Sierpinski arrowhead curve: Difference between revisions
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dc.SavePNG("sierpinski_arrowhead_curve.png")
}</syntaxhighlight>
=={{header|Java}}==
<syntaxhighlight lang="java">
import java.awt.Point;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public final class SierpinskiArrowhead {
public static void main(String[] aArgs) throws IOException {
List<Point> points = initialStraightLine();
for ( int i = 1; i < 8; i++ ) {
points = nextIteration(points);
}
String text = sierpinskiArrowheadText(points, IMAGE_SIZE);
Files.write(Paths.get("C:/Users/psnow/Desktop/sierpinkskiArrowhead.svg"), text.getBytes());
}
private static List<Point> initialStraightLine() {
final int margin = 50;
final int boxSize = IMAGE_SIZE - 2 * margin;
final int x = margin;
final int y = Math.round(( IMAGE_SIZE + SQRT3_2 * boxSize ) / 2.0F);
List<Point> points = Arrays.asList( new Point(x, y), new Point(x + boxSize, y) );
return points;
}
private static List<Point> nextIteration(List<Point> aPoints) {
List<Point> result = new ArrayList<Point>();
for ( int i = 0; i < aPoints.size() - 1; i++ ) {
final int x0 = aPoints.get(i).x;
final int y0 = aPoints.get(i).y;
final int x1 = aPoints.get(i + 1).x;
final int y1 = aPoints.get(i + 1).y;
final int dx = x1 - x0;
result.add( new Point(x0, y0) );
if ( y0 == y1 ) {
final float d = Math.abs(dx) * SQRT3_2 / 2;
result.add( new Point(x0 + dx / 4, Math.round(y0 - d)) );
result.add( new Point(x1 - dx / 4, Math.round(y0 - d)) );
} else if ( y1 < y0 ) {
result.add( new Point(x1, y0));
result.add( new Point(x1 + dx / 2, ( y0 + y1 ) / 2) );
} else {
result.add( new Point(x0 - dx / 2, ( y0 + y1 ) / 2) );
result.add( new Point(x0, y1) );
}
}
result.add(aPoints.get(aPoints.size() - 1));
return result;
}
private static String sierpinskiArrowheadText(List<Point> aPoints, int aSize) {
StringBuilder text = new StringBuilder();
text.append("<svg xmlns='http://www.w3.org/2000/svg'");
text.append(" width='" + aSize + "' height='" + aSize + "'>\n");
text.append("<rect width='100%' height='100%' fill='white'/>\n");
text.append("<path stroke-width='1' stroke='black' fill='white' d='");
for ( int i = 0; i < aPoints.size(); i++ ) {
text.append(( i == 0 ? "M" : "L" ) + aPoints.get(i).x + ", " + aPoints.get(i).y + " ");
}
text.append("'/>\n</svg>\n");
return text.toString();
}
private static final float SQRT3_2 = (float) Math.sqrt(3.0F) / 2.0F;
private static final int IMAGE_SIZE = 700;
}
</syntaxhighlight>
{{ out }}
<pre>
[[Media:sierpinskiArrowhead.svg]]
</pre>
=={{header|jq}}==
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