检查矩形是否与文本相交 [英] Checking if a rectangle intersects text
问题描述
我有一个名为"MapObject"的类，该类可让您定义它的用途.我最近在此添加了文本，但是它可以正常工作，但是碰撞是一个矩形，在某些情况下并不可怕，但是我更希望有一个与文本匹配的碰撞盒(也就是检查1x1矩形是否与文字，但仍可以在字母之间)
I have a class called 'MapObject' which allows you to define what it is, what it does. I have recently added text to this, and it works fine however the collisions is a rectangle, which in some scenarios isn't horrible, however I would prefer to have a collision box matching the text (aka check if a 1x1 rectangle collides with the text but can still be inbetween letters)
我尝试了以下操作:
GlyphVector vec = ob.font.createGlyphVector(new Canvas().getFontMetrics(ob.font).getFontRenderContext(), ob.text);
Shape textSh = vec.getOutline();
Area obSh = new Area(new Rectangle(x,y,o.width,o.height));
obSh.intersect(new Area(textSh));
boolean inter = !obSh.isEmpty();
但是，由于位置原因，我认为它不起作用，但是我不知道如何在其中添加位置. 谢谢.
However it just doesn't work, I imagine because of the location, however I don't know how to add a location into it. Thanks.
推荐答案
您可能需要做的一件事是将GlyphVector或Rectangle转换为正确的上下文.
One of the things you probably need to do is translate either the GlyphVector or Rectangle to the correct context.
我的意思是，GlyphVector仅代表原点0x0上的文本，因此，如果文本显示在屏幕上的其他位置，那么您将无法获得正确的表示形式.
What I mean is, the GlyphVector only represents the text at a origin point of 0x0, so if the text is displayed somewhere else on the screen, then you're not getting the correct representation.
幸运的是，实际上有人想到了这个用例，并提供了一些功能来做到这一点.参见
Luckily, someone actually thought about this use case and provided some functionality to do it. See GlyphVector#getOutline(float, float) for more details.
然后您可以使用类似...
You could then use it something like...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.font.FontRenderContext;
import java.awt.font.GlyphVector;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private List<Rectangle> boxes;
private Map<Rectangle, Point> vectors;
public TestPane() {
boxes = new ArrayList<>(25);
vectors = new HashMap<>(25);
Random random = new Random();
for (int index = 0; index < 10; index++) {
int x = random.nextInt(400 - 10);
int y = random.nextInt(400 - 10);
Rectangle box = new Rectangle(x, y, 10, 10);
boxes.add(box);
int xDelta = random.nextBoolean() ? 1 : -1;
int yDelta = random.nextBoolean() ? 1 : -1;
vectors.put(box, new Point(xDelta, yDelta));
}
Timer timer = new Timer(40, new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
for (Rectangle box : boxes) {
Point delta = vectors.get(box);
if (delta == null) {
int xDelta = random.nextBoolean() ? 1 : -1;
int yDelta = random.nextBoolean() ? 1 : -1;
delta = new Point(xDelta, yDelta);
}
int x = box.x + delta.x;
int y = box.y + delta.y;
if (x < 0) {
x = 0;
delta.x *= -1;
} else if (x + box.width > getWidth()) {
x = getWidth() - box.width;
delta.x *= -1;
}
if (y < 0) {
y = 0;
delta.y *= -1;
} else if (y + box.height > getHeight()) {
y = getHeight() - box.height;
delta.y *= -1;
}
box.setLocation(x, y);
vectors.put(box, delta);
}
repaint();
}
});
timer.start();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 200);
}
protected Shape getTextShape() {
Graphics2D g2d = (Graphics2D) getGraphics();
if (g2d == null) {
return null;
}
Font font = new Font("Arial", Font.BOLD, 48);
g2d.setFont(font);
FontRenderContext frc = g2d.getFontRenderContext();
GlyphVector gv = font.createGlyphVector(frc, "Cats with hats");
Rectangle2D box = gv.getVisualBounds();
// Calclate the location of the text and offset the glyph shape...
float x = (float) (getWidth() - box.getWidth()) / 2f;
float y = (float) (((getHeight() - box.getHeight()) / 2f) + (-box.getY()));
return gv.getOutline(x, y);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
Shape shape = getTextShape();
g2d.setColor(Color.BLACK);
g2d.fill(shape);
g2d.setColor(Color.RED);
g2d.draw(shape);
for (Rectangle box : boxes) {
g2d.setColor(Color.BLACK);
if (shape.intersects(box)) {
g2d.setColor(Color.RED);
}
g2d.draw(box);
}
}
}
}
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