如何正确对齐此文本？

Question

我今天写了这个极地时钟，我几乎完成了，除了我想在类似于 this。有谁知道该怎么做？我尝试使用 FontRenderContext 和字体指标，但我似乎无法让它工作。这是完整的源代码，您可以编译并亲自查看。

import java.applet.Applet;
import java.awt.AWTEvent;
import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.Toolkit;
import java.awt.font.FontRenderContext;
import java.awt.font.GlyphVector;
import java.awt.geom.AffineTransform;
import java.awt.geom.Arc2D;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.awt.image.WritableRaster;
import java.util.Calendar;
import java.util.TimeZone;

public class Clock extends Applet implements Runnable {

int[][] colorsInt = {{20,20,20},{100,100,50},{50,100,100},{10,170,50},{79,29,245},{24,69,234},{253,24,103}};
Color[] colors;
int size;
int radius;
boolean anitalias = false;
static final float HPI = (float)(Math.PI / 180f);

public void start() {
    enableEvents(AWTEvent.KEY_EVENT_MASK | AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK);
    new Thread(this).start();
}

public void run() {
    setSize(500, 500); // For AppletViewer, remove later.

    // Set up the graphics stuff, double-buffering.
    BufferedImage screen = new BufferedImage(800, 600, BufferedImage.TYPE_INT_RGB);
    Graphics2D g = (Graphics2D)screen.getGraphics();

    g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    WritableRaster wr = screen.getRaster();
    Graphics appletGraphics = getGraphics();

    // Some variables to use for the fps.
    long fpstn = 1000000000 / 600;
    int tick = 0, fps = 0, acc = 0;
    long lastTime = System.nanoTime();

    // Vars
    Calendar c;
    size = 500;
    radius = size / 2;
    Arc2D.Float arch;
    float scale, radians;
    long miliSecond;
    int second, minute, hour, month, year, dayOfWeek, dayOfMonth, dayOfYear, daysInMonth, daysInYear;
    float[] tvars = new float[6];
    float[] vars = new float[6];
    String[] names = new String[6];
    FontMetrics fm = g.getFontMetrics();
    Font font = g.getFont();
    FontRenderContext frc = g.getFontRenderContext();
    GlyphVector gv = font.createGlyphVector(frc, "Hello world");
    int length = gv.getNumGlyphs();

    // Init
    initColors();
    for (int i = 0; i < vars.length; i++)
        vars[i] = 0;

    // Game loop.
    while (true) {
        long now = System.nanoTime();
        acc += now - lastTime;
        tick++;
        if (acc >= 1000000000L) {
            acc -= 1000000000L;
            fps = tick;
            tick = 0;
        }

        // Update
        c = Calendar.getInstance();
        miliSecond = c.get(Calendar.MILLISECOND);
        second = c.get(Calendar.SECOND);
        minute = c.get(Calendar.MINUTE);
        hour = c.get(Calendar.HOUR_OF_DAY);
        dayOfMonth = c.get(Calendar.DAY_OF_MONTH);
        dayOfYear = c.get(Calendar.DAY_OF_YEAR);
        dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
        month = c.get(Calendar.MONTH);
        daysInMonth = c.getActualMaximum(Calendar.DAY_OF_MONTH);
        daysInYear = c.getActualMaximum(Calendar.DAY_OF_YEAR);

        tvars[0] = (second * 1000 + miliSecond) / 60000f * 360f;
        tvars[1] = (minute * 60f + second) / 3600f * 360f;
        tvars[2] = (hour * 60f + minute) / 1440f * 360f;
        tvars[3] = ((dayOfWeek - 2) * 24f + hour) / 168f * 360f;
        tvars[4] = ((dayOfMonth - 1) * 24f + hour) / (daysInMonth * 24f) * 360f;
        tvars[5] = dayOfYear / (float)daysInYear * 360f;

        for (int i = 0; i < vars.length; i++) {
            if (tvars[i] - vars[i] > 1) {
                vars[i] += (tvars[i] - vars[i]) / 15;
            } else if(tvars[i] - vars[i] < -1) {
                vars[i] -= (vars[i] - tvars[i]) / 15;
            } else {
                vars[i] = tvars[i];
            }
        }

        names[0] = second + " Second" + (second > 1 ? "s" : "");

        lastTime = now;

        // Render
        g.setColor(colors[0]);
        g.fillRect(0, 0, size, size);
        for (int i = 0; i < vars.length; i++) {

            scale = i / (float)vars.length * radius * 1.7f;
            g.setColor(colors[0]);
            g.fillOval((int)(scale / 2), (int)(scale / 2), (int)(size - scale), (int)(size - scale));
            g.setColor(colors[i + 1]);
            scale += 15;
            arch = new Arc2D.Float(scale / 2, scale / 2, size - scale, size - scale, 450 - vars[i], vars[i], Arc2D.PIE);
            g.fill(arch);

            g.setColor(Color.WHITE);
            radians = (vars[i]) * HPI;// vars[i] - 90
            scale = ((float)(vars.length - i) / (float)vars.length * (float)radius / 2f * 1.7f) + 15f;

            g.translate(radius, radius);
            System.out.println(i + ": " + ((1 - scale / radius) * 2));
            for (int j = 0; j < names[0].length(); j++) {

                char ch = names[0].charAt(j);
                radians = ((vars[i] - (names[0].length() - j) * 2) * (1 + (1 - scale / radius) * 2)) * HPI;
                g.rotate(radians);
                g.drawString(ch + "", 0, -scale);
                g.rotate(-radians);
            }
            g.translate(-radius, -radius);

            /*float x = (float)Math.cos(radians) * scale;
            float y = (float)Math.sin(radians) * (vars.length - i) / vars.length * radius / 2 * 1.7f;
            g.drawRect((int)x + size / 2, (int)y + size / 2, 10, 10);*/

        }
        scale = vars.length / (float)vars.length * radius * 1.7f;
        g.setColor(colors[0]);
        g.fillOval((int)(scale / 2), (int)(scale / 2), (int)(size - scale), (int)(size - scale));

        g.setColor(Color.WHITE);
        g.drawString("FPS " + String.valueOf(fps), 20, 30);

        // Draw the entire results on the screen.
        appletGraphics.drawImage(screen, 0, 0, null);

        do {
            Thread.yield();
        } while (System.nanoTime() - lastTime < 0);
        if (!isActive()) {
            return;
        }
    }
}

public void initColors() {
    colors = new Color[colorsInt.length];
    for (int i = 0; i < colors.length; i++) {
        colors[i] = new Color(colorsInt[i][0], colorsInt[i][1], colorsInt[i][2]);
    }
}

}

Answer 1

这是旋转文本的简单示例。

附录：您需要通过 stringWidth(name[n]) 调整文本的径向起点。您的程序似乎正在旋转各个字符以努力遵循圆弧，而该示例似乎正在以与圆弧相切的直线绘制文本。后一种方法可能更简单。例如，此变体使标签在弧的 getStartPoint() 上居中：

for (int i = 0; i < vars.length; i++) {
    ...
    String s = names[0];
    int w = fm.stringWidth(s);
    int h = fm.getHeight() + fm.getMaxDescent();
    Point2D p = arch.getStartPoint();
    int x = (int) p.getX();
    int y = (int) p.getY();
    radians = (vars[i]) * HPI;
    g.rotate(radians, x, y);
    g.drawString(s, x - w / 2, y + h);
    g.rotate(-radians, x, y);
}

为了方便起见，上面的代码会来回旋转rotate()；为了进行比较，以下是显示 rotate() 重复串联的原始示例：

import java.awt.*;
import java.awt.geom.AffineTransform;
import javax.swing.*;

/** @see http://stackoverflow.com/questions/6238037 */
public class RotateText extends JPanel {

    private static final Font f = new Font("Serif", Font.BOLD, 32);
    private static final String s = "Hello World!";
    private static final Color[] colors = {
        Color.red, Color.green, Color.blue, Color.cyan
    };
    private Graphics2D g2d;
    private AffineTransform at;

    public RotateText() {
        setPreferredSize(new Dimension(400, 400));
    }

    @Override
    public void paintComponent(Graphics g) {
        g2d = (Graphics2D) g;
        g2d.setFont(f);
        g2d.setColor(Color.black);
        g2d.fillRect(0, 0, getWidth(), getHeight());
        at = g2d.getTransform();
        int w = this.getWidth();
        int h = this.getHeight();
        int w2 = g2d.getFontMetrics().stringWidth(s) / 2;
        int h2 = 2 * g2d.getFontMetrics().getHeight() / 3;
        render(0, w / 2 - w2, h - h2);
        render(1, h2, h / 2 - w2);
        render(2, w / 2 + w2, h2);
        render(3, w - h2, h / 2 + w2);
        g2d.setTransform(at);
        g2d.setColor(Color.yellow);
        g2d.fillRect(w / 3, h / 3, w / 3, h / 3);
    }

    private void render(int n, int x, int y) {
        g2d.setColor(colors[n]);
        g2d.setTransform(at);
        g2d.rotate(n * Math.PI / 2, x, y);
        g2d.drawString(s, x, y);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            //@Override
            public void run() {
                JFrame f = new JFrame();
                f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                f.add(new RotateText(), BorderLayout.CENTER);
                f.pack();
                f.setVisible(true);
            }
        });
    }
}

Answer 2

您必须能够沿着曲线绘制文本。有多种方法可以做到这一点，但最简单的一种是使用 中风API。您可以在 http://www.jhlabs.com/java/java2d/lines/ 找到示例

另一种方法是使用仿射变换。该示例位于 http://www.java2s.com/Code /Java/2D-Graphics-GUI/Drawtextalongacurve.htm