praktikum-holons/src/holeg/utility/math/vector/Geometry.java

package holeg.utility.math.vector;

import holeg.utility.math.Maths;

import java.awt.*;
import java.util.Optional;

import static holeg.utility.math.Maths.EPSILON;

public class Geometry {
    public static Rectangle createRectangleFromCorners(Vec2i corner, Vec2i otherCorner){
        //Calculate left top corner, width, height
        Vec2i topLeft = new Vec2i(Math.min(corner.getX(), otherCorner.getX()), Math.min(corner.getY(), otherCorner.getY()));
        Vec2i bottomRight = new Vec2i(Math.max(corner.getX(), otherCorner.getX()), Math.max(corner.getY(), otherCorner.getY()));
        int width = bottomRight.getX() - topLeft.getX();
        int height = bottomRight.getY() - topLeft.getY();
        return new Rectangle(topLeft.getX(),topLeft.getY(), width, height);
    }

    public static Optional<Vec2f> getProjectionOnSegmentIfInRange(Line line , Circle circle){
        float lineLengthSqr = line.distanceSqr();
        if(lineLengthSqr < EPSILON) {
            if(line.p1.getSquaredDistance(circle.position) < circle.radius * circle.radius){
                return Optional.of(new Vec2f(line.p1));
            }else{
                return Optional.empty();
            }
        }
        Vec2f p2p1 = line.p2.subtract(line.p1);
        float t = Maths.Clamp(Vec2f.dot(circle.position.subtract(line.p1), p2p1) / lineLengthSqr, 0.0f, 1.0f);
        Vec2f projection = line.p1.add(p2p1.multiply(t));
        if(projection.getSquaredDistance(circle.position) < circle.radius * circle.radius){
            return Optional.of(projection);
        }else{
            return Optional.empty();
        }
    }

    public static class Circle{
        public Vec2f position;
        public float radius;
        public Circle(Vec2f position, float radius){
            this.position = position;
            this.radius = radius;
        }
    }

    public static class Line{
        Vec2f p1;
        Vec2f p2;
        public Line(Vec2f p1, Vec2f p2){
            this.p1 = p1;
            this.p2 = p2;
        }
        float distanceSqr(){
            return p1.getSquaredDistance(p2);
        }
    }
}