As many open source projects have started doing it, we're removing the
current year from the copyright notice, so that we don't need to bump
it every year.
It seems like only the first year of publication is technically
relevant for copyright notices, and even that seems to be something
that many companies stopped listing altogether (in a version controlled
codebase, the commits are a much better source of date of publication
than a hardcoded copyright statement).
We also now list Godot Engine contributors first as we're collectively
the current maintainers of the project, and we clarify that the
"exclusive" copyright of the co-founders covers the timespan before
opensourcing (their further contributions are included as part of Godot
Engine contributors).
Also fixed "cf." Frenchism - it's meant as "refer to / see".
This PR and commit adds a new IK system for 2D with the Skeleton2D node
that adds several new IK solvers, a way to control bones in a Skeleton2D
node similar to that in Skeleton3D. It also adds additional changes
and functionality.
This work was sponsored by GSoC 2020 and TwistedTwigleg.
Full list of changes:
* Adds a SkeletonModifier2D resource
* This resource is the base where all IK code is written and executed
* Has a function for clamping angles, since it is so commonly used
* Modifiers are unique when duplicated so it works with instancing
* Adds a SkeletonModifierStack2D resource
* This resource manages a series of SkeletonModification2Ds
* This is what the Skeleton2D directly interfaces with to make IK possible
* Adds SkeletonModifier2D resources for LookAt, CCDIK, FABRIK, Jiggle, and TwoBoneIK
* Each modification is in its own file
* There is also a SkeletonModifier2D resource that acts as a stack for using multiple stacks together
* Adds a PhysicalBone2D node
* Works similar to the PhysicalBone3D node, but uses a RigidBody2D node
* Changes to Skeleton2D listed below:
* Skeleton2D now holds a single SkeletonModificationStack2D for IK
* Skeleton2D now has a local_pose_override, which overrides the Bone2D position similar to how the overrides work in Skeleton3D
* Changes to Bone2D listed below:
* The default_length property has been changed to length. Length is the length of the bone to its child bone node
* New bone_angle property, which is the angle the bone has to its first child bone node
* Bone2D caches its transform when not modified by IK for IK interpolation purposes
* Bone2D draws its own editor gizmo, though this is stated to change in the future
* Changes to CanvasItemEditor listed below:
* Bone2D gizmo drawing code removed
* The 2D IK code is removed. Now Bone2D is the only bone system for 2D
* Transform2D now has a looking_at function for rotating to face a position
* Two new node notifications: NOTIFICATION_EDITOR_PRE_SAVE and NOTIFICATION_EDITOR_POST_SAVE
* These notifications only are called in the editor right before and after saving a scene
* Needed for not saving the IK position when executing IK in the editor
* Documentation for all the changes listed above.
