Added Framerate Limit Code

include/ZE_ZEngine.h

@@ -13,7 +13,7 @@
 File: ZE_ZEngine.h <br>
 Description: Header file for ZEngine class, the core of the ZEngine. <br>
 Author(s): James Turk <br>
-$Id: ZE_ZEngine.h,v 1.8 2002/12/29 06:50:19 cozman Exp $<br>
+$Id: ZE_ZEngine.h,v 1.9 2003/01/04 05:16:02 cozman Exp $<br>
 
     \file ZE_ZEngine.h
     \brief Definition file for core ZEngine class.
@@ -172,7 +172,8 @@ class ZEngine
         /*!
             \brief Update display contents.
 
-            Swap OpenGL buffers, and update screen.  Must be called every frame.
+            Swap OpenGL buffers, and update screen, if a desired framerate is set it will delay to stay under that rate.
+            Must be called every frame.
         **/
         void Update();
 
@@ -209,6 +210,10 @@ class ZEngine
         bool mPaused;
         //! Keep track of if ZEngine should unpause on active event.
         bool mUnpauseOnActive;
+        //! Value framerate strives to be at, set by SetDesiredFramerate.
+        Uint8 mDesiredFramerate;
+        //! Time scheduled for next update (used for framerate locked movement).
+        Uint32 mNextUpdate;
         //! Keep track of time game was last paused.
         Uint32 mLastPause;
         //! Keep track of total globally paused time.
@@ -252,11 +257,40 @@ class ZEngine
         /*!
             \brief Get Seconds Per Frame.
 
-            Get double that describes the time passed between screen updates. (used for Framerate Independant Movement)
+            Get double that describes the time passed between screen updates. (should be used for Framerate Independant Movement)
             \return Time between screen updates.
         **/
         double GetFrameTime();
 
+        /*!
+            \brief Get Frames Per Second.
+
+            Get double representing current (approximate) FPS.  This value is always the same as 1/GetFrameTime().
+            \since 0.8.2
+            \return Current Framerate.
+        **/
+        double GetFramerate();
+
+        /*!
+            \brief Set Desired Framerate.
+
+            Sets desired framerate, if engine gets ahead of desired rate during a frame it will stall in Update until
+            current framerate is closer to that desired.  Acceptable values are 1-255, setting this value to 0 will disable this
+            feature.  (Desired framerate is disabled upon initialization of ZEngine.)
+            \since 0.8.2
+            \param rate Desired framerate 1-255, or 0 to disable.
+        **/
+        void SetDesiredFramerate(Uint8 rate);
+
+        /*!
+            \brief Get Desired Framerate.
+
+            Get desired framerate set by SetDesiredFramerate.
+            \since 0.8.2
+            \return Current setting for desired framerate.
+        **/
+        Uint8 GetDesiredFramerate();
+
         /*!
             \brief Check Engine Paused State.
 

src/ZE_ZEngine.cpp

@@ -13,7 +13,7 @@
 File: ZE_ZEngine.cpp <br>
 Description: Implementation source file for ZEngine library main singleton class. <br>
 Author(s): James Turk <br>
-$Id: ZE_ZEngine.cpp,v 1.9 2002/12/29 06:52:07 cozman Exp $<br>
+$Id: ZE_ZEngine.cpp,v 1.10 2003/01/04 05:16:01 cozman Exp $<br>
 
     \file ZE_ZEngine.cpp
     \brief Central source file for ZEngine.
@@ -52,7 +52,8 @@ ZEngine::ZEngine()
         mKeyPress[k] = false;
 
     mUnpauseOnActive = mPaused = false;
-    mLastPause = mPausedTime = mLastTime = 0;
+    mDesiredFramerate = 0;
+    mNextUpdate = mLastPause = mPausedTime = mLastTime = 0;
     mSecPerFrame = 0.0;
 }
 
@@ -210,6 +211,13 @@ void ZEngine::Update()
 
     mSecPerFrame = (GetTime()-mLastTime)/1000.0;
     mLastTime = GetTime();
+
+    if(mDesiredFramerate)
+    {
+        if(mLastTime < mNextUpdate)
+            SDL_Delay(mNextUpdate-mLastTime);
+        mNextUpdate = GetTime()+(1000/mDesiredFramerate);
+    }
 }
 
 void ZEngine::Clear(float red, float green, float blue, float alpha)
@@ -279,6 +287,21 @@ double ZEngine::GetFrameTime()
     return mSecPerFrame;
 }
 
+double ZEngine::GetFramerate()
+{
+    return 1/mSecPerFrame;
+}
+
+void ZEngine::SetDesiredFramerate(Uint8 rate)
+{
+    mDesiredFramerate = rate;
+}
+
+Uint8 ZEngine::GetDesiredFramerate()
+{
+    return mDesiredFramerate;
+}
+
 bool ZEngine::IsPaused()
 {
     return mPaused;

test/ZFontTest.cpp

@@ -17,7 +17,7 @@ void Initialize()
 {
     ZEngine *engine = ZEngine::GetInstance();
     ZConfigFile cfg("tests.zcf");
-    int w,h,bpp;
+    int w,h,bpp,rate;
     bool fs;
     string title;
 
@@ -26,9 +26,11 @@ void Initialize()
     bpp = cfg.GetInt("ZFontTest","bpp",32);
     fs = cfg.GetBool("ZFontTest","fullscreen",false);
     title = cfg.GetString("ZFontTest","title","ZFont Test");
+    rate = cfg.GetInt("ZFontTest","framerate",60);
 
     engine->SetupDisplay(w,h,bpp,fs);
     engine->CreateDisplay(title);
+    engine->SetDesiredFramerate(rate);
 }
 
 void Test()
@@ -36,7 +38,7 @@ void Test()
     ZEngine *engine = ZEngine::GetInstance();
 
     //Open and Setup all the Fonts and Create Images//
-    ZImage text[5];
+    ZImage text[6];
     ZFont almonte("data/almontew.ttf",48), axaxax("data/axaxax.ttf",32), betsy("data/betsy.ttf",64);
     almonte.SetColor(255,0,0);
     almonte.DrawText("This is the font test.",text[0]);
@@ -58,10 +60,11 @@ void Test()
         engine->CheckEvents();
         if(engine->KeyIsPressed(SDLK_ESCAPE))
             engine->RequestQuit();
+        betsy.DrawText(FormatStr("FPS: %.2f",engine->GetFramerate()),text[5]);
 
         engine->Clear();    //clear screen
         //draw the images//
-        for(int i=0; i <= 4; i++)
+        for(int i=0; i <= 5; i++)
             text[i].Draw(10.0f*i,50.0f*i);
         engine->Update();    //update the screen
 

test/ZImageTest.cpp

@@ -17,7 +17,7 @@ void Initialize()
 {
     ZEngine *engine = ZEngine::GetInstance();
     ZConfigFile cfg("tests.zcf");
-    int w,h,bpp;
+    int w,h,bpp,rate;
     bool fs;
     string title;
 
@@ -26,9 +26,11 @@ void Initialize()
     bpp = cfg.GetInt("ZImageTest","bpp",32);
     fs = cfg.GetBool("ZImageTest","fullscreen",true);
     title = cfg.GetString("ZImageTest","title","ZImage Test");
+    rate = cfg.GetInt("ZImageTest","framerate",60);
 
     engine->SetupDisplay(w,h,bpp,fs);
     engine->CreateDisplay(title);
+    engine->SetDesiredFramerate(rate);
 }
 
 void Test()

test/ZMouseTest.cpp

@@ -17,7 +17,7 @@ void Initialize()
 {
     ZEngine *engine = ZEngine::GetInstance();
     ZConfigFile cfg("tests.zcf");
-    int w,h,bpp;
+    int w,h,bpp,rate;
     bool fs;
     string title;
 
@@ -26,9 +26,11 @@ void Initialize()
     bpp = cfg.GetInt("ZMouseTest","bpp",32);
     fs = cfg.GetBool("ZMouseTest","fullscreen",false);
     title = cfg.GetString("ZMouseTest","title","ZMouse Test");
+    rate = cfg.GetInt("ZMouseTest","framerate",60);
 
     engine->SetupDisplay(w,h,bpp,fs);
     engine->CreateDisplay(title);
+    engine->SetDesiredFramerate(rate);
 }
 
 void Test()

test/ZMusicTest.cpp

@@ -17,7 +17,7 @@ void Initialize()
 {
     ZEngine *engine = ZEngine::GetInstance();
     ZConfigFile cfg("tests.zcf");
-    int w,h,bpp;
+    int w,h,bpp,rate;
     bool fs;
     string title;
 
@@ -26,9 +26,11 @@ void Initialize()
     bpp = cfg.GetInt("ZMusicTest","bpp",32);
     fs = cfg.GetBool("ZMusicTest","fullscreen",false);
     title = cfg.GetString("ZMusicTest","title","ZMusic Test");
+    rate = cfg.GetInt("ZMusicTest","framerate",60);
 
     engine->SetupDisplay(w,h,bpp,fs);
     engine->CreateDisplay(title);
+    engine->SetDesiredFramerate(rate);
 }
 
 void Test()
@@ -51,6 +53,7 @@ void Test()
         {
             
             engine->CheckEvents();
+            engine->Update();
         } while(!engine->QuitRequested());
     }
     else    //this is the actual example

test/ZRectTest.cpp

@@ -17,7 +17,7 @@ void Initialize()
 {
     ZEngine *engine = ZEngine::GetInstance();
     ZConfigFile cfg("tests.zcf");
-    int w,h,bpp;
+    int w,h,bpp,rate;
     bool fs;
     string title;
 
@@ -26,9 +26,11 @@ void Initialize()
     bpp = cfg.GetInt("ZRectTest","bpp",32);
     fs = cfg.GetBool("ZRectTest","fullscreen",false);
     title = cfg.GetString("ZRectTest","title","ZRect Test");
+    rate = cfg.GetInt("ZRectTest","framerate",60);
 
     engine->SetupDisplay(w,h,bpp,fs);
     engine->CreateDisplay(title);
+    engine->SetDesiredFramerate(rate);
 }
 
 void Test()

test/ZSoundTest.cpp

@@ -17,7 +17,7 @@ void Initialize()
 {
     ZEngine *engine = ZEngine::GetInstance();
     ZConfigFile cfg("tests.zcf");
-    int w,h,bpp;
+    int w,h,bpp,rate;
     bool fs;
     string title;
 
@@ -26,9 +26,11 @@ void Initialize()
     bpp = cfg.GetInt("ZSoundTest","bpp",32);
     fs = cfg.GetBool("ZSoundTest","fullscreen",false);
     title = cfg.GetString("ZSoundTest","title","ZSound Test");
+    rate = cfg.GetInt("ZSoundTest","framerate",60);
 
     engine->SetupDisplay(w,h,bpp,fs);
     engine->CreateDisplay(title);
+    engine->SetDesiredFramerate(rate);
 }
 
 void Test()
@@ -79,7 +81,6 @@ void Test()
         if(engine->KeyIsPressed(SDLK_DOWN))
             sample[sampleNum].SetVolume(sample[sampleNum].Volume()-1);
 
-
         font.DrawText(FormatStr("Volume: %d",sample[sampleNum].Volume()),text[4]);
         font.DrawText(FormatStr("Sample: %s",name[sampleNum].c_str()),text[5]);
 

test/ZTimerTest.cpp

@@ -17,7 +17,7 @@ void Initialize()
 {
     ZEngine *engine = ZEngine::GetInstance();
     ZConfigFile cfg("tests.zcf");
-    int w,h,bpp;
+    int w,h,bpp,rate;
     bool fs;
     string title;
 
@@ -26,9 +26,11 @@ void Initialize()
     bpp = cfg.GetInt("ZTimerTest","bpp",32);
     fs = cfg.GetBool("ZTimerTest","fullscreen",false);
     title = cfg.GetString("ZTimerTest","title","ZTimer Test");
+    rate = cfg.GetInt("ZTimerTest","framerate",60);
 
     engine->SetupDisplay(w,h,bpp,fs);
     engine->CreateDisplay(title);
+    engine->SetDesiredFramerate(rate);
 }
 
 void Test()