add quadtree and basic world model

1 files changed, 76 insertions, 0 deletions

diff --git a/experimental/tectonics/tectonics.h b/experimental/tectonics/tectonics.h
new file mode 100644
index 0000000..5f39ff7
--- /dev/null
+++ b/experimental/tectonics/tectonics.h
@@ -0,0 +1,76 @@
+#ifndef TECTONICS_H
+#define TECTONICS_H
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <cairo.h>
+
+struct point_t {
+   double x, y;
+   void *data;
+};
+
+
+struct quad_region_t {
+   struct point_t center;
+   double half_dim;
+};
+
+
+struct quadtree_node_t {
+   struct quad_region_t region;
+
+   int id;
+   
+   /* children */
+   struct quadtree_node_t *nw, *ne, *sw, *se;
+};
+
+
+struct world_t {
+   struct point_t *points;
+   struct quadtree_node_t tree;
+   int n_points;
+};
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * quadtree
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+bool contains_point(struct quad_region_t region, struct point_t pt);
+struct quadtree_node_t new_node(struct point_t center, double half_dim);
+void subdivide(struct quadtree_node_t *node, struct point_t *points);
+bool insert(struct quadtree_node_t *node,
+	    struct point_t *points, int id);
+int get_closest(struct quadtree_node_t *root,
+		struct point_t pt);
+void draw_quadtree(cairo_t *cr, struct quadtree_node_t *root);
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * util
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+void get_cairo_size(cairo_t *cr, int *width, int *height);
+double rand01();
+double distance(double x0, double y0, double x1, double y1);
+
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * worlds
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+void create_world(struct world_t *world, int n_points);
+void free_world(struct world_t *world);
+void render_world(cairo_t *cr, struct world_t *world);
+void run_world_step(struct world_t *world);
+
+#endif