From: Timo Kokkonen <kaapeli@itanic.dy.fi>
Date: Thu, 8 Apr 2010 16:46:44 +0000 (+0300)
Subject: main.c: Use quadtrees to draw only visible planets
X-Git-Url: http://git.itanic.dy.fi/?p=sdl-planets;a=commitdiff_plain;h=b9f1e8cf06dc6ff2569551aa0b427d8468f7a802

main.c: Use quadtrees to draw only visible planets

Signed-off-by: Timo Kokkonen <kaapeli@itanic.dy.fi>
---

diff --git a/main.c b/main.c
index c383af7..be927c7 100644
--- a/main.c
+++ b/main.c
@@ -184,8 +184,11 @@ static void loop(SDL_Surface *screen, int num_of_planets, double total_mass,
 		 double range)
 {
 	struct sim_status status;
-	struct planet *planet, *pl1, *pl2;
+	struct planet *planet, *pl1, *pl2, *planet_root;
 	struct camera camera;
+	struct planet_search_iterator itr;
+	struct vector vect;
+
 	int planets;
 	int framecount = 0, last_fps_time = 0;
 	int last_framecount = 0, last_step_count = 0;
@@ -193,6 +196,7 @@ static void loop(SDL_Surface *screen, int num_of_planets, double total_mass,
 	unsigned long step_count = 0;
 	double last_fps = 0, last_sps = 0, fade_amount;
 	double step_time = 0, true_time = 0;
+	int visible_planets;
 
 	init_camera(&camera);
 
@@ -201,6 +205,11 @@ static void loop(SDL_Surface *screen, int num_of_planets, double total_mass,
 	status.screen = screen;
 	status.tracers_enabled = 0;
 
+	itr.screen = screen;
+	itr.cam = &camera;
+	itr.qt_iterator.direction = planet_search_rectangular;
+	itr.qt_iterator.callback = planet_draw_iterator;
+
 	planet = malloc(sizeof(*planet));
 	init_planet(planet);
 	create_planets(planet, num_of_planets, total_mass, range);
@@ -222,7 +231,8 @@ static void loop(SDL_Surface *screen, int num_of_planets, double total_mass,
 				pl2 = ptmp;
 			}
 
-			move_planet(pl1, step_time);
+			planet_root = move_planet(pl1, step_time);
+			planets++;
 		}
 
 		move_camera(&camera, true_time);
@@ -256,10 +266,16 @@ static void loop(SDL_Surface *screen, int num_of_planets, double total_mass,
 			clear_buf(screen);
 		}
 
-		list_for_each_entry(pl1, &planet->list, list) {
-			draw_planet(screen, pl1, &camera);
-			planets++;
-		}
+		itr.limit[0] = camera.pos;
+		vect.x = screen->w / 2;
+		vect.y = screen->h / 2;
+		vector_scale(&vect, 1 / camera.zoom, &vect);
+		vector_add(&itr.limit[0], &vect, &itr.limit[1]);
+		vector_sub(&itr.limit[0], &vect, &itr.limit[0]);
+
+		itr.qt_iterator.head = &planet_root->tree;
+
+		visible_planets = walk_quadtree(&itr.qt_iterator);
 
 		SDL_UnlockSurface(screen);
 
@@ -281,11 +297,10 @@ static void loop(SDL_Surface *screen, int num_of_planets, double total_mass,
 			last_fps_time = ticks;
 		}
 
-
 		printf("  \rFrames/s: %.2f, steps/s: %.2f, planets: %d"
-		       ", scale %.2f, zoom %.2f, step %ld",
+		       ", scale %.2f, zoom %.2f, step %ld, visible %d",
 		       last_fps, last_sps, planets, status.time_scale,
-		       camera.zoom, step_count);
+		       camera.zoom, step_count, visible_planets);
 		fflush(stdout);