Added sources.

Makefile

@@ -0,0 +1,16 @@
+LDLIBS = -lm
+
+all: CFLAGS = -O3 -ansi -pedantic
+all: ds
+
+debug: CFLAGS = -g -ansi -pedantic
+debug: ds
+
+ds: main.o ds.o
+
+main.o: main.c ds.h
+
+ds.o: ds.c ds.h
+
+clean:
+	$(RM) *.o ds

README.md

@@ -2,3 +2,17 @@ DS-Island-generator
 ===================
 
 A procedural island generator based on the diamond-square mid point displacement and the particle deposition algorithms.
+
+Compile with:
+
+    make
+
+Execute as:
+
+    ./ds N PREFIX
+
+Where N is a positive integer greater than zero and PREFIX is a string to append to the output file names.
+
+The diamond-square mid point displacement implementation is a port of the code outlined in [this post] [1] at Stack Overflow.
+
+ [1]: http://stackoverflow.com/a/2773032

ds.c

@@ -0,0 +1,209 @@
+#ifndef __cplusplus
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <float.h>
+#include <math.h>
+#include <string.h>
+
+#else
+
+#include <cstdio>
+#include <cstdlib>
+#include <ctime>
+#include <cfloat>
+#include <cmath>
+#include <cstring>
+
+#endif
+
+#include "ds.h"
+
+static const float SEED = 1000.0;
+
+static float randomFloat ();
+
+/**
+ * Port of the java implementation outlined here http://stackoverflow.com/a/2773032
+ */
+void ds ( float *** map, const unsigned int DATA_SIZE ) {
+  float    avg, r, h = SEED / 2.0;
+  int       sideLength, halfSide, x, y;
+
+  srand( time( NULL ) );
+
+  ( * map )[ 0 ][ 0 ] = ( * map )[ 0 ][ DATA_SIZE - 1 ] = ( * map )[ DATA_SIZE - 1 ][ 0 ] = ( * map )[ DATA_SIZE - 1 ][ DATA_SIZE - 1 ] = h;
+
+  for ( sideLength = DATA_SIZE - 1; sideLength >= 2; sideLength /= 2, h /= 2.0 ) {
+    halfSide = sideLength / 2;
+
+    for ( x = 0; x < DATA_SIZE -1; x += sideLength ) {
+      for ( y = 0; y < DATA_SIZE - 1; y += sideLength ) {
+	avg = ( * map )[ x ][ y ] +
+	  ( * map )[ x + sideLength ][ y ] +
+	  ( * map )[ x ][ y + sideLength ] +
+	  ( * map )[ x + sideLength ][ y + sideLength ];
+	avg /= 4.0;
+
+	r = randomFloat();
+
+	( * map )[ x + halfSide ][ y + halfSide ] = avg + ( r * 2.0 * h ) - h;
+      }
+    }
+
+    for ( x = 0; x < DATA_SIZE - 1; x += halfSide ) {
+      for ( y =  ( x + halfSide ) % sideLength; y < DATA_SIZE - 1; y += sideLength ) {
+	avg = ( * map )[ ( x - halfSide + DATA_SIZE ) % DATA_SIZE ][ y ] +
+	  ( * map )[ ( x + halfSide ) % DATA_SIZE ][ y ] +
+	  ( * map )[ x ][ ( y + halfSide ) % DATA_SIZE ] +
+	  ( * map )[ x ][ ( y - halfSide + DATA_SIZE ) % DATA_SIZE ];
+	avg /= 4.0;
+
+	r = randomFloat();
+
+	avg = avg + ( r * 2.0 * h ) - h;
+
+	( * map )[ x ][ y ] = avg;
+
+	if ( x == 0 ) ( * map )[ DATA_SIZE - 1 ][ y ] = avg;
+	if ( y == 0 ) ( * map )[ x ][ DATA_SIZE - 1 ] = avg;
+      }
+    }
+  }
+}
+
+void island ( int ***imap, unsigned int MAP_SIZE ) {
+  const int part = ( MAP_SIZE * 3000 ) / 513;
+  const int life = ( MAP_SIZE * 5000 ) / 513;
+  int x, y, dx, dy, i, c, n, nx, ny, l;
+
+  srand( time( NULL ) );
+
+  for ( i = 0; i < part; ++i ) {
+    x = ( MAP_SIZE / 4 ) + ( random() % ( MAP_SIZE / 2 ) );
+    y = ( MAP_SIZE / 4 ) + ( random() % ( MAP_SIZE / 2 ) );
+
+    for ( l = life; l >= 0; l-- ) {
+      dx = ( random() % 3 ) - 1;
+      dy = ( random() % 3 ) - 1;
+
+      ( * imap )[ x ][ y ] += 1;
+
+      c = ( * imap )[ x ][ y ];
+
+      nx = ( x + dx );
+      ny = ( y + dy );
+    
+      if ( nx < 0 || nx >= MAP_SIZE || ny < 0 || ny >= MAP_SIZE ) {
+	l--;
+	continue;
+      }
+
+      if ( ( * imap )[ nx ][ ny ] <= c ) {
+	  ( * imap )[ nx ][ ny ] += 1;
+      }
+
+      x = nx;
+      y = ny;
+    }
+  }
+}
+
+void norm ( float *** fmap, unsigned int MAP_SIZE ) {
+  int i, j;
+  float max = -FLT_MAX;
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      max = abs( ( * fmap )[ i ][ j ] ) > max ? abs ( ( * fmap )[ i ][ j ] ) : max;
+    }
+  }
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      ( * fmap )[ i ][ j ] += max;
+    }
+  }
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      max = abs( ( * fmap )[ i ][ j ] ) > max ? abs ( ( * fmap )[ i ][ j ] ) : max;
+    }
+    }
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      ( * fmap )[ i ][ j ] /= max;
+    }
+  }
+}
+
+void normInt ( int *** map, unsigned int MAP_SIZE ) {
+  int i, j, max = -1;
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      max = max < ( * map )[ i ][ j ] ? ( * map )[ i ][ j ] : max;
+    }
+  }
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      ( * map )[ i ][ j ] = ( int ) ( ( ( float ) ( * map )[ i ][ j ] / ( float ) max ) * 255.0 );
+    }
+  }
+}
+
+extern void mult ( float *** fmap, int *** imap, unsigned int MAP_SIZE ) {
+  int i, j;
+  
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      /*fprintf ( stderr, "%f %d\n", ( * fmap )[ i ][ j ], ( * imap )[ i ][ j ] );*/
+      ( * imap )[ i ][ j ] = ( int )( ( ( * fmap )[ i ][ j ] * ( ( float ) ( * imap )[ i ][ j ] / 255.0f ) ) * 250.0f );
+    }
+  }
+
+}
+
+void smooth ( int *** map, unsigned int MAP_SIZE) {
+  int i, j, avg, **temp;
+  
+  temp = ( int ** ) malloc ( sizeof ( int * ) * MAP_SIZE );
+  for ( i = 0; i < MAP_SIZE; ++i ){
+    temp[ i ] = ( int * ) malloc ( sizeof ( int ) * MAP_SIZE );
+  }
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      avg = 0;
+
+      avg += ( * map )[ i ][ j ];
+      avg += ( * map )[ ( i + 1 ) % MAP_SIZE ][ j ];
+      avg += ( * map )[ ( i - 1 ) < 0 ? MAP_SIZE - 1 : i - 1 ][ j ];
+      avg += ( * map )[ i ][ ( j + 1 ) % MAP_SIZE ];
+      avg += ( * map )[ i ][ ( j  - 1 ) < 0 ? MAP_SIZE - 1 : j - 1 ];
+      avg += ( * map )[ ( i + 1 ) % MAP_SIZE ][ ( j + 1 ) % MAP_SIZE ];
+      avg += ( * map )[ ( i + 1 ) % MAP_SIZE ][ ( j  - 1 ) < 0 ? MAP_SIZE - 1 : j - 1 ];
+      avg += ( * map )[ ( i - 1 ) < 0 ? MAP_SIZE - 1 : i - 1 ][ ( j + 1 ) % MAP_SIZE ];
+      avg += ( * map )[ ( i - 1 ) < 0 ? MAP_SIZE - 1 : i - 1 ][ ( j  - 1 ) < 0 ? MAP_SIZE - 1 : j - 1 ];
+
+      avg /= 9;
+
+      temp[ i ][ j ] = avg;
+    }
+  }
+
+  for ( i = 0; i < MAP_SIZE; ++i ){
+    memcpy ( ( * map )[ i ], temp[ i ], MAP_SIZE * sizeof ( int ) );
+  }
+
+  free ( temp );
+}
+
+static float randomFloat() {
+  float r =  ( float ) random() / ( float ) RAND_MAX;
+  r = ( r * 2.0 ) - 1.0;
+  return r;
+}

ds.h

@@ -0,0 +1,43 @@
+#ifndef DS_H
+#define DS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  /**
+   * Generate a diamond-square fractal map.
+   */
+  extern void ds ( float ***, const unsigned int );
+  
+  /**
+   * Generate a mask using particle deposition.
+   */
+  extern void island ( int ***, unsigned int );
+
+  /**
+   * Normalize a float matrix between 0 and 1.
+   */
+  extern void norm ( float ***, unsigned int );
+
+  /**
+   * Normalize an int matrix between 0 and 255.
+   */
+  extern void normInt ( int ***, unsigned int );
+
+  /**
+   * Perform a 3x3 average blur.
+   */
+  extern void smooth ( int ***, unsigned int );
+
+  /**
+   * Multiply the diamond square map with the island mask.
+   * Both matrices must have been normalized before.
+   */
+  extern void mult ( float ***, int *** , unsigned int);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

main.c

@@ -0,0 +1,223 @@
+/**
+ * Test main for the Diamond-Square island generator.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <float.h>
+#include <string.h>
+
+#include "ds.h"
+
+struct COLOR {
+  unsigned char r;
+  unsigned char g;
+  unsigned char b;
+};
+
+static void printMapAsPgm ( int ***, const unsigned int, char * );
+static void printMapAsPgm2 ( int ***, const unsigned int, char * );
+static void printFloatMapAsPgm ( float ***, const unsigned int, char * );
+static void printMapAsPpm ( int ***, const unsigned int, char * );
+static struct COLOR getTerrainType( int );
+
+int main ( int argc, char **argv ) {
+  int              i, m, ** imap;
+  unsigned int     n = 0;
+  float **        map;
+
+  if ( argc < 3 ) {
+    fprintf ( stderr, "Usage: %s N <prefix>\nN is an integer greater than 0.\n", argv[0] );
+    return EXIT_FAILURE;
+  }
+
+  m = atoi( argv[1] );
+
+  if ( m <= 0 ) {
+    fprintf ( stderr, "N must be an integer greater than zero: %d\n", m );
+    return EXIT_FAILURE;
+  }
+
+  n = (unsigned int)( pow ( 2.0, m ) ) + 1;
+
+  map = ( float ** ) malloc ( sizeof ( float * ) * n);
+  for ( i = 0; i < n; ++i ) {
+    map[ i ] = ( float * ) calloc ( n, sizeof ( float ) );
+  }
+
+  imap = ( int ** ) malloc ( sizeof ( int * ) * n);
+  for ( i = 0; i < n; ++i ) {
+    imap[ i ] = ( int * ) calloc ( n, sizeof ( int ) );
+  }
+
+  ds ( &map, n );
+  island ( &imap, n );
+  normInt ( &imap, n );
+  printMapAsPgm2 ( &imap, n, argv[2] );
+  norm ( &map, n );
+  printFloatMapAsPgm ( &map, n, argv[2] );
+  mult ( &map, &imap, n );
+  smooth( &imap, n );
+  normInt ( &imap, n );
+  printMapAsPgm ( &imap, n, argv[2] );
+  printMapAsPpm ( &imap, n, argv[2] );
+
+  for ( i = 0; i < n; ++i ) {
+    free ( map[ i ] );
+  }
+  free ( map );
+
+  for ( i = 0; i < n; ++i ) {
+    free ( imap[ i ] );
+  }
+  free ( imap );
+
+  return EXIT_SUCCESS;
+}
+
+void printFloatMapAsPgm ( float *** map, const unsigned int MAP_SIZE, char * fn ) {
+  int i, j, max = -1;
+  FILE * f;
+  char * filename = ( char * ) malloc ( ( strlen ( "ds_map.pgm" ) + strlen ( fn ) ) * sizeof ( char ) + 1);
+  
+  strcpy ( filename, fn );
+  strcat ( filename, "ds_map.pgm" );
+
+  f = fopen ( filename , "w" );
+
+  fprintf ( f, "P2\n" );
+  fprintf ( f, "%u %u\n", MAP_SIZE, MAP_SIZE );
+  fprintf ( f, "255\n" );
+  
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      fprintf( f, "%d ", ( int )( ( * map )[ i ][ j ] * 255.0f ) );
+    }
+    fprintf( f, "\n" );
+  }
+
+  fclose ( f );
+  free ( filename );
+}
+
+void printMapAsPgm ( int *** map, const unsigned int MAP_SIZE, char * fn ) {
+  int i, j, max = -1;
+  FILE * f;
+  char * filename = ( char * ) malloc ( ( strlen ( "hmmap.pgm" ) + strlen ( fn ) ) * sizeof ( char ) + 1);
+  
+  strcpy ( filename, fn );
+  strcat ( filename, "hmmap.pgm" );
+
+  f = fopen ( filename , "w" );
+
+  f = fopen ( filename, "w" );
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      max = max < ( * map )[ i ][ j ] ? ( * map )[ i ][ j ] : max;
+    }
+  }
+
+  fprintf ( f, "P2\n" );
+  fprintf ( f, "%u %u\n", MAP_SIZE, MAP_SIZE );
+  fprintf ( f, "%d\n", max );
+  
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      fprintf( f, "%d ", ( * map )[ i ][ j ] );
+    }
+    fprintf( f, "\n" );
+  }
+
+  fclose ( f );
+}
+
+void printMapAsPgm2 ( int *** map, const unsigned int MAP_SIZE, char * fn ) {
+  int i, j, max = -1;
+  FILE * f;
+  char * filename = ( char * ) malloc ( ( strlen ( "is.pgm" ) + strlen ( fn ) ) * sizeof ( char ) + 1);
+  
+  strcpy ( filename, fn );
+  strcat ( filename, "is.pgm" );
+
+  f = fopen ( filename , "w" );
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      max = max < ( * map )[ i ][ j ] ? ( * map )[ i ][ j ] : max;
+    }
+  }
+
+  fprintf ( f, "P2\n" );
+  fprintf ( f, "%u %u\n", MAP_SIZE, MAP_SIZE );
+  fprintf ( f, "%d\n", max );
+  
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      fprintf( f, "%d ", ( * map )[ i ][ j ] );
+    }
+    fprintf( f, "\n" );
+  }
+
+  fclose ( f );
+  free ( filename );
+}
+
+void printMapAsPpm ( int *** map, const unsigned int MAP_SIZE, char * fn ) {
+  struct COLOR c;
+  int i, j;
+  FILE * f;
+  char * filename = ( char * ) malloc ( ( strlen ( "map.ppm" ) + strlen ( fn ) ) * sizeof ( char ) + 1);
+  
+  strcpy ( filename, fn );
+  strcat ( filename, "map.ppm" );
+
+  f = fopen ( filename, "w" );
+
+  fprintf ( f, "P3\n" );
+  fprintf ( f, "%u %u\n", MAP_SIZE, MAP_SIZE );
+  fprintf ( f, "255\n" );
+
+  for ( i = 0; i < MAP_SIZE; ++i ) {
+    for ( j = 0; j < MAP_SIZE; ++j ) {
+      c = getTerrainType( ( * map )[ i ][ j ] );
+      fprintf( f, "%d %d %d\t", c.r, c.g, c.b );
+    }
+    fprintf( f, "\n" );
+  }
+
+  fclose ( f );
+  free ( filename );
+}
+
+struct COLOR getTerrainType( int h) {
+  struct COLOR c;
+
+  if ( h < 30 ) {
+    if ( h < 15 ) {
+      c.r = 64; c.g = 64; c.b = 200;
+      return c;
+    } else {
+      c.r = 128; c.g = 128; c.b = 255;
+      return c;
+    }
+  } else {
+    if ( h < 40 ) {
+      c.r = 255; c.g = 234; c.b = 150;
+      return c;
+    } else if ( h >= 40 && h < 100 ) {
+      c.r = 16; c.g = 180; c.b = 40;
+      return c;
+    } else if ( h >= 100 && h < 150 ) {
+      c.r = 70; c.g = 164; c.b = 25;
+      return c;
+    } else if ( h >= 180 ) {
+      c.r = 200; c.g = 200; c.b = 200;
+      return c;
+    } else {
+      c.r = 143; c.g = 111; c.b = 81;
+      return c;
+    }
+  }
+}