add Timer

projects/kiwano/kiwano.vcxproj

@@ -32,6 +32,7 @@
     <ClInclude Include="..\..\src\kiwano\core\Singleton.h" />
     <ClInclude Include="..\..\src\kiwano\core\String.h" />
     <ClInclude Include="..\..\src\kiwano\core\Time.h" />
+    <ClInclude Include="..\..\src\kiwano\core\Timer.h" />
     <ClInclude Include="..\..\src\kiwano\core\Xml.h" />
     <ClInclude Include="..\..\src\kiwano\kiwano.h" />
     <ClInclude Include="..\..\src\kiwano\config.h" />
@@ -141,6 +142,7 @@
     <ClCompile Include="..\..\src\kiwano\core\Time.cpp" />
     <ClCompile Include="..\..\src\kiwano\core\Task.cpp" />
     <ClCompile Include="..\..\src\kiwano\core\TaskManager.cpp" />
+    <ClCompile Include="..\..\src\kiwano\core\Timer.cpp" />
     <ClCompile Include="..\..\src\kiwano\platform\Application.cpp" />
     <ClCompile Include="..\..\src\kiwano\platform\FileSystem.cpp" />
     <ClCompile Include="..\..\src\kiwano\platform\Input.cpp" />

projects/kiwano/kiwano.vcxproj.filters

@@ -327,6 +327,9 @@
     <ClInclude Include="..\..\src\kiwano\core\TaskManager.h">
       <Filter>core</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\kiwano\core\Timer.h">
+      <Filter>core</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\src\kiwano\2d\Canvas.cpp">
@@ -539,6 +542,9 @@
     <ClCompile Include="..\..\src\kiwano\core\Task.cpp">
       <Filter>core</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\kiwano\core\Timer.cpp">
+      <Filter>core</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <None Include="suppress_warning.ruleset" />

src/kiwano/core/Timer.cpp

@@ -0,0 +1,104 @@
+// Copyright (c) 2016-2018 Kiwano - Nomango
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#include <kiwano/core/Timer.h>
+
+namespace kiwano
+{
+
+Timer::Timer()
+    : is_stopped_(false)
+{
+}
+
+Timer::~Timer() {}
+
+Duration Timer::GetDeltaTime() const
+{
+    return delta_time_;
+}
+
+Duration Timer::GetTotalTime() const
+{
+    if (is_stopped_)
+        return paused_time_ - start_time_ - total_idle_time_;
+    return current_time_ - start_time_ - total_idle_time_;
+}
+
+void Timer::Start()
+{
+    if (is_stopped_)
+    {
+        const auto now = Time::Now();
+
+        // add the duration of the pause to the total idle time
+        total_idle_time_ += (now - paused_time_);
+
+        // set the previous time to the current time
+        previous_time_ = now;
+
+        paused_time_ = Time();
+        is_stopped_  = false;
+    }
+}
+
+void Timer::Stop()
+{
+    if (!is_stopped_)
+    {
+        const auto now = Time::Now();
+
+        paused_time_ = now;
+        is_stopped_  = true;
+    }
+}
+
+void Timer::Tick()
+{
+    if (is_stopped_)
+    {
+        delta_time_ = 0;
+        return;
+    }
+
+    current_time_ = Time::Now();
+
+    // compute the time elapsed since the previous frame
+    delta_time_ = (current_time_ - previous_time_);
+
+    // set previous time to current time, as in the next tick, this frame will be the previous frame
+    previous_time_ = current_time_;
+
+    // delta time can be negative if the processor goes idle for example
+    if (delta_time_ < 0)
+        delta_time_ = 0;
+}
+
+void Timer::Reset()
+{
+    const auto now = Time::Now();
+
+    start_time_    = now;
+    previous_time_ = now;
+    paused_time_   = Time();
+    is_stopped_    = false;
+}
+
+}  // namespace kiwano

src/kiwano/core/Timer.h

@@ -0,0 +1,60 @@
+// Copyright (c) 2016-2018 Kiwano - Nomango
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#pragma once
+#include <kiwano/core/Time.h>
+#include <kiwano/core/ObjectBase.h>
+
+namespace kiwano
+{
+
+KGE_DECLARE_SMART_PTR(Timer);
+
+class Timer
+    : public ObjectBase
+{
+public:
+    Timer();
+
+    virtual ~Timer();
+
+    Duration GetDeltaTime() const;
+
+    Duration GetTotalTime() const;
+
+    void Start();
+
+    void Stop();
+
+    void Tick();
+
+    void Reset();
+
+private:
+    bool     is_stopped_;
+    Time     start_time_;
+    Time     paused_time_;
+    Time     current_time_;
+    Time     previous_time_;
+    Duration delta_time_;
+    Duration total_idle_time_;
+};
+
+}  // namespace kiwano