Java Swing Tips: Path2D

Showing posts with label Path2D. Show all posts

2024/10/31

Move and rotate strings to place them along the Shape curve

Code

public static Shape createTextOnPath(Shape shape, GlyphVector gv) {
  double[] points = new double[6];
  Point2D prevPt = new Point2D.Double();
  double nextAdvance = 0d;
  double next = 0d;
  Path2D result = new Path2D.Double();
  int length = gv.getNumGlyphs();
  int idx = 0;
  PathIterator pi = new FlatteningPathIterator(
      shape.getPathIterator(null), 1d);
  while (idx < length && !pi.isDone()) {
    switch (pi.currentSegment(points)) {
      case PathIterator.SEG_MOVETO:
        result.moveTo(points[0], points[1]);
        prevPt.setLocation(points[0], points[1]);
        nextAdvance = gv.getGlyphMetrics(idx).getAdvance() * .5;
        next = nextAdvance;
        break;

      case PathIterator.SEG_LINETO:
        double dx = points[0] - prevPt.getX();
        double dy = points[1] - prevPt.getY();
        double distance = Math.hypot(dx, dy);
        if (distance >= next) {
          double r = 1d / distance;
          double angle = Math.atan2(dy, dx);
          while (idx < length && distance >= next) {
            double x = prevPt.getX() + next * dx * r;
            double y = prevPt.getY() + next * dy * r;
            double advance = nextAdvance;
            nextAdvance = getNextAdvance(gv, idx, length);
            AffineTransform at = AffineTransform.getTranslateInstance(x, y);
            at.rotate(angle);
            Point2D pt = gv.getGlyphPosition(idx);
            at.translate(-pt.getX() - advance, -pt.getY());
            Shape s = gv.getGlyphOutline(idx);
            result.append(at.createTransformedShape(s), false);
            next += advance + nextAdvance;
            idx++;
          }
        }
        next -= distance;
        prevPt.setLocation(points[0], points[1]);
        break;

      default:
    }
    pi.next();
  }
  return result;
}

References

Fun with Java2D - Strokes

ShapeStroke.java

Move and rotate strings to place them along the Shape curve(Japanese)

2024/05/31

Rounding the corners of a rectilinear polygon generated by node selection in a JTree

Code

public static List<Point2D> flatteningStepsOnRightSide(
    List<Point2D> list, double arc) {
  int sz = list.size();
  for (int i = 0; i < sz; i++) {
    int i1 = (i + 1) % sz;
    int i2 = (i + 2) % sz;
    int i3 = (i + 3) % sz;
    Point2D pt0 = list.get(i);
    Point2D pt1 = list.get(i1);
    Point2D pt2 = list.get(i2);
    Point2D pt3 = list.get(i3);
    double dx1 = pt2.getX() - pt1.getX();
    if (Math.abs(dx1) > 1.0e-1 && Math.abs(dx1) < arc) {
      double max = Math.max(pt0.getX(), pt2.getX());
      replace(list, i, max, pt0.getY());
      replace(list, i1, max, pt1.getY());
      replace(list, i2, max, pt2.getY());
      replace(list, i3, max, pt3.getY());
    }
  }
  return list;
}

private static void replace(List<Point2D> list, int i, double x, double y) {
  list.remove(i);
  list.add(i, new Point2D.Double(x, y));
}

/**
 * Rounding the corners of a Rectilinear Polygon.
 */
public static Path2D convertRoundedPath(List<Point2D> list, double arc) {
  double kappa = 4d * (Math.sqrt(2d) - 1d) / 3d; // = 0.55228...;
  double akv = arc - arc * kappa;
  int sz = list.size();
  Point2D pt0 = list.get(0);
  Path2D path = new Path2D.Double();
  path.moveTo(pt0.getX() + arc, pt0.getY());
  for (int i = 0; i < sz; i++) {
    Point2D prv = list.get((i - 1 + sz) % sz);
    Point2D cur = list.get(i);
    Point2D nxt = list.get((i + 1) % sz);
    double dx0 = signum(cur.getX() - prv.getX(), arc);
    double dy0 = signum(cur.getY() - prv.getY(), arc);
    double dx1 = signum(nxt.getX() - cur.getX(), arc);
    double dy1 = signum(nxt.getY() - cur.getY(), arc);
    path.curveTo(
        cur.getX() - dx0 * akv, cur.getY() - dy0 * akv,
        cur.getX() + dx1 * akv, cur.getY() + dy1 * akv,
        cur.getX() + dx1 * arc, cur.getY() + dy1 * arc);
    path.lineTo(nxt.getX() - dx1 * arc, nxt.getY() - dy1 * arc);
  }
  path.closePath();
  return path;
}

private static double signum(double v, double arc) {
  return Math.abs(v) < arc ? 0d : Math.signum(v);
}

References

Rounding the corners of a rectilinear polygon generated by node selection in a JTree(Japanese)

2024/04/30

Rounding the corners of a rectilinear polygon generated by a selection of calendar made with JList

Code

public static Path2D convertRoundedPath(List<Point2D> list, double arc) {
  double kappa = 4d * (Math.sqrt(2d) - 1d) / 3d; // = 0.55228...;
  double akv = arc - arc * kappa;
  int sz = list.size();
  Point2D pt0 = list.get(0);
  Path2D path = new Path2D.Double();
  path.moveTo(pt0.getX() + arc, pt0.getY());
  for (int i = 0; i < sz; i++) {
    Point2D prv = list.get((i - 1 + sz) % sz);
    Point2D cur = list.get(i);
    Point2D nxt = list.get((i + 1) % sz);
    double dx0 = Math.signum(cur.getX() - prv.getX());
    double dy0 = Math.signum(cur.getY() - prv.getY());
    double dx1 = Math.signum(nxt.getX() - cur.getX());
    double dy1 = Math.signum(nxt.getY() - cur.getY());
    path.curveTo(
        cur.getX() - dx0 * akv, cur.getY() - dy0 * akv,
        cur.getX() + dx1 * akv, cur.getY() + dy1 * akv,
        cur.getX() + dx1 * arc, cur.getY() + dy1 * arc);
    path.lineTo(nxt.getX() - dx1 * arc, nxt.getY() - dy1 * arc);
  }
  path.closePath();
  return path;
}

References

Rounding the corners of a rectilinear polygon generated by a selection of calendar made with JList(Japanese)

2023/02/28

Draw a projection-transformed regular hexahedron wireframe in JPanel and rotate it in space by mouse dragging

Code

class Vertex {
  private double dx;
  private double dy;
  private double dz;
  public double vx;
  public double vy;

  protected Vertex(double dx, double dy, double dz) {
    this.dx = dx;
    this.dy = dy;
    this.dz = dz;
    projectionTransformation();
  }

  private void projectionTransformation() {
    double screenDistance = 500d;
    double depth = 1000d;
    double gz = dz + depth;
    this.vx = screenDistance * dx / gz;
    this.vy = screenDistance * dy / gz;
  }

  public void rotateTransformation(double kx, double ky, double kz) {
    double x0 = dx * Math.cos(ky) - dz * Math.sin(ky);
    double y0 = dy;
    double z0 = dx * Math.sin(ky) + dz * Math.cos(ky);
    double y1 = y0 * Math.cos(kx) - z0 * Math.sin(kx);
    double z1 = y0 * Math.sin(kx) + z0 * Math.cos(kx);
    this.dx = x0 * Math.cos(kz) - y1 * Math.sin(kz);
    this.dy = x0 * Math.sin(kz) + y1 * Math.cos(kz);
    this.dz = z1;
    projectionTransformation();
  }
}

// ...
List<Vertex> cube = new ArrayList<>(8);
double sideLength = 100;
cube.add(new Vertex(sideLength, sideLength, sideLength));
cube.add(new Vertex(sideLength, sideLength, -sideLength));
cube.add(new Vertex(-sideLength, sideLength, -sideLength));
cube.add(new Vertex(-sideLength, sideLength, sideLength));
cube.add(new Vertex(sideLength, -sideLength, sideLength));
cube.add(new Vertex(sideLength, -sideLength, -sideLength));
cube.add(new Vertex(-sideLength, -sideLength, -sideLength));
cube.add(new Vertex(-sideLength, -sideLength, sideLength));

// ...
// Projection transformation of each vertex of a regular hexahedron by moving the viewpoint to the origin, the distance to the screen to 500, and the z-axis coordinate value to the back of the screen to 1000.
// Draw a wireframe in the center of the JPanel by connecting the transformed vertex coordinates with Path2D
@Override protected void paintComponent(Graphics g) {
  super.paintComponent(g);
  Graphics2D g2 = (Graphics2D) g.create();
  g2.setRenderingHint(
    RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
  Path2D path = new Path2D.Double();
  path.moveTo(cube.get(0).vx, cube.get(0).vy);
  path.lineTo(cube.get(1).vx, cube.get(1).vy);
  path.lineTo(cube.get(2).vx, cube.get(2).vy);
  path.lineTo(cube.get(3).vx, cube.get(3).vy);
  path.lineTo(cube.get(0).vx, cube.get(0).vy);
  path.lineTo(cube.get(4).vx, cube.get(4).vy);
  path.lineTo(cube.get(5).vx, cube.get(5).vy);
  path.lineTo(cube.get(6).vx, cube.get(6).vy);
  path.lineTo(cube.get(7).vx, cube.get(7).vy);
  path.lineTo(cube.get(4).vx, cube.get(4).vy);
  path.moveTo(cube.get(1).vx, cube.get(1).vy);
  path.lineTo(cube.get(5).vx, cube.get(5).vy);
  path.moveTo(cube.get(2).vx, cube.get(2).vy);
  path.lineTo(cube.get(6).vx, cube.get(6).vy);
  path.moveTo(cube.get(3).vx, cube.get(3).vy);
  path.lineTo(cube.get(7).vx, cube.get(7).vy);
  Rectangle r = SwingUtilities.calculateInnerArea(this, null);
  g2.setPaint(Color.WHITE);
  g2.fill(r);
  g2.translate(r.getCenterX(), r.getCenterY());
  g2.setPaint(Color.BLACK);
  g2.draw(path);
  g2.dispose();
}

// ...
// Add the following `MouseAdapter` to the `JPanel` that transforms and draws the projection of the regular hexahedron, and rotate each vertex in the space
private class DragRotateHandler extends MouseAdapter {
  private final Cursor defCursor = Cursor.getDefaultCursor();
  private final Cursor hndCursor = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
  private final Point pp = new Point();

  @Override public void mouseDragged(MouseEvent e) {
    Point pt = e.getPoint();
    double rotY = (pt.x - pp.x) * .03;
    double rotX = (pt.y - pp.y) * .03;
    double rotZ = 0d;
    for (Vertex v : cube) {
      v.rotateTransformation(rotX, rotY, rotZ);
    }
    pp.setLocation(pt);
    e.getComponent().repaint();
  }

  @Override public void mousePressed(MouseEvent e) {
    e.getComponent().setCursor(hndCursor);
    pp.setLocation(e.getPoint());
  }

  @Override public void mouseReleased(MouseEvent e) {
    e.getComponent().setCursor(defCursor);
  }
}

References

Draw a projection-transformed regular hexahedron wireframe in JPanel and rotate it in space by mouse dragging(Japanese)
jdk-8-windows-x64-demos.zip\jdk1.8.0_341\demo\jfc\Java2D\src.zip\java2d\demos\Colors\Rotator3D.java
APCS wiki - Perspective

2023/01/31

Create numbers for a 7-segment digital clock using Path2D

Code

class DigitalNumber {
  private final double isosceles;
  private final double dx;
  private final double dy;
  private final double width;
  private final double height;
  private final Rectangle rect = new Rectangle();
  public static final Color OFF = new Color(0xCC_CC_CC);
  public static final Color ON = Color.DARK_GRAY;
  public static final Color BGC = Color.LIGHT_GRAY;
  private final List<Set<Seg>> numbers = Arrays.asList(
      EnumSet.of(Seg.A, Seg.B, Seg.C, Seg.D, Seg.E, Seg.F),
      EnumSet.of(Seg.B, Seg.C),
      EnumSet.of(Seg.A, Seg.B, Seg.D, Seg.E, Seg.G),
      EnumSet.of(Seg.A, Seg.B, Seg.C, Seg.D, Seg.G),
      EnumSet.of(Seg.B, Seg.C, Seg.F, Seg.G),
      EnumSet.of(Seg.A, Seg.C, Seg.D, Seg.F, Seg.G),
      EnumSet.of(Seg.A, Seg.C, Seg.D, Seg.E, Seg.F, Seg.G),
      EnumSet.of(Seg.A, Seg.B, Seg.C),
      EnumSet.of(Seg.A, Seg.B, Seg.C, Seg.D, Seg.E, Seg.F, Seg.G),
      EnumSet.of(Seg.A, Seg.B, Seg.C, Seg.D, Seg.F, Seg.G));
  private Set<Seg> led = EnumSet.noneOf(Seg.class);

  protected DigitalNumber(double dx, double dy, double isosceles) {
    this.isosceles = isosceles;
    this.dx = dx;
    this.dy = dy;
    this.width = 2d * isosceles;
    this.height = width + isosceles;
    rect.setLocation((int) dx, (int) dy);
    rect.setSize((int) (width + 3 * isosceles), (int) (height * 2));
  }

  public Rectangle getBounds() {
    return rect;
  }

  public void setNumber(int num) {
    led = numbers.get(num);
  }

  public void turnOffNumber() {
    led.clear();
  }

  public void drawNumber(Graphics2D g2) {
    EnumSet.allOf(Seg.class).forEach(s -> {
      g2.setColor(led.contains(s) ? ON : OFF);
      Shape seg = s.getShape(dx, dy, width, height, isosceles);
      g2.fill(seg);
      g2.setColor(BGC);
      g2.draw(seg);
    });
  }
}

enum Seg { A, B, C, D, E, F, G }

References

2012/11/20

Make a ToggleButtonBar with JRadioButtons

Code

class ToggleButtonBarCellIcon implements Icon {
  private static final Color TL = new Color(1f, 1f, 1f, .2f);
  private static final Color BR = new Color(0f, 0f, 0f, .2f);
  private static final Color ST = new Color(1f, 1f, 1f, .4f);
  private static final Color SB = new Color(1f, 1f, 1f, .1f);
  private Color ssc;
  private Color bgc;

  @Override public void paintIcon(Component c, Graphics g, int x, int y) {
    int r = 8;
    int w = c.getWidth();
    int h = c.getHeight();

    Container parent = c.getParent();
    if (parent == null) {
      return;
    }

    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    Path2D p = new Path2D.Float();

    if (c == parent.getComponent(0)) {
      // JButton.segmentPosition: first
      // :first-child
      p.moveTo(x, y + r);
      p.quadTo(x, y, x + r, y);
      p.lineTo(x + w, y);
      p.lineTo(x + w, y + h);
      p.lineTo(x + r, y + h);
      p.quadTo(x, y + h, x, y + h - r);
    } else if (c == parent.getComponent(parent.getComponentCount() - 1)) {
      // JButton.segmentPosition: last
      // :last-child
      p.moveTo(x, y);
      p.lineTo(x + w - r, y);
      p.quadTo(x + w, y, x + w, y + r);
      p.lineTo(x + w, y + h - r);
      p.quadTo(x + w, y + h, x + w - r, y + h);
      p.lineTo(x, y + h);
    } else {
      // JButton.segmentPosition: middle
      p.moveTo(x, y);
      p.lineTo(x + w, y);
      p.lineTo(x + w, y + h);
      p.lineTo(x, y + h);
    }
    p.closePath();
    Area area = new Area(p);

    g2.setPaint(c.getBackground());
    g2.fill(area);

    ssc = TL;
    bgc = BR;
    if (c instanceof AbstractButton) {
      ButtonModel m = ((AbstractButton) c).getModel();
      if (m.isSelected() || m.isRollover()) {
        ssc = ST;
        bgc = SB;
      }
    }
    g2.setPaint(new GradientPaint(x, y, ssc, x, y + h, bgc, true));
    g2.fill(area);

    g2.setPaint(BR);
    g2.draw(area);

    g2.dispose();
  }

  @Override public int getIconWidth()  {
    return 80;
  }

  @Override public int getIconHeight() {
    return 20;
  }
}

References

2012/07/02

Rounded corner JComboBox border

Code

class RoundedCornerBorder extends AbstractBorder {
  @Override public void paintBorder(
      Component c, Graphics g, int x, int y, int width, int height) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    int r = 12;
    int w = width  - 1;
    int h = height - 1;
    Area round = new Area(new RoundRectangle2D.Float(x, y, w, h, r, r));
    Container parent = c.getParent();
    if (parent != null) {
      g2.setColor(parent.getBackground());
      Area corner = new Area(new Rectangle2D.Float(x, y, width, height));
      corner.subtract(round);
      g2.fill(corner);
    }
    g2.setPaint(c.getForeground());
    g2.draw(round);
    g2.dispose();
  }

  @Override public Insets getBorderInsets(Component c) {
    return new Insets(4, 8, 4, 8);
  }

  @Override public Insets getBorderInsets(Component c, Insets insets) {
    insets.left = insets.right = 8;
    insets.top = insets.bottom = 4;
    return insets;
  }
}

class KamabokoBorder extends RoundedCornerBorder {
  @Override public void paintBorder(
      Component c, Graphics g, int x, int y, int width, int height) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    int r = 12;
    int w = width  - 1;
    int h = height - 1;
    Path2D p = new Path2D.Float();
    p.moveTo(x, y + h);
    p.lineTo(x, y + r);
    p.quadTo(x, y, x + r, y);
    p.lineTo(x + w - r, y);
    p.quadTo(x + w, y, x + w, y + r);
    p.lineTo(x + w, y + h);
    p.closePath();
    Area round = new Area(p);
    Container parent = c.getParent();
    if (parent != null) {
      g2.setColor(parent.getBackground());
      Area corner = new Area(new Rectangle2D.Float(x, y, width, height));
      corner.subtract(round);
      g2.fill(corner);
    }
    g2.setPaint(c.getForeground());
    g2.draw(round);
    g2.dispose();
  }
}

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2024/10/31

Code

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2024/05/31

Code

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2024/04/30

Code

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2023/02/28

Code

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2023/01/31

Code

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2012/11/20

Code

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2012/07/02

Code

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