EPhysics: add soft body bending constraints API

This patch introduces the API ephysics_body_soft_body_bending_constraints_add
used define how deformeable a soft body is supposed to be.


Patch by: Leandro Dorileo <dorileo@profusion.mobi>



SVN revision: 79592

legacy/ephysics/src/lib/EPhysics.h

@@ -2423,6 +2423,28 @@ EAPI int ephysics_body_soft_body_position_iterations_get(EPhysics_Body *body);
  */
 EAPI void ephysics_body_soft_body_triangle_move(EPhysics_Body *body, int idx, Evas_Coord x, Evas_Coord y, Evas_Coord z);
 
+/**
+ * @brief
+ * Add new bending constraints to some @p body.
+ *
+ * Bending constraints define how a soft body is to be deformeable. In fact a
+ * bending constraints represents a link between a soft body mesh triangle and
+ * other. The hardness property is used to define the bending constraint of
+ * those new links.
+ *
+ * By default EPhysics create a new soft body or cloth with a single bending
+ * constraint.
+ *
+ * @param body The body to add bending constraints to.
+ * @param number The number of bending constraints to be added, it must be
+ * greater than 0.
+ *
+ * @see ephysics_body_soft_body_hardness_set().
+ *
+ * @ingroup EPhysics_Body
+ */
+EAPI void ephysics_body_soft_body_bending_constraints_add(EPhysics_Body *body, int number);
+
 /**
  * @brief
  * Create a new circle physics body.

legacy/ephysics/src/lib/ephysics_body.cpp

@@ -749,6 +749,16 @@ _ephysics_body_soft_body_anchors_rebuild(int node, btRigidBody *rigid_body, btSo
      }
 }
 
+void
+ephysics_body_soft_body_bending_constraints_generate(EPhysics_Body *body)
+{
+   btSoftBody *soft_body = body->soft_body;
+
+   for (; body->bending_constraints; body->bending_constraints--)
+     soft_body->generateBendingConstraints(2, soft_body->m_materials
+                                           [body->material_index]);
+}
+
 static void
 _ephysics_body_cloth_constraints_rebuild(EPhysics_Body *body)
 {
@@ -776,12 +786,7 @@ _ephysics_body_cloth_constraints_rebuild(EPhysics_Body *body)
           }
      }
    soft_body->generateClusters(0);
-   if (!body->bending_constraints)
-     {
-        soft_body->generateBendingConstraints(2, soft_body->
-                                              m_materials[body->material_index]);
-        body->bending_constraints = EINA_TRUE;
-     }
+   ephysics_body_soft_body_bending_constraints_generate(body);
 }
 
 static void
@@ -802,12 +807,7 @@ _ephysics_body_soft_body_constraints_rebuild(EPhysics_Body *body)
      }
 
    soft_body->generateClusters(0);
-   if (!body->bending_constraints)
-     {
-        soft_body->generateBendingConstraints(10, soft_body->
-                                              m_materials[body->material_index]);
-        body->bending_constraints = EINA_TRUE;
-     }
+   ephysics_body_soft_body_bending_constraints_generate(body);
 }
 
 inline static double
@@ -1685,6 +1685,7 @@ ephysics_body_soft_body_hardness_get(const EPhysics_Body *body)
 static void
 _ephysics_body_soft_body_default_config(EPhysics_Body *body, btSoftBody *soft_body)
 {
+   body->bending_constraints = 1;
    body->soft_body = soft_body;
    body->soft_body->getCollisionShape()->setMargin(btScalar(0.02));
    body->soft_body->setUserPointer(body);
@@ -1892,6 +1893,26 @@ ephysics_body_soft_body_position_iterations_get(EPhysics_Body *body)
    return body->soft_body->m_cfg.piterations;
 }
 
+EAPI void
+ephysics_body_soft_body_bending_constraints_add(EPhysics_Body *body, int number)
+{
+   if (!body)
+     {
+        ERR("Could add new bending constraint, body is null.");
+        return;
+     }
+
+   if (number <= 0)
+     {
+        ERR("Could not add new bending constraints, number must be greater"
+            " than 0");
+        return;
+     }
+
+   body->bending_constraints += number;
+   DBG("Added new bending constraints to body: %p", body);
+}
+
 EAPI EPhysics_Body *
 ephysics_body_cloth_add(EPhysics_World *world, unsigned short rows, unsigned short columns)
 {

legacy/ephysics/src/lib/ephysics_private.h

@@ -151,7 +151,7 @@ struct _EPhysics_Body {
      Eina_Bool back_face_culling:1;
      Eina_Bool clockwise:1;
      Eina_Bool boundary:1;
-     Eina_Bool bending_constraints:1;
+     int bending_constraints;
 };
 
 extern int _ephysics_log_dom;
@@ -189,6 +189,7 @@ void ephysics_body_forces_apply(EPhysics_Body *body);
 void ephysics_body_activate(const EPhysics_Body *body, Eina_Bool activate);
 void ephysics_body_evas_objects_restack(EPhysics_World *world);
 void ephysics_body_soft_body_dragging_apply(EPhysics_Body *body);
+void ephysics_body_soft_body_bending_constraints_generate(EPhysics_Body *body);
 
 /* Camera */
 EPhysics_Camera *ephysics_camera_add(EPhysics_World *world);

legacy/ephysics/src/lib/ephysics_world.cpp

@@ -590,6 +590,9 @@ _th_simulate(void *data, Ecore_Thread *th)
              ephysics_body_forces_apply(body);
              if (body->dragging_data.dragging)
                ephysics_body_soft_body_dragging_apply(body);
+
+             if (body->bending_constraints)
+               ephysics_body_soft_body_bending_constraints_generate(body);
           }
 
         time_now = ecore_time_get();