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Original file (768 × 768 pixels, file size: 126 KB, MIME type: image/jpeg)

Summary

Description
English: Self made, deeply iterated Buddhabrot. A version without lossy compression is available at Buddhabrot-deep.png (500 K) Some relevant code at User:Evercat/Buddhabrot.c
Date
Source Transferred from en.wikipedia to Commons.
Author Evercat at English Wikipedia

Licensing

Public domain This work has been released into the public domain by its author, Evercat at English Wikipedia. This applies worldwide.
In some countries this may not be legally possible; if so:
Evercat grants anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

C src code

// Nebulabrot / Buddhabrot generator.
// Brought to you by Wikipedia...
// Written by User:Evercat
//
// Released under the GNU Free Documentation License
// or the GNU Public License, whichever you prefer:
// November 23, 2004
//
// This code is lame and confusing. I apologise.
// As I like to point out, my C is self-taught.
//
// Note: some folk mention possible improvements on the talk page:
// http://en.wikipedia.org/wiki/User_talk:Evercat/Buddhabrot.c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define OUTFILE "buddhabrot"

////////////////////////////////////////////////////////////////////////////////////

#define WIDTH 1024
#define HEIGHT 768

#define CENTRE_X -0.451					// For full set try -0.451 by 0
#define CENTRE_Y 0
#define ZOOM 310					// Try 310

#define SOURCE_COLUMNS (WIDTH * 10)			// These lines control the number of source values iterated.
#define SOURCE_ROWS (HEIGHT * 10)			// Try WIDTH and HEIGHT * 10

#define UPDATETICK 100					// Report status every nth column reached

#define RED_MULTIPLIER 0.09				// Multiply the number of hits in a pixel by these values
#define GREEN_MULTIPLIER 0.11				// (needs to be lower the greater the number of source
#define BLUE_MULTIPLIER 0.18				// values and iterations, else image will be too bright)

#define COLOUR_OFFSET -230				// This value is added to the number of hits before a pixel is drawn.
							// It needs to be lower the more source columns/rows there are.
#define RED_ITERATIONS_LOWER 0
#define RED_ITERATIONS_UPPER 1000
#define GREEN_ITERATIONS_LOWER 0
#define GREEN_ITERATIONS_UPPER 1000
#define BLUE_ITERATIONS_LOWER 0
#define BLUE_ITERATIONS_UPPER 1000

#define SOURCE_LEFT_X -2.102613
#define SOURCE_RIGHT_X 1.200613
#define SOURCE_TOP_Y -1.237710
#define SOURCE_BOTTOM_Y 1.239710

#undef RANDOM_SOURCE

#define OPTIMISE		// Don't bother iterating some values obviously in the set.

#define reduce(foo) (foo)	// Macro to reduce colours, can use sqrt(n), log(n), etc, or just (n)

////////////////////////////////////////////////////////////////////////////////////

void drawpath(double x, double y, double target_startx, double target_starty, double pixel_width);
double rnd (void);
void drawbmp (char * filename);

////////////////////////////////////////////////////////////////////////////////////

long long redcount[WIDTH][HEIGHT];
long long greencount[WIDTH][HEIGHT];
long long bluecount[WIDTH][HEIGHT];

int iterations;

double red_multiplier = RED_MULTIPLIER;
double green_multiplier = GREEN_MULTIPLIER;
double blue_multiplier = BLUE_MULTIPLIER;

////////////////////////////////////////////////////////////////////////////////////

int main (int argc, char * argv[]) {

	int i, j, n;				// General purpose counters
	double x, y;				// Source coordinates of particle being tracked
	int source_column, source_row;		// Source grid location
	double r, s, nextr, nexts;		// Values as particle is iterated through the Mandelbrot function
	double x_jump, y_jump;			// Distances between particles in the source grid
	double target_startx, target_starty;	// Top-left coordinates of drawn area
	double target_endx, target_endy;	// Bottom-right coordinates of drawn area
	double pixel_width;			// Actual distance represented by a pixel in the drawn area

	char filename[200];

	for (i = 0; i < WIDTH; i++)
	{
		for (j = 0; j < HEIGHT; j++)
		{
			redcount[i][j] = 0;
			greencount[i][j] = 0;
			bluecount[i][j] = 0;
		}
	}

	target_startx = CENTRE_X - ((double) WIDTH / (ZOOM * 2));
	target_endx = CENTRE_X + ((double) WIDTH / (ZOOM * 2));

	target_starty = CENTRE_Y - ((double) HEIGHT / (ZOOM * 2));
	target_endy = CENTRE_Y + ((double) HEIGHT / (ZOOM * 2));

	pixel_width = (target_endx - target_startx) / WIDTH;

	x_jump = ((double) SOURCE_RIGHT_X - SOURCE_LEFT_X) / SOURCE_COLUMNS;
	y_jump = ((double) SOURCE_BOTTOM_Y - SOURCE_TOP_Y) / SOURCE_ROWS;
	
	iterations = RED_ITERATIONS_UPPER;
	if (GREEN_ITERATIONS_UPPER > iterations) iterations = GREEN_ITERATIONS_UPPER;
	if (BLUE_ITERATIONS_UPPER > iterations) iterations = BLUE_ITERATIONS_UPPER;

	// Main bit...

	x = SOURCE_LEFT_X;
	for (source_column = 0; source_column < SOURCE_COLUMNS; source_column++, x += x_jump)
	{
		y = SOURCE_TOP_Y;
		for (source_row = 0; source_row < SOURCE_ROWS; source_row++, y += y_jump)
		{

#ifdef OPTIMISE
			if 
			(
			   (x >  -1.2 && x <=  -1.1 && y >  -0.1 && y < 0.1)
			|| (x >  -1.1 && x <=  -0.9 && y >  -0.2 && y < 0.2)
			|| (x >  -0.9 && x <=  -0.8 && y >  -0.1 && y < 0.1)
			|| (x > -0.69 && x <= -0.61 && y >  -0.2 && y < 0.2)
			|| (x > -0.61 && x <=  -0.5 && y > -0.37 && y < 0.37)
			|| (x >  -0.5 && x <= -0.39 && y > -0.48 && y < 0.48)
			|| (x > -0.39 && x <=  0.14 && y > -0.55 && y < 0.55)
			|| (x >  0.14 && x <   0.29 && y > -0.42 && y < -0.07)
			|| (x >  0.14 && x <   0.29 && y >  0.07 && y < 0.42)
			) continue;
#endif
			r = 0; s = 0;
			for (n = 0; n <= iterations; n++)
			{
				nextr = ((r * r) - (s * s)) + x;
 				nexts = (2 * r * s) + y;
				r = nextr;
				s = nexts;
				if (n == iterations)
				{
					// drawpath(x, y, target_startx, target_starty, pixel_width);
					break;
				} else if ((r * r) + (s * s) > 4) {
					drawpath(x, y, target_startx, target_starty, pixel_width);
					break;
				}
			}
		
		}
	
		if (source_column % UPDATETICK == 0)
		{
			printf("Reached source column: %d of %d\n", source_column, SOURCE_COLUMNS);
		}
	
	}

	sprintf(filename, "%s r %d g %d b %d spp %d.bmp", OUTFILE, RED_ITERATIONS_UPPER, GREEN_ITERATIONS_UPPER, BLUE_ITERATIONS_UPPER, (SOURCE_COLUMNS / WIDTH) * (SOURCE_ROWS / HEIGHT));
	drawbmp(filename);
	
	printf("Done.\n");
	return 0;
}

void drawpath (double x, double y, double target_startx, double target_starty, double pixel_width)
{
	double r, s, nextr, nexts;
	int n;
	int xpixel, ypixel;

	r = 0; s = 0;
	for (n = 0; n <= iterations; n++)
	{
		nextr = ((r * r) - (s * s)) + x;
		nexts = (2 * r * s) + y;
		r = nextr;
		s = nexts;

		if ((r * r) + (s * s) > 4) return;

		xpixel = (r - target_startx) / pixel_width;
		ypixel = (s - target_starty) / pixel_width;
		if (xpixel > 0 && xpixel < WIDTH && ypixel > 0 && ypixel < HEIGHT)
		{
			if (n >= RED_ITERATIONS_LOWER && n <= RED_ITERATIONS_UPPER)
			{
				redcount[xpixel][ypixel] += 1;
			}
			if (n >= GREEN_ITERATIONS_LOWER && n <= GREEN_ITERATIONS_UPPER)
			{
				greencount[xpixel][ypixel] += 1;
			}
			if (n >= BLUE_ITERATIONS_LOWER && n <= BLUE_ITERATIONS_UPPER)
			{
				bluecount[xpixel][ypixel] += 1;
			}
		}

	}
	return;
}

void drawbmp (char * filename) {

unsigned int headers[13];
FILE * outfile;
int extrabytes;
int paddedsize;
int x; int y; int n;
int red, green, blue;

extrabytes = 4 - ((WIDTH * 3) % 4);                 // How many bytes of padding to add to each
                                                    // horizontal line - the size of which must
                                                    // be a multiple of 4 bytes.
if (extrabytes == 4)
   extrabytes = 0;

paddedsize = ((WIDTH * 3) + extrabytes) * HEIGHT;

// Headers...
// Note that the "BM" identifier in bytes 0 and 1 is NOT included in these "headers".
                     
headers[0]  = paddedsize + 54;      // bfSize (whole file size)
headers[1]  = 0;                    // bfReserved (both)
headers[2]  = 54;                   // bfOffbits
headers[3]  = 40;                   // biSize
headers[4]  = WIDTH;  // biWidth
headers[5]  = HEIGHT; // biHeight

// Would have biPlanes and biBitCount in position 6, but they're shorts.
// It's easier to write them out separately (see below) than pretend
// they're a single int, especially with endian issues...

headers[7]  = 0;                    // biCompression
headers[8]  = paddedsize;           // biSizeImage
headers[9]  = 0;                    // biXPelsPerMeter
headers[10] = 0;                    // biYPelsPerMeter
headers[11] = 0;                    // biClrUsed
headers[12] = 0;                    // biClrImportant

outfile = fopen(filename, "wb");

//
// Headers begin...
// When printing ints and shorts, we write out 1 character at a time to avoid endian issues.
//

fprintf(outfile, "BM");

for (n = 0; n <= 5; n++)
{
   fprintf(outfile, "%c", headers[n] & 0x000000FF);
   fprintf(outfile, "%c", (headers[n] & 0x0000FF00) >> 8);
   fprintf(outfile, "%c", (headers[n] & 0x00FF0000) >> 16);
   fprintf(outfile, "%c", (headers[n] & (unsigned int) 0xFF000000) >> 24);
}

// These next 4 characters are for the biPlanes and biBitCount fields.

fprintf(outfile, "%c", 1);
fprintf(outfile, "%c", 0);
fprintf(outfile, "%c", 24);
fprintf(outfile, "%c", 0);

for (n = 7; n <= 12; n++)
{
   fprintf(outfile, "%c", headers[n] & 0x000000FF);
   fprintf(outfile, "%c", (headers[n] & 0x0000FF00) >> 8);
   fprintf(outfile, "%c", (headers[n] & 0x00FF0000) >> 16);
   fprintf(outfile, "%c", (headers[n] & (unsigned int) 0xFF000000) >> 24);
}

//
// Headers done, now write the data...
//

for (y = HEIGHT - 1; y >= 0; y--)     // BMP image format is written from bottom to top...
{
   for (x = 0; x <= WIDTH - 1; x++)
   {

      red = reduce(redcount[x][y] + COLOUR_OFFSET) * red_multiplier;
      green = reduce(greencount[x][y] + COLOUR_OFFSET) * green_multiplier;
      blue = reduce(bluecount[x][y] + COLOUR_OFFSET) * blue_multiplier;
      
      if (red > 255) red = 255; if (red < 0) red = 0;
      if (green > 255) green = 255; if (green < 0) green = 0;
      if (blue > 255) blue = 255; if (blue < 0) blue = 0;
      
      // Also, it's written in (b,g,r) format...

      fprintf(outfile, "%c", blue);
      fprintf(outfile, "%c", green);
      fprintf(outfile, "%c", red);
   }
   if (extrabytes)      // See above - BMP lines must be of lengths divisible by 4.
   {
      for (n = 1; n <= extrabytes; n++)
      {
         fprintf(outfile, "%c", 0);
      }
   }
}

fclose(outfile);
return;
}

Original upload log

The original description page was here. All following user names refer to en.wikipedia.
  • 2005-02-15 21:28 Evercat 768×768× (234806 bytes) Self made

...

  • (cur | prev) 00:13, 9 November 2004 Evercat (talk | contribs | block) (9 bytes) (Self made)

Original upload log

Verklaring: (huidig) = huidige afbeelding, (verw) = verwijder de oude versie, (herstel) = breng oude versie terug.

Klik op de datum om de afbeeldingen die geüpload zijn op die datum te zien.

date/time username edit summary
24 nov 2004 15:29 nl:Gebruiker:82.41.253.249 (heh)
10 nov 2004 21:42 nl:Gebruiker:Pethan (bron)
10 nov 2004 21:38 nl:Gebruiker:Pethan (Buddha Mandelbrot)

nl:Afbeelding:Buddhabrot-deep.jpg

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9 November 2004

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440760e72cde9462c96da5d70512b8047924eb96

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768 pixel

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Date/TimeThumbnailDimensionsUserComment
current15:13, 21 January 2006Thumbnail for version as of 15:13, 21 January 2006768 × 768 (126 KB)MaksimLa bildo estas kopiita de wikipedia:nl. La originala priskribo estas: Buddha Mandelbrot van en:wikipedia door Evercat {{GFDL}} {| border="1" ! date/time || username || edit summary |---- | 24 nov 2004 15:29 || [[:nl:Gebruiker:82.4

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