Hilbert空间填充曲线在图像采样等方面十分有用关于什么希尔伯特

空间填充曲线看这里：http://en.wikipedia.org/wiki/Hilbert_curve

程序效果:

模拟Hilbert空间填充曲线效果，点击鼠标自动叠加！运行效果截图

Hilbert源程序代码：

package com.gloomyfish.p_w_picpath.hilbert;

import java.awt.Color;

import java.awt.Graphics;

import java.awt.Point;

public class Hilbert {

public static final int WHEELSIZE = 1024;

// four edges

public static final int NORTH = 0;

public static final int EAST = 90;

public static final int SOUTH = 180;

public static final int WEST = 270;

// four corners

public static final int NE = 45;

public static final int SE = 135;

public static final int SW = 225;

public static final int NW = 315;

// attributes

private Point location;

private Color[] colorWheel;

private int colorIdx;

public Hilbert() {

// build color lookup table

this.colorWheel = new Color[1024];

for (int i = 0; i < 128; ++i)

this.colorWheel[i] = new Color(0, 255 - i, i);

for (int j = 128; j < 256; ++j)

this.colorWheel[j] = new Color(0, j, j);

for (int k = 0; k < 256; ++k)

this.colorWheel[(k + 256)] = new Color(0, 255 - k, 255);

for (int l = 0; l < 128; ++l)

this.colorWheel[(l + 512)] = new Color(0, l, 255 - l);

for (int i1 = 0; i1 < 128; ++i1)

this.colorWheel[(i1 + 640)] = new Color(0, 127 - i1, 127 - i1);

for (int i2 = 0; i2 < 256; ++i2)

this.colorWheel[(i2 + 768)] = new Color(0, i2, 0);

this.colorIdx = 0;

}

public void process(Graphics graphic, int level, int width, int height) {

this.location = null;

if(level > 32 )

{

graphic.drawString("could get max depth is 32!", 40, 40);

return;

}

hilbert(graphic, level, 0, 0, width, height, 0, 225);

}

public void hilbert(Graphics g, int depth, int startx, int starty, int width, int height, int startgray, int endgray) {

int centerX = width / 2;

int centerY = height / 2;

if (depth == 0) {

if (this.location != null) {

g.setColor(this.colorWheel[this.colorIdx]);

g.drawLine(this.location.x, this.location.y,

startx + centerX, starty + centerY);

if (++this.colorIdx >= 1024)

this.colorIdx = 0;

}

this.location = new Point(startx + centerX, starty + centerY);

return;

}

switch (startgray) {

case 0:

if (endgray == 225) {

hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 90, 225); // bottom-left

hilbert(g, depth - 1, startx, starty, centerX, centerY, 0, 225); // upper-left

hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 0, 225); // upper-right

hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 270, 45); // bottom-right

return;

}

if (endgray != 135)

return;

hilbert(g, depth - 1, startx + centerX, starty + centerY, centerX, centerY, 270, 135);

hilbert(g, depth - 1, startx + centerX, starty, centerX, centerY, 0, 135);

hilbert(g, depth - 1, startx, starty, centerX, centerY, 0, 135);

hilbert(g, depth - 1, startx, starty + centerY, centerX, centerY, 90, 315);

return;

case 90:

if (endgray == 315) {

hilbert(g, depth - 1, startx, starty, centerX,

centerY, 180, 315);

hilbert(g, depth - 1, startx + centerX, starty,

centerX, centerY, 90, 315);

hilbert(g, depth - 1, startx + centerX, starty

+ centerY, centerX, centerY, 90, 315);

hilbert(g, depth - 1, startx, starty + centerY,

centerX, centerY, 0, 135);

return;

}

if (endgray != 225)

return;

hilbert(g, depth - 1, startx, starty + centerY, centerX,

centerY, 0, 225);

hilbert(g, depth - 1, startx + centerX, starty + centerY,

centerX, centerY, 90, 225);

hilbert(g, depth - 1, startx + centerX, starty, centerX,

centerY, 90, 225);

hilbert(g, depth - 1, startx, starty, centerX, centerY,

180, 45);

return;

case 180:

if (endgray == 45) {

hilbert(g, depth - 1, startx + centerX, starty,

centerX, centerY, 270, 45);

hilbert(g, depth - 1, startx + centerX, starty

+ centerY, centerX, centerY, 180, 45);

hilbert(g, depth - 1, startx, starty + centerY,

centerX, centerY, 180, 45);

hilbert(g, depth - 1, startx, starty, centerX,

centerY, 90, 225);

return;

}

if (endgray != 315)

return;

hilbert(g, depth - 1, startx, starty, centerX, centerY,

90, 315);

hilbert(g, depth - 1, startx, starty + centerY, centerX,

centerY, 180, 315);

hilbert(g, depth - 1, startx + centerX, starty + centerY,

centerX, centerY, 180, 315);

hilbert(g, depth - 1, startx + centerX, starty, centerX,

centerY, 270, 135);

return;

case 270:

if (endgray == 45) {

hilbert(g, depth - 1, startx + centerX, starty,

centerX, centerY, 180, 45);

hilbert(g, depth - 1, startx, starty, centerX,

centerY, 270, 45);

hilbert(g, depth - 1, startx, starty + centerY,

centerX, centerY, 270, 45);

hilbert(g, depth - 1, startx + centerX, starty

+ centerY, centerX, centerY, 0, 225);

return;

}

if (endgray != 135)

return;

hilbert(g, depth - 1, startx + centerX, starty + centerY,

centerX, centerY, 0, 135);

hilbert(g, depth - 1, startx, starty + centerY, centerX,

centerY, 270, 135);

hilbert(g, depth - 1, startx, starty, centerX, centerY,

270, 135);

hilbert(g, depth - 1, startx + centerX, starty, centerX,

centerY, 180, 315);

return;

}

}

}

UI部分代码：

package com.gloomyfish.p_w_picpath.hilbert;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import javax.swing.JComponent;

import javax.swing.JFrame;

public class HilbertUI extends JComponent implements MouseListener {

/**

*

*/

private static final long serialVersionUID = 1L;

private int level;

private Hilbert hilbert;

private Dimension size;

public HilbertUI() {

this.level = 1;

size = new Dimension(405, 405);

this.hilbert = new Hilbert();

addMouseListener(this);

}

@Override

protected void paintComponent(Graphics g) {

g.setColor(Color.BLACK);

g.clearRect(0, 0, (int)size.getWidth(), (int)size.getHeight());

this.hilbert.process(g, this.level, (int)size.getWidth()-5, (int)size.getHeight()-5);

}

@Override

public Dimension getPreferredSize() {

return size;

}

@Override

public Dimension getMaximumSize() {

return size;

}

@Override

public Dimension getMinimumSize() {

return size;

}

public void mousePressed(MouseEvent paramMouseEvent) {

}

public void mouseEntered(MouseEvent paramMouseEvent) {

}

public void mouseExited(MouseEvent paramMouseEvent) {

}

public void mouseReleased(MouseEvent paramMouseEvent) {

}

public void mouseClicked(MouseEvent event) {

int i = event.getModifiers();

if ((i & 0x10) > 0)

this.level += 1;

else if (((i & 0xC) > 0) && (this.level > 0))

this.level -= 1;

repaint();

}

public static void main(String[] args)

{

JFrame mainFrame = new JFrame("Hilbert Demo - Gloomyfish");

mainFrame.getContentPane().setLayout(new BorderLayout());

mainFrame.getContentPane().add(new HilbertUI(), BorderLayout.CENTER);

mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

mainFrame.pack();

mainFrame.setVisible(true);

}

}