initial C import

src/dir.c

@@ -0,0 +1,39 @@
+#include "dir.h"
+#include "rnd.h"
+
+
+int directions[] = {
+	DIRECTION_N,
+	DIRECTION_NE,
+	DIRECTION_E,
+	DIRECTION_SE,
+	DIRECTION_S,
+	DIRECTION_SW,
+	DIRECTION_W,
+	DIRECTION_NW
+};
+
+
+int get_direction(int simple) {
+	if(simple) {
+		if(random_number(0, 1) == 0) {
+			return DIRECTION_E;
+		} else {
+			return DIRECTION_S;
+		}
+	} else {
+		return directions[random_number(0, NUM_DIRECTIONS)];
+	}
+}
+
+#ifdef DEBUG_DIR_MAIN
+#include <stdio.h>
+
+int main() {
+	int n = 32;
+	while(--n > 0) {
+		printf("%d\n", get_direction(1));
+	}
+	return 0;
+}
+#endif

src/dir.h

@@ -0,0 +1,19 @@
+#ifndef WORDSEARCH_DIR
+#define WORDSEARCH_DIR
+
+enum direction {
+	DIRECTION_N,
+	DIRECTION_NE,
+	DIRECTION_E,
+	DIRECTION_SE,
+	DIRECTION_S,
+	DIRECTION_SW,
+	DIRECTION_W,
+	DIRECTION_NW
+};
+
+#define NUM_DIRECTIONS 8
+
+int get_direction(int simple);
+
+#endif

src/grid.c

@@ -0,0 +1,69 @@
+#include <stdlib.h>
+
+#include "rnd.h"
+#include "dir.h"
+#include "grid.h"
+
+bounds *get_bounds(int height, int width, enum direction direction, int length) {
+	if(length > height || length > width) {
+		return NULL;
+	}
+
+	bounds *b = (bounds *) malloc (sizeof(bounds));
+
+	b->min_x = 0;
+	b->max_x = width;
+	b->min_y = 0;
+	b->max_y = height;
+	if(
+		direction == DIRECTION_N  ||
+		direction == DIRECTION_NE ||
+		direction == DIRECTION_NW
+	) {
+		b->min_y = length;
+	}
+
+	if(
+		direction == DIRECTION_W  ||
+		direction == DIRECTION_NW ||
+		direction == DIRECTION_SW
+	) {
+		b->min_x = length;
+	}
+
+	if(
+		direction == DIRECTION_E  ||
+		direction == DIRECTION_NE ||
+		direction == DIRECTION_SE
+	) {
+		b->max_x = width - length;
+	}
+
+	if(
+		direction == DIRECTION_S  ||
+		direction == DIRECTION_SW ||
+		direction == DIRECTION_SE
+	) {
+		b->max_y = height - length;
+	}
+
+	return b;
+}
+
+char** makegrid (char** words, int height, int width, int simple) {
+ return NULL;
+}
+
+#ifdef DEBUG_GRID_MAIN
+#include <stdio.h>
+int main() {
+	int dir = get_direction(0); 
+	bounds* bounds = get_bounds(10, 10, dir, 8);
+	printf("DIR=%d =>  %d < height < %d  &  %d < width < %d\n", 
+		dir, 
+		bounds->min_y, bounds->max_y,
+		bounds->min_x, bounds->max_x
+		);
+	free(bounds);
+}
+#endif

src/grid.h

@@ -0,0 +1,18 @@
+#ifndef WORDSEARCH_GRID
+#define WORDSEARCH_GRID
+
+#define WORDSEARCH_MAXTRIES 500
+
+char** makegrid (char** words, int height, int width, int simple);
+
+typedef struct bounds {
+    int min_y;
+    int max_y;
+    int min_x;
+    int max_x;
+} bounds;
+
+/* returns NULL if cannot fit word; caller needs to free() the response */
+bounds* get_bounds(int height, int width, enum direction direction, int length);
+
+#endif

src/rnd.c

@@ -0,0 +1,87 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+
+#include "rnd.h"
+
+ /* https://www.math.cornell.edu/~mec/2003-2004/cryptography/subs/frequencies.html */
+
+#define ALPHABET_SIZE 26
+#define RND_MAXINT 10000
+
+struct letter_frequency {
+    int p; /* pegged to 10000 rather than 1 */
+    char c;
+} letter_frequencies[] = {
+    {7,    'Z'},
+    {10,   'J'},
+    {11,   'Q'},
+    {17,   'X'},
+    {69,   'K'},
+    {111,  'V'},
+    {149,  'B'},
+    {182,  'P'},
+    {203,  'G'},
+    {209,  'W'},
+    {211,  'Y'},
+    {230,  'F'},
+    {261,  'M'},
+    {271,  'C'},
+    {288,  'U'},
+    {398,  'L'},
+    {432,  'D'},
+    {592,  'H'},
+    {602,  'R'},
+    {628,  'S'},
+    {695,  'N'},
+    {731,  'I'},
+    {768,  'O'},
+    {812,  'A'},
+    {910,  'T'},
+    {1202, 'E'},
+};
+
+/* from http://stackoverflow.com/questions/822323/how-to-generate-a-random-number-in-c */
+int random_number(int min_num, int max_num) {
+	static int initialised = 0;
+    int result  = 0;
+    int low_num = 0;
+    int hi_num  = 0;
+    if(min_num < max_num) {
+        low_num = min_num;
+        hi_num = max_num + 1; // this is done to include max_num in output.
+    } else {
+        low_num = max_num + 1;// this is done to include max_num in output.
+        hi_num = min_num;
+    }
+    if(!initialised) {
+    	srand(time(NULL));
+    	initialised = 1;
+    }
+    result = ( rand() % (hi_num - low_num) ) + low_num;
+    return result;
+}
+
+char get_random_letter() {
+	int rnd = random_number(0, RND_MAXINT);
+	for(int i=0; i < ALPHABET_SIZE; i++) {
+		if(rnd < letter_frequencies[i].p) {
+			return letter_frequencies[i].c;
+		}
+		rnd -= letter_frequencies[i].p;
+	}
+    return '\0';
+}
+
+#ifdef DEBUG_RND_MAIN
+#include <stdio.h>
+
+int main() {
+	int n = 32;
+	while(--n > 0) {
+		printf("%c", get_random_letter());
+	}
+	return 0;
+}
+
+#endif

src/rnd.h

@@ -0,0 +1,7 @@
+#ifndef WORDSEARCH_RND
+#define WORDSEARCH_RND
+
+char get_random_letter();
+int random_number(int min_num, int max_num);
+
+#endif