私は、ユーザー Andrew Thompson によって提供された次の例から作業しています ->複雑な形状の衝突検出
メソッド 'draw' のプログラム (以下のコード) でこれを実装しようとしましたが、何らかの理由で、正方形の色を「赤」に変更するステートメントが true として評価されず、理由がわかりません。この時点でほとんどすべてを試しましたが、Andrew からのさらなる助けがなければ、三角形の群れが正方形と接触すると正方形の色が赤に変わるように、このコードを正しく実装することができないようです。
すべてのヘルプが大歓迎です（以下のコード）：
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.geom.*;
import static java.lang.Math.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.*;
import javax.swing.Timer;
public class Boids extends JPanel {
Flock flock;
Flock flock2;
final int w, h;
public Boids() {
w = 1200;
h = 600;
setPreferredSize(new Dimension(w, h));
setBackground(Color.black);
spawnFlock();
new Timer(17, (ActionEvent e) -> {
if (flock.hasLeftTheBuilding(w))
spawnFlock();
repaint();
}).start();
}
public void spawnFlock() {
Random rand = new Random();
int n = rand.nextInt(599) + 1;
flock = Flock.spawn(100, h - n, 20);
}
@Override
public void paintComponent(Graphics gg) {
super.paintComponent(gg);
Graphics2D g = (Graphics2D) gg;
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
flock.run(g, w, h);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setTitle("Simulator v0.6");
f.setResizable(false);
f.add(new Boids(), BorderLayout.CENTER);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
});
}
}
class Boid {
static final Random r = new Random();
static final Vec migrate = new Vec(0.02, 0);
static final int size = 3;
final double maxForce, maxSpeed;
Vec location, velocity, acceleration;
private boolean included = true;
Boid(double x, double y) {
acceleration = new Vec();
velocity = new Vec(r.nextInt(3) + 1, r.nextInt(3) - 1);
location = new Vec(x, y);
maxSpeed = 3.0;
maxForce = 0.05;
}
void update() {
velocity.add(acceleration);
velocity.limit(maxSpeed);
location.add(velocity);
acceleration.mult(0);
}
void applyForce(Vec force) {
acceleration.add(force);
}
Vec seek(Vec target) {
Vec steer = Vec.sub(target, location);
steer.normalize();
steer.mult(maxSpeed);
steer.sub(velocity);
steer.limit(maxForce);
return steer;
}
void flock(Graphics2D g, List<Boid> boids) {
view(g, boids);
Vec rule1 = separation(boids);
Vec rule2 = alignment(boids);
Vec rule3 = cohesion(boids);
rule1.mult(2.5);
rule2.mult(1.5);
rule3.mult(1.3);
applyForce(rule1);
applyForce(rule2);
applyForce(rule3);
applyForce(migrate);
}
public boolean doAreasCollide(Area area1, Area area2) {
boolean collide = false;
Area collide1 = new Area(area1);
collide1.subtract(area2);
if (!collide1.equals(area1)) {
collide = true;
}
Area collide2 = new Area(area2);
collide2.subtract(area1);
if (!collide2.equals(area2)) {
collide = true;
}
return collide;
}
void view(Graphics2D g, List<Boid> boids) {
double sightDistance = 100;
double peripheryAngle = PI * 0.85;
for (Boid b : boids) {
b.included = false;
if (b == this)
continue;
double d = Vec.dist(location, b.location);
if (d <= 0 || d > sightDistance)
continue;
Vec lineOfSight = Vec.sub(b.location, location);
double angle = Vec.angleBetween(lineOfSight, velocity);
if (angle < peripheryAngle)
b.included = true;
}
}
Vec separation(List<Boid> boids) {
double desiredSeparation = 25;
Vec steer = new Vec(0, 0);
int count = 0;
for (Boid b : boids) {
if (!b.included)
continue;
double d = Vec.dist(location, b.location);
if ((d > 0) && (d < desiredSeparation)) {
Vec diff = Vec.sub(location, b.location);
diff.normalize();
diff.div(d); // weight by distance
steer.add(diff);
count++;
}
}
if (count > 0) {
steer.div(count);
}
if (steer.mag() > 0) {
steer.normalize();
steer.mult(maxSpeed);
steer.sub(velocity);
steer.limit(maxForce);
return steer;
}
return new Vec(0, 0);
}
Vec alignment(List<Boid> boids) {
double preferredDist = 50;
Vec steer = new Vec(0, 0);
int count = 0;
for (Boid b : boids) {
if (!b.included)
continue;
double d = Vec.dist(location, b.location);
if ((d > 0) && (d < preferredDist)) {
steer.add(b.velocity);
count++;
}
}
if (count > 0) {
steer.div(count);
steer.normalize();
steer.mult(maxSpeed);
steer.sub(velocity);
steer.limit(maxForce);
}
return steer;
}
Vec cohesion(List<Boid> boids) {
double preferredDist = 50;
Vec target = new Vec(0, 0);
int count = 0;
for (Boid b : boids) {
if (!b.included)
continue;
double d = Vec.dist(location, b.location);
if ((d > 0) && (d < preferredDist)) {
target.add(b.location);
count++;
}
}
if (count > 0) {
target.div(count);
return seek(target);
}
return target;
}
void draw(Graphics2D g) {
AffineTransform save = g.getTransform();
int[] xTriangle = {33,36,34};
int[] yTriangle = {30,30,20};
Area triangle = new Area(new Polygon(xTriangle, yTriangle, 3));
g.translate(location.x, location.y);
g.rotate(velocity.heading() + PI / 2);
g.setColor(Color.green);
// g.fill(shape);
g.setColor(Color.green);
g.draw(triangle);
g.fill(triangle);
g.setTransform(save);
Area square = new Area(new Rectangle(600,250,200,200));
g.draw(square);
if (doAreasCollide(square, triangle)) {
g.setColor(Color.RED);
System.out.println("Collision");
} else {
g.setColor(Color.GREEN);
System.out.println("noCollision");
}
g.fill(square);
}
public void run(Graphics2D g, List<Boid> boids, int w, int h) {
flock(g, boids);
update();
draw(g);
}
}
class Flock {
List<Boid> boids;
Flock() {
boids = new ArrayList<>();
}
void run(Graphics2D g, int w, int h) {
for (Boid b : boids) {
b.run(g, boids, w, h);
}
}
boolean hasLeftTheBuilding(int w) {
int count = 0;
for (Boid b : boids) {
if (b.location.x + Boid.size > w)
count++;
}
return boids.size() == count;
}
void addBoid(Boid b) {
boids.add(b);
}
static Flock spawn(double w, double h, int numBoids) {
Flock flock = new Flock();
for (int i = 0; i < numBoids; i++)
flock.addBoid(new Boid(w, h));
return flock;
}
}
class Vec {
double x, y;
Vec() {
}
Vec(double x, double y) {
this.x = x;
this.y = y;
}
void add(Vec v) {
x += v.x;
y += v.y;
}
void sub(Vec v) {
x -= v.x;
y -= v.y;
}
void div(double val) {
x /= val;
y /= val;
}
void mult(double val) {
x *= val;
y *= val;
}
double mag() {
return sqrt(pow(x, 2) + pow(y, 2));
}
double dot(Vec v) {
return x * v.x + y * v.y;
}
void normalize() {
double mag = mag();
if (mag != 0) {
x /= mag;
y /= mag;
}
}
void limit(double lim) {
double mag = mag();
if (mag != 0 && mag > lim) {
x *= lim / mag;
y *= lim / mag;
}
}
double heading() {
return atan2(y, x);
}
static Vec sub(Vec v, Vec v2) {
return new Vec(v.x - v2.x, v.y - v2.y);
}
static double dist(Vec v, Vec v2) {
return sqrt(pow(v.x - v2.x, 2) + pow(v.y - v2.y, 2));
}
static double angleBetween(Vec v, Vec v2) {
return acos(v.dot(v2) / (v.mag() * v2.mag()));
}
}