update thread setup with a good cap

[physics.git] / src / main.cpp

diff --git a/src/main.cpp b/src/main.cpp
index 5381a86..1309824 100644 (file)
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -38,7 +38,6 @@ void sighandler( int sig );
 void run();
 void clean();
 
-void blockUpdate();
 void updateFPSCounters();
 
 void handleInput();
@@ -52,26 +51,29 @@ bool is_Running;
 
 /* Values for the main game loop
  * target_UPS := the amount of updates that is wanted in one second
- * last_Update := stores the time of the last update
- * update_Sum := used to determine the updates needs for this run
-
+ *
  * ups := updates per second for the last second
  * fps := frames per second for the last second
  * update_Count := counts this seconds updates
  * draw_Count  := counts this seconds draws
  * last_Second := stores the time of the last second, used for ups and fps
  */
-int target_UPS = 250;
-long int last_Block_Update;
-float update_Sum = 0;
+int target_UPS = 100;
+float update_Wait = 0;
 
 int ups, fps;
 int update_Count, draw_Count;
-long int last_Second;
+MICRO last_Second;
 
+const int min_wait_milli = 20;
+const int min_wait_micro = min_wait_milli * 1000;
+const float game_step    = 10;
+
+int startUpdateThread(void*);
+int startDrawThread(void*);
 
 /// ***** MAIN Method *****
-int main()
+int main(int argc, char** args)
 {
     init();
     run();
@@ -86,23 +88,23 @@ void init()
     installSignal();
 
     graphics::init();
+    DPF(0, "Graphics initialized");
 
     game::init();
+    DPF(0, "Game initialized");
 
     input::init();
+    DPF(0, "Input initialized");
 
     cfg::init();
+    DPF(0, "Configs initialized");
 
-#ifdef DEBUGGING
-    cout << "Initialization Complete" << endl;
-#endif
+    DPF(0, "Initialization Complete");
 }
 
 void clean()
 {
-#ifdef DEBUGGING
-    cout << "Cleaning up" << endl;
-#endif
+    DPF(0, "Cleaning up");
 
     cfg::clean();
 
@@ -118,44 +120,13 @@ void clean()
 void run()
 {
     is_Running = true;
-    last_Block_Update = tickCountMicro();
-    last_Second = tickCountMicro();
-
-    while(is_Running)
-    {
-        blockUpdate();
-        updateFPSCounters();
-        draw();
-    }
-}
-
-void blockUpdate()
-{
-    long int start = tickCountMicro();
 
-    // Calculate the updates that should be run for the next draw
-    update_Sum += (start - last_Block_Update) / (1000000 / (float)target_UPS);
+    SDL_Thread* updates = SDL_CreateThread(startUpdateThread, NULL);
 
-    // insures the float to int cast is done once.
-    int iupdate_sum = (int)update_Sum;
+    // for some reason this needs to be on the main thread ...?
+    startDrawThread(NULL);
 
-    // TODO the main run loop needs to be tested and pruned
-    if (iupdate_sum > 0)
-    {
-        // Calculate a time step that spreads the updates out as much as possible
-        // used because really quick updates are nearly wasted
-        float time_step = ((float)(start - last_Block_Update)) / iupdate_sum;
-
-        // run the updates
-        for (int i = 1; i <= iupdate_sum; i++)
-        {
-            handleInput();
-            update(time_step*i / 1000);
-        }
-        // remove the updates that where run from the sum
-        update_Sum -= iupdate_sum;
-        last_Block_Update = tickCountMicro();
-    }
+    SDL_WaitThread(updates, NULL);
 }
 
 void updateFPSCounters()
@@ -165,8 +136,10 @@ void updateFPSCounters()
     {
         ups = update_Count;
         fps = draw_Count;
-        update_Count = 0;
-        draw_Count = 0;
+
+        // NOT thread safe, but they're estimates anyways
+        update_Count -= ups;
+        draw_Count -= fps;
 
         last_Second = tickCountMicro();
 
@@ -181,7 +154,7 @@ void handleInput()
 {
     input::update();
 
-    game::input();
+    game::handleInput();
 
     if(cfg::endGame())
         is_Running = false;
@@ -189,18 +162,53 @@ void handleInput()
 
 void update(float time_step)
 {
-    update_Count++;
-
     game::update(time_step);
+    update_Count++;
 }
 
 void draw()
 {
-    draw_Count++;
-
     game::draw();
 
     SDL_GL_SwapBuffers();
 
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    draw_Count++;
+}
+
+int startUpdateThread(void*)
+{
+    last_Second = tickCountMicro();
+
+    while(is_Running)
+    {
+        MICRO time = tickCountMicro();
+            handleInput();
+            update(game_step);
+
+            updateFPSCounters();
+        time = tickCountMicro() - time;
+
+        float wait = (1000000.0 / target_UPS - time);
+        update_Wait += 0 < wait ? wait : 0;
+
+        while(min_wait_micro < update_Wait)
+        {
+            update_Wait -= min_wait_micro;
+            SDL_Delay(min_wait_milli);
+        }
+    }
+
+    return 0;
+}
+
+int startDrawThread(void*)
+{
+    while(is_Running)
+    {
+        draw();
+    }
+
+    return 0;
 }