#ttp 341724 - FEATURE REQUEST: PAPER2D: Add or insert a key into a terrain spline
#ttp 341720 - FEATURE REQUEST: PAPER2D: Rename Key on terrain splines
#ttp 341378 - Spline Component/Meshs: Controls points only editable in worldspace. no localpace transformation
#reviewedby James.Golding
[CL 2228433 by Richard TalbotWatkin in Main branch]
Breaking changes include:
* Rename of GEditorModeTools -> GLevelEditorModeTools to signify that it applies only to the level editor modes
* Addition of FEditorModeRegistry, responsible for managing and creating new editor modes. Modes are no longer registered with an instance of the mode, instead with a mode factory that is able to create a new mode of that type.
* Editor modes now operate on FEditorViewportClients rather than FLevelEditorViewportClients
* Added ability to specify an FEditorModeTools when creating an FEditorViewport
Moved component vizualiser manager handling outside of individual editor modes, and into FLevelEditorViewportClient. This should make it easier to transplant in future.
This work addresses TTP#334640 - EDITOR: Investigate making editor modes a per-'editor' concept
Reviewed by Michael Noland, Matt Kuhlenschmidt
[CL 2109245 by Andrew Rodham in Main branch]
#branch UE4
#proj Editor.ComponentVisualizers, Editor.UnrealEd, Runtime.Core, Runtime.Engine
#change FInterpCurve now uses a binary search to obtain the correct key. Removed the optional out-parameter on Eval, EvalDerivative, etc. Removed FORCEINLINEs on large methods.
#change USplineComponent now builds the remap table with points spaced at equal distances, which leads to better results. Added internal methods to obtain the segment length, and the interpolation parameter along the segment at a given distance.
#add Added Duration to USplineComponent.
#add Added a number of different methods for obtaining position, tangent and rotation at a specified distance, or a specified time (optionally at constant velocity).
#add Added methods for building the spline procedurally.
#add Supports right-click context menu on ComponentVisualizers in the standard interface.
#add Key tangents can be manually edited.
#change FLevelEditorViewportClient::ProcessClick now handles right clicks to the Unreal gizmo in the same manner as left clicks, i.e. the method recurses using a version of the hit proxy with the gizmo removed, so we can look at what's underneath. This allows for "genuine" context menus, i.e. depending on what was clicked, instead of using a single default provided by the current level editor.
#reviewedby James.Golding
[CL 2089561 by Richard TalbotWatkin in Main branch]
