diff options
| author | Joe Ludwig <[email protected]> | 2013-06-26 15:22:04 -0700 |
|---|---|---|
| committer | Joe Ludwig <[email protected]> | 2013-06-26 15:22:04 -0700 |
| commit | 39ed87570bdb2f86969d4be821c94b722dc71179 (patch) | |
| tree | abc53757f75f40c80278e87650ea92808274aa59 /sp/src/public/simple_physics.cpp | |
| download | source-sdk-2013-39ed87570bdb2f86969d4be821c94b722dc71179.tar.xz source-sdk-2013-39ed87570bdb2f86969d4be821c94b722dc71179.zip | |
First version of the SOurce SDK 2013
Diffstat (limited to 'sp/src/public/simple_physics.cpp')
| -rw-r--r-- | sp/src/public/simple_physics.cpp | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/sp/src/public/simple_physics.cpp b/sp/src/public/simple_physics.cpp new file mode 100644 index 00000000..d08c041d --- /dev/null +++ b/sp/src/public/simple_physics.cpp @@ -0,0 +1,72 @@ +//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose:
+//
+// $NoKeywords: $
+//
+//=============================================================================//
+
+#include "simple_physics.h"
+#include "tier0/dbg.h"
+
+// memdbgon must be the last include file in a .cpp file!!!
+#include "tier0/memdbgon.h"
+
+CSimplePhysics::CSimplePhysics()
+{
+ Init( 1.0f / 30.0f ); // default is 30 steps per second
+}
+
+
+void CSimplePhysics::Init( float flTimeStep )
+{
+ m_flPredictedTime = 0;
+ m_iCurTimeStep = 0;
+ m_flTimeStep = flTimeStep;
+ m_flTimeStepMul = m_flTimeStep*m_flTimeStep*0.5f;
+}
+
+
+void CSimplePhysics::Simulate(
+ CSimplePhysics::CNode *pNodes,
+ int nNodes,
+ CSimplePhysics::IHelper *pHelper,
+ float dt,
+ float flDamp )
+{
+ // Figure out how many time steps to run.
+ m_flPredictedTime += dt;
+ int newTimeStep = (int)ceil( m_flPredictedTime / m_flTimeStep );
+ int nTimeSteps = newTimeStep - m_iCurTimeStep;
+ for( int iTimeStep=0; iTimeStep < nTimeSteps; iTimeStep++ )
+ {
+ // Simulate everything..
+ for( int iNode=0; iNode < nNodes; iNode++ )
+ {
+ CSimplePhysics::CNode *pNode = &pNodes[iNode];
+
+ // Apply forces.
+ Vector vAccel;
+ pHelper->GetNodeForces( pNodes, iNode, &vAccel );
+ Assert( vAccel.IsValid() );
+
+ Vector vPrevPos = pNode->m_vPos;
+ pNode->m_vPos = pNode->m_vPos + (pNode->m_vPos - pNode->m_vPrevPos) * flDamp + vAccel * m_flTimeStepMul;
+ pNode->m_vPrevPos = vPrevPos;
+ }
+
+ // Apply constraints.
+ pHelper->ApplyConstraints( pNodes, nNodes );
+ }
+ m_iCurTimeStep = newTimeStep;
+
+ // Setup predicted positions.
+ float flInterpolant = (m_flPredictedTime - (GetCurTime() - m_flTimeStep)) / m_flTimeStep;
+ for( int iNode=0; iNode < nNodes; iNode++ )
+ {
+ CSimplePhysics::CNode *pNode = &pNodes[iNode];
+ VectorLerp( pNode->m_vPrevPos, pNode->m_vPos, flInterpolant, pNode->m_vPredicted );
+ }
+}
+
+
|