collision scale for static prop scaling (uniformscale)

engine/cmodel.cpp

@@ -392,6 +392,65 @@ vcollide_t* CM_VCollideForModel( int modelindex, const model_t* pModel )
 	return 0;
 }
 
+//-----------------------------------------------------------------------------
+// returns a physcollide that is scaled based off input data
+//-----------------------------------------------------------------------------
+CPhysCollide* CM_ScalePhysCollide( vcollide_t *pVCollide, float flScale )
+{
+	CPhysCollide *pNewCollide = pVCollide->solids[0];
+
+	if ( flScale != 1.0f )
+	{
+		// Create a query to get more information from the collision object
+		ICollisionQuery *pQuery = physcollision->CreateQueryModel( pVCollide->solids[0] );	// FIXME: This should iterate over all solids!
+		if ( pQuery == NULL )
+			return pVCollide->solids[0];
+
+		// Create a container to hold all the convexes we'll create
+		const int nNumConvex = pQuery->ConvexCount();
+		CPhysConvex **pConvexes = (CPhysConvex **) stackalloc( sizeof( CPhysConvex * ) * nNumConvex );
+
+		// For each convex, collect the verts and create a convex from it we'll retain for later
+		for ( int i = 0; i < nNumConvex; i++ )
+		{
+			int nNumTris = pQuery->TriangleCount( i );
+			int nNumVerts = nNumTris * 3;
+			// FIXME: Really?  stackalloc?
+			Vector *pVerts = (Vector *) stackalloc( sizeof( Vector ) * nNumVerts );
+			Vector **ppVerts = (Vector **) stackalloc( sizeof( Vector * ) * nNumVerts );
+			for ( int j = 0; j < nNumTris; j++ )
+			{
+				// Get all the verts for this triangle and scale them up
+				pQuery->GetTriangleVerts( i, j, pVerts + (j * 3) );
+				*(pVerts + (j * 3)) *= flScale;
+				*(pVerts + (j * 3) + 1) *= flScale;
+				*(pVerts + (j * 3) + 2) *= flScale;
+
+				// Setup our pointers (blech!)
+				*(ppVerts + (j * 3)) = pVerts + (j * 3);
+				*(ppVerts + (j * 3) + 1) = pVerts + (j * 3) + 1;
+				*(ppVerts + (j * 3) + 2) = pVerts + (j * 3) + 2;
+			}
+
+			// Convert it back to a convex
+			pConvexes[i] = physcollision->ConvexFromVerts( ppVerts, nNumVerts );
+			Assert( pConvexes[i] != NULL );
+			if ( pConvexes[i] == NULL )
+				return pVCollide->solids[0];
+		}
+
+		// Clean up
+		physcollision->DestroyQueryModel( pQuery );
+
+		// Create a collision model from all the convexes
+		pNewCollide = physcollision->ConvertConvexToCollide( pConvexes, nNumConvex );
+		if ( !pNewCollide )
+			return pVCollide->solids[0];
+	}
+
+	return pNewCollide;
+}
+