Question

我有一个分配，我需要动画一个3d立方体，用逐行连接的线条来形成立方体。在此之后，立方体的每一面都需要以不同的颜色着色，一旦被涂上颜色，暂停，然后为下一面着色。

我该怎么做呢？我提供了我的代码，我尝试在制作多维数据集后立即填充背景方块，但是我收到以下错误：

 Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Coordinate out of   bounds!
    at    sun.awt.image.IntegerInterleavedRaster.getDataElements(IntegerInterleavedRaster.java:203)
    at java.awt.image.BufferedImage.getRGB(BufferedImage.java:881)
    at drawCube.floodFill(drawCube.java:50)
    at drawCube.main(drawCube.java:181)

这是我的代码，让我知道最好的方法是什么。

import java.awt.image.BufferedImage;
import javax.swing.JLabel;
import javax.swing.ImageIcon;
import java.awt.Point;

class drawCube
{
  static void fillImage(BufferedImage image, int red, int green, int blue)
{
int packedRGB = packRgb(255,255,255);//white

for (int y=0;y<image.getHeight(null);y++)
{
  for (int x=0;x<image.getWidth(null);x++)
    image.setRGB(x,y,packedRGB);
}
}

public static void floodFill(BufferedImage image, int x,int y, int fillColor)
{
java.util.ArrayList<Point> examList=new java.util.ArrayList<Point>();

int initialColor=image.getRGB(x,y);
examList.add(new Point(x,y));

while (examList.size()>0)
{
  Point p = examList.remove(0);  // get and remove the first point in the list
  if (image.getRGB(p.x,p.y)==initialColor)
  {
    x = p.x;  y = p.y;
    image.setRGB(x, y, fillColor);  // fill current pixel

    examList.add(new Point(x-1,y));        // check west neighbor
    examList.add(new Point(x+1,y));        // check east neighbor
    examList.add(new Point(x,y-1));        // check north neighbor
    examList.add(new Point(x,y+1));        // check south neighbor

   // waitNS(1);    // delay to see floodFill() work
   // repaintImage(image);

  }
}
} 

 private static void repaintImage(BufferedImage image)
 {
_imageLabel.setIcon(new ImageIcon(image));
_imageLabel.repaint();   
 }

public static void waitNS(long ns)  
{
try {  Thread.sleep(ns);  }   // Pause ns
  catch (Exception ignore) { ; }
}

public static int packRgb(int r,int g,int b)
{
 return (r*256+g)*256+b;
}

static JLabel _imageLabel;
public static void main(String[] args) throws Exception
{
// create an 300x300 RGB image
BufferedImage image=new BufferedImage(300,300,BufferedImage.TYPE_INT_RGB);

// fill the image with green color
fillImage(image,0,255,0);        

JLabel imageLabel=new JLabel();
_imageLabel = imageLabel;  // make it global
imageLabel.setIcon(new ImageIcon(image));
imageLabel.setText("Filling the box with yellow color ...");

javax.swing.JFrame window=new javax.swing.JFrame();
window.setTitle("Cube Experiment");
window.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);

window.add(imageLabel);

window.pack();
window.setVisible(true);

java.awt.Graphics2D gr=(java.awt.Graphics2D) image.getGraphics();

int x1 = 50; int y1 = 150;
int x2 = 150; int y2 = 150;
int x3 = 150; int y3 = 250;
int x4 = 50; int y4 = 250;

gr.setColor(new java.awt.Color(0,0,0));  // blue
gr.setStroke(new java.awt.BasicStroke(2));  // set pen width to 2 pixels

gr.drawLine(50, 150, 150, 150);
repaintImage(image);
waitNS(500);

gr.drawLine(150, 150, 150, 250);
repaintImage(image);
waitNS(500);

gr.drawLine(150, 250, 50, 250);
repaintImage(image);
waitNS(500);

gr.drawLine(50, 250, 50, 150);
repaintImage(image);
waitNS(500);

 gr.drawLine(0, 300, 100, 300);
 repaintImage(image);
 waitNS(500);

 gr.drawLine(0, 300, 50, 250);
 repaintImage(image);
 waitNS(500);

 gr.drawLine(100, 300, 150, 250);
 repaintImage(image);
 waitNS(500);


 gr.drawLine(100, 300, 100, 200);
repaintImage(image);
waitNS(500);

 gr.drawLine(0, 285, 0, 200);
repaintImage(image);
waitNS(500);

 gr.drawLine(0, 200, 100, 200);
repaintImage(image);
waitNS(500);

 gr.drawLine(0, 200, 50, 150);
 repaintImage(image);
 waitNS(500);

 gr.drawLine(100, 200, 150, 150);
 repaintImage(image);
 waitNS(500);

// fill the square with yellow color
int yellow = packRgb(255,255,0);
int black = packRgb(0,0,0);
//floodFill(image,(x1+x2)/2, (y1+y4)/2, yellow);//flood fill at center

imageLabel.setIcon(new ImageIcon(image));
imageLabel.setText("Completed !");

}
}

Answer 1

这里有两个问题：ArrayIndexOutOfBoundsException和一个不幸的巧合。

您的泛滥方法包括一个循环，该循环在前一个测试点的每个方向上生成点，但不会说何时停止。结果是可以在300x300区域之外生成一个点，在调用image.getRGB（int，int）时抛出异常。
在对元素进行循环操作时，记住数组的限制通常是个好主意。例如：

if(x-1>0) examList.add(new Point(x-1,y));   // check west neighbour
if(x+1<300) examList.add(new Point(x+1,y)); // check east neighbour
if(y-1>0) examList.add(new Point(x,y-1));   // check north neighbour
if(y+1<300) examList.add(new Point(x,y+1)); // check south neighbour

或者不那么精确：

 if (p.x>0 && p.y>0 && p.x<300 && p.y<300 && image.getRGB(p.x,p.y)==initialColor)

此外，您开始泛滥的点恰好位于立方体的一条构造线上，因此线条被填充而不是空格。选择要点时要更加小心。

floodFill(image, 60, 160, java.awt.Color.yellow.hashCode());

应该有用。

希望这有帮助。

java GUI 3d立方体着色四面八方

1 个答案: