void Snake::move(const SteerDirection& dir) {
if (!_is_alive)
return;
switch (dir) {
case Left:
_rotation_angle += _radians_per_move;
_move_vector = Matrix(MatrixOp::rotateZ, _rotation_angle) * _translation_vector;
break;
case Right:
_rotation_angle -= _radians_per_move;
_move_vector = Matrix(MatrixOp::rotateZ, _rotation_angle) * _translation_vector;
break;
case Forward:
// do nothing
break;
}
if (_move_vector.is_zero())
return;
const auto newPoint = _points[_head].topMiddle() + _move_vector;
if (_time_to_grow.tick()) {
if (is_growing())
_remaining_growth--;
else {
before_tail_remove();
-- _tail;
}
const int rem_head = _head;
-- _head;
_points[_head].assign(newPoint, &_points[_previous_head]);
on_head_added();
ASSERT(rem_head != _previous_head);
_previous_head = rem_head;
} else
_points[_head].assign(newPoint, &_points[_previous_head]);
}
void
ipc_space_terminate(
ipc_space_t space)
{
ipc_entry_t table;
ipc_entry_num_t size;
mach_port_index_t index;
assert(space != IS_NULL);
is_write_lock(space);
if (!is_active(space)) {
is_write_unlock(space);
return;
}
is_mark_inactive(space);
/*
* If somebody is trying to grow the table,
* we must wait until they finish and figure
* out the space died.
*/
while (is_growing(space))
is_write_sleep(space);
is_write_unlock(space);
/*
* Now we can futz with it unlocked.
*/
table = space->is_table;
size = space->is_table_size;
for (index = 0; index < size; index++) {
ipc_entry_t entry = &table[index];
mach_port_type_t type;
type = IE_BITS_TYPE(entry->ie_bits);
if (type != MACH_PORT_TYPE_NONE) {
mach_port_name_t name;
name = MACH_PORT_MAKE(index,
IE_BITS_GEN(entry->ie_bits));
ipc_right_terminate(space, name, entry);
}
}
it_entries_free(space->is_table_next-1, table);
space->is_table_size = 0;
/*
* Because the space is now dead,
* we must release the "active" reference for it.
* Our caller still has his reference.
*/
is_release(space);
}
/*
* ipc_space_clean - remove all port references from an ipc space.
*
* In order to follow the traditional semantic, ipc_space_destroy
* will not destroy the entire port table of a shared space. Instead
* it will simply clear its own sub-space.
*/
void
ipc_space_clean(
ipc_space_t space)
{
ipc_entry_t table;
ipc_entry_num_t size;
mach_port_index_t index;
/*
* If somebody is trying to grow the table,
* we must wait until they finish and figure
* out the space died.
*/
retry:
is_write_lock(space);
while (is_growing(space))
is_write_sleep(space);
if (!is_active(space)) {
is_write_unlock(space);
return;
}
/*
* Now we can futz with it since we have the write lock.
*/
table = space->is_table;
size = space->is_table_size;
for (index = 0; index < size; index++) {
ipc_entry_t entry = &table[index];
mach_port_type_t type;
type = IE_BITS_TYPE(entry->ie_bits);
if (type != MACH_PORT_TYPE_NONE) {
mach_port_name_t name = MACH_PORT_MAKE(index,
IE_BITS_GEN(entry->ie_bits));
ipc_right_destroy(space, name, entry, FALSE, 0); /* unlocks space */
goto retry;
}
}
/*
* JMM - Now the table is cleaned out. We don't bother shrinking the
* size of the table at this point, but we probably should if it is
* really large.
*/
is_write_unlock(space);
}
