From a016a156e76f7394c5632da325ab0b453cfb3b37 Mon Sep 17 00:00:00 2001
From: Paweł Redman <pawel.redman@gmail.com>
Date: Mon, 26 Mar 2018 14:19:50 +0200
Subject: Independent game timing.

---
 src/common.hpp | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

(limited to 'src/common.hpp')

diff --git a/src/common.hpp b/src/common.hpp
index 846b166..df9c8d1 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -35,6 +35,11 @@ extern bool debug_draw_paths;
 extern bool debug_draw_tile_coords;
 extern bool debug_AI;
 
+// time in nanoseconds
+// nclock() never returns 0, so it can be used as a null value
+typedef uint64_t ntime_t;
+ntime_t nclock(void);
+
 namespace procgen {
 	class prng_t {
 		uint32_t state = 0;
@@ -240,15 +245,23 @@ namespace game {
 	public:
 		world::world_t world;
 		interface::state_t *interface;
-		double now = 0.0, dt;
-		bool paused = false;
 		procgen::prng_t dice_prng;
 		std::unordered_set<entity_t*> awake_entities;
 		std::unordered_set<unit_t*> selected_units;
 
+		ntime_t time; // game time
+		double now, dt; // FIXME: refactor the code, use ntime_t everywhere
+
+		// frame timing data (game runs at a different frequency than the renderer)
+		bool paused;
+		ntime_t t0;
+		size_t frames = 0, frames_since_t0, frames_behind = 0;
+
 		void start(void);
 		void stop(void);
-		void tick(double now_, double dt_);
+		void tick(ntime_t time);
+		void pause(void);
+		void resume(void);
 
 		// These are called by the interface.
 		void select(rectf_t rect);
@@ -355,14 +368,15 @@ namespace render {
 		void drender_text(rectf_t rect, std::string str);
 		void drender_entity(world::entity_t *ent);
 	public:
-		double now, dt;
+		ntime_t time;
+		double dt;
 
 		struct {
 			size_t sectors, tiles, entities;
 		} stats;
 
 		state_t(sf::RenderWindow *window_);
-		void begin_frame(double time_, double dt_);
+		void begin_frame(ntime_t time_, double dt);
 		void end_frame(void);
 
 		void render(game::state_t *game);
-- 
cgit