- Made a new EmptyVertexDeclaration, for vertex shaders that don't need any inputs (eg, they generate verts based on vertex index)
- Split BeginRenderingSceneColor into 2 functions, adding BeginRenderingGBuffer
#codereview nick.penwarden,martin.mittring,rolando.caloca
[CL 2339044 by Josh Adams in Main branch]
- Removed default shader platform parameter from GetGlobalShaderMap()
- Added an inline overload of GetGlobalShaderMap() that takes a feature level instead, and translates to the correct shader platform
- Cached feature level on FSceneView for faster access
- Cached shader map on FViewInfo for faster access
- Cached featurelevel/shadermap on rendering composition graph execution context, for faster access
Fixed a couple of crashes when switching feature level dynamically
- Needed to allow certain shader permutations to be generated if feature level was ES2, but still on a PC platform. (i.e. hitproxy shaders, and basepass shaders used by editor primitives system)
#codereview Nick.Penwarden
[CL 2275937 by Graeme Thornton in Main branch]
