Added some performance measuring tools.

Speeded up collision detection significantly.

Extras/GPUphysics/clock.cpp

@@ -0,0 +1,79 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "GPU_physics.h"
+#include "clock.h"
+
+#ifdef GPUP_CYGWIN
+  typedef long long _int64;
+  #define LARGEINTEGER _int64
+#endif
+
+#ifndef GPUP_WIN32
+#  include <sys/time.h>
+#endif
+
+#include <time.h>
+
+#ifdef GPUP_WIN32
+
+double Clock::res ;
+int Clock::perf_timer = -1;
+
+void Clock::initPerformanceTimer ()
+{
+  if ( perf_timer == -1 )
+  {
+    /* Use Performance Timer if it's available, mmtimer if not.  */
+
+    __int64 frequency ;
+
+    perf_timer = QueryPerformanceFrequency ( (LARGE_INTEGER *) & frequency ) ;
+
+    if ( perf_timer )
+    {
+      res = 1.0 / (double) frequency ;
+      perf_timer = 1 ;
+    }
+  }
+}
+#endif
+
+double Clock::getRawTime () const
+{
+#ifdef GPUP_WIN32
+
+  /* Use Performance Timer if it's available, mmtimer if not.  */
+
+  if ( perf_timer )
+  {
+    __int64 t ;
+ 
+    QueryPerformanceCounter ( (LARGE_INTEGER *) &t ) ;
+ 
+    return res * (double) t ;
+  }
+ 
+  return (double) timeGetTime() * 0.001 ;
+
+#else
+  timeval tv ;
+
+  gettimeofday ( & tv, NULL ) ;
+
+  return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0 ;
+#endif
+}
+
+
+void Clock::update ()
+{
+  now = getRawTime() - start ;
+
+  delta = now - last_time ;
+
+  last_time = now ;
+}
+
+
+