source: code/branches/physics/src/bullet/LinearMath/btQuickprof.cpp @ 2305

/*

/***************************************************************************************************
**
** profile.cpp
**
** Real-Time Hierarchical Profiling for Game Programming Gems 3
**
** by Greg Hjelstrom & Byon Garrabrant
**
***************************************************************************************************/

// Credits: The Clock class was inspired by the Timer classes in 
// Ogre (www.ogre3d.org).

#include "LinearMath/btQuickprof.h"


#ifdef USE_BT_CLOCK

static btClock gProfileClock;

inline void Profile_Get_Ticks(unsigned long int * ticks)
{
        *ticks = gProfileClock.getTimeMicroseconds();
}

inline float Profile_Get_Tick_Rate(void)
{
//      return 1000000.f;
        return 1000.f;

}



/***************************************************************************************************
**
** CProfileNode
**
***************************************************************************************************/

/***********************************************************************************************
 * INPUT:                                                                                      *
 * name - pointer to a static string which is the name of this profile node                    *
 * parent - parent pointer                                                                     *
 *                                                                                             *
 * WARNINGS:                                                                                   *
 * The name is assumed to be a static pointer, only the pointer is stored and compared for     *
 * efficiency reasons.                                                                         *
 *=============================================================================================*/
CProfileNode::CProfileNode( const char * name, CProfileNode * parent ) :
        Name( name ),
        TotalCalls( 0 ),
        TotalTime( 0 ),
        StartTime( 0 ),
        RecursionCounter( 0 ),
        Parent( parent ),
        Child( NULL ),
        Sibling( NULL )
{
        Reset();
}


void    CProfileNode::CleanupMemory()
{
        delete ( Child);
        Child = NULL;
        delete ( Sibling);
        Sibling = NULL;
}

CProfileNode::~CProfileNode( void )
{
        delete ( Child);
        delete ( Sibling);
}


/***********************************************************************************************
 * INPUT:                                                                                      *
 * name - static string pointer to the name of the node we are searching for                   *
 *                                                                                             *
 * WARNINGS:                                                                                   *
 * All profile names are assumed to be static strings so this function uses pointer compares   *
 * to find the named node.                                                                     *
 *=============================================================================================*/
CProfileNode * CProfileNode::Get_Sub_Node( const char * name )
{
        // Try to find this sub node
        CProfileNode * child = Child;
        while ( child ) {
                if ( child->Name == name ) {
                        return child;
                }
                child = child->Sibling;
        }

        // We didn't find it, so add it
        
        CProfileNode * node = new CProfileNode( name, this );
        node->Sibling = Child;
        Child = node;
        return node;
}


void    CProfileNode::Reset( void )
{
        TotalCalls = 0;
        TotalTime = 0.0f;
        gProfileClock.reset();

        if ( Child ) {
                Child->Reset();
        }
        if ( Sibling ) {
                Sibling->Reset();
        }
}


void    CProfileNode::Call( void )
{
        TotalCalls++;
        if (RecursionCounter++ == 0) {
                Profile_Get_Ticks(&StartTime);
        }
}


bool    CProfileNode::Return( void )
{
        if ( --RecursionCounter == 0 && TotalCalls != 0 ) { 
                unsigned long int time;
                Profile_Get_Ticks(&time);
                time-=StartTime;
                TotalTime += (float)time / Profile_Get_Tick_Rate();
        }
        return ( RecursionCounter == 0 );
}


/***************************************************************************************************
**
** CProfileIterator
**
***************************************************************************************************/
CProfileIterator::CProfileIterator( CProfileNode * start )
{
        CurrentParent = start;
        CurrentChild = CurrentParent->Get_Child();
}


void    CProfileIterator::First(void)
{
        CurrentChild = CurrentParent->Get_Child();
}


void    CProfileIterator::Next(void)
{
        CurrentChild = CurrentChild->Get_Sibling();
}


bool    CProfileIterator::Is_Done(void)
{
        return CurrentChild == NULL;
}


void    CProfileIterator::Enter_Child( int index )
{
        CurrentChild = CurrentParent->Get_Child();
        while ( (CurrentChild != NULL) && (index != 0) ) {
                index--;
                CurrentChild = CurrentChild->Get_Sibling();
        }

        if ( CurrentChild != NULL ) {
                CurrentParent = CurrentChild;
                CurrentChild = CurrentParent->Get_Child();
        }
}


void    CProfileIterator::Enter_Parent( void )
{
        if ( CurrentParent->Get_Parent() != NULL ) {
                CurrentParent = CurrentParent->Get_Parent();
        }
        CurrentChild = CurrentParent->Get_Child();
}


/***************************************************************************************************
**
** CProfileManager
**
***************************************************************************************************/

CProfileNode    CProfileManager::Root( "Root", NULL );
CProfileNode *  CProfileManager::CurrentNode = &CProfileManager::Root;
int                             CProfileManager::FrameCounter = 0;
unsigned long int                       CProfileManager::ResetTime = 0;


/***********************************************************************************************
 * CProfileManager::Start_Profile -- Begin a named profile                                    *
 *                                                                                             *
 * Steps one level deeper into the tree, if a child already exists with the specified name     *
 * then it accumulates the profiling; otherwise a new child node is added to the profile tree. *
 *                                                                                             *
 * INPUT:                                                                                      *
 * name - name of this profiling record                                                        *
 *                                                                                             *
 * WARNINGS:                                                                                   *
 * The string used is assumed to be a static string; pointer compares are used throughout      *
 * the profiling code for efficiency.                                                          *
 *=============================================================================================*/
void    CProfileManager::Start_Profile( const char * name )
{
        if (name != CurrentNode->Get_Name()) {
                CurrentNode = CurrentNode->Get_Sub_Node( name );
        } 
        
        CurrentNode->Call();
}


/***********************************************************************************************
 * CProfileManager::Stop_Profile -- Stop timing and record the results.                       *
 *=============================================================================================*/
void    CProfileManager::Stop_Profile( void )
{
        // Return will indicate whether we should back up to our parent (we may
        // be profiling a recursive function)
        if (CurrentNode->Return()) {
                CurrentNode = CurrentNode->Get_Parent();
        }
}


/***********************************************************************************************
 * CProfileManager::Reset -- Reset the contents of the profiling system                       *
 *                                                                                             *
 *    This resets everything except for the tree structure.  All of the timing data is reset.  *
 *=============================================================================================*/
void    CProfileManager::Reset( void )
{ 
        Root.Reset();
    Root.Call();
        FrameCounter = 0;
        Profile_Get_Ticks(&ResetTime);
}


/***********************************************************************************************
 * CProfileManager::Increment_Frame_Counter -- Increment the frame counter                    *
 *=============================================================================================*/
void CProfileManager::Increment_Frame_Counter( void )
{
        FrameCounter++;
}


/***********************************************************************************************
 * CProfileManager::Get_Time_Since_Reset -- returns the elapsed time since last reset         *
 *=============================================================================================*/
float CProfileManager::Get_Time_Since_Reset( void )
{
        unsigned long int time;
        Profile_Get_Ticks(&time);
        time -= ResetTime;
        return (float)time / Profile_Get_Tick_Rate();
}

#endif //USE_BT_CLOCK