refactor: move drawing functions into drawing.h/drawing.c

1 files changed, 56 insertions, 0 deletions

diff --git a/experimental/tectonics/drawing.c b/experimental/tectonics/drawing.c
new file mode 100644
index 0000000..91f873b
--- /dev/null
+++ b/experimental/tectonics/drawing.c
@@ -0,0 +1,56 @@
+#include <stddef.h>
+#include <math.h>
+
+#include "tectonics.h"
+#include "geometry.h"
+#include "drawing.h"
+
+void get_cairo_size(cairo_t *cr, int *width, int *height)
+{
+   cairo_surface_t *surface = cairo_get_target(cr);
+   *width = cairo_image_surface_get_width(surface);
+   *height = cairo_image_surface_get_height(surface);
+}
+
+
+void draw_world(cairo_t *cr, struct world_t *world)
+{
+   int width, height;
+   get_cairo_size(cr, &width, &height);
+   double r = ((double)width) / (100*sqrt(world->n_points));
+   cairo_set_source_rgba(cr, 1, 0, 0, 1);
+
+   for (int i=0; i<world->n_points; i++) {
+      struct point_t *pt = world->points + i;
+      double xc = pt->x * width;
+      double yc = pt->y * height;
+      cairo_arc(cr, xc, yc, r, 0, 2*M_PI);
+      cairo_stroke(cr);
+   }
+
+   //draw_quadtree(cr, &(world->tree));
+}
+
+
+void draw_quadtree(cairo_t *cr, struct quadtree_node_t *node)
+{
+   int width, height;
+   get_cairo_size(cr, &width, &height);
+
+   cairo_set_source_rgba(cr, 0, 0, 1, 1);
+   struct point_t center = node->region.center;
+   double half_dim = node->region.half_dim;
+
+   double x = (center.x - half_dim) * width;
+   double y = (center.y - half_dim) * height;
+   
+   cairo_rectangle(cr, x, y, 2*half_dim * width, 2*half_dim * height);
+   cairo_stroke(cr);
+
+   if (node->nw != NULL) {
+      draw_quadtree(cr, node->nw);
+      draw_quadtree(cr, node->ne);
+      draw_quadtree(cr, node->sw);
+      draw_quadtree(cr, node->se);
+   }
+}