Unable to draw pixels, Pi number in Synesthetic way

Question

I want to print each digit of the pi number as a color pixel, so I get the input with the pi number, then parse it in the list, each node containing the digit (I know, I will use the array later), but I never get it on the screen. .. Can someone help me 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); } } 

Answer 1

I am not familiar with MemoryImageSource . Here are the first 16,300 digits of π repeated in BufferedImage and using your color chart.

 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); } }); } } 

Answer 2

@trashgod

Thanks for your answer, I modified it a bit to achieve what I was looking for; )

Now you can easily change the width in order to better see the image and adjust its contents, and the number is not repeated, which facilitates the perception of drawings (if any). Oh, and I added about 2 ~ 3 lines at the end to clarify this.

 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); } }); } }