Sierpinski curve: Difference between revisions
Added Java solution
(Added C++ solution) |
(Added Java solution) |
||
Line 187:
dc.Stroke()
dc.SavePNG("sierpinski_curve.png")
}</lang>
=={{header|Java}}==
{{trans|C++}}
<lang java>import java.io.*;
public class SierpinskiCurve implements AutoCloseable {
public static void main(final String[] args) {
try (SierpinskiCurve s = new SierpinskiCurve("sierpinski_curve.svg", 545)) {
s.currentAngle = 45;
s.currentX = 535;
s.currentY = 5;
s.lineLength = 7;
s.execute(rewrite(5));
s.end();
} catch (final Exception ex) {
ex.printStackTrace();
}
}
private SierpinskiCurve(final String file, final int size) throws IOException {
writer = new BufferedWriter(new FileWriter(file));
write("<svg xmlns='http://www.w3.org/2000/svg' width='%d' height='%d'>\n", size, size);
write("<rect width='100%%' height='100%%' fill='white'/>\n");
write("<path stroke-width='1' stroke='black' fill='none' d='");
}
public void close() throws IOException {
writer.close();
}
private void end() throws IOException {
write("'/>\n</svg>\n");
}
private void execute(final String s) throws IOException {
write("M%g,%g\n", currentX, currentY);
for (int i = 0, n = s.length(); i < n; ++i) {
switch (s.charAt(i)) {
case 'F':
case 'G':
line(lineLength);
break;
case '+':
turn(-ANGLE);
break;
case '-':
turn(ANGLE);
break;
}
}
}
private void line(final double length) throws IOException {
final double theta = (Math.PI * currentAngle) / 180.0;
currentX += length * Math.cos(theta);
currentY += length * Math.sin(theta);
write("L%g,%g\n", currentX, currentY);
}
private void turn(final int angle) {
currentAngle = (currentAngle + angle) % 360;
}
private void write(final String format, final Object... args) throws IOException {
writer.write(String.format(format, args));
}
private static String rewrite(final int order) {
String s = AXIOM;
for (int i = 0; i < order; ++i) {
final StringBuilder sb = new StringBuilder();
for (int j = 0, n = s.length(); j < n; ++j) {
final char ch = s.charAt(j);
if (ch == 'X')
sb.append(PRODUCTION);
else
sb.append(ch);
}
s = sb.toString();
}
return s;
}
private final Writer writer;
private double lineLength;
private double currentX;
private double currentY;
private int currentAngle;
private static final String AXIOM = "F--XF--F--XF";
private static final String PRODUCTION = "XF+G+XF--F--XF+G+X";
private static final int ANGLE = 45;
}</lang>
| |||