#lockdown Nick.Penwarden
#rb none
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MAJOR FEATURES + CHANGES
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Change 3209340 on 2016/11/23 by Ben.Marsh
Convert UE4 codebase to an "include what you use" model - where every header just includes the dependencies it needs, rather than every source file including large monolithic headers like Engine.h and UnrealEd.h.
Measured full rebuild times around 2x faster using XGE on Windows, and improvements of 25% or more for incremental builds and full rebuilds on most other platforms.
* Every header now includes everything it needs to compile.
* There's a CoreMinimal.h header that gets you a set of ubiquitous types from Core (eg. FString, FName, TArray, FVector, etc...). Most headers now include this first.
* There's a CoreTypes.h header that sets up primitive UE4 types and build macros (int32, PLATFORM_WIN64, etc...). All headers in Core include this first, as does CoreMinimal.h.
* Every .cpp file includes its matching .h file first.
* This helps validate that each header is including everything it needs to compile.
* No engine code includes a monolithic header such as Engine.h or UnrealEd.h any more.
* You will get a warning if you try to include one of these from the engine. They still exist for compatibility with game projects and do not produce warnings when included there.
* There have only been minor changes to our internal games down to accommodate these changes. The intent is for this to be as seamless as possible.
* No engine code explicitly includes a precompiled header any more.
* We still use PCHs, but they're force-included on the compiler command line by UnrealBuildTool instead. This lets us tune what they contain without breaking any existing include dependencies.
* PCHs are generated by a tool to get a statistical amount of coverage for the source files using it, and I've seeded the new shared PCHs to contain any header included by > 15% of source files.
Tool used to generate this transform is at Engine\Source\Programs\IncludeTool.
[CL 3209342 by Ben Marsh in Main branch]
#jira UE-16413 - Applying materials to BSP takes a long time once shells reach a basic level of complexity
Previously, setting a material or its texture transform on a BSP surface triggered CommitModelSurfaces, which iterated all the ModelComponents in the level and caused (among other things) the physics state to be recreated, a very expensive operation. This is clearly unnecessary when only the surface material or texture transform has changed, so introduced a new path in which only the Material Index Buffers are updated for the level's UModel.
[CL 2613582 by Richard TalbotWatkin in Main branch]
I have reviewed each change carefully, but it is a large change and I could have missed something! Here is a summary of the types of changes in this CL:
* Made nullptr checks consistent (the plurality of the changes are of this type)
* Completed switch statements (IE, switch did not explicitly handle default case, but had unhandled enum entries - this is the second most popular type of fix)
* Removed unused variables
* Removed redundant initializations
* WidgetNavigationCustomization.cpp was fixed by the owner
* integers converted to floats where result was stored in a float
* Removed redundent null checks (e.g. before delete statements)
* Renamed variables to prevent non-obvious shadowing
* Fixed use of bitwise & when checking for equality to an enum entry (which is often 0)
* Fixes for some copy paste errors (e.g. FoliageEdMode.cpp)
[CL 2498053 by Dan Oconnor 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]