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.
* OB prefix is needed when specifying the object for the Message Actuator, this is very bad since other object fields in the BGE dont need this prefix - a real fix would need do_versions to keep old files running.
* RotationMatrix was all nans if the rotation vector axis was 0,0,0, Changed so in this case just return a matrix that doesn't rotate anything,
spent some angry hours to find these issues, maybe this will save others the hassle ;)
* For 2D filters, don't require opengl 2.0 but just the extensions,
so it works on computers without full 2.0 support too.
* In debug mode, don't print memory statistics for preview render.
Shape Action are now supported in the BGE. A new type of actuator "Shape Action" is available on mesh objects. It can be combined with Action actuator on parent armature. Only relative keys are supported. All the usual action options are available: type, blending, priority, Python API. Only actions with shape channels should be specified of course, otherwise the actuator has no effect. Shape action will still work after a mesh replacement provided that the new mesh has compatible shape keys.
GLEW
====
Added the GLEW opengl extension library into extern/, always compiled
into Blender now. This is much nicer than doing this kind of extension
management manually, and will be used in the game engine, for GLSL, and
other opengl extensions.
* According to the GLEW website it works on Windows, Linux, Mac OS X,
FreeBSD, Irix, and Solaris. There might still be platform specific
issues due to this commit, so let me know and I'll look into it.
* This means also that all extensions will now always be compiled in,
regardless of the glext.h on the platform where compilation happens.
Game Engine
===========
Refactoring of the use of opengl extensions and other drawing code
in the game engine, and cleaning up some hacks related to GLSL
integration. These changes will be merged into trunk too after this.
The game engine graphics demos & apricot level survived my tests,
but this could use some good testing of course.
For users: please test with the options "Generate Display Lists" and
"Vertex Arrays" enabled, these should be the fastest and are supposed
to be "unreliable", but if that's the case that's probably due to bugs
that can be fixed.
* The game engine now also uses GLEW for extensions, replacing the
custom opengl extensions code that was there. Removes a lot of
#ifdef's, but the runtime checks stay of course.
* Removed the WITHOUT_GLEXT environment variable. This was added to
work around a specific bug and only disabled multitexturing anyway.
It might also have caused a slowdown since it was retrieving the
environment variable for every vertex in immediate mode (bug #13680).
* Refactored the code to allow drawing skinned meshes with vertex
arrays too, removing some specific immediate mode drawing functions
for this that only did extra normal calculation. Now it always splits
vertices of flat faces instead.
* Refactored normal recalculation with some minor optimizations,
required for the above change.
* Removed some outdated code behind the __NLA_OLDDEFORM #ifdef.
* Fixed various bugs in setting of multitexture coordinates and vertex
attributes for vertex arrays. These were not being enabled/disabled
correct according to the opengl spec, leading to crashes. Also tangent
attributes used an immediate mode call for vertex arrays, which can't
work.
* Fixed use of uninitialized variable in RAS_TexVert.
* Exporting skinned meshes was doing O(n^2) lookups for vertices and
deform weights, now uses same trick as regular meshes.
The best rules for stereo rendering are now applied to Blender. Here is the new situation:
1) The focal distance is now settable through the GUI: select the camera (each camera can have a different setting) and go to the camera data (F9): the "Dof Dist" and "Dof Ob" can be used to set the focal distance for that camera. The "Dof Ob" is interesting because it sets the focal distance so that the center this object will appear at the surface of the screen when running the game.
2) The eye separation is automatically set to focal_distance/30, which is considered to be a reasonable value. If you need a different value, you can always use Python scripting.
Notes:
- If you switch camera during the game, the focal distance will also change unless you have set the focal distance by scripting, in which case it overwrites the focal distance setting of all cameras.
- If you don't set the focal distance in the camera data or by scripting, the default value will be used. The default value corresponds more of less to the near clipping plane which means that all the objects will be very far with little 3D effect.
- If you don't set the eye separation by scripting, it is automatically computed as focal_distance/30, regardless on how the focal distance was set.
Add a function GameLogic.expandPath() that works like Blender.sys.expandpath() and is also available in the BlenderPlayer.
Fix the game actuator in the BlenderPlayer to work like in Blender:
- try first to load the .blend from the current working directory
- if not found, try to load from the startup .blend or runtime base directory
Now you can do one of the following to disable it:
export NAN_NO_PLUGIN=true
export WITH_BF_WEBPLUGIN=false
or
export WITH_BF_WEBPLUGIN=true to enable building it.
(Its set to false by default)
Kent
The current layer information is now stored in KX_GameObject and inherited from the parent object when dynamically added. This information is used during the rendering the select the lamps. As the selected lamps are always coming from active layers, their position and orientation are correct.
