From 01790cddb907e2fad0be4e824746bf889d778dd2 Mon Sep 17 00:00:00 2001
From: mogemimi <mogemimi@enginetrouble.net>
Date: Sun, 26 Aug 2018 04:47:37 +0900
Subject: [PATCH] Fix scaling frame duration twice in Timer

---
 src/Application/Timer.cpp                    |  2 +-
 test/FrameworkTest/Application/TimerTest.cpp | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/Application/Timer.cpp b/src/Application/Timer.cpp
index aab61df5d..4dd72c54d 100644
--- a/src/Application/Timer.cpp
+++ b/src/Application/Timer.cpp
@@ -19,7 +19,7 @@ Timer::Timer(GameClock & clock)
             return;
         }
         this->frameDuration = (frameDurationIn * this->scale);
-        this->totalTime += (frameDuration * this->scale);
+        totalTime += (frameDurationIn * scale);
 
         if (interval && (totalTime >= *interval)) {
             totalTime = *interval;
diff --git a/test/FrameworkTest/Application/TimerTest.cpp b/test/FrameworkTest/Application/TimerTest.cpp
index 4de621d0b..3092dbd6a 100644
--- a/test/FrameworkTest/Application/TimerTest.cpp
+++ b/test/FrameworkTest/Application/TimerTest.cpp
@@ -4,6 +4,7 @@
 #include <Pomdog/Application/GameClock.hpp>
 #include <gtest/iutest_switch.hpp>
 #include <chrono>
+#include <thread>
 
 using namespace Pomdog;
 
@@ -47,3 +48,22 @@ TEST(Timer, Scale)
     timer.SetScale(-0.5);
     EXPECT_EQ(-0.5, timer.GetScale());
 }
+
+TEST(Timer, Scaling)
+{
+    constexpr double scale = 0.4;
+    constexpr double epsilon = 0.001;
+
+    GameClock clock;
+    Timer timer(clock);
+    timer.SetScale(scale);
+    timer.Start();
+
+    for (int i = 0; i < 100; i++) {
+        clock.Tick();
+        std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    }
+
+    ASSERT_EQ(scale, timer.GetScale());
+    EXPECT_NEAR(clock.GetTotalGameTime().count() * scale, timer.GetTotalTime().count(), epsilon);
+}