings;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.geometry.BoundingBox;
import javafx.geometry.Bounds;
import javafx.geometry.Dimension2D;
import javafx.geometry.Point2D;
import java.io.IOException;
import java.io.Serializable;
/**
* A bounding collision box.
*
* @author Almas Baimagambetov (AlmasB) ([email protected])
*/
public final class HitBox implements Serializable {
/**
* Name of this hit box.
*/
private String name;
/**
* Shape of this hit box.
*/
private BoundingShape shape;
/**
* Bounding box (computed from shape) of this hit box.
*/
private Bounds bounds;
/**
* Creates a hit box with the given shape.
* The name of the {@code {@link HitBox}} will be auto generated
* based upon the {@code hashCode} of the given {@code {@link BoundingShape}}.
*
* @param shape bounding shape
*/
public HitBox(BoundingShape shape) {
this(String.valueOf(shape.hashCode()), shape);
}
/**
* Creates a hit box with the given local origin and shape.
* The name of the {@code {@link HitBox}} will be auto generated
* based upon the {@code hashCode} of the given {@code {@link BoundingShape}}.
*
* @param localOrigin origin of hit box
* @param shape bounding shape
*/
public HitBox(Point2D localOrigin, BoundingShape shape){
this(String.valueOf(shape.hashCode()), localOrigin, shape);
}
/**
* Creates a hit box with given name and shape.
* Local origin is set to default (0, 0).
*
* @param name name of the hit box
* @param shape bounding shape
*/
public HitBox(String name, BoundingShape shape) {
this(name, Point2D.ZERO, shape);
}
/**
* Creates a hit box with given name, local origin (top-left) and shape.
*
* @param name name of the hit box
* @param localOrigin origin of hit box
* @param shape bounding shape
*/
public HitBox(String name, Point2D localOrigin, BoundingShape shape) {
this.name = name;
this.shape = shape;
this.bounds = new BoundingBox(localOrigin.getX(), localOrigin.getY(),
shape.getSize().getWidth(), shape.getSize().getHeight());
}
private void writeObject(java.io.ObjectOutputStream out) throws IOException {
out.writeObject(name);
out.writeDouble(bounds.getMinX());
out.writeDouble(bounds.getMinY());
out.writeDouble(bounds.getWidth());
out.writeDouble(bounds.getHeight());
out.writeDouble(shape.size.getWidth());
out.writeDouble(shape.size.getHeight());
out.writeObject(shape.type);
if (shape.type == ShapeType.CHAIN) {
Point2D[] points = (Point2D[]) shape.data;
out.writeInt(points.length);
for (Point2D p : points) {
out.writeDouble(p.getX());
out.writeDouble(p.getY());
}
}
}
private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
name = (String) in.readObject();
bounds = new BoundingBox(in.readDouble(), in.readDouble(), in.readDouble(), in.readDouble());
Dimension2D size = new Dimension2D(in.readDouble(), in.readDouble());
ShapeType type = (ShapeType) in.readObject();
switch (type) {
case CIRCLE:
shape = BoundingShape.circle(size.getWidth() / 2);
break;
case POLYGON:
shape = BoundingShape.box(size.getWidth(), size.getHeight());
break;
case CHAIN:
int length = in.readInt();
Point2D[] points = new Point2D[length];
for (int i = 0; i < length; i++) {
points[i] = new Point2D(in.readDouble(), in.readDouble());
}
shape = BoundingShape.chain(points);
break;
default:
throw new IllegalArgumentException("Unknown shape type");
}
}
/**
* @return bounds
*/
public Bounds getBounds() {
return bounds;
}
/**
* @return hit box shape
*/
public BoundingShape getShape() {
return shape;
}
/**
* @return min x
*/
public double getMinX() {
return bounds.getMinX();
}
/**
* @return min y
*/
public double getMinY() {
return bounds.getMinY();
}
/**
* @return maxX of internal bounds (x + width)
*/
public double getMaxX() {
return bounds.getMaxX();
}
/**
* @return maxY of internal bounds (y + height)
*/
public double getMaxY() {
return bounds.getMaxY();
}
/**
* @return width of this hit box
*/
public double getWidth() {
return bounds.getWidth();
}
/**
* @return height of this hit box
*/
public double getHeight() {
return bounds.getHeight();
}
/**
* @return hit box name
*/
public String getName() {
return name;
}
/*
* These are lazily evaluated and used for caching
* bbox data in the world coord space.
* Otherwise these would have to be recomputed every time
* this hit box is used for collision detection.
*/
private transient DoubleProperty minXWorld = new SimpleDoubleProperty();
private transient DoubleProperty maxXWorld = new SimpleDoubleProperty();
private transient DoubleProperty minYWorld = new SimpleDoubleProperty();
private transient DoubleProperty maxYWorld = new SimpleDoubleProperty();
/**
* Bind to x property of entity.
*/
public void bindXY(TransformComponent transform) {
// compute local min and max, then convert to world coord
// var minXWorldNew1 = center1.x - (center1.x - box1.minX) * transform1.scaleX + transform1.x;
// var maxXWorldNew1 = center1.x - (center1.x - box1.maxX) * transform1.scaleX + transform1.x;
var x1 = Bindings.createDoubleBinding(() ->
transform.getScaleOrigin().getX() - (transform.getScaleOrigin().getX() - getMinX()) * transform.getScaleX() + transform.getX(),
// dependencies
transform.scaleOriginXProperty(), transform.scaleXProperty(), transform.xProperty()
);
var x2 = Bindings.createDoubleBinding(() ->
transform.getScaleOrigin().getX() - (transform.getScaleOrigin().getX() - getMaxX()) * transform.getScaleX() + transform.getX(),
// dependencies
transform.scaleOriginXProperty(), transform.scaleXProperty(), transform.xProperty()
);
var y1 = Bindings.createDoubleBinding(() ->
transform.getScaleOrigin().getY() - (transform.getScaleOrigin().getY() - getMinY()) * transform.getScaleY() + transform.getY(),
// dependencies
transform.scaleOriginYProperty(), transform.scaleYProperty(), transform.yProperty()
);
var y2 = Bindings.createDoubleBinding(() ->
transform.getScaleOrigin().getY() - (transform.getScaleOrigin().getY() - getMaxY()) * transform.getScaleY() + transform.getY(),
// dependencies
transform.scaleOriginYProperty(), transform.scaleYProperty(), transform.yProperty()
);
minXWorld.bind(
Bindings.when(x1.greaterThan(x2)).then(x2).otherwise(x1)
);
maxXWorld.bind(
Bindings.when(x1.greaterThan(x2)).then(x1).otherwise(x2)
);
minYWorld.bind(
Bindings.when(y1.greaterThan(y2)).then(y2).otherwise(y1)
);
maxYWorld.bind(
Bindings.when(y1.greaterThan(y2)).then(y1).otherwise(y2)
);
}
/**
* Unbind the hit box.
*/
public void unbind() {
minXWorld.unbind();
maxXWorld.unbind();
minYWorld.unbind();
maxYWorld.unbind();
}
public double getMinXWorld() {
return minXWorld.get();
}
public double getMaxXWorld() {
return maxXWorld.get();
}
public double getMinYWorld() {
return minYWorld.get();
}
public double getMaxYWorld() {
return maxYWorld.get();
}
/**
* @return center point of this hit box, local to 0,0 (top,left) of the entity
*/
public Point2D centerLocal() {
return new Point2D((bounds.getMinX() + bounds.getMaxX()) / 2,
(bounds.getMinY() + bounds.getMaxY()) / 2);
}
/**
* @param x position x of entity
* @param y position y of entity
* @return center point of this hit box in world coordinates
*/
public Point2D centerWorld(double x, double y) {
return centerLocal().add(x, y);
}
public HitBox copy() {
return new HitBox(name, new Point2D(bounds.getMinX(), bounds.getMinY()), shape);
}
@Override
public String toString() {
return "HitBox(" + name + "," + shape + ")";
}
}
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