Do more iterative steps per game loop up to 8msec

MrSapps · Jul 22, 2017 · b80d468 · b80d468
1 parent ec85224
commit b80d468
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Showing 4 changed files with 86 additions and 25 deletions.
diff --git a/include/iterativeforloop.hpp b/include/iterativeforloop.hpp
@@ -2,6 +2,43 @@
 
 #include "types.hpp"
 #include <functional>
+#include <chrono>
+
+constexpr u32 kMaxExecutionTimeMs = 8;
+
+class Timer
+{
+public:
+    Timer() : mStartTime(TClock::now())
+    {
+
+    }
+
+    void Reset()
+    { 
+        mStartTime = TClock::now();
+    }
+
+    u32 Elapsed() const 
+    {
+        const u32 ret = static_cast<u32>(std::chrono::duration_cast<std::chrono::milliseconds>(TClock::now() - mStartTime).count());
+        return ret;
+    }
+
+private:
+    using TClock = std::chrono::high_resolution_clock;
+    std::chrono::time_point<TClock> mStartTime;
+};
+
+template<class Func>
+inline void RunForAtLeast(u32 millisecondsTimeBox, Func func)
+{
+    Timer time;
+    do
+    {
+        func();
+    } while (time.Elapsed() < millisecondsTimeBox);
+}
 
 template<class LoopIndexType>
 class IterativeForLoop
@@ -15,6 +52,27 @@ class IterativeForLoop
         return mCurrentIndex;
     }
 
+    template<class Func>
+    bool IterateTimeBoxed(u32 millisecondsTimeBox, LoopIndexType bound, Func loopIterationFunc)
+    {
+        Timer time;
+        bool iterationCompleted = false;
+        do
+        {
+            iterationCompleted = IterateCommon(bound, [&]()
+            {
+                // For the most nested iterate we run the loop body and always increment
+                loopIterationFunc();
+                return true;
+            });
+            if (iterationCompleted)
+            {
+                break;
+            }
+        } while (time.Elapsed() < millisecondsTimeBox);
+        return iterationCompleted;
+    }
+
     template<class Func>
     bool Iterate(LoopIndexType bound, Func loopIterationFunc)
     {
@@ -38,6 +96,28 @@ class IterativeForLoop
         });
     }
 
+    template<class Func>
+    bool IterateTimeBoxedIf(u32 millisecondsTimeBox, LoopIndexType bound, Func loopIterationFunc)
+    {
+        Timer time;
+        bool iterationCompleted = false;
+        do
+        {
+            iterationCompleted = IterateCommon(bound, [&]()
+            {
+                // The caller supplied loop function determines if we increment, typically
+                // this is the result of another Iterate, i.e the outer loop only increments
+                // if the inner loop iteration is done.
+                return loopIterationFunc();
+            });
+            if (iterationCompleted)
+            {
+                break;
+            }
+        } while (time.Elapsed() < millisecondsTimeBox);
+        return iterationCompleted;
+    }
+
 private:
     template<class Func>
     bool IterateCommon(LoopIndexType bound, Func executeLoopIterationAndCheckIfShouldIncrement)

diff --git a/src/engine.cpp b/src/engine.cpp
@@ -346,7 +346,7 @@ void Engine::RunInitScript()
 }
 
 // TODO: Using averaging value or anything that is more accurate than this
-typedef std::chrono::high_resolution_clock THighResClock;
+using THighResClock = std::chrono::high_resolution_clock;
 class BasicFramesPerSecondCounter
 {
 public:

diff --git a/src/gridmap.cpp b/src/gridmap.cpp
@@ -159,7 +159,7 @@ GridMap::GridMap()
     mEditorMode = std::make_unique<EditorMode>(mMapState);
     mGameMode = std::make_unique<GameMode>(mMapState);
 
-    // Size of the screen you see during normal game play, this is always less the the "block" the camera image fits into
+    // Size of the screen you see during normal game play, this is always less than the "block" the camera image fits into
     mMapState.kVirtualScreenSize = glm::vec2(368.0f, 240.0f);
 }
 
@@ -201,7 +201,7 @@ void GridMap::Loader::HandleAllocateCameraMemory(const Oddlib::Path& path)
 
 void GridMap::Loader::HandleLoadCameras(const Oddlib::Path& path, ResourceLocator& locator)
 {
-    if (mXForLoop.IterateIf(path.XSize(), [&]()
+    if (mXForLoop.IterateTimeBoxedIf(kMaxExecutionTimeMs, path.XSize(), [&]()
     {
         return mYForLoop.Iterate(path.YSize(), [&]()
         {
@@ -350,7 +350,7 @@ bool GridMap::Loader::Load(const Oddlib::Path& path, ResourceLocator& locator)
         break;
 
     case LoaderStates::eLoadObjects:
-        HandleLoadObjects(path, locator);
+        RunForAtLeast(kMaxExecutionTimeMs, [&]() { HandleLoadObjects(path, locator); });
         break;
 
     case LoaderStates::eHackToPlaceAbeInValidCamera:

diff --git a/src/mapobject.cpp b/src/mapobject.cpp
@@ -47,25 +47,6 @@
     }
 }
 
-
-template<class T, class U>
-static void IterateArray(Sqrat::Object& sqObj, const char* arrayName, U callBack)
-{
-    Sqrat::Array sqArray = sqObj[arrayName];
-    if (!sqArray.IsNull())
-    {
-        const SQInteger arraySize = sqArray.GetSize();
-        for (SQInteger i = 0; i < arraySize; i++)
-        {
-            Sqrat::SharedPtr<T> item = sqArray.GetValue<T>(static_cast<int>(i));
-            if (item)
-            {
-                callBack(*item);
-            }
-        }
-    }
-}
-
 static bool GetArray(Sqrat::Object& sqObj, const char* arrayName, Sqrat::Array& sqArray)
 {
     sqArray = sqObj[arrayName];
@@ -116,7 +97,7 @@ void MapObject::Loader::LoadAnimations()
     Sqrat::Array animsArray;
     if (GetArray(mMapObj.mScriptObject, "kAnimationResources", animsArray))
     {
-        if (mForLoop.Iterate(animsArray.GetSize(), [&]()
+        if (mForLoop.IterateTimeBoxed(kMaxExecutionTimeMs, animsArray.GetSize(), [&]()
         {
             Sqrat::SharedPtr<std::string> item = animsArray.GetValue<std::string>(static_cast<int>(mForLoop.Value()));
             if (item)
@@ -139,7 +120,7 @@ void MapObject::Loader::LoadSounds()
     Sqrat::Array soundsArray;
     if (GetArray(mMapObj.mScriptObject, "kSoundResources", soundsArray))
     {
-        if (mForLoop.Iterate(soundsArray.GetSize(), [&]()
+        if (mForLoop.IterateTimeBoxed(kMaxExecutionTimeMs, soundsArray.GetSize(), [&]()
         {
             Sqrat::SharedPtr<std::string> item = soundsArray.GetValue<std::string>(static_cast<int>(mForLoop.Value()));
             if (item)