1 files changed, 93 insertions, 0 deletions
diff --git a/src/pattern/pattern.h b/src/pattern/pattern.h
new file mode 100644
index 0000000..d53576e
--- /dev/null
+++ b/src/pattern/pattern.h
@@ -0,0 +1,93 @@
+#ifndef PLOC_GEN_PATTERN_PATTERN_H
+#define PLOC_GEN_PATTERN_PATTERN_H
+
+#include <stdbool.h>
+
+struct coord
+{
+    int x;
+    int y;
+};
+
+struct pattern_type
+{
+    int width;
+    int height;
+    int min_length;
+    int max_length;
+};
+
+struct pattern
+{
+    struct pattern_type type;
+    struct coord *path;
+    int length;
+};
+
+/*
+ * Creates a pattern_type.
+ * If max has an invalid value the max_length is set to the
+ * maximum possible length.
+ */
+struct pattern_type gen_pattern_type(int side_len, int min, int max);
+
+/*
+ * Returns 0 if a equals b.
+ */
+int coord_cmp(const void *a, const void *b);
+
+/*
+ * If the point happend to be on the line that connects start and end,
+ * the result is true, otherwise is false.
+ */
+bool is_in_line(struct coord a, struct coord c, struct coord b);
+
+/*
+ * Returns the index of coord in pattern->path.
+ * The return value is negative if coord not found in pattern->path.
+ */
+int find_in_pattern(struct pattern *pattern, struct coord *coord);
+
+/*
+ * Gives back the points in arr, that are between from and to.
+ */
+int inbetween(int width, int height, struct coord *from, struct coord *to, struct coord *arr);
+
+/*
+ * Returns true if there's no unvisited point between
+ * the last point of path and next.
+ */
+bool nothing_inbetween(struct pattern *pattern, struct coord *next);
+
+/*
+ * Inline functions.
+ */
+inline bool len_is_max(struct pattern *pattern)
+{
+    return pattern->length >= pattern->type.max_length;
+}
+
+inline bool len_is_min(struct pattern *pattern)
+{
+    return pattern->length <= pattern->type.min_length;
+}
+
+inline int coord_to_index(int width, struct coord point)
+{
+    return (point.y * width) + point.x;
+}
+
+inline struct coord index_to_coord(int width, int index)
+{
+    struct coord result;
+    result.y = index / width;
+    result.x = index % width;
+    return result;
+}
+
+inline int pattern_point_to_index(struct pattern *pattern, int index)
+{
+    return coord_to_index(pattern->type.width, pattern->path[index]);
+}
+
+#endif
+\ No newline at end of file