brad/2744 handle shader errors (#3105)

* Partial solution to secondlife/viewer#2744 crash with better error handling.

Handles shader compile errors better, and should turn crash into an LL_ERRS assertion failure.
Strengthed more assertions and improved shader error line numbers

* Even more error handling to get a handle on crash secondlife/viewer#2744
* Improved GLSL correctness on Intel chips that lack OpenGL 4.6 support. secondlife/viewer#2744
* Removed non-working fallback code for gDeferredPostProgram
* Fixed incorrect llmax call

1 files changed, 15 insertions, 0 deletions

diff --git a/indra/newview/llfeaturemanager.cpp b/indra/newview/llfeaturemanager.cpp
index b5d8f70c2e..c5d074a5e8 100644
--- a/indra/newview/llfeaturemanager.cpp
+++ b/indra/newview/llfeaturemanager.cpp
@@ -655,6 +655,21 @@ void LLFeatureManager::applyBaseMasks()
     if (gGLManager.mIsIntel)
     {
         maskFeatures("Intel");
+        if (gGLManager.mGLVersion < 4.59f)
+        {
+            // if we don't have OpenGL 4.6 on intel, set it to OpenGL 3.3
+            // we also want to trigger the GL3 fallbacks on these chipsets
+            // this is expected to be mainly pre-Haswell Intel HD Graphics 4X00 and 5X00.
+            // A lot of these chips claim 4.3 or 4.4 support, but don't seem to work.
+            // https://code.blender.org/2019/04/supported-gpus-in-blender-2-80/
+            // https://docs.blender.org/manual/en/latest/troubleshooting/gpu/windows/intel.html#legacy-intel-hd-4000-5000
+            // https://www.intel.com/content/www/us/en/support/articles/000005524/graphics.html
+            // this will disable things like reflection probes, HDR, FXAA and SMAA
+            gGLManager.mGLVersion = llmin(gGLManager.mGLVersion, 3.33f);
+            // and select GLSL version for OpenGL 3.3
+            gGLManager.mGLSLVersionMajor = 3;
+            gGLManager.mGLSLVersionMinor = 30;
+        }
     }
     if (gGLManager.mIsApple)
     {