I want to print each digit of pi number as a colored pixel, so, I get an input, with the pi number, then parse it into a list, each node containing a digit (I know, I'll use an array later), but I never get this painted to screen... Can someone help me to see where I'm wrong?
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.MemoryImageSource;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class PiPainter extends JPanel
{
private static final long serialVersionUID = 6416932054834995251L;
private static int pixels[];
private static List<Integer> pi = new ArrayList<Integer>();
private final static int[] color = {
0xFF000000, 0xFF787878, 0xFF008B00, 0xFF00008B, 0xFF008B8B,
0xFF008B00, 0xFFCDCD00, 0xFFFF4500, 0xFF8B0000, 0xFFFF0000
};
public static void readFile(String name)
{
File file = new File(name);
BufferedReader reader = null;
char[] digits;
try
{
reader = new BufferedReader(new FileReader(file));
String text = null;
while((text = reader.readLine()) != null)
{
digits = text.toCharArray();
for(char el : digits)
if(el != ' ')
pi.add(Character.getNumericValue(el));
}
} catch (Exception e)
{
e.printStackTrace();
}
}
public void paint(Graphics gg)
{
// page containing pi number, http://gc3.net84.net/pi.htm
// other source, http://newton.ex.ac.uk/research/qsystems/collabs/pi/pi6.txt
readFile("c:\\pi.txt");
int h = 300;
int w = 300;
int digit;
int i = 0;
pixels = new int[w * h];
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
pixels[i] = color[pi.get(i)];
i++;
}
}
Image art = createImage(new MemoryImageSource(w, h, pixels, 0, w));
gg.drawImage(art, 0, 0, this);
}
public static void main(String[] args)
{
JFrame frame = new JFrame();
frame.getContentPane().add(new PiPainter(), BorderLayout.CENTER);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400,400);
frame.setVisible(true);
}
}
trashgod
I'm not familiar with MemoryImageSource. Here's the first 16 300 digits of π, repeated in a BufferedImage and using your color table.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class PiRaster extends JPanel {
private static final int W = 30;
private static final int H = 30;
private static List<Integer> pi = new ArrayList<Integer>();
BufferedImage image;
private int[] clut = {
0x000000, 0x787878, 0x008B00, 0x00008B, 0x008B8B,
0x008B00, 0xCDCD00, 0xFF4500, 0x8B0000, 0xFF0000
};
public PiRaster() {
this.setPreferredSize(new Dimension(W * 16, H * 10));
String s = ""
+ "31415926535897932384626433832795028841971693993751"
+ "05820974944592307816406286208998628034825342117067"
+ "98214808651328230664709384460955058223172535940812"
+ "84811174502841027019385211055596446229489549303819"
+ "64428810975665933446128475648233786783165271201909"
+ "14564856692346034861045432664821339360726024914127";
for (int i = 0; i < s.length(); i++) {
pi.add(s.charAt(i) - '0');
}
}
@Override
public void paintComponent(Graphics g) {
if (image == null) {
image = (BufferedImage) createImage(W, H);
int i = 0;
for (int row = 0; row < H; row++) {
for (int col = 0; col < W; col++) {
image.setRGB(col, row, clut[pi.get(i)]);
if (++i == pi.size()) {
i = 0;
}
}
}
}
g.drawImage(image, 0, 0, getWidth(), getHeight(), null);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new PiRaster());
frame.pack();
frame.setVisible(true);
}
});
}
}
gfe
@trashgod
Thanks for your answer, I changed it a little bit to achieve what I was looking for ; )
Now you can change the width easily to achieve a better view of the image and fit the contents, and the number don't repeats, making it easy to perceive patterns (if there might be). Oh, and I added about 2~3 lines at the end, to clarify it.
package edu.pi;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class PiRaster extends JPanel
{
private static final long serialVersionUID = -1298205187260747210L;
private static int W;
private static int H;
private static List<Integer> pi = new ArrayList<Integer>();
BufferedImage image;
private int[] clut = {
0x000000, 0x787878, 0x008B00, 0x00008B, 0x008B8B,
0x008B00, 0xCDCD00, 0xFF4500, 0x8B0000, 0xFF0000
};
public PiRaster()
{
String s = "3."
+ "14159265358979323846264338327950288419716939937510"
+ "58209749445923078164062862089986280348253421170679"
+ "82148086513282306647093844609550582231725359408128"
+ "48111745028410270193852110555964462294895493038196"
+ "44288109756659334461284756482337867831652712019091"
+ "45648566923460348610454326648213393607260249141273"
+ "72458700660631558817488152092096282925409171536436"
+ "78925903600113305305488204665213841469519415116094"
+ "33057270365759591953092186117381932611793105118548"
+ "07446237996274956735188575272489122793818301194912"
+ "98336733624406566430860213949463952247371907021798"
+ "60943702770539217176293176752384674818467669405132"
+ "00056812714526356082778577134275778960917363717872"
+ "14684409012249534301465495853710507922796892589235"
+ "42019956112129021960864034418159813629774771309960"
+ "51870721134999999837297804995105973173281609631859"
+ "50244594553469083026425223082533446850352619311881"
+ "71010003137838752886587533208381420617177669147303"
+ "59825349042875546873115956286388235378759375195778"
+ "18577805321712268066130019278766111959092164201989";
char temp;
for (int i = 0; i < s.length(); i++)
{
temp = s.charAt(i);
if (temp >= 48 && temp <= 57)
pi.add(s.charAt(i) - '0');
}
W = 50;
H = s.length() / W + 3;
this.setPreferredSize(new Dimension(W * 10, H * 10));
}
@Override
public void paintComponent(Graphics g)
{
if (image == null)
{
image = (BufferedImage) createImage(W, H);
int i = 0;
boolean end = false;
for (int row = 0; row < H && !end; row++)
{
for (int col = 0; col < W && !end; col++)
{
image.setRGB(col, row, clut[pi.get(i)]);
if (++i == pi.size())
{
i = 0;
end = true;
}
}
}
}
g.drawImage(image, 0, 0, getWidth(), getHeight(), null);
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
JFrame frame = new JFrame("Pi raster");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new PiRaster());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
来源：https://stackoverflow.com/questions/2626731/cannot-draw-pixels-pi-number-in-a-synesthetic-way