SL-18869 Optimizations -- Decruftify LLRenderTarget, use a shader to copy color/depth instead of glCopyTexSubImage or glBlitFrameBuffer

Fixes SL-18484.

SL-18692 Fix for fullbright alpha not clipping against water plane (also fixes ultraspace particles).

SL-18662

Mostly just making it actually kind of work.  Still needs a lot more tweaking - but can revisit later.
SL-18332

original fix by Beq Janus

Jonathan Goodman authored 2 years ago and David Parks committed 2 years ago

First pass of Screen Space Reflections

Approved-by: Dave Parks

SL-18485: Render GLTF materials with extension KHR_texture_transform with approprate texture transforms

SL-18453 WIP -- Use GLTF draw pool to render shadows.  Still need a GLTF specific shadow shader to multiply alpha.

SL-18105 Clean up class1/deferred/materialF.glsl (merge cleanup), make override messaging LLSD where it ought to be and JSON where it ought to be.

SL-18105 Hook up render pipe directly to LLTextureEntry::mGLTFMaterial and add LLViewerFetchedTextures to LLFetchedGLTFMaterial.  Lower reflection probe resolution to 128x128 per side.

SL-18190 Cleanup -- convert some vec4's to vec3's (as they really are), remove some unused glsl files.

SL-18190 Fix for mystery circle showing up on east side of reflection probes.  Add one probe to rule them all as a fallback for pixels that aren't inside any influence volume.

SL-18190 Fix alpha not playing nice with water surface by split LLDrawPoolAlpha into two passes, one above water, one below water, and clip against water plane.  Currently brute forces two complete alpha passes, still need to cull against water plane and add support for fullbright shaders.

SL-18190 Use funky distance based error correction only on water surface (revisit for general use later).

SL-18190 Move water shaders to class 3, add debug stub for underWaterF.glsl, make underWaterF and softenLightF apply water fog in linear space.

SL-18190 Temporarily disable occlusion culling by default -- not compatible with depth buffer management changes.

SL-18190 Water shader WIP.  Better parallax correction for sphere probes.  Reduce probe memory footprint.  Remove framebuffer copies and move to deprecate stencil buffer usage.

SL-18293, SL-18190 -- Fix for debug displays not showing up (wireframe still busted).  WIP on reflection probe/PBR driven water shader.

SL-18239 Unify PBR and non-PBR treatment of ambient/SSAO/irradiance.  Restore SSAO to release version.