--- linuxsampler/trunk/src/modulationsystem.cpp	2004/01/18 20:31:31	31
+++ linuxsampler/trunk/src/modulationsystem.cpp	2004/02/03 13:21:19	32
@@ -25,6 +25,7 @@
 float** ModulationSystem::pDestinationParameter = NULL;
 uint    ModulationSystem::uiSampleRate;
 uint    ModulationSystem::uiMaxSamplesPerCycle;
+ModulationSystem::__FragmentTime__ ModulationSystem::FragmentTime;
 
 void ModulationSystem::Initialize(uint SampleRate, uint MaxSamplesPerCycle) {
     ModulationSystem::uiMaxSamplesPerCycle = MaxSamplesPerCycle;
@@ -36,6 +37,7 @@
             pDestinationParameter[i] = pDestinationParameter[i - 1] + MaxSamplesPerCycle;
         }
     }
+    ModulationSystem::FragmentTime.end = ModulationSystem::CreateTimeStamp();
 }
 
 void ModulationSystem::Close() {
@@ -52,3 +54,58 @@
 void ModulationSystem::ResetDestinationParameter(ModulationSystem::destination_t dst, float val) {
     for (int i = 0; i < uiMaxSamplesPerCycle; i++) pDestinationParameter[dst][i] = val;
 }
+
+/**
+ * Updates the time stamps for the beginning and end of the current audio
+ * fragment. This is needed to be able to calculate the respective sample
+ * point later for which an event belongs to.
+ */
+void ModulationSystem::UpdateFragmentTime() {
+    // update time stamp for this audio fragment cycle
+    ModulationSystem::FragmentTime.begin = ModulationSystem::FragmentTime.end;
+    ModulationSystem::FragmentTime.end   = ModulationSystem::CreateTimeStamp();
+
+    // recalculate sample ratio for this audio fragment
+    real_time_t fragmentDuration = ModulationSystem::FragmentTime.end - ModulationSystem::FragmentTime.begin;
+    ModulationSystem::FragmentTime.sample_ratio = (float) ModulationSystem::uiMaxSamplesPerCycle / (float) fragmentDuration;
+}
+
+/**
+ * Creates a real time stamp for the current moment. Out of efficiency this
+ * is implemented in inline assembly for each CPU independently; we currently
+ * don't use a generic solution for CPUs that are not yet covered by the
+ * assembly code, instead an error message is prompted on compile time, forcing
+ * the user to contact us.
+ */
+ModulationSystem::real_time_t ModulationSystem::CreateTimeStamp() {
+    #if defined(__i386__) || defined(__x86_64__)
+        uint64_t t;
+        __asm__ __volatile__ ("rdtsc" : "=A" (t));
+        return t >> 8;
+    #elif defined(__ia64__)
+        real_time_t t;
+        __asm__ __volatile__ ("mov %0=ar.itc" : "=r"(t));
+        return t;
+    #elif defined(__powerpc__)
+        real_time_t t;
+        __asm__ __volatile__ (
+            "98:	mftb %0\n"
+            "99:\n"
+            ".section __ftr_fixup,\"a\"\n"
+            "	.long %1\n"
+            "	.long 0\n"
+            "	.long 98b\n"
+            "	.long 99b\n"
+            ".previous"
+            : "=r" (t) : "i" (0x00000100)
+        );
+        return t;
+    #elif defined(__alpha__)
+        real_time_t t;
+        __asm__ __volatile__ ("rpcc %0" : "=r"(t));
+        return t;
+    #else // we don't want to use a slow generic solution
+    #  error Sorry, LinuxSampler lacks time stamp code for your system.
+    #  error Please report this error and the CPU you are using to the LinuxSampler developers mailing list!
+    #endif
+}