1

game/shared/tf2/plasmaprojectile_shared.cpp

@@ -0,0 +1,72 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//=============================================================================//
+#include "cbase.h"
+#include "plasmaprojectile_shared.h"
+
+#define PLASMA_LIFETIME				2.0
+
+ConVar	plasma_gravity( "plasma_gravity","1000", FCVAR_REPLICATED, "Plasma gravity" );
+ConVar	plasma_drag( "plasma_drag","2", FCVAR_REPLICATED, "Plasma drag" );
+
+
+//-----------------------------------------------------------------------------
+// Setup state needed to perform the physics computation
+//-----------------------------------------------------------------------------
+void CPlasmaProjectileShared::Init( const Vector &vecStart, const Vector &vecDir, float flSpawnSpeed )
+{
+	m_vecSpawnPosition = vecStart;
+	m_vTracerDir = vecDir;
+	m_flSpawnSpeed = flSpawnSpeed;
+}
+
+void CPlasmaProjectileShared::SetSpawnTime( float flSpawnTime )
+{
+	m_flSpawnTime = flSpawnTime;
+}
+
+void CPlasmaProjectileShared::SetDeathTime( float flDeathTime )
+{
+	m_flDeathTime = flDeathTime;
+}
+
+
+//-----------------------------------------------------------------------------
+// Perform custom physics on this dude (when we're in ballistic mode)
+//-----------------------------------------------------------------------------
+void CPlasmaProjectileShared::ComputePosition( float flTime, Vector *pNewPosition, Vector *pNewVelocity, QAngle *pNewAngles, QAngle *pNewAngVelocity )
+{
+	float flLifeTime = flTime - m_flSpawnTime;
+	if (flLifeTime < 0)
+		return;
+
+	// Travel ballistically until we run out of juice..
+	if (flTime <= m_flDeathTime)
+	{
+		VectorMultiply( m_vTracerDir, m_flSpawnSpeed, *pNewVelocity );
+		VectorMA( m_vecSpawnPosition, flLifeTime, *pNewVelocity, *pNewPosition );
+	}
+	else
+	{
+		VectorMultiply( m_vTracerDir, m_flSpawnSpeed, *pNewVelocity );
+		VectorMA( m_vecSpawnPosition, m_flDeathTime - m_flSpawnTime, *pNewVelocity, *pNewPosition );
+
+		// Ran out of juice... fall!
+		float flFallTime = flTime - m_flDeathTime;
+
+		float flDragFactor = exp( -plasma_drag.GetFloat() * flFallTime );
+		*pNewVelocity *= flDragFactor;
+
+		float flDist = (m_flSpawnSpeed / plasma_drag.GetFloat()) * ( 1.0f - flDragFactor );
+		VectorMA( *pNewPosition, flDist, m_vTracerDir, *pNewPosition );
+
+		// Add in the effects of gravity!
+		pNewVelocity->z -= flFallTime * plasma_gravity.GetFloat();
+		pNewPosition->z -= 0.5f * plasma_gravity.GetFloat() * flFallTime * flFallTime; 
+	}
+}
+
+