hlslcc - Fix empty if() generation
Converts from
if(!EXPR) {}
to
EXPR
#codereview Mark.Satterthwaite, Chris.Babcock, Dmitry.Rekman, Michael.Trepka
[CL 2457355 by Rolando Caloca in Main branch]
- Shaders which emit layout location data use INTERFACE_LOCATION & INTERFACE_BLOCK macros to defer to the runtime whether they can be used as separable or non-separable shaders.
- The runtime supplies the correct #define for each so that the shaders still work on platforms where the glLinkProgram implementation fails with separable shader code.
- Shader model 5 platforms (GLSL 430 or ES 3.10) which were already specifying & using layout location data continue to do so, even when using glLinkProgram.
- The 'OpenGL.UseSeparateShaderObjects' console variable allows switching between SSO/Link modes between executions, but not dynamically at runtime.
- Only defaults to on for Mac as that is the only platform which can guarantee that the extension is always available & so far the most tested platform.
- Updated hlslcc binaries are supplied for Mac, Linux & Windows.
- Added an OpenGL RHI stat for shader first draw time so that it is easy to see why hitches occur during runtime due to in-driver shader compilation.
reviewedby michael.trepka, nick.penwarden, dmitry.rekman, rolando.caloca
[CL 2435530 by Mark Satterthwaite in Main branch]
