Munching squares
Render a graphical pattern where each pixel is colored by the value of 'x xor y' from a color table.
C
<lang c>#include <stdlib.h>
- include <stdio.h>
int main(void) {
const int width = 512, height = 512; const unsigned int color_table_size = 256; unsigned char color_table[color_table_size][3]; unsigned int i, x, y; for (i = 0; i < color_table_size; ++i) { color_table[i][0] = 255 - i; /* red */ color_table[i][1] = i / 2; /* green */ color_table[i][2] = i; /* blue */ } FILE *fp = fopen("xor_pattern.ppm", "wb"); (void) fprintf(fp, "P6\n%d %d\n255\n", width, height); for (y = 0; y < height; ++y) { for (x = 0; x < width; ++x) { (void) fwrite(color_table[(x ^ y) % color_table_size], 1, 3, fp); } } (void) fclose(fp); return EXIT_SUCCESS;
}</lang>
D
<lang d>import std.stdio;
void main() {
enum width = 512, height = 512;
auto f = File("xor_pattern.ppm", "wb"); f.writefln("P6\n%d %d\n255", width, height); foreach (y; 0 .. height) foreach (x; 0 .. width) { ubyte c = (x ^ y) & ubyte.max; ubyte[3] rgb = [255 - c, c / 2, c]; f.rawWrite(rgb); }
}</lang>
Java
This example will repeat the pattern if you expand the window. <lang java>import java.awt.Color; import java.awt.Graphics;
import javax.swing.JFrame; import javax.swing.JPanel;
public class XorPattern extends JFrame{
private JPanel xorPanel;
public XorPattern(){ xorPanel = new JPanel(){ @Override public void paint(Graphics g) { for(int y = 0; y < XorPattern.this.xorPanel.getHeight();y++){ for(int x = 0; x < XorPattern.this.xorPanel.getWidth();x++){ g.setColor(new Color(0, (x ^ y) % 256, 0)); g.drawLine(x, y, x, y); } } } }; add(xorPanel); setSize(300, 300); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setVisible(true); }
public static void main(String[] args){ new XorPattern(); }
Mathematica
<lang Mathematica> ListDensityPlot[
Table[Table[ FromDigits[BitXor[IntegerDigits[x, 2, 8], IntegerDigits[y, 2, 8]], 2], {x, 0, 255}], {y, 0, 255}]]
</lang>
Output #1:
<lang Mathematica> ArrayPlot[Array[BitXor, {511, 511}]] </lang>
Output #2:
OCaml
<lang ocaml>open Graphics
let () =
open_graph ""; resize_window 256 256; for y = 0 to pred (size_y()) do for x = 0 to pred (size_x()) do let v = (x lxor y) land 0xFF in set_color (rgb v (255 - v) 0); plot x y done; done; ignore(read_key())</lang>
Run with:
$ ocaml graphics.cma xor_pattern.ml
Output:
PHP
<lang php>header("Content-Type: image/png");
$w = 256; $h = 256;
$im = imagecreate($w, $h)
or die("Cannot Initialize new GD image stream");
$color = array(); for($i=0;$i<256;$i++) {
array_push($color,imagecolorallocate($im,sin(($i)*(2*3.14/256))*128+128,$i/2,$i));
}
for($i=0;$i<$w;$i++) {
for($j=0;$j<$h;$j++) { imagesetpixel($im,$i,$j,$color[$i^$j]); }
}
imagepng($im); imagedestroy($im);</lang>
Tcl
<lang tcl>package require Tk
proc xorImage {img table} {
set data {} set h [image height $img] set w [image width $img] for {set y 0} {$y < $h} {incr y} {
set row {} for {set x 0} {$x < $w} {incr x} { lappend row [lindex $table [expr {($x^$y) % [llength $table]}]] } lappend data $row
} $img put $data
} proc inRange {i f t} {expr {$f + ($t-$f)*$i/255}} proc mkTable {rf rt gf gt bf bt} {
for {set i 0} {$i < 256} {incr i} {
lappend tbl [format "#%02x%02x%02x" \ [inRange $i $rf $rt] [inRange $i $gf $gt] [inRange $i $bf $bt]]
} return $tbl
}
set img [image create photo -width 512 -height 512] xorImage $img [mkTable 0 255 64 192 255 0] pack [label .l -image $img]</lang>