surface collsion dampening (can be used for rolling resistance)

panda/src/ode/odeWorld.cxx

@@ -48,30 +48,40 @@ destroy() {
   dWorldDestroy(_id);
 }
 
+void OdeWorld:: 
+assign_surface_body(OdeBody& body, int surface)
+{
+    _body_surface_map[body.get_id()].surfaceType = surface;
+    _body_surface_map[body.get_id()].dampen = 0.0f;
+}
+
 void OdeWorld::
 init_surface_table(PN_uint8 num_surfaces)
 {
-    _surface_table = new dSurfaceParameters[num_surfaces * num_surfaces];
+    _surface_table = new sSurfaceParams[num_surfaces * num_surfaces];
+    //_dampen_table = new sSurfaceParams[num_surfaces * num_surfaces];
     _num_surfaces = num_surfaces;
 }
 
 void OdeWorld::
-set_surface(int pos1, int pos2, dSurfaceParameters& entry)
+set_surface(int pos1, int pos2, sSurfaceParams& entry)
 {
     int true_pos = (pos1 * _num_surfaces) + pos2;
-    _surface_table[true_pos].mode = entry.mode;
-    _surface_table[true_pos].mu = entry.mu;
-    _surface_table[true_pos].mu2 = entry.mu2;
-    _surface_table[true_pos].bounce = entry.bounce;
-    _surface_table[true_pos].bounce_vel = entry.bounce_vel;
-    _surface_table[true_pos].soft_cfm = entry.soft_cfm;
-    _surface_table[true_pos].motion1 = entry.motion1;
-    _surface_table[true_pos].motion2 = entry.motion2;
-    _surface_table[true_pos].slip1 = entry.slip1;
-    _surface_table[true_pos].slip2 = entry.slip2;
+    _surface_table[true_pos].colparams.mode = entry.colparams.mode;
+    _surface_table[true_pos].colparams.mu = entry.colparams.mu;
+    _surface_table[true_pos].colparams.mu2 = entry.colparams.mu2;
+    _surface_table[true_pos].colparams.bounce = entry.colparams.bounce;
+    _surface_table[true_pos].colparams.bounce_vel = entry.colparams.bounce_vel;
+    _surface_table[true_pos].colparams.soft_cfm = entry.colparams.soft_cfm;
+    _surface_table[true_pos].colparams.motion1 = entry.colparams.motion1;
+    _surface_table[true_pos].colparams.motion2 = entry.colparams.motion2;
+    _surface_table[true_pos].colparams.slip1 = entry.colparams.slip1;
+    _surface_table[true_pos].colparams.slip2 = entry.colparams.slip2;
+    _surface_table[true_pos].dampen = entry.dampen;
 }
 
-dSurfaceParameters& OdeWorld::
+
+sSurfaceParams& OdeWorld::
 get_surface(PN_uint8 surface1, PN_uint8 surface2)
 {
     int true_pos = 0;
@@ -93,21 +103,40 @@ set_surface_entry(  PN_uint8 pos1, PN_uint8 pos2,
                     dReal bounce_vel, 
                     dReal soft_erp, 
                     dReal soft_cfm,
-                    dReal slip)
+                    dReal slip,
+                    dReal dampen)
 {
     //todo: add mode
-    dSurfaceParameters new_params;
-    new_params.mode = 0;
-    new_params.mu = mu;
-    new_params.mu2 = mu;
-    new_params.bounce = bounce;
-    new_params.bounce_vel = bounce_vel;
-    new_params.soft_erp = soft_erp;
-    new_params.soft_cfm = soft_cfm;
-    new_params.slip1 = slip;
-    new_params.slip2 = slip;
-    new_params.motion1 = 0.0;
-    new_params.motion2 = 0.0;
+    sSurfaceParams new_params;
+    int someMode = 0;
+    if (bounce > 0.0001)
+    {
+        someMode |= dContactBounce;
+    }
+    if (soft_erp > 0.0001)
+    {
+        someMode |= dContactSoftERP;
+    }
+    if (soft_cfm > 0.0001)
+    {
+        someMode |= dContactSoftCFM;
+    }
+    if (slip > 0.0001)
+    {
+        someMode = someMode | dContactSlip1 | dContactSlip2;
+    }
+    new_params.colparams.mode = dContactBounce | dContactSoftCFM | dContactApprox1;// | dContactSoftERP;
+    new_params.colparams.mu = mu;
+    new_params.colparams.mu2 = mu;
+    new_params.colparams.bounce = bounce;
+    new_params.colparams.bounce_vel = bounce_vel;
+    new_params.colparams.soft_erp = soft_erp;
+    new_params.colparams.soft_cfm = soft_cfm;
+    new_params.colparams.slip1 = slip;
+    new_params.colparams.slip2 = slip;
+    new_params.colparams.motion1 = 0.0;
+    new_params.colparams.motion2 = 0.0;
+    new_params.dampen = dampen;
     //todo: a bit of wasted space here
     set_surface(pos1, pos2, new_params);
    
@@ -121,18 +150,44 @@ set_surface_entry(  PN_uint8 pos1, PN_uint8 pos2,
     }
 }
 
-void OdeWorld:: 
-assign_surface_body(OdeBody& body, int surface)
-{
-    _body_surface_map[body.get_id()] = surface;
-}
 
-int OdeWorld::
+
+sBodyParams OdeWorld::
 get_surface_body(dBodyID id)
 {
+    
   BodySurfaceMap::iterator iter = _body_surface_map.find(id);
   if (iter != _body_surface_map.end()) {
     return iter->second;
   }
-  return 0;
+  sBodyParams defaultParams;
+  defaultParams.surfaceType = 0;
+  defaultParams.dampen = 0.0f;
+  return defaultParams;
+}
+
+void OdeWorld::
+set_dampen_on_bodies(dBodyID id1, dBodyID id2,dReal damp)
+{
+    if(_body_surface_map[id1].dampen < damp)
+    {
+        _body_surface_map[id1].dampen = damp;
+    }
+    if(_body_surface_map[id2].dampen < damp)
+    {
+        _body_surface_map[id2].dampen = damp;
+    }
+}
+
+float OdeWorld:: 
+apply_dampening(float dt, OdeBody& body)
+{
+    dBodyID bodyId = body.get_id();
+    dReal damp = _body_surface_map[bodyId].dampen;
+    float dampening = 1.00 - (damp * dt);
+    body.set_angular_vel(body.get_angular_vel() * dampening);
+    body.set_linear_vel(body.get_linear_vel() * dampening);
+    _body_surface_map[bodyId].dampen = 0.0;
+    return dampening;
+    
 }

panda/src/ode/odeWorld.h

@@ -26,8 +26,15 @@
 #include "pmap.h"
 #include "numeric_types.h"
 
+
+#include "ode_includes.h"
+#include "odeHelperStructs.h"
+
 class OdeBody;
 class OdeJoint;
+    
+
+
 
 ////////////////////////////////////////////////////////////////////
 //       Class : OdeWorld
@@ -80,6 +87,7 @@ PUBLISHED:
   INLINE void step_fast1(dReal stepsize, int maxiterations);
 
   INLINE int compare_to(const OdeWorld &other) const;
+
   void init_surface_table(PN_uint8 num_surfaces);
   void assign_surface_body(OdeBody& body, int surface);
   void set_surface_entry(PN_uint8 pos1, PN_uint8 pos2, 
@@ -88,22 +96,29 @@ PUBLISHED:
                          dReal bounce_vel, 
                          dReal soft_erp,
                          dReal soft_cfm,
-                         dReal slip);
+                         dReal slip,
+                         dReal dampen);
+  float apply_dampening(float dt, OdeBody& body);
+
   
     
 public: 
   INLINE dWorldID get_id() const;
-  INLINE dSurfaceParameters& get_surface(PN_uint8 surface1, PN_uint8 surface2);
-  INLINE void set_surface(int pos1, int pos2, dSurfaceParameters& entry);
-  INLINE int get_surface_body(dBodyID id);
+  INLINE sSurfaceParams& get_surface(PN_uint8 surface1, PN_uint8 surface2);
+  INLINE void set_surface(int pos1, int pos2, sSurfaceParams& entry);
+  INLINE sBodyParams get_surface_body(dBodyID id);
+  INLINE void set_dampen_on_bodies(dBodyID id1, dBodyID id2,dReal damp);
+
   
 private:
   dWorldID _id;
-  dSurfaceParameters *_surface_table;
+  sSurfaceParams *_surface_table;
   PN_uint8 _num_surfaces;
-  typedef pmap<dBodyID, int> BodySurfaceMap;
+  typedef pmap<dBodyID, sBodyParams> BodySurfaceMap;
   BodySurfaceMap _body_surface_map;
 
+
+
 public:
   static TypeHandle get_class_type() {
     return _type_handle;