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, 18 insertions, 9 deletions

diff --git a/indra/newview/pipeline.cpp b/indra/newview/pipeline.cpp
index d8bd6fc882..6bef6b3438 100644
--- a/indra/newview/pipeline.cpp
+++ b/indra/newview/pipeline.cpp
@@ -1436,15 +1436,24 @@ void LLPipeline::createLUTBuffers()
 
     mPbrBrdfLut.allocate(512, 512, GL_RG16F);
     mPbrBrdfLut.bindTarget();
-    gDeferredGenBrdfLutProgram.bind();
-
-    gGL.begin(LLRender::TRIANGLE_STRIP);
-    gGL.vertex2f(-1, -1);
-    gGL.vertex2f(-1, 1);
-    gGL.vertex2f(1, -1);
-    gGL.vertex2f(1, 1);
-    gGL.end();
-    gGL.flush();
+
+    if (gDeferredGenBrdfLutProgram.isComplete())
+    {
+        gDeferredGenBrdfLutProgram.bind();
+        llassert_always(LLGLSLShader::sCurBoundShaderPtr != nullptr);
+
+        gGL.begin(LLRender::TRIANGLE_STRIP);
+        gGL.vertex2f(-1, -1);
+        gGL.vertex2f(-1, 1);
+        gGL.vertex2f(1, -1);
+        gGL.vertex2f(1, 1);
+        gGL.end();
+        gGL.flush();
+    }
+    else
+    {
+        LL_WARNS("Brad") << gDeferredGenBrdfLutProgram.mName << " failed to load, cannot be used!" << LL_ENDL;
+    }
 
     gDeferredGenBrdfLutProgram.unbind();
     mPbrBrdfLut.flush();