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.
+ 'scons blenderplayer' builds blender AND blenderplayer now (tested on Linux
only, but was only linking issue, so should work on other platforms too).
NOTE: I noticed some compileflags for GE specific libs that were left out -
I re-enabled them in the SConscripts, but I'm going to do a test build my-
self now, so if there are problems with them on win32, I probably already
know about them :)
* This commit is all of the rewrite work done on the SCons system. For
documentation see doc/blender-scons.txt and doc/blender-scons-dev.txt.
Also http://mediawiki.blender.org/index.php/BlenderDev/SconsRefactoring
contains valuable information, along with what still needs to be done.
- linux, os x and windows compile now.
- files are compiled to BF_INSTALLDIR (see config/(platform)-config.py)
- NOTE: Jean-Luc P will commit sometime during the weekend proper
appit() for OS X. For now, copy the resulting binary to an
existing .app bundle.
- features:
- cleaner structure for better maintenance
- cleaner output during compile
- better handling of build options
- general overall speed increase
- see the wiki for more info
Cygwin, FreeBSD and Solaris systems still need work. For these systems:
1) copy a config/(platform)-config.py to ie. config/cygwin-config.py
2) set the proper defaults for your platform
3) mail me at jesterking at letwory dot net with you configuration. if
you need any modifications to the system, do send a patch, too.
I'll be giving first-aid today and tomorrow, after that it'll be all
regular development work :)
/Nathan
Keyboard sensors can now hook escape key. Ctrl-Break can be used from within blender if you've forgotten an end game actuator.
Fixed a stupid bug preventing some actuators working (like TrackTo).
Message using a python function of the MessageSensor.
Thats a nice thing if you want complex message handling in one python
script. Just get all messages, check the subject and do what you
want. In the current situation you end up with several MessageSensors
connected to the python script, instead of one Sensor and a smart
script.
Some developer (cant remember who) did implement that function, but
however not the way I wanted (maybe I was not clear enough) ;-) So the
getSubject() function will return whats entered in the "Subject:"
filter field of the MessageSensor. Quite useless IMHO.
So I added a new function getSubjects() which is similar to
getBodies(), in fact I stole the code from there ;-)
I left the getSubject() alone, because of backward compatibility
(never saw someone using that function, but...)
The future:
In conjunction with a wildcard subject: filter field the getSubjects()
function will be even more usefull.
i.e. Player* will filter for PlayerScore, PlayerKill etc.
-- Carsten Wartmann
* Blender static now links. By default this option is disabled on all
platforms. Simply set the option in config.opts to 'true'.
* Added the following flags to config.opts:
- HOST_CC. This is the C compiler for the host platform. This value is the
same as TARGET_CC when not cross compiling.
- HOST_CXX. This is the C++ compiler for the host platform. This value is
the same as TARGET_CXX when not cross compiling.
- TARGET_CC. This is the C compiler for the target platform.
- TARGET_CXX. This is the C++ compiler for the target platform.
- TARGET_AR. This is the linker command for linking libraries.
- PATH This is the standard search path
All SConscript files have been updated to reflect these changes. Now it's
possible to change only the root SConstruct file, and all compiler specific
variables are passed automatically to all SConscript files. Of course, this
does not apply to makesdna because there the host and target platform is
different from all other libraries.
To pass a variable that applies to all platforms, all we now have to do is
set the correct value in library_env
Note: as usual, to get the latest options in the config.opts file, first
remove your version.
* Almost all library settings are now available in the config.opts user option
file.
* All platform variables had to be updated to make this possible. Things are
much clearer now, but I only was able to test the changes on Linux. I've
tried to update all other platform variables, but things are most likely to
be broken. Please contact me how to resolve the issues.
Note: Before running scons, remove your existing config.opts file to get all
new options.
* libraries are now generated in [BUILD_DIR]/lib
* passed the user_options to all libraries now.
This means I could remove a couple of Export/Import lines.
* Changed the order in source/blender/src/SConscript and
source/gameengine/SConscript.
All libraries are now sorted alphabetically. This has no impact on the build
process.
* Windows .exe file now includes the blender icon.
* Builds with game engine on Windows only.
I tried building the game engine on Linux, but I get weird errors when
building with ode. There's a dirty #include path in
Physics/BlOde/OdePhysicsEnvironment.cpp (../ode/src/joint.h). gcc doesn't
like this somehow.
* Other platforms need to add a couple of flags to the SConstruct:
use_sumo, use_ode, solid_include and ode_include
(adding)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
also the Makefile.in's were from previous patch adding
the system depend stuff to configure.ac
Kent
--
mein@cs.umn.edu
