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.
* Shader compilation is now cached. Subsequent loads take less than a millisecond.
* Improved game, editor and project manager startup time.
* Editor uses .godot/shader_cache to store shaders.
* Game uses user://shader_cache
* Project manager uses $config_dir/shader_cache
* Options to tweak shader caching in project settings.
* Editor path configuration moved from EditorSettings to new class, EditorPaths, so it can be available early on (before shaders are compiled).
* Reworked ShaderCompilerRD to ensure deterministic shader code creation (else shader may change and cache will be invalidated).
* Added shader compression with SMOLV: https://github.com/aras-p/smol-v
This also acts as a general-purpose "deselect" shortcut since pressing
it a second time will deselect text.
This is available both in the script editor and in TextEdit fields
in use, both in the editor and projects.
The Duplicate Line script editor shortcut was moved to Ctrl + Shift + D
since it conflicts with the new shortcut (Ctrl + D). The rationale for
doing so is that Duplicate Line is a less commonly used action, and
its behavior can be replicated by copying and pasting the current line
anyway. (With no selection active, the whole line will be copied.)
