path: root/src/lib/ephysics/ephysics_body.cpp

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <Evas.h>
#include <Ecore.h>

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wshadow"

#include <BulletCollision/CollisionShapes/btShapeHull.h>
#include <LinearMath/btGeometryUtil.h>

#pragma GCC diagnostic pop

#include <math.h>

#include "ephysics_private.h"
#include "ephysics_trimesh.h"
#include "ephysics_body_materials.h"

#ifdef  __cplusplus
extern "C" {
#endif

#define BODY_CLOTH_CHECK() \
   do { \
     if (body->type == EPHYSICS_BODY_TYPE_CLOTH) \
       { \
          WRN("Not supported for cloth"); \
          return; \
       } \
   } while(0)

typedef struct _EPhysics_Body_Callback EPhysics_Body_Callback;
typedef struct _EPhysics_Body_Evas_Stacking EPhysics_Body_Evas_Stacking;
typedef struct _EPhysics_Body_Soft_Body_Slice EPhysics_Body_Soft_Body_Slice;
typedef struct _EPhysics_Body_Face_Obj EPhysics_Body_Face_Obj;
typedef struct _EPhysics_Quaternion EPhysics_Quaternion;

struct _EPhysics_Body_Callback {
     EINA_INLIST;
     void (*func) (void *data, EPhysics_Body *body, void *event_info);
     void *data;
     EPhysics_Callback_Body_Type type;
     Eina_Bool deleted:1;
};

struct _EPhysics_Body_Collision {
     EPhysics_Body *contact_body;
     Evas_Coord x;
     Evas_Coord y;
     Evas_Coord z;
};

struct _EPhysics_Body_Evas_Stacking {
     Evas_Object *evas;
     float stacking;
};

struct _EPhysics_Body_Soft_Body_Slice
{
     Evas_Object *evas_obj;
     int index;
     struct {
          double x;
          double y;
     } p[3];
     float stacking;
};

struct _EPhysics_Body_Face_Obj {
    EPhysics_Body_Face face;
    Evas_Object *obj;
};

static void
_ephysics_body_cloth_anchor_mass_reset(EPhysics_Body *body)
{
   double anchor_mass;
   anchor_mass = 1 / (body->soft_body->m_nodes.size() * 0.025);

   for (int i = 0; i < body->soft_body->m_anchors.size(); i++)
     body->soft_body->m_anchors[i].m_node->m_im = anchor_mass;

   DBG("Cloth anchors mass reset.");
}

EAPI void
_ephysics_body_soft_body_light_apply(Evas_Map *m, Evas_Coord lx, Evas_Coord ly, Evas_Coord lz, int lr, int lg, int lb, int ar, int ag, int ab, Evas_Coord bx, Evas_Coord by, Evas_Coord bz)
{
   double x, y, z, nx, ny, nz, ln, br;
   Evas_Coord mx, my, mz, mr, mg, mb, ma;
   int i;

   for (i = 0; i < 4; i++)
     {

        evas_map_point_coord_get(m, i, &mx, &my, &mz);
        evas_map_point_color_get(m, i, NULL, NULL, NULL, &ma);

        x = mx;
        y = my;
        z = mz;

        nx = sqrt(pow(bx - x, 2));
        ny = sqrt(pow(by - y, 2));
        nz = sqrt(pow(bz - z, 2));
        ln = nx + ny + nz;

        if (ln != 0.0)
          {
             nx /= ln;
             ny /= ln;
             nz /= ln;
          }

        x = lx - bx;
        y = ly - by;
        z = lz - bz;

        ln = pow(x, 2) + pow(y, 2) + pow(z, 2);
        ln = sqrt(ln);

        if (ln != 0.0)
          {
             x /= ln;
             y /= ln;
             z /= ln;
          }

        br = (nx * x) + (ny * y) + (nz * z);
        if (br < 0.0) br = 0.0;

        mr = ar + ((lr - ar) * br);
        mg = ag + ((lg - ag) * br);
        mb = ab + ((lb - ab) * br);

        evas_map_point_color_set(m, i, mr, mg, mb, ma);
     }
}

static void
_ephysics_body_soft_body_slices_apply(EPhysics_Body *body, Evas_Object *evas_obj, Eina_List *slices)
{
   double rate;
   void *list_data;
   Eina_List *l;
   Evas_Coord wy, wh, y0, y1, y2, x0, x1, x2, z0, z1, z2, w, h, bx, by, bz;
   Evas_Map *map;
   btVector3 p0, p1, p2;
   btSoftBody::tFaceArray faces;
   EPhysics_Body_Soft_Body_Slice *slice;
   int lr, lg, lb, ar, ag, ab;
   Evas_Coord lx, ly, lz;
   Eina_Bool light = EINA_FALSE;
   EPhysics_Camera *camera;

   int px, py, pz, foc;
   Eina_Bool perspective = EINA_FALSE;

   camera = ephysics_world_camera_get(body->world);
   rate = ephysics_world_rate_get(body->world);
   ephysics_world_render_geometry_get(body->world, NULL, &wy, NULL, NULL, &wh,
                                      NULL);
   evas_object_geometry_get(evas_obj, NULL, NULL, &w, &h);

   ephysics_body_geometry_get(body, &bx, &by, &bz, NULL, NULL, NULL);

   if ((body->light_apply) ||
       (ephysics_world_light_all_bodies_get(body->world)))
     {
        ephysics_world_point_light_position_get(body->world, &lx, &ly, &lz);
        ephysics_world_point_light_color_get(body->world, &lr, &lg, &lb);
        ephysics_world_ambient_light_color_get(body->world, &ar, &ag, &ab);
        light = EINA_TRUE;
     }

   if (ephysics_camera_perspective_enabled_get(camera))
     {
        ephysics_camera_perspective_get(camera, &px, &py, &pz, &foc);
        perspective = EINA_TRUE;
     }

   EINA_LIST_FOREACH(slices, l, list_data)
     {
        slice = (EPhysics_Body_Soft_Body_Slice *)list_data;

        faces = body->soft_body->m_faces;
        p0 = faces[slice->index].m_n[0]->m_x;
        p1 = faces[slice->index].m_n[1]->m_x;
        p2 = faces[slice->index].m_n[2]->m_x;

        slice->stacking = p0.z() + p1.z() + p2.z();

        map = evas_map_new(4);

        evas_map_point_image_uv_set(map, 0, slice->p[0].x * w,
                                    slice->p[0].y * h);
        evas_map_point_image_uv_set(map, 1, slice->p[1].x * w,
                                    slice->p[1].y * h);
        evas_map_point_image_uv_set(map, 2, slice->p[2].x * w,
                                    slice->p[2].y * h);
        evas_map_point_image_uv_set(map, 3, slice->p[2].x * w,
                                    slice->p[2].y * h);

        x0 = p0.x() * rate;
        x1 = p1.x() * rate;
        x2 = p2.x() * rate;

        y0 = wh + wy - (p0.y() * rate);
        y1 = wh + wy - (p1.y() * rate);
        y2 = wh + wy - (p2.y() * rate);

        z0 = p0.z() * rate;
        z1 = p1.z() * rate;
        z2 = p2.z() * rate;

        evas_map_point_coord_set(map, 0, x0, y0, z0);
        evas_map_point_coord_set(map, 1, x1, y1, z1);
        evas_map_point_coord_set(map, 2, x2, y2, z2);
        evas_map_point_coord_set(map, 3, x2, y2, z2);

        if (perspective)
          evas_map_util_3d_perspective(map, px, py, pz, foc);

        if (body->back_face_culling)
          {
             if (evas_map_util_clockwise_get(map))
                  evas_object_show(slice->evas_obj);
             else
               {
                  evas_map_free(map);
                  evas_object_hide(slice->evas_obj);
                  continue;
               }
          }

        if (light)
          _ephysics_body_soft_body_light_apply(map, lx, ly, lz, lr, lg, lb, ar,
                                               ag, ab, bx, by, bz);

        evas_object_map_set(slice->evas_obj, map);
        evas_object_map_enable_set(slice->evas_obj, EINA_TRUE);
        evas_map_free(map);
     }
}

static inline double
_ephysics_body_soft_body_slice_calc(double val, double delta, double max)
{
   double ret = val + delta / max;
   if (ret < 0)
     ret = 0;
   else if (ret > 1)
     ret = 1;
   return ret;
}

static EPhysics_Body_Soft_Body_Slice *
_ephysics_body_soft_body_slice_new(EPhysics_Body *body, double delta, double max, int index)
{
   EPhysics_Body_Soft_Body_Slice *slice;
   btSoftBody::tFaceArray faces;

   slice = (EPhysics_Body_Soft_Body_Slice *)calloc(
      1, sizeof(EPhysics_Body_Soft_Body_Slice));
   if (!slice)
     {
        ERR("Couldn't allocate EPhysics_Soft_Body_Slice memory.");
        return NULL;
     }

   faces = body->soft_body->m_faces;

   slice->index = index;
   slice->p[0].x = _ephysics_body_soft_body_slice_calc(
      faces[slice->index].m_n[0]->m_x.x(), delta, max);
   slice->p[0].y = 1 - _ephysics_body_soft_body_slice_calc(
      faces[slice->index].m_n[0]->m_x.y(), delta, max);
   slice->p[1].x = _ephysics_body_soft_body_slice_calc(
      faces[slice->index].m_n[1]->m_x.x(), delta, max);
   slice->p[1].y = 1 - _ephysics_body_soft_body_slice_calc(
      faces[slice->index].m_n[1]->m_x.y(), delta, max);
   slice->p[2].x = _ephysics_body_soft_body_slice_calc(
      faces[slice->index].m_n[2]->m_x.x(), delta, max);
   slice->p[2].y = 1 - _ephysics_body_soft_body_slice_calc(
      faces[slice->index].m_n[2]->m_x.y(), delta, max);

   return slice;
}

static Eina_List *
_ephysics_body_soft_body_slices_get(EPhysics_Body *body)
{
   Eina_List *l, *slices_list, *slices = NULL;
   void *ldata, *slice_data;
   EPhysics_Body_Face_Slice *face_slice;

   EINA_LIST_FOREACH(body->faces_slices, l, ldata)
     {
        face_slice = (EPhysics_Body_Face_Slice *)ldata;
        EINA_LIST_FOREACH(face_slice->slices, slices_list, slice_data)
             slices = eina_list_append(slices, slice_data);
     }

   return slices;
}

EAPI int
ephysics_body_soft_body_slice_index_get(EPhysics_Body *body, Evas_Object *slice)
{
   Eina_List *slices;
   void *ldata;
   EPhysics_Body_Soft_Body_Slice *slice_data;

   if (!body)
     {
        ERR("Can't get soft body slice index, body is null.");
        return -1;
     }

   if (body->type == EPHYSICS_BODY_TYPE_RIGID)
     {
        ERR("Can't get soft body slice index, operation not allowed for rigid"
            " bodies.");
        return -1;
     }

   slices = _ephysics_body_soft_body_slices_get(body);
   EINA_LIST_FREE(slices, ldata)
     {
        slice_data = (EPhysics_Body_Soft_Body_Slice *)ldata;
        if (slice_data->evas_obj == slice)
          return slice_data->index;
     }

   return -1;
}

static void
_ephysics_body_soft_body_slice_del_cb(void *data, Evas *evas EINA_UNUSED, Evas_Object *obj, void *event_info EINA_UNUSED)
{
   EPhysics_Body_Soft_Body_Slice *slice = (EPhysics_Body_Soft_Body_Slice *)data;
   slice->evas_obj = NULL;
   evas_object_event_callback_del(obj, EVAS_CALLBACK_DEL,
                                  _ephysics_body_soft_body_slice_del_cb);
}

static void
_ephysics_body_soft_body_slices_init(EPhysics_Body *body, Evas_Object *obj, Eina_List *slices)
{
   EPhysics_Body_Soft_Body_Slice *slice = NULL;
   btVector3 p0, p1, p2;
   void *slice_data;
   Evas_Coord w, h;
   Eina_List *l;
   Evas *evas;
   Evas_Object *parent;

   evas = evas_object_evas_get(obj);
   evas_object_geometry_get(obj, NULL, NULL, &w, &h);

   parent = evas_object_smart_parent_get(obj);
   EINA_LIST_FOREACH(slices, l, slice_data)
     {
        slice = (EPhysics_Body_Soft_Body_Slice *) slice_data;
        slice->evas_obj = evas_object_image_filled_add(evas);
        evas_object_layer_set(slice->evas_obj,
                              evas_object_layer_get(obj));
        evas_object_image_source_set(slice->evas_obj, obj);
        evas_object_image_source_events_set(slice->evas_obj, EINA_TRUE);
        evas_object_resize(slice->evas_obj, w, h);
        evas_object_show(slice->evas_obj);
        evas_object_image_smooth_scale_set(slice->evas_obj, EINA_TRUE);
        evas_object_event_callback_add(slice->evas_obj, EVAS_CALLBACK_DEL,
                                       _ephysics_body_soft_body_slice_del_cb,
                                       slice);

        if (parent) evas_object_smart_member_add(slice->evas_obj, parent);
     }

   if (slice)
     evas_object_image_source_visible_set(slice->evas_obj, EINA_FALSE);

   _ephysics_body_soft_body_slices_apply(body, obj, slices);
}

static void
_ephysics_body_soft_body_slices_free(Eina_List *slices)
{
   EPhysics_Body_Soft_Body_Slice *slice;
   void *slice_data;

   EINA_LIST_FREE(slices, slice_data)
     {
        slice = (EPhysics_Body_Soft_Body_Slice *)slice_data;
        if (slice->evas_obj)
          evas_object_del(slice->evas_obj);
        free(slice);
     }
}

static void
_ephysics_body_soft_body_slices_clean(Eina_List *slices)
{
   EPhysics_Body_Soft_Body_Slice *slice;
   void *slice_data;
   Eina_List *l;

   EINA_LIST_FOREACH(slices, l, slice_data)
     {
        slice = (EPhysics_Body_Soft_Body_Slice *)slice_data;
        if (slice->evas_obj)
          evas_object_del(slice->evas_obj);
     }
}

static btTransform
_ephysics_body_transform_get(const EPhysics_Body *body)
{
   btTransform trans;
   btVector3 center;
   btScalar radius;

   if (body->type == EPHYSICS_BODY_TYPE_RIGID)
     {
        body->rigid_body->getMotionState()->getWorldTransform(trans);
        return trans;
     }

   body->soft_body->getCollisionShape()->getBoundingSphere(center, radius);
   trans.setIdentity();
   trans.setOrigin(center);
   return trans;
}

static int
_ephysics_body_evas_stacking_sort_cb(const void *d1, const void *d2)
{
   const EPhysics_Body_Evas_Stacking *stacking1, *stacking2;

   stacking1 = (const EPhysics_Body_Evas_Stacking *)d1;
   stacking2 = (const EPhysics_Body_Evas_Stacking *)d2;

   if (!stacking1) return 1;
   if (!stacking2) return -1;

   if (stacking1->stacking < stacking2->stacking) return -1;
   if (stacking2->stacking > stacking2->stacking) return 1;

   return 0;
}

static EPhysics_Body_Evas_Stacking *
_ephysics_body_evas_stacking_new(Evas_Object *obj, float index)
{
   EPhysics_Body_Evas_Stacking *stacking;

   stacking = (EPhysics_Body_Evas_Stacking *)calloc(
                1, sizeof(EPhysics_Body_Evas_Stacking));

   if (!stacking)
     {
        ERR("Could not allocate ephysics soft body evas stacking data.");
        return NULL;
     }

   stacking->evas = obj;
   stacking->stacking = index;
   return stacking;
}

void
ephysics_body_evas_objects_restack(EPhysics_World *world)
{
   void *data, *slice_data, *stack_data;
   EPhysics_Body *body;
   btTransform trans;
   EPhysics_Body_Evas_Stacking *stacking;
   EPhysics_Body_Soft_Body_Slice *slice;
   Eina_List *l, *slices, *bodies, *stack_list = NULL;
   Evas_Object *prev_obj = NULL;
   Eina_Hash *hash;
   Eina_Iterator *it;
   int layer;
   Eina_List *ll = NULL;

   bodies = ephysics_world_bodies_get(world);

   if (!eina_list_count(bodies))
     return;

   hash = eina_hash_int32_new(NULL);

   EINA_LIST_FREE(bodies, data)
     {
        body = (EPhysics_Body *)data;
        if (body->deleted) continue;

        if (body->type == EPHYSICS_BODY_TYPE_RIGID)
          {
             if (!body->evas_obj) continue;
             trans = _ephysics_body_transform_get(body);
             stacking = _ephysics_body_evas_stacking_new(body->evas_obj,
                                                         trans.getOrigin().z());
             if (!stacking) goto error;

             layer = evas_object_layer_get(stacking->evas);
             stack_list = (Eina_List *)eina_hash_find(hash, &layer);
             stack_list = eina_list_append(stack_list, stacking);
             eina_hash_set(hash, &layer, stack_list);

             continue;
          }

        slices = _ephysics_body_soft_body_slices_get(body);
        if (!slices) continue;

        EINA_LIST_FREE(slices, slice_data)
          {
             slice = (EPhysics_Body_Soft_Body_Slice *)slice_data;

             stacking = _ephysics_body_evas_stacking_new(slice->evas_obj,
                                                         slice->stacking);
             if (!stacking) goto error;

             layer = evas_object_layer_get(stacking->evas);
             stack_list = (Eina_List *)eina_hash_find(hash, &layer);
             stack_list = eina_list_append(stack_list, stacking);
             eina_hash_set(hash, &layer, stack_list);
          }
     }


   it = eina_hash_iterator_data_new(hash);
   while (eina_iterator_next(it, &data))
     {
        stack_list = (Eina_List *)data;
        stack_list = eina_list_sort(stack_list, eina_list_count(stack_list),
                                    _ephysics_body_evas_stacking_sort_cb);
        prev_obj = NULL;

        ll = eina_list_append(ll, stack_list);

        EINA_LIST_FOREACH(stack_list, l, stack_data)
          {
             stacking = (EPhysics_Body_Evas_Stacking *)stack_data;

             if (prev_obj)
               evas_object_stack_below(stacking->evas, prev_obj);

             prev_obj = stacking->evas;
          }
     }

   eina_iterator_free(it);

   EINA_LIST_FREE(ll, stack_data)
     {
        stack_list = (Eina_List *) stack_data;
        eina_hash_del_by_data(hash, stack_list);
        EINA_LIST_FREE(stack_list, slice_data)
          free(slice_data);
     }

   eina_hash_free(hash);
   return;

 error:
   ERR("Could not allocate evas stacking data memory.");
   eina_hash_free(hash);
}

static void
_ephysics_body_transform_set(EPhysics_Body *body, btTransform trans)
{
   btTransform origin;

   if (body->type != EPHYSICS_BODY_TYPE_RIGID)
     {
        origin = _ephysics_body_transform_get(body);
        body->soft_body->translate(trans.getOrigin() - origin.getOrigin());
        return;
     }
   body->rigid_body->getMotionState()->setWorldTransform(trans);
}

void
ephysics_body_activate(const EPhysics_Body *body, Eina_Bool activate)
{
   if (body->type == EPHYSICS_BODY_TYPE_RIGID)
     {
        body->rigid_body->activate(activate);
        return;
     }

   body->soft_body->activate(activate);
}

static void
_ephysics_body_forces_update(EPhysics_Body *body)
{
   body->force.x = body->rigid_body->getTotalForce().getX();
   body->force.y = body->rigid_body->getTotalForce().getY();
   body->force.z = body->rigid_body->getTotalForce().getZ();
   body->force.torque_x = body->rigid_body->getTotalTorque().getX();
   body->force.torque_y = body->rigid_body->getTotalTorque().getY();
   body->force.torque_z = body->rigid_body->getTotalTorque().getZ();
   body->rigid_body->clearForces();

   DBG("forces updated: %lf, %lf, %lf", body->force.x, body->force.y,
       body->force.z);
   DBG("torque updated: %lf, %lf, %lf", body->force.torque_x,
       body->force.torque_y, body->force.torque_z);
}

static inline void
_ephysics_body_sleeping_threshold_set(EPhysics_Body *body, double linear_threshold, double angular_threshold, double rate)
{
   body->rigid_body->setSleepingThresholds(linear_threshold / rate,
                                           angular_threshold / RAD_TO_DEG);
}

static inline void
_ephysics_body_linear_velocity_set(EPhysics_Body *body, double x, double y, double z, double rate)
{
   btVector3 linear_velocity = btVector3(x / rate, -y / rate, z / rate);

   ephysics_body_activate(body, EINA_TRUE);
   if (body->rigid_body)
     body->rigid_body->setLinearVelocity(linear_velocity);

   if (body->soft_body)
     {
        for (int i = 0; i < body->soft_body->m_nodes.size(); i++)
          body->soft_body->m_nodes[i].m_v = linear_velocity;
     }
}

static void
_ephysics_body_event_callback_del(EPhysics_Body *body, EPhysics_Body_Callback *cb)
{
   if (cb->deleted) return;

   cb->deleted = EINA_TRUE;

   if (body->walking)
     {
        body->to_delete = eina_list_append(body->to_delete, cb);
        return;
     }

   body->callbacks = eina_inlist_remove(body->callbacks, EINA_INLIST_GET(cb));
   free(cb);
}

static Eina_Bool
_ephysics_body_event_callback_call(EPhysics_Body *body, EPhysics_Callback_Body_Type type, void *event_info)
{
   Eina_Bool called = EINA_FALSE;
   EPhysics_Body_Callback *cb;
   void *clb;

   body->walking++;
   EINA_INLIST_FOREACH(body->callbacks, cb)
     {
        if ((cb->type == type) && (!cb->deleted))
          {
             cb->func(cb->data, body, event_info);
             called = EINA_TRUE;
          }
     }
   body->walking--;

   if (body->walking > 0) return called;

   EINA_LIST_FREE(body->to_delete, clb)
     {
        cb = (EPhysics_Body_Callback *) clb;
        body->callbacks = eina_inlist_remove(body->callbacks,
                                             EINA_INLIST_GET(cb));
        free(cb);
     }

   return called;
}

void
ephysics_body_active_set(EPhysics_Body *body, Eina_Bool active)
{
   if (body->active == !!active) return;
   body->active = !!active;
   if (active) return;

   _ephysics_body_event_callback_call(body, EPHYSICS_CALLBACK_BODY_STOPPED,
                                      (void *) body->evas_obj);
};

Eina_Bool
ephysics_body_filter_collision(EPhysics_Body *body0, EPhysics_Body *body1)
{
   Eina_List *l;
   void *grp;

   if ((!body0->collision_groups) || (!body1->collision_groups))
     return EINA_TRUE;

   EINA_LIST_FOREACH(body0->collision_groups, l, grp)
     {
        if (eina_list_data_find(body1->collision_groups, grp))
          return EINA_TRUE;
     }

   return EINA_FALSE;
}

EAPI Eina_Bool
ephysics_body_collision_group_add(EPhysics_Body *body, const char *group)
{
   Eina_Stringshare *group_str;

   if (!body)
     {
        ERR("Can't add body collision group, body is null.");
        return EINA_FALSE;
     }

   ephysics_world_lock_take(body->world);
   group_str = eina_stringshare_add(group);
   if (eina_list_data_find(body->collision_groups, group_str))
     {
        INF("Body already added to group: %s", group);
        eina_stringshare_del(group_str);
        ephysics_world_lock_release(body->world);
        return EINA_TRUE;
     }

   body->collision_groups = eina_list_append(body->collision_groups, group_str);
   ephysics_world_lock_release(body->world);
   return EINA_TRUE;
}

EAPI Eina_Bool
ephysics_body_collision_group_del(EPhysics_Body *body, const char *group)
{
   Eina_Stringshare *group_str;

   if (!body)
     {
        ERR("Can't remove body collision group, body is null.");
        return EINA_FALSE;
     }

   ephysics_world_lock_take(body->world);
   group_str = eina_stringshare_add(group);
   if (!eina_list_data_find(body->collision_groups, group_str))
     {
        INF("Body isn't part of group: %s", group);
        eina_stringshare_del(group_str);
        ephysics_world_lock_release(body->world);
        return EINA_TRUE;
     }

   body->collision_groups = eina_list_remove(body->collision_groups, group_str);
   eina_stringshare_del(group_str);
   eina_stringshare_del(group_str);
   ephysics_world_lock_release(body->world);
   return EINA_TRUE;
}

EAPI const Eina_List *
ephysics_body_collision_group_list_get(const EPhysics_Body *body)
{
   if (!body)
     {
        ERR("Can't get the body's collision group, body is null.");
        return NULL;
     }

   return body->collision_groups;
}

static EPhysics_Body *
_ephysics_body_new(EPhysics_World *world, btScalar mass, double cm_x, double cm_y, double cm_z)
{
   EPhysics_Body *body;
   double rate;

   body = (EPhysics_Body *) calloc(1, sizeof(EPhysics_Body));
   if (!body)
     {
        ERR("Couldn't create a new body instance.");
        return NULL;
     }

   rate = ephysics_world_rate_get(world);
   body->scale[0] = 1;
   body->scale[1] = 1;
   body->scale[2] = 1;
   body->size.w = rate;
   body->size.h = rate;
   body->size.d = rate;
   body->mass = mass;
   body->world = world;
   body->cm.x = cm_x;
   body->cm.y = cm_y;
   body->cm.z = cm_z;

   return body;
}

static EPhysics_Body *
_ephysics_body_rigid_body_add(EPhysics_World *world, btCollisionShape *collision_shape, const char *type, double cm_x, double cm_y, double cm_z)
{
   btRigidBody::btRigidBodyConstructionInfo *rigid_body_ci;
   btDefaultMotionState *motion_state;
   btRigidBody *rigid_body;
   EPhysics_Body *body;
   btScalar mass = 1;
   btVector3 inertia;

   if (!collision_shape)
     {
        ERR("Couldn't create a %s shape.", type);
        return NULL;
     }

   body = _ephysics_body_new(world, mass, cm_x, cm_y, cm_z);
   if (!body)
     {
        ERR("Couldn't create a new body instance.");
        goto err_body;
     }

   motion_state = new btDefaultMotionState();
   if (!motion_state)
     {
        ERR("Couldn't create a motion state.");
        goto err_motion_state;
     }

   inertia = btVector3(0, 0, 0);
   collision_shape->calculateLocalInertia(mass, inertia);

   rigid_body_ci = new btRigidBody::btRigidBodyConstructionInfo(
      mass, motion_state, collision_shape, inertia);
   if (!rigid_body_ci)
     {
        ERR("Couldn't create a rigid body construction info.");
        goto err_rigid_body_ci;
     }

   rigid_body = new btRigidBody(*rigid_body_ci);
   if (!rigid_body)
     {
        ERR("Couldn't create a rigid body.");
        goto err_rigid_body;
     }

   body->type = EPHYSICS_BODY_TYPE_RIGID;
   body->collision_shape = collision_shape;
   body->rigid_body = rigid_body;
   body->rigid_body->setUserPointer(body);
   body->rigid_body->setLinearFactor(btVector3(1, 1, 0));
   body->rigid_body->setAngularFactor(btVector3(0, 0, 1));

   if (!ephysics_world_body_add(body->world, body))
     {
        ERR("Couldn't add body to world's bodies list");
        goto err_world_add;
     }

   delete rigid_body_ci;

   INF("Body %p of type %s added.", body, type);
   return body;

err_world_add:
   delete rigid_body;
err_rigid_body:
   delete rigid_body_ci;
err_rigid_body_ci:
   delete motion_state;
err_motion_state:
   free(body);
err_body:
   delete collision_shape;
   return NULL;
}

static void
_ephysics_body_evas_obj_del_cb(void *data, Evas *e EINA_UNUSED, Evas_Object *obj EINA_UNUSED, void *event_info EINA_UNUSED)
{
   EPhysics_Body *body = (EPhysics_Body *) data;

   if (body->default_face)
     _ephysics_body_soft_body_slices_clean(body->default_face->slices);

   body->evas_obj = NULL;
   DBG("Evas object deleted. Updating body: %p", body);
}

static void
_ephysics_body_soft_body_anchors_rebuild(int node, btRigidBody *rigid_body, btSoftBody *soft_body)
{
   btTransform world_trans = rigid_body->getWorldTransform();
   btVector3 local = world_trans.inverse() * soft_body->m_nodes[node].m_x;

   for (int i = 0; i < soft_body->m_anchors.size(); i++)
     {
        if (soft_body->m_anchors[i].m_node == &soft_body->m_nodes[node])
          soft_body->m_anchors[i].m_local = local;
     }
}

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)
{
   btRigidBody *rigid_body;
   btSoftBody *soft_body;
   btSoftBody::Node *node;
   btSoftBody::Anchor anchor;
   int anchors_size = body->soft_body->m_anchors.size();

   soft_body = body->soft_body;

   if (anchors_size)
     {
        rigid_body = soft_body->m_anchors[0].m_body;
        for (int m = 0; m < anchors_size; m++)
          {
             anchor = soft_body->m_anchors[m];
             node = anchor.m_node;
             for (int n = 0; n < soft_body->m_nodes.size(); n++)
               {
                  if (node == &soft_body->m_nodes[n])
                    _ephysics_body_soft_body_anchors_rebuild(n, rigid_body,
                                                             soft_body);
               }
          }
     }
   soft_body->generateClusters(0);
   ephysics_body_soft_body_bending_constraints_generate(body);
}

static void
_ephysics_body_soft_body_constraints_rebuild(EPhysics_Body *body)
{
   btSoftBody *soft_body = body->soft_body;
   btRigidBody *rigid_body = body->rigid_body;

   if (soft_body->m_anchors.size() > 0)
     {
        for (int i = 0; i < soft_body->m_nodes.size(); i++)
          _ephysics_body_soft_body_anchors_rebuild(i, rigid_body, soft_body);
     }
   else
     {
        for (int i = 0; i < soft_body->m_nodes.size(); i++)
          soft_body->appendAnchor(i, rigid_body);
     }

   soft_body->generateClusters(0);
   ephysics_body_soft_body_bending_constraints_generate(body);
}

inline static double
_ephysics_body_volume_get(const EPhysics_Body *body)
{
   btVector3 vector = body->collision_shape->getLocalScaling();
   return vector.x() * vector.y() * vector.z();
}

void
_ephysics_body_soft_body_dragging_set(EPhysics_Body *body, int triangle)
{
   btSoftBody::Face face;
   btSoftBody::Node *node;

   body->dragging_data.triangle = triangle;
   body->dragging_data.dragging = EINA_TRUE;

   face = body->soft_body->m_faces[triangle];
   node = face.m_n[0];
   body->dragging_data.mass = node->m_im;
}

static void
_ephysics_body_soft_body_mass_set(EPhysics_Body *body, double mass)
{
   int valid_nodes;
   btSoftBody::Node node;
   double inverse_mass;

   if (body->type == EPHYSICS_BODY_TYPE_SOFT)
        body->soft_body->setTotalMass(mass);
   else
     {
        valid_nodes = 0;
        for (int i = 0; i < body->soft_body->m_nodes.size(); i++)
          {
             node = body->soft_body->m_nodes[i];
             if (node.m_im && !node.m_battach)
               valid_nodes++;
          }

        inverse_mass = 1 / (mass / valid_nodes);
        if (body->dragging_data.dragging)
          {
             valid_nodes++;
             inverse_mass = 1 / (mass / valid_nodes);
             body->dragging_data.mass = inverse_mass;
          }

        for (int i = 0; i < body->soft_body->m_nodes.size(); i++)
          {
             node = body->soft_body->m_nodes[i];
             if (node.m_im && !node.m_battach)
                  node.m_im = inverse_mass;
          }
     }
}

static void
_ephysics_body_mass_set(EPhysics_Body *body, double mass)
{
   btVector3 inertia(0, 0, 0);

   if (body->density)
     mass = body->density * _ephysics_body_volume_get(body);

   if (body->soft_body)
     _ephysics_body_soft_body_mass_set(body, mass);
   else
     {
        body->collision_shape->calculateLocalInertia(mass, inertia);
        body->rigid_body->setMassProps(mass, inertia);
        body->rigid_body->updateInertiaTensor();
     }

   body->mass = mass;
   DBG("Body %p mass changed to %lf.", body, mass);
}

static void
_ephysics_body_geometry_set(EPhysics_Body *body, Evas_Coord x, Evas_Coord y, Evas_Coord z, Evas_Coord w, Evas_Coord h, Evas_Coord d, double rate)
{
   double mx, my, mz, sx, sy, sz;
   btTransform trans;
   int wy, height;
   btVector3 body_scale, old_scale;

   ephysics_world_render_geometry_get(body->world, NULL, &wy, NULL,
                                      NULL, &height, NULL);
   height += wy;

   mx = (x + w * body->cm.x) / rate;
   my = (height - (y + h * body->cm.y)) / rate;
   mz = (z + d * body->cm.z) / rate;
   sx = (w <= 0) ? 1 : w / rate;
   sy = (h <= 0) ? 1 : h / rate;
   sz = (d <= 0) ? 1 : d / rate;

   trans = _ephysics_body_transform_get(body);
   trans.setOrigin(btVector3(mx, my, mz));
   body_scale = btVector3(sx, sy, sz);
   old_scale = btVector3(body->scale[0], body->scale[1], body->scale[2]);

   if (body->type == EPHYSICS_BODY_TYPE_SOFT)
     {
        body->soft_body->scale(btVector3(1, 1, 1) / old_scale);
        body->soft_body->scale(body_scale);
        body->rigid_body->proceedToTransform(trans);
        _ephysics_body_transform_set(body, trans);
        _ephysics_body_soft_body_constraints_rebuild(body);
     }
   else if (body->type == EPHYSICS_BODY_TYPE_CLOTH)
     {
        body->soft_body->setTotalMass(body->mass, true);
        body->soft_body->scale(btVector3(1, 1, 1) / old_scale);
        body->soft_body->scale(body_scale);
        _ephysics_body_transform_set(body, trans);
        _ephysics_body_cloth_constraints_rebuild(body);
        body->soft_body->setTotalMass(body->mass, false);
        _ephysics_body_cloth_anchor_mass_reset(body);
     }
   else
     {
        body->collision_shape->setLocalScaling(body_scale);
        body->rigid_body->proceedToTransform(trans);

        if (!body->rigid_body->isStaticObject())
          _ephysics_body_mass_set(body, ephysics_body_mass_get(body));
     }

   _ephysics_body_transform_set(body, trans);
   ephysics_body_activate(body, EINA_TRUE);

   body->size.w = w;
   body->size.h = h;
   body->size.d = d;
   body->scale[0] = sx;
   body->scale[1] = sy;
   body->scale[2] = sz;

   DBG("Body %p position changed to (%lf, %lf, %lf).", body, mx, my, mz);
   DBG("Body %p scale changed to (%lf, %lf, %lf).", body, sx, sy, sz);
}

static void
_ephysics_body_resize(EPhysics_Body *body, Evas_Coord w, Evas_Coord h, Evas_Coord d)
{
   Evas_Coord bx, by, bz;
   double rate, sx, sy, sz;
   btVector3 body_scale, center;
   btTransform trans;

   rate = ephysics_world_rate_get(body->world);
   sx = w / rate;
   sy = h / rate;
   sz = d / rate;

   DBG("Body %p scale changed to (%lf, %lf, %lf).", body, sx, sy, sz);

   body_scale = btVector3(sx, sy, sz);
   if (body->type == EPHYSICS_BODY_TYPE_SOFT)
     {
        btVector3 old_scale(body->scale[0], body->scale[1], body->scale[2]);
        trans = _ephysics_body_transform_get(body);

        body->soft_body->scale(btVector3(1, 1, 1) / old_scale);
        body->soft_body->scale(body_scale);

        _ephysics_body_transform_set(body, trans);
        body->rigid_body->proceedToTransform(trans);

        _ephysics_body_soft_body_constraints_rebuild(body);
     }
   else if (body->type == EPHYSICS_BODY_TYPE_CLOTH)
     {
        ephysics_body_geometry_get(body, &bx, &by, &bz, NULL, NULL, NULL);
        _ephysics_body_geometry_set(body, bx, by, bz, w, h, d, rate);
        return;
     }
   else
     {
        body->collision_shape->setLocalScaling(body_scale);

        if(!body->rigid_body->isStaticObject())
          _ephysics_body_mass_set(body, ephysics_body_mass_get(body));
     }

   body->size.w = w;
   body->size.h = h;
   body->size.d = d;
   body->scale[0] = sx;
   body->scale[1] = sy;
   body->scale[2] = sz;

   ephysics_body_activate(body, EINA_TRUE);
}

static void
_ephysics_body_move(EPhysics_Body *body, Evas_Coord x, Evas_Coord y, Evas_Coord z)
{
   double rate, mx, my, mz;
   btTransform trans;
   int wy, height;
   btVector3 body_scale;

   rate = ephysics_world_rate_get(body->world);
   ephysics_world_render_geometry_get(body->world, NULL, &wy, NULL,
                                      NULL, &height, NULL);
   height += wy;

   mx = (x + body->size.w * body->cm.x) / rate;
   my = (height - (y + body->size.h * body->cm.y)) / rate;
   mz = (z + body->size.d * body->cm.z) / rate;

   trans = _ephysics_body_transform_get(body);
   trans.setOrigin(btVector3(mx, my, mz));

   if (body->type == EPHYSICS_BODY_TYPE_CLOTH)
     _ephysics_body_transform_set(body, trans);
   else if (body->type == EPHYSICS_BODY_TYPE_SOFT)
     {
        _ephysics_body_transform_set(body, trans);
        body->rigid_body->proceedToTransform(trans);
        body->rigid_body->getMotionState()->setWorldTransform(trans);
     }
   else
     {
        body->rigid_body->proceedToTransform(trans);
        body->rigid_body->getMotionState()->setWorldTransform(trans);
     }

   ephysics_body_activate(body, EINA_TRUE);

   DBG("Body %p position changed to (%lf, %lf, %lf).", body, mx, my, mz);
}

static void
_ephysics_body_evas_obj_resize_cb(void *data, Evas *e EINA_UNUSED, Evas_Object *obj, void *event_info EINA_UNUSED)
{
   EPhysics_Body *body = (EPhysics_Body *) data;
   int w, h;

   evas_object_geometry_get(obj, NULL, NULL, &w, &h);
   if ((w == body->size.w) && (h == body->size.h))
     return;

   DBG("Resizing body %p to w=%i, h=%i, d=%i", body, w, h, body->size.d);

   ephysics_world_lock_take(body->world);
   _ephysics_body_resize(body, w, h, body->size.d);

   if (body->type == EPHYSICS_BODY_TYPE_CLOTH)
     {
        _ephysics_body_soft_body_slices_clean(body->default_face->slices);
        _ephysics_body_soft_body_slices_init(body, body->evas_obj,
                                             body->default_face->slices);
     }

   ephysics_world_lock_release(body->world);
}

 static void
_ephysics_body_soft_body_evas_restack_cb(void *data, Evas *evas EINA_UNUSED, Evas_Object *obj, void *event_info EINA_UNUSED)
{
   EPhysics_Body *body = (EPhysics_Body *)data;
   Eina_List *slices;
   void *ldata;
   EPhysics_Body_Soft_Body_Slice *slice;
   short layer = evas_object_layer_get(obj);

   slices = _ephysics_body_soft_body_slices_get(body);
   EINA_LIST_FREE(slices, ldata)
     {
        slice = (EPhysics_Body_Soft_Body_Slice *)ldata;
        evas_object_layer_set(slice->evas_obj, layer);
     }
   DBG("Body's slices layer reset to: %d", layer);
}

static void
_ephysics_body_face_slice_del(EPhysics_Body_Face_Slice *face_slice)
{
   _ephysics_body_soft_body_slices_free(face_slice->slices);
   free(face_slice->points_deform);
   free(face_slice);
}

static EPhysics_Body_Face_Slice *
_ephysics_body_face_slice_add(EPhysics_Body *body, EPhysics_Body_Face face)
{
   EPhysics_Body_Face_Slice *face_slice;

   face_slice = (EPhysics_Body_Face_Slice *)calloc(1,
                                               sizeof(EPhysics_Body_Face_Slice));
   if (!face_slice)
     return NULL;

   face_slice->face = face;
   body->faces_slices = eina_list_append(body->faces_slices, face_slice);
   face_slice->body = body;
   return face_slice;
   DBG("New face slice added to body %p", body);
}

static EPhysics_Body_Face_Slice *
_ephysics_body_face_slice_get(EPhysics_Body *body, EPhysics_Body_Face face)
{
   Eina_List *l;
   void *ldata;
   EPhysics_Body_Face_Slice *face_slice = NULL;

   EINA_LIST_FOREACH(body->faces_slices, l, ldata)
     {
        if (((EPhysics_Body_Face_Slice *)ldata)->face == face)
          {
             face_slice = (EPhysics_Body_Face_Slice *)ldata;
             break;
          }
     }

   return face_slice;
}

static EPhysics_Body_Face_Obj *
_ephysics_body_face_evas_object_get(EPhysics_Body *body, EPhysics_Body_Face face)
{
   Eina_List *l;
   void *ldata;
   EPhysics_Body_Face_Obj *face_obj;

   EINA_LIST_FOREACH(body->face_objs, l, ldata)
     {
        face_obj = (EPhysics_Body_Face_Obj *)ldata;
        if (face_obj->face == face)
          return face_obj;
     }

   DBG("Could not find requested face");
   return NULL;
}

static void
_ephysics_body_del(EPhysics_Body *body)
{
   EPhysics_Body_Callback *cb;
   void *ldata;
   void *group;
   EPhysics_Body_Face_Slice *face_slice;

   if (body->evas_obj)
     {
        evas_object_event_callback_del(body->evas_obj, EVAS_CALLBACK_DEL,
                                       _ephysics_body_evas_obj_del_cb);
        evas_object_event_callback_del(body->evas_obj, EVAS_CALLBACK_RESIZE,
                                       _ephysics_body_evas_obj_resize_cb);

        if (body->faces_slices)
          evas_object_event_callback_del(body->evas_obj, EVAS_CALLBACK_RESTACK,
                                       _ephysics_body_soft_body_evas_restack_cb);
     }

   while (body->callbacks)
     {
        cb = EINA_INLIST_CONTAINER_GET(body->callbacks,
                                       EPhysics_Body_Callback);
        body->callbacks = eina_inlist_remove(body->callbacks, body->callbacks);
        free(cb);
     }

   ephysics_constraint_body_del(body);

   EINA_LIST_FREE(body->collision_groups, group)
      eina_stringshare_del((Eina_Stringshare *)group);

   EINA_LIST_FREE(body->faces_slices, ldata)
     {
        face_slice = (EPhysics_Body_Face_Slice *)ldata;
        if (_ephysics_body_face_evas_object_get(body, face_slice->face))
          ephysics_body_face_evas_object_unset(body, face_slice->face);
        _ephysics_body_face_slice_del(face_slice);
     }

   if (body->rigid_body)
     {
        delete body->rigid_body->getMotionState();
        delete body->collision_shape;
        delete body->rigid_body;
     }

   delete body->soft_body;

   free(body);
}

static void
_ephysics_body_evas_obj_map_apply(EPhysics_Body *body, Evas_Map *map, Evas_Object *obj, Eina_Bool bfc, Eina_Bool update_cw)
{
   EPhysics_Camera *camera = ephysics_world_camera_get(body->world);

   if (ephysics_camera_perspective_enabled_get(camera))
     {
        int px, py, z0, foc;
        ephysics_camera_perspective_get(camera, &px, &py, &z0, &foc);
        evas_map_util_3d_perspective(map, px, py, z0, foc);
     }

   if (bfc)
     {
        if (evas_map_util_clockwise_get(map))
          {
             if (update_cw)
               body->clockwise = EINA_TRUE;
             evas_object_show(obj);
          }
        else
          {
             if (update_cw)
               body->clockwise = EINA_FALSE;
             evas_map_free(map);
             evas_object_hide(obj);
             return;
          }
     }
   else
       evas_object_show(obj);

   if ((body->light_apply) ||
       (ephysics_world_light_all_bodies_get(body->world)))
     {
        int lr, lg, lb, ar, ag, ab;
        Evas_Coord lx, ly, lz;

        ephysics_world_point_light_position_get(body->world, &lx, &ly, &lz);
        ephysics_world_point_light_color_get(body->world, &lr, &lg, &lb);
        ephysics_world_ambient_light_color_get(body->world, &ar, &ag, &ab);
        evas_map_util_3d_lighting(map, lx, ly, lz, lr, lg, lb, ar, ag, ab);
     }

   evas_object_map_set(obj, map);
   evas_object_map_enable_set(obj, EINA_TRUE);
   evas_map_free(map);
}

static void
_ephysics_cloth_face_objs_update(EPhysics_Body *body EINA_UNUSED)
{

}

static void
_ephysics_cylinder_face_objs_update(EPhysics_Body *body)
{
   int bx, by, x, y, z, wx, wy, wh, cx, cy;
   EPhysics_Body_Face_Obj *face_obj;
   EPhysics_Camera *camera;
   btQuaternion quat;
   btTransform trans;
   Evas_Map *map;
   Eina_List *l;
   double rate;
   void *ldata;

   ephysics_world_render_geometry_get(body->world, &wx, &wy, NULL,
                                      NULL, &wh, NULL);
   camera = ephysics_world_camera_get(body->world);
   ephysics_camera_position_get(camera, &cx, &cy);
   cx -= wx;
   cy -= wy;

   rate = ephysics_world_rate_get(body->world);
   trans = _ephysics_body_transform_get(body);

   bx = (int) (trans.getOrigin().getX() * rate) - cx;
   by = wh + wy - (int) (trans.getOrigin().getY() * rate) - cy;
   x = bx - body->size.w / 2;
   y = by - body->size.h / 2;
   z = (int) (trans.getOrigin().getZ() * rate);

   quat = trans.getRotation();
   quat.normalize();

   EINA_LIST_FOREACH(body->face_objs, l, ldata)
     {
        Evas_Object *obj;
        Evas_Coord w, h;

        face_obj = (EPhysics_Body_Face_Obj *)ldata;
        obj = face_obj->obj;

        evas_object_geometry_get(obj, NULL, NULL, &w, &h);
        evas_object_move(obj, x, y);
        if ((!w) || (!h))
          {
             DBG("Evas object with no geometry: %p, w=%i h=%i", obj, w, h);
             continue;
          }

        map = evas_map_new(4);

        switch(face_obj->face)
          {
           case EPHYSICS_BODY_CYLINDER_FACE_MIDDLE_FRONT:
              evas_map_util_points_populate_from_object_full(map, obj, z);
              break;
           case EPHYSICS_BODY_CYLINDER_FACE_MIDDLE_BACK:
              evas_map_util_points_populate_from_object_full(map, obj, z + 1);
              evas_map_util_3d_rotate(map, 0, 180, 0, bx, by, z + 1);
              break;
           case EPHYSICS_BODY_CYLINDER_FACE_FRONT:
              evas_map_util_points_populate_from_object_full(
                 map, obj, z - body->size.d / 2);
              break;
           case EPHYSICS_BODY_CYLINDER_FACE_BACK:
              evas_map_util_points_populate_from_object_full(
                 map, obj, z + body->size.d / 2);
              evas_map_util_3d_rotate(map, 0, 180, 0, bx, by,
                                      z + body->size.d / 2);
              break;
           default:
              WRN("Face %i not updated", face_obj->face);
              evas_map_free(map);
              continue;
          }

        evas_map_util_quat_rotate(map, quat.x(), -quat.y(), quat.z(), -quat.w(),
                                  bx, by, z);

        _ephysics_body_evas_obj_map_apply(body, map, obj, EINA_TRUE,
                                          EINA_FALSE);
     }
}

static void
_ephysics_box_face_objs_update(EPhysics_Body *body)
{
   EPhysics_Body_Face_Obj *face_obj;
   int i, x, y, z, wx, wy, wh, cx, cy;
   EPhysics_Camera *camera;
   Evas_Coord v[8][3];
   btQuaternion quat;
   btTransform trans;
   btBoxShape *shape;
   Evas_Map *map;
   Eina_List *l;
   double rate;
   void *ldata;

   ephysics_world_render_geometry_get(body->world, &wx, &wy, NULL,
                                      NULL, &wh, NULL);
   camera = ephysics_world_camera_get(body->world);
   ephysics_camera_position_get(camera, &cx, &cy);
   cx -= wx;
   cy -= wy;

   rate = ephysics_world_rate_get(body->world);
   trans = _ephysics_body_transform_get(body);

   x = (int) (trans.getOrigin().getX() * rate) - cx;
   y = wh + wy - (int) (trans.getOrigin().getY() * rate) - cy;
   z = (int) (trans.getOrigin().getZ() * rate);

   shape = (btBoxShape *) body->collision_shape;
   for (i = 0; i < 8; i++)
     {
        btVector3 vertice;
        shape->getVertex(i, vertice);
        v[i][0] = vertice.getX() * rate + x;
        v[i][1] = - vertice.getY() * rate + y;
        v[i][2] = vertice.getZ() * rate + z;
     }

   quat = trans.getRotation();
   quat.normalize();

   EINA_LIST_FOREACH(body->face_objs, l, ldata)
     {
        Evas_Object *obj;
        Evas_Coord w, h;

        face_obj = (EPhysics_Body_Face_Obj *)ldata;
        obj = face_obj->obj;
        evas_object_geometry_get(obj, NULL, NULL, &w, &h);

        map = evas_map_new(4);
        evas_map_point_image_uv_set(map, 0, 0, 0);
        evas_map_point_image_uv_set(map, 1, w, 0);
        evas_map_point_image_uv_set(map, 2, w, h);
        evas_map_point_image_uv_set(map, 3, 0, h);

        switch(face_obj->face)
          {
           case EPHYSICS_BODY_BOX_FACE_MIDDLE_FRONT:
              evas_map_point_coord_set(map, 0, v[5][0], v[5][1], z);
              evas_map_point_coord_set(map, 1, v[4][0], v[4][1], z);
              evas_map_point_coord_set(map, 2, v[6][0], v[6][1], z);
              evas_map_point_coord_set(map, 3, v[7][0], v[7][1], z);
              break;
           case EPHYSICS_BODY_BOX_FACE_MIDDLE_BACK:
              evas_map_point_coord_set(map, 0, v[0][0], v[0][1], z);
              evas_map_point_coord_set(map, 1, v[1][0], v[1][1], z);
              evas_map_point_coord_set(map, 2, v[3][0], v[3][1], z);
              evas_map_point_coord_set(map, 3, v[2][0], v[2][1], z);
              break;
           case EPHYSICS_BODY_BOX_FACE_FRONT:
              evas_map_point_coord_set(map, 0, v[5][0], v[5][1], v[5][2]);
              evas_map_point_coord_set(map, 1, v[4][0], v[4][1], v[4][2]);
              evas_map_point_coord_set(map, 2, v[6][0], v[6][1], v[6][2]);
              evas_map_point_coord_set(map, 3, v[7][0], v[7][1], v[7][2]);
              break;
           case EPHYSICS_BODY_BOX_FACE_BACK:
              evas_map_point_coord_set(map, 0, v[0][0], v[0][1], v[0][2]);
              evas_map_point_coord_set(map, 1, v[1][0], v[1][1], v[1][2]);
              evas_map_point_coord_set(map, 2, v[3][0], v[3][1], v[3][2]);
              evas_map_point_coord_set(map, 3, v[2][0], v[2][1], v[2][2]);
              break;
           case EPHYSICS_BODY_BOX_FACE_RIGHT:
              evas_map_point_coord_set(map, 0, v[4][0], v[4][1], v[4][2]);
              evas_map_point_coord_set(map, 1, v[0][0], v[0][1], v[0][2]);
              evas_map_point_coord_set(map, 2, v[2][0], v[2][1], v[2][2]);
              evas_map_point_coord_set(map, 3, v[6][0], v[6][1], v[6][2]);
              break;
           case EPHYSICS_BODY_BOX_FACE_LEFT:
              evas_map_point_coord_set(map, 0, v[1][0], v[1][1], v[1][2]);
              evas_map_point_coord_set(map, 1, v[5][0], v[5][1], v[5][2]);
              evas_map_point_coord_set(map, 2, v[7][0], v[7][1], v[7][2]);
              evas_map_point_coord_set(map, 3, v[3][0], v[3][1], v[3][2]);
              break;
           case EPHYSICS_BODY_BOX_FACE_TOP:
              evas_map_point_coord_set(map, 0, v[1][0], v[1][1], v[1][2]);
              evas_map_point_coord_set(map, 1, v[0][0], v[0][1], v[0][2]);
              evas_map_point_coord_set(map, 2, v[4][0], v[4][1], v[4][2]);
              evas_map_point_coord_set(map, 3, v[5][0], v[5][1], v[5][2]);
              break;
           case EPHYSICS_BODY_BOX_FACE_BOTTOM:
              evas_map_point_coord_set(map, 0, v[7][0], v[7][1], v[7][2]);
              evas_map_point_coord_set(map, 1, v[6][0], v[6][1], v[6][2]);
              evas_map_point_coord_set(map, 2, v[2][0], v[2][1], v[2][2]);
              evas_map_point_coord_set(map, 3, v[3][0], v[3][1], v[3][2]);
              break;
           default:
              WRN("Face %i not updated", face_obj->face);
              evas_map_free(map);
              continue;
          }

        evas_map_util_quat_rotate(map, quat.x(), -quat.y(), quat.z(), -quat.w(),
                                  x, y, z);
        _ephysics_body_evas_obj_map_apply(body, map, obj, EINA_TRUE,
                                          EINA_FALSE);
     }
}

static void
_ephysics_body_evas_object_update(EPhysics_Body *body, Evas_Object *evas_obj)
{
   int bx, by, x, y, z, w, h, wx, wy, wh, cx, cy;
   EPhysics_Camera *camera;
   btTransform trans;
   btQuaternion quat;
   Evas_Map *map;
   double rate;

   trans = _ephysics_body_transform_get(body);
   ephysics_world_render_geometry_get(body->world, &wx, &wy, NULL,
                                      NULL, &wh, NULL);
   camera = ephysics_world_camera_get(body->world);
   ephysics_camera_position_get(camera, &cx, &cy);
   cx -= wx;
   cy -= wy;

   evas_object_geometry_get(evas_obj, NULL, NULL, &w, &h);
   rate = ephysics_world_rate_get(body->world);
   bx = (int) (trans.getOrigin().getX() * rate) - cx;
   by = wh + wy - (int) (trans.getOrigin().getY() * rate) - cy;
   x = bx - w * body->cm.x;
   y = by - h * body->cm.y;
   z = (int) (trans.getOrigin().getZ() * rate);

   evas_object_move(evas_obj, x, y);

   if ((!w) || (!h))
     {
        DBG("Evas object with no geometry: %p, w=%i h=%i", evas_obj, w, h);
        return;
     }

   if (body->type != EPHYSICS_BODY_TYPE_RIGID)
     {
        if (!body->back_face_culling)
          evas_object_show(body->evas_obj);
        _ephysics_body_soft_body_slices_apply(body, body->evas_obj,
                                              body->default_face->slices);
        return;
     }

   map = evas_map_new(4);
   evas_map_util_points_populate_from_object(map, body->evas_obj);

   quat = trans.getRotation();
   quat.normalize();
   evas_map_util_quat_rotate(map, quat.x(), -quat.y(), quat.z(), -quat.w(),
                             bx, by, z);

   _ephysics_body_evas_obj_map_apply(body, map, evas_obj,
                                     body->back_face_culling, EINA_TRUE);
}

static void
_ephysics_body_soft_body_update(EPhysics_Body *body)
{
   Eina_List *l;
   void *ldata;
   EPhysics_Body_Face_Slice *face_slice;
   EPhysics_Body_Face_Obj *face_obj;

   EINA_LIST_FOREACH(body->faces_slices, l, ldata)
     {
        face_slice = (EPhysics_Body_Face_Slice *)ldata;
        face_obj = _ephysics_body_face_evas_object_get(body,
                                                       face_slice->face);
        if (!face_obj) continue;
        _ephysics_body_soft_body_slices_apply(body, face_obj->obj,
                                              face_slice->slices);
     }
}

static void
_ephysics_body_evas_object_default_update(EPhysics_Body *body)
{
   if (body->face_objs)
     {
        if (body->type == EPHYSICS_BODY_TYPE_CLOTH)
          _ephysics_cloth_face_objs_update(body);
        else if (body->type == EPHYSICS_BODY_TYPE_RIGID)
          {
             if (body->shape == EPHYSICS_BODY_SHAPE_CYLINDER)
               _ephysics_cylinder_face_objs_update(body);
             else if (body->shape == EPHYSICS_BODY_SHAPE_BOX)
               _ephysics_box_face_objs_update(body);
          }
        else if (body->type == EPHYSICS_BODY_TYPE_SOFT)
          _ephysics_body_soft_body_update(body);

        if (body->evas_obj)
            evas_object_hide(body->evas_obj);

        return;
     }

   if (!body->evas_obj)
     return;

   _ephysics_body_evas_object_update(body, body->evas_obj);
}

static void
_ephysics_body_outside_render_area_check(EPhysics_Body *body)
{
   int wx, wy, wz, ww, wh, wd, bx, by, bz, bw, bh, bd;

   ephysics_world_render_geometry_get(body->world, &wx, &wy, &wz,
                                      &ww, &wh, &wd);
   ephysics_body_geometry_get(body, &bx, &by, &bz, &bw, &bh, &bd);

   // FIXME: check what should be done regarding rotated bodies
   if (((ephysics_world_bodies_outside_top_autodel_get(body->world)) &&
        (by + bh < wy)) ||
       ((ephysics_world_bodies_outside_bottom_autodel_get(body->world)) &&
        (by > wy + wh)) ||
       ((ephysics_world_bodies_outside_left_autodel_get(body->world)) &&
        (bx + bh < wx)) ||
       ((ephysics_world_bodies_outside_right_autodel_get(body->world)) &&
        (bx > wx + ww)) ||
       ((ephysics_world_bodies_outside_front_autodel_get(body->world)) &&
        (bz + bd < wz)) ||
       ((ephysics_world_bodies_outside_back_autodel_get(body->world)) &&
        (bz > wz + wd)))
     {
        DBG("Body %p out of render area", body);
        ephysics_body_del(body);
     }
}

void
ephysics_body_forces_apply(EPhysics_Body *body)
{
   if (!((body->force.x) || (body->force.y) || (body->force.z) ||
         (body->force.torque_x) || (body->force.torque_y) ||
         (body->force.torque_z)))
     return;

   DBG("body: %p, applying forces: %lf, %lf, %lf", body, body->force.x,
       body->force.y, body->force.z);

   ephysics_body_activate(body, EINA_TRUE);
   body->rigid_body->applyCentralForce(btVector3(body->force.x,
                                                 body->force.y,
                                                 body->force.z));
   body->rigid_body->applyTorque(btVector3(body->force.torque_x,
                                           body->force.torque_y,
                                           body->force.torque_z));
}

void
ephysics_body_recalc(EPhysics_Body *body, double rate)
{
   Evas_Coord x, y, z, w, h, d;
   double vx, vy, vz, lt, at;

   ephysics_body_geometry_get(body, &x, &y, &z, &w, &h, &d);
   ephysics_body_linear_velocity_get(body, &vx, &vy, &vz);
   ephysics_body_sleeping_threshold_get(body, &lt, &at);

   _ephysics_body_geometry_set(body, x, y, z, w, h, d, rate);
   _ephysics_body_linear_velocity_set(body, vx, vy, vz, rate);
   _ephysics_body_sleeping_threshold_set(body, lt, at, rate);
}

void
ephysics_body_evas_object_update_select(EPhysics_Body *body)
{
   Eina_Bool callback_called = EINA_FALSE;

   if (!body || body->deleted)
     return;

   callback_called = _ephysics_body_event_callback_call(
      body, EPHYSICS_CALLBACK_BODY_UPDATE, (void *) body->evas_obj);

   if (!callback_called)
     _ephysics_body_evas_object_default_update(body);

   if (ephysics_world_bodies_outside_autodel_get(body->world))
     _ephysics_body_outside_render_area_check(body);
}

EAPI void
ephysics_body_collision_position_get(const EPhysics_Body_Collision *collision, Evas_Coord *x, Evas_Coord *y, Evas_Coord *z)
{
   if (!collision)
     {
        ERR("Can't get body's collision data, collision is null.");
        return;
     }

   if (x) *x = collision->x;
   if (y) *y = collision->y;
   if (z) *z = collision->z;
}

EAPI EPhysics_Body *
ephysics_body_collision_contact_body_get(const EPhysics_Body_Collision *collision)
{
   if (!collision)
     {
        ERR("Can't get body's collision contact body, collision is null.");
        return NULL;
     }

   return collision->contact_body;
}

void
ephysics_body_contact_processed(EPhysics_Body *body, EPhysics_Body *contact_body, btVector3 position)
{
   EPhysics_Body_Collision *collision;
   EPhysics_World *world;;
   double rate;
   int wy, wh;

   if ((!body) || (!contact_body) || (body->collision_cb < 1))
     return;

   collision = (EPhysics_Body_Collision *)calloc(
      1, sizeof(EPhysics_Body_Collision));

   if (!collision)
     {
        ERR("Can't allocate collision data structure.");
        return;
     }

   world = contact_body->world;
   ephysics_world_render_geometry_get(world, NULL, &wy, NULL, NULL, &wh, NULL);
   rate = ephysics_world_rate_get(world);

   collision->contact_body = contact_body;
   collision->x = position.getX() * rate;
   collision->y = wh + wy - (position.getY() * rate);
   collision->z = position.getZ() * rate;

   _ephysics_body_event_callback_call(body, EPHYSICS_CALLBACK_BODY_COLLISION,
                                      (void *) collision);

   free(collision);
}

btRigidBody *
ephysics_body_rigid_body_get(const EPhysics_Body *body)
{
   return body->rigid_body;
}

btSoftBody *
ephysics_body_soft_body_get(const EPhysics_Body *body)
{
   return body->soft_body;
}

EAPI void
ephysics_body_soft_body_anchor_hardness_set(EPhysics_Body *body, double hardness)
{
   if (!body)
     {
        ERR("Can't set soft body's anchor hardness, body is null.");
        return;
     }

   if (!body->soft_body)
     {
        ERR("Can't set soft body's anchor hardness, body seems not to be a soft"
            " body.");
        return;
     }

   if (hardness < 0 || hardness > 100)
     {
        ERR("Can't set soft body's anchor hardness, it must be between 0 and"
            " 100.");
        return;
     }

   ephysics_world_lock_take(body->world);
   body->anchor_hardness = EINA_TRUE;
   body->soft_body->m_cfg.kAHR = 1 - (hardness / 100);
   ephysics_world_lock_release(body->world);
   DBG("Soft body anchor hardness set to: %lf", hardness);
}

EAPI double
ephysics_body_soft_body_anchor_hardness_get(EPhysics_Body *body)
{
   if (!body)
     {
        ERR("Can't get soft body's anchor hardness, body is null.");
        return -1;
     }

   if (!body->soft_body)
     {
        ERR("Can't get soft body's anchor hardness, body seems not to be a soft"
            " body.");
        return -1;
     }

   return body->soft_body->m_cfg.kAHR * 100;
}

EAPI void
ephysics_body_soft_body_drag_coefficient_set(EPhysics_Body *body, double coefficient)
{
   if (!body)
     {
        ERR("Can't set soft body's drag coefficient, body is null.");
        return;
     }

   if (!body->soft_body)
     {
        ERR("Can't set soft body's drag coefficient, body seems not to be a soft"
            " body.");
        return;
     }

   body->soft_body->m_cfg.kDG = coefficient;
   DBG("Soft body drag coefficient set to: %lf", coefficient);
}

EAPI double
ephysics_body_