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blender/source/gameengine/Ketsji/KX_StateActuator.h

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BGE patch: add state engine support in the logic bricks. This patch introduces a simple state engine system with the logic bricks. This system features full backward compatibility, multiple active states, multiple state transitions, automatic disabling of sensor and actuators, full GUI support and selective display of sensors and actuators. Note: Python API is available but not documented yet. It will be added asap. State internals =============== The state system is object based. The current state mask is stored in the object as a 32 bit value; each bit set in the mask is an active state. The controllers have a state mask too but only one bit can be set: a controller belongs to a single state. The game engine will only execute controllers that belong to active states. Sensors and actuators don't have a state mask but are effectively attached to states via their links to the controllers. Sensors and actuators can be connected to more than one state. When a controller becomes inactive because of a state change, its links to sensors and actuators are temporarily broken (until the state becomes active again). If an actuator gets isolated, i.e all the links to controllers are broken, it is automatically disabled. If a sensor gets isolated, the game engine will stop calling it to save CPU. It will also reset the sensor internal state so that it can react as if the game just started when it gets reconnected to an active controller. For example, an Always sensor in no pulse mode that is connected to a single state (i.e connected to one or more controllers of a single state) will generate a pulse each time the state becomes active. This feature is not available on all sensors, see the notes below. GUI === This system system is fully configurable through the GUI: the object state mask is visible under the object bar in the controller's colum as an array of buttons just like the 3D view layer mask. Click on a state bit to only display the controllers of that state. You can select more than one state with SHIFT-click. The All button sets all the bits so that you can see all the controllers of the object. The Ini button sets the state mask back to the object default state. You can change the default state of object by first selecting the desired state mask and storing using the menu under the State button. If you define a default state mask, it will be loaded into the object state make when you load the blend file or when you run the game under the blenderplayer. However, when you run the game under Blender, the current selected state mask will be used as the startup state for the object. This allows you to test specific state during the game design. The controller display the state they belong to with a new button in the controller header. When you add a new controller, it is added by default in the lowest enabled state. You can change the controller state by clicking on the button and selecting another state. If more than one state is enabled in the object state mask, controllers are grouped by state for more readibility. The new Sta button in the sensor and actuator column header allows you to display only the sensors and actuators that are linked to visible controllers. A new state actuator is available to modify the state during the game. It defines a bit mask and the operation to apply on the current object state mask: Cpy: the bit mask is copied to the object state mask. Add: the bits that set in the bit mask will be turned on in the object state mask. Sub: the bits that set in the bit mask will be turned off in the object state mask. Inv: the bits that set in the bit mask will be inverted in the objecyy state mask. Notes ===== - Although states have no name, a simply convention consists in using the name of the first controller of the state as the state name. The GUI will support that convention by displaying as a hint the name of the first controller of the state when you move the mouse over a state bit of the object state mask or of the state actuator bit mask. - Each object has a state mask and each object can have a state engine but if several objects are part of a logical group, it is recommended to put the state engine only in the main object and to link the controllers of that object to the sensors and actuators of the different objects. - When loading an old blend file, the state mask of all objects and controllers are initialized to 1 so that all the controllers belong to this single state. This ensures backward compatibility with existing game. - When the state actuator is activated at the same time as other actuators, these actuators are guaranteed to execute before being eventually disabled due to the state change. This is useful for example to send a message or update a property at the time of changing the state. - Sensors that depend on underlying resource won't reset fully when they are isolated. By the time they are acticated again, they will behave as follow: * keyboard sensor: keys already pressed won't be detected. The keyboard sensor is only sensitive to new key press. * collision sensor: objects already colliding won't be detected. Only new collisions are detected. * near and radar sensor: same as collision sensor.
2008-06-22 14:23:57 +00:00
/*
* $Id$
*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL LICENSE BLOCK *****
* Actuator to toggle visibility/invisibility of objects
*/
#ifndef __KX_STATEACTUATOR
#define __KX_STATEACTUATOR
#include "SCA_IActuator.h"
class KX_StateActuator : public SCA_IActuator
{
Py_Header;
/** Make visible? */
enum {
OP_CPY = 0,
OP_SET,
OP_CLR,
OP_NEG
};
int m_operation;
unsigned int m_mask;
public:
KX_StateActuator(
SCA_IObject* gameobj,
int operation,
unsigned int mask,
PyTypeObject* T=&Type
);
virtual
~KX_StateActuator(
void
);
virtual CValue*
GetReplica(
void
);
virtual bool
Update();
/* --------------------------------------------------------------------- */
/* Python interface ---------------------------------------------------- */
/* --------------------------------------------------------------------- */
virtual PyObject* _getattr(const STR_String& attr);
//KX_PYMETHOD_DOC
KX_PYMETHOD_DOC(KX_StateActuator,SetOperation);
KX_PYMETHOD_DOC(KX_StateActuator,SetMask);
};
#endif
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