Commit Graph

175 Commits

Author SHA1 Message Date
8d2cb5bea4 BGE Python API
This changes how the BGE classes and Python work together, which hasnt changed since blender went opensource.
The main difference is PyObjectPlus - the base class for most game engine classes, no longer inherit from PyObject, and cannot be cast to a PyObject.

This has the advantage that the BGE does not have to keep 2 reference counts valid for C++ and Python.

Previously C++ classes would never be freed while python held a reference, however this reference could be problematic eg: a GameObject that isnt in a scene anymore should not be used by python, doing so could even crash blender in some cases.

Instead PyObjectPlus has a member "PyObject *m_proxy" which is lazily initialized when python needs it. m_proxy reference counts are managed by python, though it should never be freed while the C++ class exists since it holds a reference to avoid making and freeing it all the time.
When the C++ class is free'd it sets the m_proxy reference to NULL, If python accesses this variable it will raise a RuntimeError, (check the isValid attribute to see if its valid without raising an error).
- This replaces the m_zombie bool and IsZombie() tests added recently.

In python return values that used to be..
 return value->AddRef();
Are now
 return value->GetProxy();
or...
 return value->NewProxy(true); // true means python owns this C++ value which will be deleted when the PyObject is freed
2009-04-19 12:46:39 +00:00
d2ec468cd3 Hidden faces were not rendering displayed in the game engine, only the invisible face flag should be used for this.
Hiding faces is a editing option like selection and should not change rendering, it wasn't even working right because meshes without UVs ignored it.
I thought this was needed for compatibility with old files but just noticed this messes up 2 of the files in demos-2.42.zip
2009-04-19 06:29:15 +00:00
3511f8ef9f BGE Physics
Clamp objects min/max velocity.
Accessed with bullet physics from the advanced button with dynamic and rigid body objects.
- useful for preventing unstable physics in cases where objects move too fast.
- can add linear velocity with the motion actuator to give smooth motion transitions, without moving too fast.
- minimum velocity means objects don't stop moving.
- python scripts can adjust these values speedup or throttle velocity in the existing direction.

Also made copy properties from an object with no properties work (in case you want to clear all props)
2009-04-14 12:34:39 +00:00
0b8661ab4d BGE: Occlusion culling and other performance improvements.
Added occlusion culling capability in the BGE. 
More info: http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.49/Game_Engine#BGE_Scenegraph_improvement
MSVC, scons, cmake, Makefile updated.

Other minor performance improvements:
- The rasterizer was computing the openGL model matrix of the objects too many times
- DBVT view frustrum culling was not properly culling behind the near plane:
  Large objects behind the camera were sent to the GPU
- Remove all references to mesh split/join feature as it is not yet functional
2009-04-13 20:08:33 +00:00
1ee970e03b small bge edits
- Only try and remove light objects from the light list.
- Only loop over mesh verts once when getting the bounding box
- dont return None from python attribute localInertia when theres no physics objects. better return a vector still.
- add names to send message PyArg_ParseTuple functions.
2009-04-08 17:40:09 +00:00
51b4145841 BGE Scenegraph and View frustrum culling improvement.
This commit contains a number of performance improvements for the
BGE in the Scenegraph (parent relation between objects in the
scene) and view frustrum culling.

The scenegraph improvement consists in avoiding position update
if the object has not moved since last update and the removal
of redundant updates and synchronization with the physics engine.

The view frustrum culling improvement consists in using the DBVT
broadphase facility of Bullet to build a tree of graphical objects
in the scene. The elements of the tree are Aabb boxes (Aligned 
Axis Bounding Boxes) enclosing the objects. This provides good
precision in closed and opened scenes. This new culling system
is enabled by default but just in case, it can be disabled with
a button in the World settings. There is no do_version in this
commit but it will be added before the 2.49 release. For now you
must manually enable the DBVT culling option in World settings
when you open an old file.

The above improvements speed up scenegraph and culling up to 5x.
However, this performance improvement is only visible when
you have hundreds or thousands of objects.

The main interest of the DBVT tree is to allow easy occlusion
culling and automatic LOD system. This will be the object of further
improvements.
2009-04-07 22:14:06 +00:00
d52400bfbd 2.50: svn merge https://svn.blender.org/svnroot/bf-blender/trunk/blender -r18677:19317
Notes:
* Sequence transform strip uses G.scene global, this is commented
  out now, should be fixed.
* Etch-a-ton code was most difficult to merge. The files already in
  2.5 got merged, but no new files were added. Calls to these files
  are commented out with "XXX etch-a-ton". editarmature.c and
  transform_snap.c were complex to merge. Martin, please check?
* Game engine compiles and links again here for scons/make/cmake
  (player still fails to link).
2009-03-17 21:44:58 +00:00
06d455f428 Add support to lock individual axis during rigid body simulation, for translation and rotation. This makes it easier to do 1D or 2D physics (tetris, blockout)
todo: create some example/demo.blend.
2009-03-09 07:12:16 +00:00
c77af31166 Minor speedups for the BGE
* Where possible use vec.setValue(x,y,z) to assign values to a vector instead of vec= MT_Vector3(x,y,z), for MT_Point and MT_Matrix types too.
* Comparing TexVerts was creating 10 MT_Vector types - instead compare as floats.
* Added SG_Spatial::SetWorldFromLocalTransform() since the local transform is use for world transform in some cases.
* removed some unneeded vars from UpdateChildCoordinates functions 
* Py API - Mouse, Ray, Radar sensors - use PyObjectFrom(vec) rather then filling the lists in each function. Use METH_NOARGS for get*() functions.
2009-02-25 06:43:03 +00:00
2eb85c01f3 remove warnings for the BGE
- variables that shadow vers declared earlier
- Py_Fatal print an error to the stderr
- gcc was complaining about the order of initialized vars (for classes)
- const return values for ints and bools didnt do anything.
- braces for ambiguous if  statements
2009-02-25 03:26:02 +00:00
cdec2b3d15 BGE Python API
Use 'const char *' rather then the C++ 'STR_String' type for the attribute identifier of python attributes.

Each attribute and method access from python was allocating and freeing the string.
A simple test with getting an attribute a loop shows this speeds up attribute lookups a bit over 2x.
2009-02-19 13:42:07 +00:00
41ee139c16 Yeah, and then the game engine too! 2009-01-05 15:48:24 +00:00
6ea6edfa32 2.5: patch to comment out some more bad level calls in the game engine,
apparently msvc is more strict here, provided by Jean-Michel Soler.
2008-11-16 21:13:53 +00:00
bdfe7d89e2 Merge of trunk into blender 2.5:
svn merge https://svn.blender.org/svnroot/bf-blender/trunk/blender -r12987:17416

Issues:
* GHOST/X11 had conflicting changes. Some code was added in 2.5, which was
  later added in trunk also, but reverted partially, specifically revision
  16683. I have left out this reversion in the 2.5 branch since I think it is
  needed there.
  http://projects.blender.org/plugins/scmsvn/viewcvs.php?view=rev&root=bf-blender&revision=16683
* Scons had various conflicting changes, I decided to go with trunk version
  for everything except priorities and some library renaming.
* In creator.c, there were various fixes and fixes for fixes related to the -w
  -W and -p options. In 2.5 -w and -W is not coded yet, and -p is done
  differently. Since this is changed so much, and I don't think those fixes
  would be needed in 2.5, I've left them out.
* Also in creator.c: there was code for a python bugfix where the screen was not
  initialized when running with -P. The code that initializes the screen there
  I had to disable, that can't work in 2.5 anymore but left it commented as a
  reminder.

Further I had to disable some new function calls. using src/ and python/, as
was done already in this branch, disabled function calls:
* bpath.c: error reporting
* BME_conversions.c: editmesh conversion functions.
* SHD_dynamic: disabled almost completely, there is no python/.
* KX_PythonInit.cpp and Ketsji/ build files: Mathutils is not there, disabled.
* text.c: clipboard copy call.
* object.c: OB_SUPPORT_MATERIAL.
* DerivedMesh.c and subsurf_ccg, stipple_quarttone.

Still to be done:
* Go over files and functions that were moved to a different location but could
  still use changes that were done in trunk.
2008-11-12 21:16:53 +00:00
0749bf7be7 Fix bug in rigid body constraint buttons drawing, and while we are at it, add 'Collision' button to disable collisions between bodies, linked between constraint. 2008-10-10 05:12:57 +00:00
425264d7cc Update the Bullet/game buttons_bullet, to better reflect usage.
1) Anisotropic friction works for static and dynamic objects
2) For soft bodies, assume triangle mesh if no bounds a chosen
3) Form factor == inertia scaling factor, it was actually hooked up in Bullet
4) Only show 'radius' if sphere is chosen, or no bounds+dynamics (== sphere bounds)
2008-09-29 04:14:47 +00:00
28684b1c09 make gui backwards compatible with this weeks softbody blend files 2008-09-28 03:17:45 +00:00
f8fb61f9fa enable -noaudio option, so it actually works (and doesn't get overwritten by a game flag). audio initialization delays startup of game engine 2 seconds
add -nojoystick commandline option: it takes 5 seconds everytime to start the game engine, while there IS no joystick.

In other words: blender -noaudio -nojoystick improves workflow turnaround times for P - ESC from 7 seconds to 1 second!

Improved Bullet soft body advanced options, still work-in-progress. Make sure to create game Bullet soft bodies from scratch, it is not compatible with last weeks builds.
2008-09-28 03:07:13 +00:00
c723b91446 BGE patch: create new BulletSoftBody data block to store bullet soft body specific parameters.
Previously we tried to share the parameters with the
blender render soft body but there were too many differences.

MSVC project files updated.
2008-09-27 21:52:20 +00:00
bc28feb997 re-use some Blender soft body settings for Bullet game soft bodies 2008-09-25 16:48:25 +00:00
718e2bf74f improved game soft bodies, works for objects that are using 'set smooth'
use shape matching by default for game soft bodies
store soft body index for game vertices
2008-09-25 03:02:30 +00:00
3b09c0b0d5 Created a KX_SoftBodyDeformer for real-time soft bodies.
Added SetDeformer/GetDeformer() to KX_GameObject.
Store mapping between graphics/soft body vertices (work-in-progress)
Real-time soft body integration is still very premature, but
for a quick preview, see this testfile:
http://bulletphysics.com/ftp/pub/test/index.php?dir=blender/&file=soft_test.blend
2008-09-24 03:12:10 +00:00
1c29d02305 BGE real-time soft bodies, step 2 / 3: create a btSoftBody. Next step is hooking up / deform graphics mesh and choose collision shape.
Note: feature is still disabled.
2008-09-21 15:17:50 +00:00
2064f5542a set the visibility state based on the objects render option in the outliner.
- saves adding UV's to faces just to set the invisibility option or having an logic bricks to set the visibility state.
2008-09-21 04:39:40 +00:00
f510057fef [#17600] char* -> const char*
Thanks to Sean Bartell (wtachi), was causing many many warnings which distracted from the real problems.
2008-09-20 11:08:35 +00:00
a44177a401 BGE patch: new 'Advanced Settings' button to keep special Bullet options away from main UI.
Three features that were on the main UI interface are now 
moved to the Advanced Settings panel:
Margin, Actor (that becomes Sensor Actor) and No sleeping.

Sensor Actor is now a feature: it can be turned on and off
for all types of objects, and not just static objects.
Select the Sensor Actor button to make the object visible
to Near and Radar sensor.
The button is selected by default for dynamic objects
and unselected by default for static objects, to match
previous behavior.
2008-09-19 20:41:38 +00:00
0a7767d597 Fix for bug #3858: the game engine mouse focus sensor did not work
correct if there was more than one camera. It shoots rays from the
active camera, but used the viewport from whichever camera was drawn
last, now it uses the correct vieport.
2008-09-18 01:46:28 +00:00
9b7d40dbae BGE patch: bullet buttons UI change after discussion with Erwin: use a drop down instead of a series of buttons. Introduction of soft body option. 2008-09-16 22:52:42 +00:00
41a0b56b70 BGE patch: new Physics button and margin parameter in Logic panel. Change subversion.
The Physics button controls the creation of a physics representation 
of the object when starting the game. If the button is not selected,
the object is a pure graphical object with no physics representation
and all the other physics buttons are hidden.
Selecting this button gives access to the usual physics buttons.
The physics button is enabled by default to match previous Blender
behavior.

The margin parameter allows to control the collision margin from
the UI. Previously, this parameter was only accessible through 
Python. By default, the collision margin is set to 0.0 on static 
objects and 0.06 on dynamic objects. 
To maintain compatibility with older games, the collision margin
is set to 0.06 on all objects when loading older blend file.

Note about the collision algorithms in Bullet 2.71
--------------------------------------------------
Bullet 2.71 handles the collision margin differently than Bullet 2.53
(the previous Bullet version in Blender). The collision margin is 
now kept "inside" the object for box, sphere and cylinder bound 
shapes. This means that two objects bound to any of these shape will
come in close contact when colliding. 
The static mesh, convex hull and cone shapes still have their
collision margin "outside" the object, which leaves a space of 1
or 2 times the collision margin between objects. 

The situation with Bullet 2.53 was more complicated, generally
leading to more space between objects, except for box-box collisions. 

This means that running a old game under Bullet 2.71 may cause
visual problems, especially if the objects are small. You can fix
these problems by changing some visual aspect of the objects: 
center, shape, size, position of children, etc.
2008-09-14 19:34:06 +00:00
59b202fc32 Fix a game engine crash with mesh objects parented to an armature
without vertex groups.
2008-09-14 17:59:22 +00:00
c4cde9a027 Fix for bug #7097: blender multitexture materials in the game engine
player did not enable mipmapping when falling back to texfaces.

Also commented out code that disabled mipmapping in the player on
Mac OS X. If that is a workaround for a bug it is a really poor one,
and hopefully fixed now since this code is from 2002 or earlier.
2008-09-14 01:10:45 +00:00
704fef314a Various game engine fixes:
* Fix issue with add transparency mode with blender materials.
* Possible fix at frontface flip in the game engine.
* Fix color buffering clearing for multiple viewports, it used
  to clear as if there was one.
* Fix for zoom level in user defined viewports, it was based on
  the full window before, now it is based on the viewport itself.
* For user defined viewports, always use Expose instead of
  Letterbox with bars, the latter doesn't make sense then.
2008-09-14 00:32:18 +00:00
0bf03ef2f1 BGE patch: Simulate dupligroup operation when parent and child are not active/inactive at the same time: don't convert the child. This unusual situation is used in Apricot for testing. 2008-09-07 10:47:33 +00:00
667c8d83fb BGE patch: break parent relationship when child and parent are not active/inactive at the same time. This unusual situation is used in Apricot for test purposes. 2008-09-06 22:06:01 +00:00
cb89decfdc Merge of first part of changes from the apricot branch, especially
the features that are needed to run the game. Compile tested with
scons, make, but not cmake, that seems to have an issue not related
to these changes. The changes include:

* GLSL support in the viewport and game engine, enable in the game
  menu in textured draw mode.
* Synced and merged part of the duplicated blender and gameengine/
  gameplayer drawing code.
* Further refactoring of game engine drawing code, especially mesh
  storage changed a lot.
* Optimizations in game engine armatures to avoid recomputations.
* A python function to get the framerate estimate in game.

* An option take object color into account in materials.
* An option to restrict shadow casters to a lamp's layers.
* Increase from 10 to 18 texture slots for materials, lamps, word.
  An extra texture slot shows up once the last slot is used.

* Memory limit for undo, not enabled by default yet because it
  needs the .B.blend to be changed.
* Multiple undo for image painting.

* An offset for dupligroups, so not all objects in a group have to
  be at the origin.
2008-09-04 20:51:28 +00:00
528722f472 BGE bug fix: the fix in revision 16022 for bug #17450 was wrong: the formula used to extract scaling and rotation was giving incorrect results for some type of rotation, leading to wrong position and orientation for parented objects with no scale applied. The new formula follows Blender's internal math. 2008-08-15 22:17:50 +00:00
62f9ba67c0 BGE bug #17450 fixed: When we have parented objects with no scale-applyed objects the ray hit system doesn't work properly. Fix by separating rotation and scaling in the parent inverse node to keep scaling correct down to the leaf objects. Only isotropric scaling should be used, as always with the BGE. 2008-08-08 09:57:17 +00:00
8a8a12ed84 BGE patch: logic optimization part 2: remove inactive sensors from logic manager.
With this patch, only sensors that are connected to 
active states are actually registered in the logic
manager. Inactive sensors won't take any CPU,
especially the Radar and Near sensors that use a
physical object for the detection: these objects
are removed from the physics engine.

To take advantage of this optimization patch, you
need to define very light idle state when the 
objects are inactive: make them transparent, suspend
the physics, keep few sensors active (e,g a message
sensor to wake up), etc.
2008-07-30 17:41:47 +00:00
7f170c18bb Bugfixes: fix for two memory leaks related to dupligroups,
and a missing reference count in the trackto actuator. This
showed up as leaked pose data, but actually the whole object
was not being freed.
2008-07-30 16:15:15 +00:00
908337bee1 Game Engine: alpha blending and sorting
=======================================

Alpha blending + sorting was revised, to fix bugs and get it
to work more predictable.

* A new per texture face "Sort" setting defines if the face
  is alpha sorted or not, instead of abusing the "ZTransp"
  setting as it did before.
* Existing files are converted to hopefully match the old
  behavior as much as possible with a version patch.
* On new meshes the Sort flag is disabled by the default, to
  avoid unexpected and hard to find slowdowns.
* Alpha sorting for faces was incredibly slow. Sorting faces
  in a mesh with 600 faces lowered the framerate from 200 to
  70 fps in my test.. the sorting there case goes about 15x
  faster now, but it is still advised to use Clip Alpha if
  possible instead of regular Alpha.
* There still various limitations in the alpha sorting code,
  I've added some comments to the code about this.

Some docs at the bottom of the page:
http://www.blender.org/development/current-projects/changes-since-246/realtime-glsl-materials/

Merged some fixes from the apricot branch, most important
change is that  tangents are now exactly the same as the rest
of Blender, instead of being computed in the game engine with a
different algorithm.

Also, the subversion was bumped to 1.
2008-07-29 15:48:31 +00:00
bc85f11e68 Bugfix: game engine does not support non-camera type objects as a
camera, would crash, so disabled using the object as a camera then.
2008-07-28 14:28:19 +00:00
c4116a7f8d BGE patch: support runtime duplication of groups. Adding an object with Dupligroup option set will cause the group to be instantiated. No special actuator is needed for this feature, just put dupligroup objects in inactive layers and add them dynamically 2008-07-26 11:00:21 +00:00
a7f951f25e BGE patch: approve patch #17312: Multiple material IPOs per mesh in BGE. 2008-07-25 13:45:57 +00:00
7afacb6ea8 BGE patch: DUPLIGROUP option supported in BGE.
Blender duplicates groups in the 3D view at the location of objects having the DUPLIGROUP option set. This feature is now supported in the BGE: the groups will be instantiated as in the 3D view when the scene is converted. This is useful to populate a scene with multiple enemies without having to actually duplicate the objects in the blend file.

Notes: * The BGE applies the same criteria to instantiate the group as Blender to display them: if you see the group in the 3D view, it will be instantiated in the BGE.
       * Groups are instantiated as if the object having the DUPLIGROUP option (usually an empty) executed an AddObject actuator on the top objects of the group (objects without parent).
       * As a result, only intra-group parent relationship is supported: the BGE will not instantiate objects that have parents outside the group.
       * Intra-group logic bricks connections are preserved between the duplicated objects, even between the top objects of the group.
       * For best result, the state engine of the objects in the group should be self-contained: logic bricks should only have intra-group connections. Use messages to communicate with state engines outside the group.
       * Nested groups are supported: if one or more objects in the group have the DUPLIGROUP option set, the corresponding groups will be instantiated at the corresponding position and orientation. 
       * Nested groups are instantiated as separate groups, not as one big group.
       * Linked groups are supported as well as groups containing objects from the active layers.
       * There is a difference in the way Blender displays the groups in the 3D view and how BGE instantiates them: Blender does not take into account the parent relationship in the group and displays the objects as if they were all children of the object having the DUPLIGROUP option. That's correct for the top objects of the group but not for the children. Hence the orientation of the children objects may be different in the BGE.
       * An AddGroup actuator will be added in a future release.
2008-07-15 20:05:23 +00:00
99fdf27af9 Sync with Apricot Game Engine
=============================

* Clean up and optimizations in skinned/deformed mesh code.
* Compatibility fixes and clean up in the rasterizer.
* Changes related to GLSL shadow buffers which should have no
  effect, to keep the code in sync with apricot.
2008-07-10 12:47:20 +00:00
d1fd99b070 BGE logic patch: new "Add" mode for Ipo actuator, several corrections in state system.
New Add mode for Ipo actuator
=============================
A new Add button, mutually exclusive with Force button, is available in
the Ipo actuator. When selected, it activates the Add mode that consists
in adding the Ipo curve to the current object situation in world
coordinates, or parent coordinates if the object has a parent. Scale Ipo
curves are multiplied instead of added to the object current scale.
If the local flag is selected, the Ipo curve is added (multiplied) in 
the object's local coordinates. 
Delta Ipo curves are handled identically to normal Ipo curve and there 
is no need to work with Delta Ipo curves provided that you make sure 
that the Ipo curve starts from origin. Origin means location 0 for 
Location Ipo curve, rotation 0 for Rotation Ipo curve and scale 1 for 
Scale Ipo curve.

The "current object situation" means the object's location, rotation 
and scale at the start of the Ipo curve. For Loop Stop and Loop End Ipo 
actuators, this means at the start of each loop. This initial state is
used as a base during the execution of the Ipo Curve but when the Ipo 
curve is restarted (later or immediately in case of Loop mode), the  
object current situation at that time is used as the new base.

For reference, here is the exact operation of the Add mode for each
type of Ipo curve (oLoc, oRot, oScale, oMat: object's loc/rot/scale
and orientation matrix at the start of the curve; iLoc, iRot, iScale,
iMat: Ipo curve loc/rot/scale and orientation matrix resulting from
the rotation).

Location
  Local=false: newLoc = oLoc+iLoc
  Local=true : newLoc = oLoc+oScale*(oMat*iLoc)
Rotation
  Local=false: newMat = iMat*oMat
  Local=true : newMat = oMat*iMat
Scale
  Local=false: newScale = oScale*iScale
  Local=true : newScale = oScale*iScale

Add+Local mode is very useful to have dynamic object executing complex
movement relative to their current location/orientation. Of cource, 
dynamics should be disabled during the execution of the curve.

Several corrections in state system
===================================
- Object initial state is taken into account when adding object
  dynamically
- Fix bug with link count when adding object dynamically
- Fix false on-off detection for Actuator sensor when actuator is
  trigged on negative event.
- Fix Parent actuator false activation on negative event
- Loop Ipo curve not restarting at correct frame when start frame is
  different from one.
2008-07-08 12:18:43 +00:00
820c2df12c BGE patch: Add automatic support for armature driven shape keys.
To take advantage of this feature, you must have a mesh with 
relative shape keys and shape Ipo curves with drivers referring
to bones of the mesh's parent armature. 
The BGE will automatically detect the dependency between the 
shape keys and the armature and execute the Ipo drivers during
the rendering of the armature actions.
This technique is used to make the armature action more natural: 
the shape keys compensate in places where the armature deformation 
is uggly and the drivers make sure that the shape correction
is synchronized with the bone position.

Note: This is not compatible with shape actions; BLender does 
not allow to have Shape Ipo Curves and Shape actions at the same
time.
2008-06-24 22:19:00 +00:00
4d478cbe86 BGE patch: remove Shape key driver code from previous commit 2008-06-24 21:39:45 +00:00
15c105c157 BGE patch: Add damping and clamping option to motion actuator.
This patch introduces two options for the motion actuator:

damping: number of frames to reach the target velocity. It takes
into account the startup velocityin the target velocity direction
and add 1/damping fraction of target velocity until the full 
velocity is reached. Works only with linear and angular velocity.
It will be extended to delta and force motion method in a future
release.

clamping: apply the force and torque as long as the target velocity
is not reached. If this option is set, the velocity specified 
in linV or angV are not applied to the object but used as target
velocity. You should also specify a force in force or torque field: 
the force will be applied as long as the velocity along the axis of
the vector set in linV or angV is not reached. Works best in low
friction environment.
2008-06-24 19:37:43 +00:00
5372def2b0 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