X-Git-Url: http://nitlanguage.org

diff --git a/lib/mnit/mnit_fps.nit b/lib/mnit/mnit_fps.nit
index 38f0d48..f4abd92 100644
--- a/lib/mnit/mnit_fps.nit
+++ b/lib/mnit/mnit_fps.nit
@@ -24,7 +24,11 @@ redef class App
 	# Zero (or a negative value) means no limit.
 	#
 	# Applications can modify this value even during the main-loop.
-	var maximum_fps writable = 60
+	var maximum_fps = 60.0 is writable
+
+	# Current frame-rate
+	# Updated each 5 seconds.
+	var current_fps = 0.0
 
 	redef fun full_frame
 	do
@@ -35,20 +39,36 @@ redef class App
 	# The clock for limit_fps
 	private var clock = new Clock
 
+	# Number of frames since the last deadline
+	# Used tocompute `current_fps`.
+	private var frame_count = 0
+
+	# Deadline used to compute `current_fps`
+	private var frame_count_deadline = 0.0
+
 	# Check and sleep to maitain a frame-rate bellow `maximum_fps`
+	# Also periodically uptate `current_fps`
 	# Is automatically called at the end of `full_frame`.
 	fun limit_fps
 	do
+		var t = clock.total
+		if t >= frame_count_deadline then
+			var cfps = frame_count.to_f / 5.0
+			self.current_fps = cfps
+			frame_count = 0
+			frame_count_deadline = t + 5.0
+		end
+		frame_count += 1
+
 		var mfps = maximum_fps
-		if mfps <= 0 then return
-		var dt = clock.lapse
-		var target_dt = 1000000000 / mfps
-		var sec = dt.sec
-		var nanosec = dt.nanosec
-		if sec == 0 and nanosec < target_dt then
-			var sleep_t = target_dt - nanosec
-			sys.nanosleep(0, sleep_t)
-			dt = clock.lapse
+		if mfps <= 0.0 then return
+		var lapse = clock.lapse
+		var dt = lapse.to_f
+		var target_dt = 1.0 / mfps
+		if dt < target_dt then
+			var sleep_t = target_dt - dt
+			sleep_t.sleep
+			clock.lapse
 		end
 	end
 end