/* This source-code is (C) 2009 by folkert@vanheusden.com
 * and was released under GPL version 2.
 *
 * This Java program generates a script for Povray. It calculates the
 * 3D Mandelbrot-fractal as designed by Daniel White.
 * Daniel's site is at: http://www.skytopia.com/project/fractal/mandelbulb.html
 * It will calculate a hollow one; if you e.g. cut some of it away (by e.g.
 * limiting the z-direction, see *1), you'll see it is hollow.
 *
 * Please note that while this program hardly uses any memory, it the
 * povray-renderer does. If you would like to optimize this program, start
 * by replacing the box { ... } by a mesh { ... }.
 *
 * You might want to adapt the first nine final declared variables like
 * width/height, order, x1/y1 etc. Also the texture might be worth looking at.
 *
 * Compile with javac Fractal3DMandDW.java
 * Invoke with java Fractal3DMandDW > Fractal3DMandDW.pov
 * After that you can delete the "testdw.bitmap" file as it is entirely
 * temporarily.
 * Render the pov-file with e.g.:
 *  povray +W800 +H600 +A0.1 +FN16 +I Fractal3DMandDW.pov
 * This will procude Fractal3DMandDW.png which should be viewable with all
 * picture viewers and webbrowsers.
 */
import java.io.FileOutputStream;
import java.io.RandomAccessFile;

class Fractal3DMandDW
{
	final static int width = 512, height = 512, depth = 512;
	final static double cameraX = 512.0, cameraY = 512.0, cameraZ = 512.0;
	final static double cameraPointAtX = 256.0, cameraPointAtY = 256.0, cameraPointAtZ = 256.0;
	// the following texture is a glass-like texture. replace by e.g.:
	// texture { pigment { color <0.5, 1.0, 0.5> } }
	// to have a solid object
	final static String texture = "texture { pigment { color red 1.0 green 1.0 blue 1.0 filter 0.95 } finish { ambient 0.0 diffuse 0.0 reflection 0.1 phong 0.3 phong_size 90 } }";
	final static int iterations = 256;
	final static double order = 8.0;
	final static double x1 = -2.0, x2 = 2.0;
	final static double y1 = -2.0, y2 = 2.0;
	final static double z1 = -2.0, z2 = 2.0;
	//
	final static double xStep = (x2 - x1) / (double)width;
	final static double yStep = (y2 - y1) / (double)height;
	final static double zStep = (z2 - z1) / (double)depth;

	public static boolean getBit(RandomAccessFile raf, int width, int height, int x, int y, int z) throws Exception
	{
		int bit = 7 - (x & 7);
		int offset = (x / 8) + (y * (width / 8)) + (z * (width / 8) * height);

		raf.seek(offset);

		int curByte = raf.readByte();

		if ((curByte & (1 << bit)) != 0)
			return true;

		return false;
	}

	public static void main(String [] args)
	{
		System.err.println("Fractal3DMandDW (C) 2009 by folkert@vanheusden.com");
		System.err.println("");

		try
		{
			String fileName = "testdw.bitmap";
			FileOutputStream fos = new FileOutputStream(fileName);
			int bOut = 0, bits = 0;

			int x, y, z;

			for(z=0; z<depth; z++)
			{
				double c = z1 + zStep * (double)z;

				System.err.println("" + (depth - z));

				for(y=0; y<height; y++)
				{
					double b = y1 + yStep * (double)y;

					for(x=0; x<width; x++)
					{
						double a = x1 + xStep * (double)x;
						int it = 0;
						double xc=0.0, yc=0.0, zc=0.0;

						for(;;)
						{
							it++;

							double xck = xc * xc;
							double yck = yc * yc;
							double zck = zc * zc;
							double len = xck + yck + zck;
							if (len >= 8.0 || it > iterations)
								break;

							double r = Math.sqrt(len);
							double theta = Math.atan2(Math.sqrt(xck + yck), zc);
							double phi = Math.atan2(yc, xc);

							double ro = Math.pow(r, order);
							double sto = Math.sin(theta * order);
							double newx = ro * sto * Math.cos(phi*order) + a;
							double newy = ro * sto * Math.sin(phi*order) + b;
							double newz = ro * Math.cos(theta*order) + c;

							xc = newx;
							yc = newy;
							zc = newz;
						}

						bOut <<= 1;
						if (it > iterations)
							bOut |= 1;
						bits++;

						if (bits == 8)
						{
							fos.write(bOut);
							bits = bOut = 0;
						}
					}
				}
			}
			fos.close();


			RandomAccessFile raf = new RandomAccessFile(fileName, "r");
			System.out.println("camera { location<" + cameraX + ", " + cameraY + ", " + cameraZ + "> look_at<" + cameraPointAtX + ", " + cameraPointAtY + ", " + cameraPointAtZ + "> }");
			System.out.println("light_source { <-3000, -3000, -3000 > color rgb <1.0, 1.0, 1.0> }");
			System.out.println("light_source { <-3000, -3000,  3000 > color <1.0, 1.0, 1.0> }");
			System.out.println("light_source { <-3000,  3000, -3000 > color <1.0, 1.0, 1.0> }");
			System.out.println("light_source { <-3000,  3000,  3000 > color <1.0, 1.0, 1.0> }");
			System.out.println("light_source { < 3000, -3000, -3000 > color <1.0, 1.0, 1.0> }");
			System.out.println("light_source { < 3000, -3000,  3000 > color <1.0, 1.0, 1.0> }");
			System.out.println("light_source { < 3000,  3000, -3000 > color <1.0, 1.0, 1.0> }");
			System.out.println("light_source { < 3000,  3000,  3000 > color <1.0, 1.0, 1.0> }");
			// for(z=1; z<(depth / 2); z++)  // *1
			for(z=1; z<(depth - 1); z++)
			{
				System.err.println("" + (depth - z));

				for(y=1; y<(height - 1); y++)
				{
					for(x=1; x<(width - 1); x++)
					{
						if (!getBit(raf, width, height, x, y, z))
							continue;

						int cnt = 0;
						cnt += getBit(raf, width, height, x - 1, y    , z    ) ? 1 : 0;
						cnt += getBit(raf, width, height, x    , y - 1, z    ) ? 1 : 0;
						cnt += getBit(raf, width, height, x + 1, y    , z    ) ? 1 : 0;
						cnt += getBit(raf, width, height, x    , y + 1, z    ) ? 1 : 0;
						cnt += getBit(raf, width, height, x    , y    , z - 1) ? 1 : 0;
						cnt += getBit(raf, width, height, x    , y    , z + 1) ? 1 : 0;

						if (cnt < 6)
						{
							System.out.println(" box{ <" + x + ", " + y + ", " + z + "> <" + (x + 1.0) + ", " + (y + 1.0) + ", " + (z + 1.0) + "> " +
								texture +
								" }");
						}
					}
				}
			}

			raf.close();
		}
		catch(Exception e)
		{
			System.out.println("Exception: " + e);
		}
	}
}