5 files changed, 83 insertions, 20 deletions

diff --git a/src/common.hpp b/src/common.hpp
index 1cd1921..bb95f0e 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -40,6 +40,27 @@ extern bool debug_AI;
 typedef uint64_t ntime_t;
 ntime_t nclock(void);
 
+class freq_counter_t {
+	ntime_t *samples;
+	size_t num_samples, collected = 0;
+	ntime_t last_tick = 0;
+
+	float last_ma;
+	ntime_t last_ma_time = 0;
+
+	void push(ntime_t sample);
+
+public:
+	freq_counter_t(size_t num_samples_);
+	~freq_counter_t(void);
+
+	void tick(void);
+	float freq_ma(void);
+};
+
+extern freq_counter_t fc_render;
+extern freq_counter_t fc_game;
+
 namespace procgen {
 	class prng_t {
 		uint32_t state = 0;
@@ -351,9 +372,6 @@ namespace interface {
 
 		std::list<log_entry_t> log;
 
-		double perf_hist[10] = {0};
-		size_t perf_hist_index = 0;
-
 		void start_following(void);
 		void stop_following(void);
 
diff --git a/src/game/game.cpp b/src/game/game.cpp
index 2a944af..4cac4eb 100644
--- a/src/game/game.cpp
+++ b/src/game/game.cpp
@@ -288,11 +288,12 @@ void state_t::resume(void)
 	paused = false;
 }
 
-#define TIME_DELTA ((ntime_t)1000000000 / 60)
+#define TIME_DELTA ((ntime_t)1000000000 / 100)
+#define TIME_LIMIT ((ntime_t)1000000000 / 10)
 
 void state_t::tick(ntime_t time_)
 {
-	size_t target, frames_this_tick = 0;
+	size_t target;
 
 	if (paused)
 		return;
@@ -315,13 +316,12 @@ void state_t::tick(ntime_t time_)
 
 		frames++;
 		frames_since_t0++;
-		frames_this_tick++;
 		time += TIME_DELTA;
 
-		if (frames_this_tick == 3) {
-			t0 = time_;
-			frames_since_t0 = 0;
-			frames_behind++;
+		fc_game.tick();
+
+		if (nclock() - time_ > TIME_LIMIT) {
+			frames_behind += target - frames_since_t0;
 			break;
 		}
 	}
diff --git a/src/game/interface.cpp b/src/game/interface.cpp
index b187d42..c6d5e19 100644
--- a/src/game/interface.cpp
+++ b/src/game/interface.cpp
@@ -332,7 +332,6 @@ void state_t::render_to(render::state_t *render)
 	size_t w = window->getSize().x, h = window->getSize().y;
 	v2f_t x;
 	std::stringstream ss;
-	double fps;
 
 	if (select.selecting) {
 		sf::Color color;
@@ -391,18 +390,10 @@ void state_t::render_to(render::state_t *render)
 	ss << render->stats.entities;
 	render->render_text(x, em, ss.str(), render::ALIGN_LEFT_TOP, sf::Color::White);
 
-	perf_hist_index = (perf_hist_index + 1) % COUNT(perf_hist);
-	perf_hist[perf_hist_index] = 1.0 / render->dt;
-
-	fps = 0.0;
-	for (size_t i = 0; i < COUNT(perf_hist); i++)
-		fps += perf_hist[i];
-	fps /= COUNT(perf_hist);
-
 	x[1] += em;
 	ss.str(std::string());
 	ss << std::fixed << std::setprecision(1);
-	ss << "FPS: " << fps;
+	ss << "FPS: " << fc_render.freq_ma() << ", " << fc_game.freq_ma() << " Hz";
 	render->render_text(x, em, ss.str(), render::ALIGN_LEFT_TOP, sf::Color::White);
 
 	x[1] += em;
diff --git a/src/main.cpp b/src/main.cpp
index 9af2736..1e43d76 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -33,6 +33,58 @@ ntime_t nclock(void)
 	       std::chrono::nanoseconds(1) - nclock_ref;
 }
 
+freq_counter_t::freq_counter_t(size_t num_samples_)
+{
+	num_samples = num_samples_;
+	samples = (ntime_t*)malloc(sizeof(ntime_t) * num_samples);
+}
+
+freq_counter_t::~freq_counter_t(void)
+{
+	free(samples);
+}
+
+void freq_counter_t::push(ntime_t sample)
+{
+	collected++;
+	samples[collected % num_samples] = sample;
+}
+
+void freq_counter_t::tick(void)
+{
+	ntime_t now = nclock();
+
+	if (last_tick)
+		push(now - last_tick);
+
+	last_tick = now;
+}
+
+float freq_counter_t::freq_ma(void)
+{
+	ntime_t now;
+	float res = 0.0f;
+	size_t to_count;
+
+	now = nclock();
+
+	if (last_ma_time && now - last_ma_time < 500000000)
+		return last_ma;
+
+	to_count = std::min(collected, num_samples);
+
+	for (size_t i = 0; i < to_count; i++)
+		res += samples[i] * 1.0e-9f;
+	res = 1.0f / (res / to_count);
+
+	last_ma_time = now;
+	last_ma = res;
+	return res;
+}
+
+freq_counter_t fc_render = freq_counter_t(20);
+freq_counter_t fc_game = freq_counter_t(10);
+
 int main()
 {
 	nclock_ref = nclock() - 1;
diff --git a/src/render.cpp b/src/render.cpp
index 9056d9c..88ad25f 100644
--- a/src/render.cpp
+++ b/src/render.cpp
@@ -317,6 +317,8 @@ void state_t::render(game::state_t *game)
 		if (debug_draw_cmodels)
 			drender_entity(ent);
 	}
+
+	fc_render.tick();
 }
 
 void state_t::render(double phase, animated_texture_t *anim, rectf_t bounds, sf::Color color, bool mirror){