BGE modifier: generate correct physic shape, share static derived mesh, share display list.

This commit completes the support for modifiers in the BGE.
- The physic shape is generated according to the derived mesh. 
  This is true for all types of shapes and all types of 
  objects except soft body.
- Optimization for static derived mesh (mesh with modifiers
  but no armature and no shape keys). Replicas will share
  the derived mesh and the display list: less memory and
  faster rendering. With this optimization, the static 
  derived mesh will render as fast as if the modifiers were
  applied.

Known Limits:
- Sharing of mesh and display list is only possible between
  in-game replicas or dupligroup. If you want to instantiate
  multiple objects with modifiers, use dupligroup to ensure
  best memory and GPU utilization.
- rayCast() will interact with the derived mesh as follow:
  Hit position and hit normal are the real values according
  to the derived mesh but the KX_PolyProxy object refers to
  the original mesh. You should use it only to retrieve the
  material.
- Dynamic derived mesh have very poor performance:
  They use direct openGL calls for rendering (no support
  for display list and vertex array) and they dont't share
  the derived mesh memory. Always apply modifiers on dynamic
  mesh for best performance.
- Time dependent modifiers are not supported.
- Modifiers are not supported for Bullet soft body.

1 files changed, 25 insertions, 26 deletions

diff --git a/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp b/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
index 07fdc8ec41b..f18ffb56ccb 100644
--- a/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
+++ b/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
@@ -52,6 +52,10 @@
 
 #include "KX_MotionState.h" // bridge between motionstate and scenegraph node
 
+extern "C"{
+	#include "BKE_DerivedMesh.h"
+}
+
 #ifdef USE_ODE
 
 #include "KX_OdePhysicsController.h"
@@ -792,6 +796,7 @@ void	KX_ConvertODEEngineObject(KX_GameObject* gameobj,
 
 void	KX_ConvertBulletObject(	class	KX_GameObject* gameobj,
 	class	RAS_MeshObject* meshobj,
+	struct  DerivedMesh* dm,
 	class	KX_Scene* kxscene,
 	struct	PHY_ShapeProps* shapeprops,
 	struct	PHY_MaterialProps*	smmaterial,
@@ -884,42 +889,36 @@ void	KX_ConvertBulletObject(	class	KX_GameObject* gameobj,
 		}
 	case KX_BOUNDPOLYTOPE:
 		{
-			shapeInfo->SetMesh(meshobj, true,false);
+			shapeInfo->SetMesh(meshobj, dm,true,false);
 			bm = shapeInfo->CreateBulletShape();
 			break;
 		}
 	case KX_BOUNDMESH:
 		{
-			
-			if (!ci.m_mass ||objprop->m_softbody)
-			{				
-				// mesh shapes can be shared, check first if we already have a shape on that mesh
-				class CcdShapeConstructionInfo *sharedShapeInfo = CcdShapeConstructionInfo::FindMesh(meshobj, false);
-				if (sharedShapeInfo != NULL) 
-				{
-					delete shapeInfo;
-					shapeInfo = sharedShapeInfo;
-					shapeInfo->AddRef();
-				} else
-				{
-					shapeInfo->SetMesh(meshobj, false,false);
-				}
+			bool useGimpact = (ci.m_mass && !objprop->m_softbody);
 
-				// Soft bodies require welding. Only avoid remove doubles for non-soft bodies!
-				if (objprop->m_softbody)
-				{
-					shapeInfo->setVertexWeldingThreshold1(objprop->m_soft_welding); //todo: expose this to the UI
-				}
-
-				bm = shapeInfo->CreateBulletShape();
-				//no moving concave meshes, so don't bother calculating inertia
-				//bm->calculateLocalInertia(ci.m_mass,ci.m_localInertiaTensor);
+			// mesh shapes can be shared, check first if we already have a shape on that mesh
+			class CcdShapeConstructionInfo *sharedShapeInfo = CcdShapeConstructionInfo::FindMesh(meshobj, dm, false,useGimpact);
+			if (sharedShapeInfo != NULL) 
+			{
+				delete shapeInfo;
+				shapeInfo = sharedShapeInfo;
+				shapeInfo->AddRef();
 			} else
 			{
-				shapeInfo->SetMesh(meshobj, false,true);
-				bm = shapeInfo->CreateBulletShape();
+				shapeInfo->SetMesh(meshobj, dm, false,useGimpact);
 			}
 
+			// Soft bodies require welding. Only avoid remove doubles for non-soft bodies!
+			if (objprop->m_softbody)
+			{
+				shapeInfo->setVertexWeldingThreshold1(objprop->m_soft_welding); //todo: expose this to the UI
+			}
+
+			bm = shapeInfo->CreateBulletShape();
+			//should we compute inertia for dynamic shape?
+			//bm->calculateLocalInertia(ci.m_mass,ci.m_localInertiaTensor);
+
 			break;
 		}
 	}