javashapesgraphics2dfillcontour
Java fillPolygon(Polygon p) doesn't work when p is circle contour?
I have here a situation, I can't handle by myself.
I'd like to draw and fill Polygon onto JPanel. I have written Moore-Neighbor Tracing algorithm (http://www.imageprocessingplace.com/downloads_V3/root_downloads/tutorials/contour_tracing_Abeer_George_Ghuneim/moore.html), for detecting contours in image.
Algorithm works just fine, but then I'd like to visualize the result. It works for me in many scenarios, but when the traced shape is circle, I mean the resulting polygon describes a circle (and it realy is), the Java Graphics2D.fillPolygon(Polygon p) is unable to fill it. It is well drawed by drawPolygon(Polygon p), but not filled. And of course a need it filled (actualy I am drawing and filling it in an BufferedImage instance with a background color, so it seems to be "deleted"), so the example with JPanel is just for testing purpose.
My code:
package x;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
public class NewClass extends javax.swing.JFrame {
public NewClass() {
initComponents();
}
@SuppressWarnings("unchecked")
private void initComponents() {
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
pack();
}
public static void main(String args[]) {
NewClass f = new NewClass();
f.getContentPane().add(new Draw(), java.awt.BorderLayout.CENTER);
f.setSize(100, 200);
f.setVisible(true);
}
static class Draw extends javax.swing.JPanel {
private static final Polygon p;
static {
p = new Polygon();
p.addPoint(27, 50);
p.addPoint(28, 49);
p.addPoint(28, 48);
p.addPoint(28, 47);
p.addPoint(29, 46);
p.addPoint(29, 45);
p.addPoint(30, 44);
p.addPoint(30, 43);
p.addPoint(31, 42);
p.addPoint(31, 41);
p.addPoint(32, 40);
p.addPoint(32, 39);
p.addPoint(33, 38);
p.addPoint(33, 37);
p.addPoint(34, 36);
p.addPoint(35, 35);
p.addPoint(36, 34);
p.addPoint(37, 33);
p.addPoint(38, 32);
p.addPoint(39, 31);
p.addPoint(40, 31);
p.addPoint(41, 30);
p.addPoint(42, 30);
p.addPoint(43, 29);
p.addPoint(44, 28);
p.addPoint(45, 28);
p.addPoint(46, 27);
p.addPoint(47, 27);
p.addPoint(48, 27);
p.addPoint(49, 26);
p.addPoint(50, 26);
p.addPoint(51, 26);
p.addPoint(52, 25);
p.addPoint(53, 25);
p.addPoint(54, 25);
p.addPoint(55, 25);
p.addPoint(56, 25);
p.addPoint(57, 25);
p.addPoint(58, 25);
p.addPoint(59, 25);
p.addPoint(60, 25);
p.addPoint(61, 25);
p.addPoint(62, 25);
p.addPoint(63, 25);
p.addPoint(64, 25);
p.addPoint(65, 25);
p.addPoint(66, 26);
p.addPoint(67, 26);
p.addPoint(68, 26);
p.addPoint(69, 27);
p.addPoint(70, 27);
p.addPoint(71, 28);
p.addPoint(72, 28);
p.addPoint(73, 29);
p.addPoint(74, 29);
p.addPoint(75, 30);
p.addPoint(76, 30);
p.addPoint(77, 31);
p.addPoint(78, 31);
p.addPoint(79, 32);
p.addPoint(80, 33);
p.addPoint(81, 34);
p.addPoint(82, 35);
p.addPoint(83, 36);
p.addPoint(84, 37);
p.addPoint(84, 38);
p.addPoint(85, 39);
p.addPoint(85, 40);
p.addPoint(86, 41);
p.addPoint(86, 42);
p.addPoint(87, 43);
p.addPoint(87, 44);
p.addPoint(88, 45);
p.addPoint(88, 46);
p.addPoint(89, 47);
p.addPoint(89, 48);
p.addPoint(89, 49);
p.addPoint(90, 50);
p.addPoint(90, 51);
p.addPoint(90, 52);
p.addPoint(90, 53);
p.addPoint(90, 54);
p.addPoint(90, 55);
p.addPoint(90, 56);
p.addPoint(90, 57);
p.addPoint(90, 58);
p.addPoint(90, 59);
p.addPoint(90, 60);
p.addPoint(90, 61);
p.addPoint(90, 62);
p.addPoint(90, 63);
p.addPoint(89, 64);
p.addPoint(89, 65);
p.addPoint(89, 66);
p.addPoint(88, 67);
p.addPoint(88, 68);
p.addPoint(87, 69);
p.addPoint(87, 70);
p.addPoint(86, 71);
p.addPoint(86, 72);
p.addPoint(85, 73);
p.addPoint(85, 74);
p.addPoint(84, 75);
p.addPoint(84, 76);
p.addPoint(83, 77);
p.addPoint(82, 78);
p.addPoint(81, 79);
p.addPoint(80, 80);
p.addPoint(79, 81);
p.addPoint(78, 82);
p.addPoint(77, 82);
p.addPoint(76, 83);
p.addPoint(75, 83);
p.addPoint(74, 84);
p.addPoint(73, 84);
p.addPoint(72, 85);
p.addPoint(71, 85);
p.addPoint(70, 86);
p.addPoint(69, 86);
p.addPoint(68, 87);
p.addPoint(67, 87);
p.addPoint(66, 87);
p.addPoint(65, 88);
p.addPoint(64, 88);
p.addPoint(63, 88);
p.addPoint(62, 88);
p.addPoint(61, 88);
p.addPoint(60, 88);
p.addPoint(59, 88);
p.addPoint(58, 88);
p.addPoint(57, 88);
p.addPoint(56, 88);
p.addPoint(55, 88);
p.addPoint(54, 88);
p.addPoint(53, 88);
p.addPoint(52, 88);
p.addPoint(51, 87);
p.addPoint(50, 87);
p.addPoint(49, 87);
p.addPoint(48, 86);
p.addPoint(47, 86);
p.addPoint(46, 86);
p.addPoint(45, 85);
p.addPoint(44, 85);
p.addPoint(43, 84);
p.addPoint(42, 83);
p.addPoint(41, 83);
p.addPoint(40, 82);
p.addPoint(39, 82);
p.addPoint(38, 81);
p.addPoint(37, 80);
p.addPoint(36, 79);
p.addPoint(35, 78);
p.addPoint(34, 77);
p.addPoint(33, 76);
p.addPoint(33, 75);
p.addPoint(32, 74);
p.addPoint(32, 73);
p.addPoint(31, 72);
p.addPoint(31, 71);
p.addPoint(30, 70);
p.addPoint(30, 69);
p.addPoint(29, 68);
p.addPoint(29, 67);
p.addPoint(28, 66);
p.addPoint(28, 65);
p.addPoint(28, 64);
p.addPoint(27, 63);
p.addPoint(27, 62);
p.addPoint(27, 61);
p.addPoint(27, 60);
p.addPoint(27, 59);
p.addPoint(27, 58);
p.addPoint(27, 57);
p.addPoint(27, 56);
p.addPoint(27, 55);
p.addPoint(27, 54);
p.addPoint(27, 53);
p.addPoint(27, 52);
p.addPoint(27, 51);
p.addPoint(27, 50);
p.addPoint(28, 49);
p.addPoint(28, 48);
p.addPoint(28, 47);
p.addPoint(29, 46);
p.addPoint(29, 45);
p.addPoint(30, 44);
p.addPoint(30, 43);
p.addPoint(31, 42);
p.addPoint(31, 41);
p.addPoint(32, 40);
p.addPoint(32, 39);
p.addPoint(33, 38);
p.addPoint(33, 37);
p.addPoint(34, 36);
p.addPoint(35, 35);
p.addPoint(36, 34);
p.addPoint(37, 33);
p.addPoint(38, 32);
p.addPoint(39, 31);
p.addPoint(40, 31);
p.addPoint(41, 30);
p.addPoint(42, 30);
p.addPoint(43, 29);
p.addPoint(44, 28);
p.addPoint(45, 28);
p.addPoint(46, 27);
p.addPoint(47, 27);
p.addPoint(48, 27);
p.addPoint(49, 26);
p.addPoint(50, 26);
p.addPoint(51, 26);
p.addPoint(52, 25);
p.addPoint(53, 25);
p.addPoint(54, 25);
p.addPoint(55, 25);
p.addPoint(56, 25);
p.addPoint(57, 25);
p.addPoint(58, 25);
p.addPoint(59, 25);
p.addPoint(60, 25);
p.addPoint(61, 25);
p.addPoint(62, 25);
p.addPoint(63, 25);
p.addPoint(64, 25);
p.addPoint(65, 25);
p.addPoint(66, 26);
p.addPoint(67, 26);
p.addPoint(68, 26);
p.addPoint(69, 27);
p.addPoint(70, 27);
p.addPoint(71, 28);
p.addPoint(72, 28);
p.addPoint(73, 29);
p.addPoint(74, 29);
p.addPoint(75, 30);
p.addPoint(76, 30);
p.addPoint(77, 31);
p.addPoint(78, 31);
p.addPoint(79, 32);
p.addPoint(80, 33);
p.addPoint(81, 34);
p.addPoint(82, 35);
p.addPoint(83, 36);
p.addPoint(84, 37);
p.addPoint(84, 38);
p.addPoint(85, 39);
p.addPoint(85, 40);
p.addPoint(86, 41);
p.addPoint(86, 42);
p.addPoint(87, 43);
p.addPoint(87, 44);
p.addPoint(88, 45);
p.addPoint(88, 46);
p.addPoint(89, 47);
p.addPoint(89, 48);
p.addPoint(89, 49);
p.addPoint(90, 50);
p.addPoint(90, 51);
p.addPoint(90, 52);
p.addPoint(90, 53);
p.addPoint(90, 54);
p.addPoint(90, 55);
p.addPoint(90, 56);
p.addPoint(90, 57);
p.addPoint(90, 58);
p.addPoint(90, 59);
p.addPoint(90, 60);
p.addPoint(90, 61);
p.addPoint(90, 62);
p.addPoint(90, 63);
p.addPoint(89, 64);
p.addPoint(89, 65);
p.addPoint(89, 66);
p.addPoint(88, 67);
p.addPoint(88, 68);
p.addPoint(87, 69);
p.addPoint(87, 70);
p.addPoint(86, 71);
p.addPoint(86, 72);
p.addPoint(85, 73);
p.addPoint(85, 74);
p.addPoint(84, 75);
p.addPoint(84, 76);
p.addPoint(83, 77);
p.addPoint(82, 78);
p.addPoint(81, 79);
p.addPoint(80, 80);
p.addPoint(79, 81);
p.addPoint(78, 82);
p.addPoint(77, 82);
p.addPoint(76, 83);
p.addPoint(75, 83);
p.addPoint(74, 84);
p.addPoint(73, 84);
p.addPoint(72, 85);
p.addPoint(71, 85);
p.addPoint(70, 86);
p.addPoint(69, 86);
p.addPoint(68, 87);
p.addPoint(67, 87);
p.addPoint(66, 87);
p.addPoint(65, 88);
p.addPoint(64, 88);
p.addPoint(63, 88);
p.addPoint(62, 88);
p.addPoint(61, 88);
p.addPoint(60, 88);
p.addPoint(59, 88);
p.addPoint(58, 88);
p.addPoint(57, 88);
p.addPoint(56, 88);
p.addPoint(55, 88);
p.addPoint(54, 88);
p.addPoint(53, 88);
p.addPoint(52, 88);
p.addPoint(51, 87);
p.addPoint(50, 87);
p.addPoint(49, 87);
p.addPoint(48, 86);
p.addPoint(47, 86);
p.addPoint(46, 86);
p.addPoint(45, 85);
p.addPoint(44, 85);
p.addPoint(43, 84);
p.addPoint(42, 83);
p.addPoint(41, 83);
p.addPoint(40, 82);
p.addPoint(39, 82);
p.addPoint(38, 81);
p.addPoint(37, 80);
p.addPoint(36, 79);
p.addPoint(35, 78);
p.addPoint(34, 77);
p.addPoint(33, 76);
p.addPoint(33, 75);
p.addPoint(32, 74);
p.addPoint(32, 73);
p.addPoint(31, 72);
p.addPoint(31, 71);
p.addPoint(30, 70);
p.addPoint(30, 69);
p.addPoint(29, 68);
p.addPoint(29, 67);
p.addPoint(28, 66);
p.addPoint(28, 65);
p.addPoint(28, 64);
p.addPoint(27, 63);
p.addPoint(27, 62);
p.addPoint(27, 61);
p.addPoint(27, 60);
p.addPoint(27, 59);
p.addPoint(27, 58);
p.addPoint(27, 57);
p.addPoint(27, 56);
p.addPoint(27, 55);
p.addPoint(27, 54);
p.addPoint(27, 53);
p.addPoint(27, 52);
p.addPoint(27, 51);
}
@Override
public void paintComponent(Graphics gg) {
super.paintComponent(gg);
Graphics2D g = (Graphics2D) gg;
g.setColor(Color.WHITE);
g.fillRect(0, 0, getWidth(), getHeight());
if (p != null) {
g.setColor(Color.BLUE);
g.fillPolygon(p);
g.drawPolygon(p);
}
}
}
}
Am I doing something wrong ? Or I just "created" a shape, which even-odd filling rule can't handle ?
Result looks like this:
Solution
Your points describe a double circle (that is, two rounds). Apparently, fillPolygon doesn't like that. Remove half of the points (only keep the part below) and it works fine (see my screenshot).
p.addPoint(27, 50);
p.addPoint(28, 49);
p.addPoint(28, 48);
p.addPoint(28, 47);
p.addPoint(29, 46);
p.addPoint(29, 45);
p.addPoint(30, 44);
p.addPoint(30, 43);
p.addPoint(31, 42);
p.addPoint(31, 41);
p.addPoint(32, 40);
p.addPoint(32, 39);
p.addPoint(33, 38);
p.addPoint(33, 37);
p.addPoint(34, 36);
p.addPoint(35, 35);
p.addPoint(36, 34);
p.addPoint(37, 33);
p.addPoint(38, 32);
p.addPoint(39, 31);
p.addPoint(40, 31);
p.addPoint(41, 30);
p.addPoint(42, 30);
p.addPoint(43, 29);
p.addPoint(44, 28);
p.addPoint(45, 28);
p.addPoint(46, 27);
p.addPoint(47, 27);
p.addPoint(48, 27);
p.addPoint(49, 26);
p.addPoint(50, 26);
p.addPoint(51, 26);
p.addPoint(52, 25);
p.addPoint(53, 25);
p.addPoint(54, 25);
p.addPoint(55, 25);
p.addPoint(56, 25);
p.addPoint(57, 25);
p.addPoint(58, 25);
p.addPoint(59, 25);
p.addPoint(60, 25);
p.addPoint(61, 25);
p.addPoint(62, 25);
p.addPoint(63, 25);
p.addPoint(64, 25);
p.addPoint(65, 25);
p.addPoint(66, 26);
p.addPoint(67, 26);
p.addPoint(68, 26);
p.addPoint(69, 27);
p.addPoint(70, 27);
p.addPoint(71, 28);
p.addPoint(72, 28);
p.addPoint(73, 29);
p.addPoint(74, 29);
p.addPoint(75, 30);
p.addPoint(76, 30);
p.addPoint(77, 31);
p.addPoint(78, 31);
p.addPoint(79, 32);
p.addPoint(80, 33);
p.addPoint(81, 34);
p.addPoint(82, 35);
p.addPoint(83, 36);
p.addPoint(84, 37);
p.addPoint(84, 38);
p.addPoint(85, 39);
p.addPoint(85, 40);
p.addPoint(86, 41);
p.addPoint(86, 42);
p.addPoint(87, 43);
p.addPoint(87, 44);
p.addPoint(88, 45);
p.addPoint(88, 46);
p.addPoint(89, 47);
p.addPoint(89, 48);
p.addPoint(89, 49);
p.addPoint(90, 50);
p.addPoint(90, 51);
p.addPoint(90, 52);
p.addPoint(90, 53);
p.addPoint(90, 54);
p.addPoint(90, 55);
p.addPoint(90, 56);
p.addPoint(90, 57);
p.addPoint(90, 58);
p.addPoint(90, 59);
p.addPoint(90, 60);
p.addPoint(90, 61);
p.addPoint(90, 62);
p.addPoint(90, 63);
p.addPoint(89, 64);
p.addPoint(89, 65);
p.addPoint(89, 66);
p.addPoint(88, 67);
p.addPoint(88, 68);
p.addPoint(87, 69);
p.addPoint(87, 70);
p.addPoint(86, 71);
p.addPoint(86, 72);
p.addPoint(85, 73);
p.addPoint(85, 74);
p.addPoint(84, 75);
p.addPoint(84, 76);
p.addPoint(83, 77);
p.addPoint(82, 78);
p.addPoint(81, 79);
p.addPoint(80, 80);
p.addPoint(79, 81);
p.addPoint(78, 82);
p.addPoint(77, 82);
p.addPoint(76, 83);
p.addPoint(75, 83);
p.addPoint(74, 84);
p.addPoint(73, 84);
p.addPoint(72, 85);
p.addPoint(71, 85);
p.addPoint(70, 86);
p.addPoint(69, 86);
p.addPoint(68, 87);
p.addPoint(67, 87);
p.addPoint(66, 87);
p.addPoint(65, 88);
p.addPoint(64, 88);
p.addPoint(63, 88);
p.addPoint(62, 88);
p.addPoint(61, 88);
p.addPoint(60, 88);
p.addPoint(59, 88);
p.addPoint(58, 88);
p.addPoint(57, 88);
p.addPoint(56, 88);
p.addPoint(55, 88);
p.addPoint(54, 88);
p.addPoint(53, 88);
p.addPoint(52, 88);
p.addPoint(51, 87);
p.addPoint(50, 87);
p.addPoint(49, 87);
p.addPoint(48, 86);
p.addPoint(47, 86);
p.addPoint(46, 86);
p.addPoint(45, 85);
p.addPoint(44, 85);
p.addPoint(43, 84);
p.addPoint(42, 83);
p.addPoint(41, 83);
p.addPoint(40, 82);
p.addPoint(39, 82);
p.addPoint(38, 81);
p.addPoint(37, 80);
p.addPoint(36, 79);
p.addPoint(35, 78);
p.addPoint(34, 77);
p.addPoint(33, 76);
p.addPoint(33, 75);
p.addPoint(32, 74);
p.addPoint(32, 73);
p.addPoint(31, 72);
p.addPoint(31, 71);
p.addPoint(30, 70);
p.addPoint(30, 69);
p.addPoint(29, 68);
p.addPoint(29, 67);
p.addPoint(28, 66);
p.addPoint(28, 65);
p.addPoint(28, 64);
p.addPoint(27, 63);
p.addPoint(27, 62);
p.addPoint(27, 61);
p.addPoint(27, 60);
p.addPoint(27, 59);
p.addPoint(27, 58);
p.addPoint(27, 57);
p.addPoint(27, 56);
p.addPoint(27, 55);
p.addPoint(27, 54);
p.addPoint(27, 53);
p.addPoint(27, 52);
p.addPoint(27, 51);
- 'wsimport' is not recognized error in command prompt
- Best way to compare two JSON files in Java
- Java get month sort name from date
- Obtain and download Javadoc (JDK API documentation) to a local file for offline reading
- How to get the number of days in a specific month using Java Calendar?
- Custom Spring annotation for request parameters
- License for package Android SDK Platform 29 not accepted
- Java Compile Time Error: reached end of file while parsing
- ShellIpcClient and NonCelloThread errors java
- How to verify a signature from the Phantom wallet?
- FirebaseAuth - Get tokenId in Java backend
- How to hide constructor on a Java record that offers a public static factory method?
- Is it possible to get MariaDB4J to work on an M1 Mac?
- Cannot run simple compiled java program?
- Getting IntelliJ to generate Java Sources from Proto files
- Insert a java string constant in a quarkus qute template?
- Why is the run button not working in Eclipse?
- Stuck on Card/Deck exercise from Java official tutorial
- Spring Batch - Deleting metadata post job completion throws error - Incorrect result size: expected 1, actual 0
- Simple export and import of a SQLite database on Android
- How to serialize a date to a specific format?
- How to make the Youtube's rotating spinner loading screen on Java Swing
- How to sort List<Integer[]> in java?
- How to prevent spring boot from auto creating instance of bean 'entityManagerFactory' at startup?
- Sharing instance of a class between multiple tests running in parallel in Junit5
- Launch4J not recognizing Eclipse Temurin OpenJDK Java 17
- Turn my stack into a string?
- How can I document or exclude the generated BuildConfig class in my documentation?
- Is it a bad practice to catch Throwable?
- Java: Right Click Copy Cut Paste On TextField