Merge branch 'main' into marchcat/b-main-sync

# Conflicts:
#	indra/newview/llviewertexturelist.cpp

20 files changed, 209 insertions, 144 deletions

diff --git a/indra/llrender/llgl.cpp b/indra/llrender/llgl.cpp
index 6f1744b042..02996ecc86 100644
--- a/indra/llrender/llgl.cpp
+++ b/indra/llrender/llgl.cpp
@@ -1034,6 +1034,7 @@ void LLGLManager::initWGL()
         GLH_EXT_NAME(wglGetGPUIDsAMD) = (PFNWGLGETGPUIDSAMDPROC)GLH_EXT_GET_PROC_ADDRESS("wglGetGPUIDsAMD");
         GLH_EXT_NAME(wglGetGPUInfoAMD) = (PFNWGLGETGPUINFOAMDPROC)GLH_EXT_GET_PROC_ADDRESS("wglGetGPUInfoAMD");
     }
+    mHasNVXGpuMemoryInfo = ExtensionExists("GL_NVX_gpu_memory_info", gGLHExts.mSysExts);
 
     if (ExtensionExists("WGL_EXT_swap_control", gGLHExts.mSysExts))
     {
@@ -1201,6 +1202,17 @@ bool LLGLManager::initGL()
             LL_WARNS("RenderInit") << "VRAM Detected (AMDAssociations):" << mVRAM << LL_ENDL;
         }
     }
+    else if (mHasNVXGpuMemoryInfo)
+    {
+        GLint mem_kb = 0;
+        glGetIntegerv(GL_GPU_MEMORY_INFO_DEDICATED_VIDMEM_NVX, &mem_kb);
+        mVRAM = mem_kb / 1024;
+
+        if (mVRAM != 0)
+        {
+            LL_WARNS("RenderInit") << "VRAM Detected (NVXGpuMemoryInfo):" << mVRAM << LL_ENDL;
+        }
+    }
 #endif
 
 #if LL_WINDOWS
diff --git a/indra/llrender/llgl.h b/indra/llrender/llgl.h
index be1c0a532a..cd1ba55b16 100644
--- a/indra/llrender/llgl.h
+++ b/indra/llrender/llgl.h
@@ -97,6 +97,7 @@ public:
 
     // Vendor-specific extensions
     bool mHasAMDAssociations = false;
+    bool mHasNVXGpuMemoryInfo = false;
 
     bool mIsAMD;
     bool mIsNVIDIA;
diff --git a/indra/llwindow/llwindowwin32.cpp b/indra/llwindow/llwindowwin32.cpp
index ad657429ef..76788de876 100644
--- a/indra/llwindow/llwindowwin32.cpp
+++ b/indra/llwindow/llwindowwin32.cpp
@@ -4631,6 +4631,12 @@ void LLWindowWin32::LLWindowWin32Thread::checkDXMem()
 {
     if (!mGLReady || mGotGLBuffer) { return; }
 
+    if ((gGLManager.mHasAMDAssociations || gGLManager.mHasNVXGpuMemoryInfo) && gGLManager.mVRAM != 0)
+    { // OpenGL already told us the memory budget, don't ask DX
+        mGotGLBuffer = true;
+        return;
+    }
+
     IDXGIFactory4* p_factory = nullptr;
 
     HRESULT res = CreateDXGIFactory1(__uuidof(IDXGIFactory4), (void**)&p_factory);
@@ -4727,7 +4733,7 @@ void LLWindowWin32::LLWindowWin32Thread::run()
     {
         LL_PROFILE_ZONE_SCOPED_CATEGORY_WIN32;
 
-        // Check memory budget using DirectX
+        // Check memory budget using DirectX if OpenGL doesn't have the means to tell us
         checkDXMem();
 
         if (mWindowHandleThrd != 0)
diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index e1556e9a1b..72c0888644 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -7194,6 +7194,17 @@
         <key>Value</key>
         <integer>1</integer>
     </map>
+    <key>RenderCanUseTerrainBakeShaders</key>
+    <map>
+        <key>Comment</key>
+        <string>Hardware has support for Terrain Bake shaders</string>
+        <key>Persist</key>
+        <integer>0</integer>
+        <key>Type</key>
+        <string>Boolean</string>
+        <key>Value</key>
+        <integer>1</integer>
+    </map>
   <key>RenderClass1MemoryBandwidth</key>
   <map>
     <key>Comment</key>
@@ -9402,7 +9413,7 @@
       <key>Comment</key>
       <string>EXPERIMENTAL: Enable PBR Terrain texture transforms.</string>
       <key>Persist</key>
-      <integer>1</integer>
+      <integer>0</integer>
       <key>Type</key>
       <string>Boolean</string>
       <key>Value</key>
diff --git a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
index ab0e4fd4d8..3319e32cdf 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
@@ -99,10 +99,13 @@ void calcHalfVectors(vec3 lv, vec3 n, vec3 v,
 {
     l  = normalize(lv);
     h  = normalize(l + v);
-    nh = clamp(dot(n, h), 0.0, 1.0);
-    nl = clamp(dot(n, l), 0.0, 1.0);
-    nv = clamp(dot(n, v), 0.0, 1.0);
-    vh = clamp(dot(v, h), 0.0, 1.0);
+
+    // lower bound to avoid divide by zero
+    float eps = 0.000001;
+    nh = clamp(dot(n, h), eps, 1.0);
+    nl = clamp(dot(n, l), eps, 1.0);
+    nv = clamp(dot(n, v), eps, 1.0);
+    vh = clamp(dot(v, h), eps, 1.0);
 
     lightDist = length(lv);
 }
diff --git a/indra/newview/featuretable.txt b/indra/newview/featuretable.txt
index 9c585f1ef8..24fd7928a6 100644
--- a/indra/newview/featuretable.txt
+++ b/indra/newview/featuretable.txt
@@ -208,7 +208,7 @@ RenderFlexTimeFactor		1	1.0
 RenderGlowResolutionPow		1	9
 RenderMaxPartCount			1	4096
 RenderLocalLightCount		1	1024
-RenderTransparentWater      1   1
+RenderTransparentWater      1   0
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
 RenderTerrainPBRDetail      1   0
diff --git a/indra/newview/featuretable_mac.txt b/indra/newview/featuretable_mac.txt
index d66717e2c7..2e220d2b1c 100644
--- a/indra/newview/featuretable_mac.txt
+++ b/indra/newview/featuretable_mac.txt
@@ -135,7 +135,7 @@ RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	1.0
 RenderTerrainPBRDetail      1   -1
 RenderTerrainPBRPlanarSampleCount 1   1
-RenderTransparentWater		1	1
+RenderTransparentWater		1	0
 RenderTreeLODFactor			1	0.5
 RenderVolumeLODFactor		1	1.125
 RenderDeferredSSAO			1	0
@@ -172,7 +172,7 @@ RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
 RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   1
-RenderTransparentWater		1	1
+RenderTransparentWater		1	0
 RenderTreeLODFactor			1	0.5
 RenderVolumeLODFactor		1	1.25
 RenderDeferredSSAO			1	0
@@ -209,7 +209,7 @@ RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
 RenderTerrainPBRDetail      1   0
 RenderTerrainPBRPlanarSampleCount 1   1
-RenderTransparentWater		1	1
+RenderTransparentWater		1	0
 RenderTreeLODFactor			1	0.5
 RenderVolumeLODFactor		1	1.375
 RenderDeferredSSAO			1	0
diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index 76b828aebf..f204bdf0eb 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -747,7 +747,9 @@ bool LLAppViewer::init()
     // inits from settings.xml and from strings.xml
     if (!initConfiguration())
     {
-        LL_ERRS("InitInfo") << "initConfiguration() failed." << LL_ENDL;
+        LL_WARNS("InitInfo") << "initConfiguration() failed." << LL_ENDL;
+        // quit immediately
+        return false;
     }
 
     LL_INFOS("InitInfo") << "Configuration initialized." << LL_ENDL ;
@@ -914,7 +916,9 @@ bool LLAppViewer::init()
     if (!initHardwareTest())
     {
         // Early out from user choice.
-        LL_ERRS("InitInfo") << "initHardwareTest() failed." << LL_ENDL;
+        LL_WARNS("InitInfo") << "initHardwareTest() failed." << LL_ENDL;
+        // quit immediately
+        return false;
     }
     LL_INFOS("InitInfo") << "Hardware test initialization done." << LL_ENDL ;
 
@@ -930,7 +934,9 @@ bool LLAppViewer::init()
     {
         std::string msg = LLTrans::getString("MBUnableToAccessFile");
         OSMessageBox(msg.c_str(), LLStringUtil::null, OSMB_OK);
-        LL_ERRS("InitInfo") << "Failed to init cache" << LL_ENDL;
+        LL_WARNS("InitInfo") << "Failed to init cache" << LL_ENDL;
+        // quit immediately
+        return false;
     }
     LL_INFOS("InitInfo") << "Cache initialization is done." << LL_ENDL ;
 
@@ -963,7 +969,9 @@ bool LLAppViewer::init()
     if (!gGLManager.mHasRequirements)
     {
         // Already handled with a MBVideoDrvErr
-        LL_ERRS("InitInfo") << "gGLManager.mHasRequirements is false." << LL_ENDL;
+        LL_WARNS("InitInfo") << "gGLManager.mHasRequirements is false." << LL_ENDL;
+        // quit immediately
+        return false;
     }
 
     // Without SSE2 support we will crash almost immediately, warn here.
@@ -973,7 +981,9 @@ bool LLAppViewer::init()
         // all hell breaks lose.
         std::string msg = LLNotifications::instance().getGlobalString("UnsupportedCPUSSE2");
         OSMessageBox(msg.c_str(), LLStringUtil::null, OSMB_OK);
-        LL_ERRS("InitInfo") << "SSE2 is not supported" << LL_ENDL;
+        LL_WARNS("InitInfo") << "SSE2 is not supported" << LL_ENDL;
+        // quit immediately
+        return false;
     }
 
     // alert the user if they are using unsupported hardware
@@ -3977,7 +3987,6 @@ void LLAppViewer::forceQuit()
     LLApp::setQuitting();
 }
 
-//TODO: remove
 void LLAppViewer::fastQuit(S32 error_code)
 {
     // finish pending transfers
diff --git a/indra/newview/llfloaterregioninfo.cpp b/indra/newview/llfloaterregioninfo.cpp
index a94661ad7c..0da250644e 100644
--- a/indra/newview/llfloaterregioninfo.cpp
+++ b/indra/newview/llfloaterregioninfo.cpp
@@ -268,7 +268,7 @@ bool LLFloaterRegionInfo::postBuild()
     mInfoPanels.push_back(panel);
     static LLCachedControl<bool> feature_pbr_terrain_enabled(gSavedSettings, "RenderTerrainPBREnabled", false);
     static LLCachedControl<bool> feature_pbr_terrain_transforms_enabled(gSavedSettings, "RenderTerrainPBRTransformsEnabled", false);
-    if (!feature_pbr_terrain_transforms_enabled || !feature_pbr_terrain_enabled)
+    if (!feature_pbr_terrain_transforms_enabled() || !feature_pbr_terrain_enabled())
     {
         panel->buildFromFile("panel_region_terrain.xml");
     }
@@ -1694,7 +1694,7 @@ bool LLPanelRegionTerrainInfo::refreshFromRegion(LLViewerRegion* region)
         static LLCachedControl<bool> feature_pbr_terrain_enabled(gSavedSettings, "RenderTerrainPBREnabled", false);
 
         const bool textures_ready = compp->makeTexturesReady(false, false);
-        const bool materials_ready = feature_pbr_terrain_enabled && compp->makeMaterialsReady(false, false);
+        const bool materials_ready = feature_pbr_terrain_enabled() && compp->makeMaterialsReady(false, false);
 
         bool set_texture_swatches;
         bool set_material_swatches;
@@ -1724,7 +1724,7 @@ bool LLPanelRegionTerrainInfo::refreshFromRegion(LLViewerRegion* region)
         {
             material_type_to_ctrl(mMaterialTypeCtrl, material_type);
             updateForMaterialType();
-            mMaterialTypeCtrl->setVisible(feature_pbr_terrain_enabled);
+            mMaterialTypeCtrl->setVisible(feature_pbr_terrain_enabled());
         }
 
         if (set_texture_swatches)
@@ -1938,7 +1938,7 @@ bool LLPanelRegionTerrainInfo::sendUpdate()
     // POST to ModifyRegion endpoint, if enabled
 
     static LLCachedControl<bool> feature_pbr_terrain_transforms_enabled(gSavedSettings, "RenderTerrainPBRTransformsEnabled", false);
-    if (material_type == LLTerrainMaterials::Type::PBR && feature_pbr_terrain_transforms_enabled)
+    if (material_type == LLTerrainMaterials::Type::PBR && feature_pbr_terrain_transforms_enabled())
     {
         LLTerrainMaterials composition;
         for (S32 i = 0; i < LLTerrainMaterials::ASSET_COUNT; ++i)
diff --git a/indra/newview/llglsandbox.cpp b/indra/newview/llglsandbox.cpp
index 19cb4d04e2..0248f5710f 100644
--- a/indra/newview/llglsandbox.cpp
+++ b/indra/newview/llglsandbox.cpp
@@ -1075,6 +1075,9 @@ F32 gpu_benchmark()
             return -1.f;
         }
         LLImageGL::setManualImage(GL_TEXTURE_2D, 0, GL_RGBA, res,res,GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+        // disable mipmaps and use point filtering to cause cache misses
+        gGL.getTexUnit(0)->setHasMipMaps(false);
+        gGL.getTexUnit(0)->setTextureFilteringOption(LLTexUnit::TFO_POINT);
 
         if (alloc_timer.getElapsedTimeF32() > time_limit)
         {
@@ -1118,57 +1121,6 @@ F32 gpu_benchmark()
 
     LLGLSLShader::unbind();
 
-    F32 time_passed = 0; // seconds
-
-    { //run CPU timer benchmark
-        glFinish();
-        gBenchmarkProgram.bind();
-        for (S32 c = -1; c < samples && time_passed < time_limit; ++c)
-        {
-            LLTimer timer;
-            timer.start();
-
-            for (U32 i = 0; i < count; ++i)
-            {
-                dest[i].bindTarget();
-                texHolder.bind(i);
-                buff->setBuffer();
-                buff->drawArrays(LLRender::TRIANGLES, 0, 3);
-                dest[i].flush();
-            }
-
-            //wait for current batch of copies to finish
-            glFinish();
-
-            F32 time = timer.getElapsedTimeF32();
-            time_passed += time;
-
-            if (c >= 0) // <-- ignore the first sample as it tends to be artificially slow
-            {
-                //store result in gigabytes per second
-                F32 gb = (F32)((F64)(res * res * 8 * count)) / (1000000000);
-                F32 gbps = gb / time;
-                results.push_back(gbps);
-            }
-        }
-        gBenchmarkProgram.unbind();
-    }
-
-    std::sort(results.begin(), results.end());
-
-    F32 gbps = results[results.size()/2];
-
-    LL_INFOS("Benchmark") << "Memory bandwidth is " << llformat("%.3f", gbps) << " GB/sec according to CPU timers, " << (F32)results.size() << " tests took " << time_passed << " seconds" << LL_ENDL;
-
-#if LL_DARWIN
-    if (gbps > 512.f)
-    {
-        LL_WARNS("Benchmark") << "Memory bandwidth is improbably high and likely incorrect; discarding result." << LL_ENDL;
-        //OSX is probably lying, discard result
-        return -1.f;
-    }
-#endif
-
     // run GPU timer benchmark
     {
         ShaderProfileHelper initProfile;
@@ -1191,8 +1143,9 @@ F32 gpu_benchmark()
     F32 seconds = ms/1000.f;
 
     F64 samples_drawn = (F64)gBenchmarkProgram.mSamplesDrawn;
-    F32 samples_sec = (F32)((samples_drawn/1000000000.0)/seconds);
-    gbps = samples_sec*4;  // 4 bytes per sample
+    F64 gpixels_drawn = samples_drawn / 1000000000.0;
+    F32 samples_sec = (F32)(gpixels_drawn/seconds);
+    F32 gbps = samples_sec*4;  // 4 bytes per sample
 
     LL_INFOS("Benchmark") << "Memory bandwidth is " << llformat("%.3f", gbps) << " GB/sec according to ARB_timer_query, total time " << seconds << " seconds" << LL_ENDL;
 
diff --git a/indra/newview/llviewermenu.cpp b/indra/newview/llviewermenu.cpp
index a32e5d23e3..344a9737b1 100644
--- a/indra/newview/llviewermenu.cpp
+++ b/indra/newview/llviewermenu.cpp
@@ -3446,6 +3446,12 @@ bool enable_gltf_upload()
     return enable_gltf_save_as();
 }
 
+bool enable_terrain_local_paintmap()
+{
+    static LLCachedControl<bool> can_use_shaders(gSavedSettings, "RenderCanUseTerrainBakeShaders", true);
+    return can_use_shaders;
+}
+
 class LLSelfRemoveAllAttachments : public view_listener_t
 {
     bool handleEvent(const LLSD& userdata)
@@ -10223,6 +10229,7 @@ void initialize_menus()
     enable.add("EnableGLTF", boost::bind(&enable_gltf));
     enable.add("EnableGLTFSaveAs", boost::bind(&enable_gltf_save_as));
     enable.add("EnableGLTFUpload", boost::bind(&enable_gltf_upload));
+    enable.add("EnableTerrainLocalPaintMap", std::bind(&enable_terrain_local_paintmap));
 
     view_listener_t::addMenu(new LLFloaterVisible(), "FloaterVisible");
     view_listener_t::addMenu(new LLShowSidetrayPanel(), "ShowSidetrayPanel");
diff --git a/indra/newview/llviewerregion.cpp b/indra/newview/llviewerregion.cpp
index 72e066eb74..d315183ad0 100755
--- a/indra/newview/llviewerregion.cpp
+++ b/indra/newview/llviewerregion.cpp
@@ -2488,7 +2488,16 @@ void LLViewerRegion::setSimulatorFeatures(const LLSD& sim_features)
             if (features.has("GLTFEnabled"))
             {
                 bool enabled = features["GLTFEnabled"];
-                gSavedSettings.setBOOL("GLTFEnabled", enabled);
+
+                // call setShaders the first time GLTFEnabled is received as true (causes GLTF specific shaders to be loaded)
+                if (enabled != gSavedSettings.getBOOL("GLTFEnabled"))
+                {
+                    gSavedSettings.setBOOL("GLTFEnabled", enabled);
+                    if (enabled)
+                    {
+                        LLViewerShaderMgr::instance()->setShaders();
+                    }
+                }
             }
             else
             {
diff --git a/indra/newview/llviewershadermgr.cpp b/indra/newview/llviewershadermgr.cpp
index c422e1d3ae..58b541b19b 100644
--- a/indra/newview/llviewershadermgr.cpp
+++ b/indra/newview/llviewershadermgr.cpp
@@ -439,13 +439,20 @@ void LLViewerShaderMgr::finalizeShaderList()
     mShaderList.push_back(&gDeferredDiffuseProgram);
     mShaderList.push_back(&gDeferredBumpProgram);
     mShaderList.push_back(&gDeferredPBROpaqueProgram);
-    mShaderList.push_back(&gGLTFPBRMetallicRoughnessProgram);
+
+    if (gSavedSettings.getBOOL("GLTFEnabled"))
+    {
+        mShaderList.push_back(&gGLTFPBRMetallicRoughnessProgram);
+    }
+
     mShaderList.push_back(&gDeferredAvatarProgram);
     mShaderList.push_back(&gDeferredTerrainProgram);
+
     for (U32 paint_type = 0; paint_type < TERRAIN_PAINT_TYPE_COUNT; ++paint_type)
     {
         mShaderList.push_back(&gDeferredPBRTerrainProgram[paint_type]);
     }
+
     mShaderList.push_back(&gDeferredDiffuseAlphaMaskProgram);
     mShaderList.push_back(&gDeferredNonIndexedDiffuseAlphaMaskProgram);
     mShaderList.push_back(&gDeferredTreeProgram);
@@ -1340,26 +1347,29 @@ bool LLViewerShaderMgr::loadShadersDeferred()
         llassert(success);
     }
 
-    if (success)
+    if (gSavedSettings.getBOOL("GLTFEnabled"))
     {
-        gGLTFPBRMetallicRoughnessProgram.mName = "GLTF PBR Metallic Roughness Shader";
-        gGLTFPBRMetallicRoughnessProgram.mFeatures.hasSrgb = true;
+        if (success)
+        {
+            gGLTFPBRMetallicRoughnessProgram.mName = "GLTF PBR Metallic Roughness Shader";
+            gGLTFPBRMetallicRoughnessProgram.mFeatures.hasSrgb = true;
 
-        gGLTFPBRMetallicRoughnessProgram.mShaderFiles.clear();
-        gGLTFPBRMetallicRoughnessProgram.mShaderFiles.push_back(make_pair("gltf/pbrmetallicroughnessV.glsl", GL_VERTEX_SHADER));
-        gGLTFPBRMetallicRoughnessProgram.mShaderFiles.push_back(make_pair("gltf/pbrmetallicroughnessF.glsl", GL_FRAGMENT_SHADER));
-        gGLTFPBRMetallicRoughnessProgram.mShaderLevel = mShaderLevel[SHADER_DEFERRED];
-        gGLTFPBRMetallicRoughnessProgram.clearPermutations();
+            gGLTFPBRMetallicRoughnessProgram.mShaderFiles.clear();
+            gGLTFPBRMetallicRoughnessProgram.mShaderFiles.push_back(make_pair("gltf/pbrmetallicroughnessV.glsl", GL_VERTEX_SHADER));
+            gGLTFPBRMetallicRoughnessProgram.mShaderFiles.push_back(make_pair("gltf/pbrmetallicroughnessF.glsl", GL_FRAGMENT_SHADER));
+            gGLTFPBRMetallicRoughnessProgram.mShaderLevel = mShaderLevel[SHADER_DEFERRED];
+            gGLTFPBRMetallicRoughnessProgram.clearPermutations();
 
-        success = make_gltf_variants(gGLTFPBRMetallicRoughnessProgram, use_sun_shadow);
+            success = make_gltf_variants(gGLTFPBRMetallicRoughnessProgram, use_sun_shadow);
 
-        //llassert(success);
-        if (!success)
-        {
-            LL_WARNS() << "Failed to create GLTF PBR Metallic Roughness Shader, disabling!" << LL_ENDL;
-            gSavedSettings.setBOOL("RenderCanUseGLTFPBROpaqueShaders", false);
-            // continue as if this shader never happened
-            success = true;
+            //llassert(success);
+            if (!success)
+            {
+                LL_WARNS() << "Failed to create GLTF PBR Metallic Roughness Shader, disabling!" << LL_ENDL;
+                gSavedSettings.setBOOL("RenderCanUseGLTFPBROpaqueShaders", false);
+                // continue as if this shader never happened
+                success = true;
+            }
         }
     }
 
@@ -3140,23 +3150,33 @@ bool LLViewerShaderMgr::loadShadersInterface()
         success = gCopyDepthProgram.createShader();
     }
 
-    if (success)
+    if (gSavedSettings.getBOOL("LocalTerrainPaintEnabled"))
     {
-        LLGLSLShader* shader = &gPBRTerrainBakeProgram;
-        U32 bit_depth = gSavedSettings.getU32("TerrainPaintBitDepth");
-        // LLTerrainPaintMap currently uses an RGB8 texture internally
-        bit_depth = llclamp(bit_depth, 1, 8);
-        shader->mName = llformat("Terrain Bake Shader RGB%o", bit_depth);
-        shader->mFeatures.isPBRTerrain = true;
+        if (success)
+        {
+            LLGLSLShader* shader = &gPBRTerrainBakeProgram;
+            U32 bit_depth = gSavedSettings.getU32("TerrainPaintBitDepth");
+            // LLTerrainPaintMap currently uses an RGB8 texture internally
+            bit_depth = llclamp(bit_depth, 1, 8);
+            shader->mName = llformat("Terrain Bake Shader RGB%o", bit_depth);
+            shader->mFeatures.isPBRTerrain = true;
 
-        shader->mShaderFiles.clear();
-        shader->mShaderFiles.push_back(make_pair("interface/pbrTerrainBakeV.glsl", GL_VERTEX_SHADER));
-        shader->mShaderFiles.push_back(make_pair("interface/pbrTerrainBakeF.glsl", GL_FRAGMENT_SHADER));
-        shader->mShaderLevel = mShaderLevel[SHADER_INTERFACE];
-        const U32 value_range = (1 << bit_depth) - 1;
-        shader->addPermutation("TERRAIN_PAINT_PRECISION", llformat("%d", value_range));
-        success = success && shader->createShader();
-        llassert(success);
+            shader->mShaderFiles.clear();
+            shader->mShaderFiles.push_back(make_pair("interface/pbrTerrainBakeV.glsl", GL_VERTEX_SHADER));
+            shader->mShaderFiles.push_back(make_pair("interface/pbrTerrainBakeF.glsl", GL_FRAGMENT_SHADER));
+            shader->mShaderLevel = mShaderLevel[SHADER_INTERFACE];
+            const U32 value_range = (1 << bit_depth) - 1;
+            shader->addPermutation("TERRAIN_PAINT_PRECISION", llformat("%d", value_range));
+            success = success && shader->createShader();
+            //llassert(success);
+            if (!success)
+            {
+                LL_WARNS() << "Failed to create shader '" << shader->mName << "', disabling!" << LL_ENDL;
+                gSavedSettings.setBOOL("RenderCanUseTerrainBakeShaders", false);
+                // continue as if this shader never happened
+                success = true;
+            }
+        }
     }
 
     if (success)
diff --git a/indra/newview/llviewerstats.cpp b/indra/newview/llviewerstats.cpp
index 0cc2eb8b7c..ad503cbac7 100644
--- a/indra/newview/llviewerstats.cpp
+++ b/indra/newview/llviewerstats.cpp
@@ -541,6 +541,9 @@ void send_viewer_stats(bool include_preferences)
         agent["run_time"] = run_time;
     }
 
+    // report time the viewer has spent in the foreground
+    agent["foreground_time"] = gForegroundTime.getElapsedTimeF32();
+
     // send fps only for time app spends in foreground
     agent["fps"] = (F32)gForegroundFrameCount / gForegroundTime.getElapsedTimeF32();
     agent["version"] = LLVersionInfo::instance().getChannelAndVersion();
diff --git a/indra/newview/llviewertexture.cpp b/indra/newview/llviewertexture.cpp
index bb16fec32a..012ef5924a 100644
--- a/indra/newview/llviewertexture.cpp
+++ b/indra/newview/llviewertexture.cpp
@@ -511,44 +511,52 @@ void LLViewerTexture::updateClass()
 
     F32 over_pct = (used - target) / target;
 
-    bool is_low = over_pct > 0.f;
+    bool is_sys_low = isSystemMemoryLow();
+    bool is_low = is_sys_low || over_pct > 0.f;
 
-    if (isSystemMemoryLow())
+    static bool was_low = false;
+    static bool was_sys_low = false;
+
+    if (is_low && !was_low)
+    {
+        // slam to 1.5 bias the moment we hit low memory (discards off screen textures immediately)
+        sDesiredDiscardBias = llmax(sDesiredDiscardBias, 1.5f);
+
+        if (is_sys_low)
+        { // if we're low on system memory, emergency purge off screen textures to avoid a death spiral
+            LL_WARNS() << "Low system memory detected, emergency downrezzing off screen textures" << LL_ENDL;
+            for (auto& image : gTextureList)
+            {
+                gTextureList.updateImageDecodePriority(image, false /*will modify gTextureList otherwise!*/);
+            }
+        }
+    }
+
+    was_low = is_low;
+    was_sys_low = is_sys_low;
+
+    if (is_low)
     {
-        is_low = true;
-        // System RAM is low -> ramp up discard bias over time to free memory
+        // ramp up discard bias over time to free memory
         if (sEvaluationTimer.getElapsedTimeF32() > MEMORY_CHECK_WAIT_TIME)
         {
             static LLCachedControl<F32> low_mem_min_discard_increment(gSavedSettings, "RenderLowMemMinDiscardIncrement", .1f);
-            sDesiredDiscardBias += (F32) low_mem_min_discard_increment * (F32) gFrameIntervalSeconds;
+            sDesiredDiscardBias += (F32)low_mem_min_discard_increment * (F32)gFrameIntervalSeconds;
             sEvaluationTimer.reset();
         }
     }
     else
     {
-        sDesiredDiscardBias = llmax(sDesiredDiscardBias, 1.f + over_pct);
+        // don't execute above until the slam to 1.5 has a chance to take effect
+        sEvaluationTimer.reset();
 
+        // lower discard bias over time when free memory is available
         if (sDesiredDiscardBias > 1.f && over_pct < 0.f)
         {
             sDesiredDiscardBias -= gFrameIntervalSeconds * 0.01f;
         }
     }
 
-    static bool was_low = false;
-    if (is_low && !was_low)
-    {
-        LL_WARNS() << "Low system memory detected, emergency downrezzing off screen textures" << LL_ENDL;
-        sDesiredDiscardBias = llmax(sDesiredDiscardBias, 1.5f);
-
-        for (auto& image : gTextureList)
-        {
-            gTextureList.updateImageDecodePriority(image, false /*will modify gTextureList otherwise!*/);
-        }
-    }
-
-    was_low = is_low;
-
-
     // set to max discard bias if the window has been backgrounded for a while
     static bool was_backgrounded = false;
     static LLFrameTimer backgrounded_timer;
@@ -1545,6 +1553,17 @@ void LLViewerFetchedTexture::postCreateTexture()
 
     setActive();
 
+    // rebuild any volumes that are using this texture for sculpts in case their LoD has changed
+    for (U32 i = 0; i < mNumVolumes[LLRender::SCULPT_TEX]; ++i)
+    {
+        LLVOVolume* volume = mVolumeList[LLRender::SCULPT_TEX][i];
+        if (volume)
+        {
+            volume->mSculptChanged = true;
+            gPipeline.markRebuild(volume->mDrawable);
+        }
+    }
+
     if (!needsToSaveRawImage())
     {
         mNeedsAux = false;
@@ -2639,7 +2658,7 @@ void LLViewerFetchedTexture::destroyRawImage()
     if (mAuxRawImage.notNull() && !needsToSaveRawImage())
     {
         sAuxCount--;
-        mAuxRawImage = NULL;
+        mAuxRawImage = nullptr;
     }
 
     if (mRawImage.notNull())
@@ -2654,7 +2673,7 @@ void LLViewerFetchedTexture::destroyRawImage()
             }
         }
 
-        mRawImage = NULL;
+        mRawImage = nullptr;
 
         mIsRawImageValid = false;
         mRawDiscardLevel = INVALID_DISCARD_LEVEL;
@@ -2766,7 +2785,9 @@ void LLViewerFetchedTexture::readbackRawImage()
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 
-    if (mGLTexturep.notNull() && mGLTexturep->getTexName() != 0 && mRawImage.isNull())
+    // readback the raw image from vram if the current raw image is null or smaller than the texture
+    if (mGLTexturep.notNull() && mGLTexturep->getTexName() != 0 &&
+        (mRawImage.isNull() || mRawImage->getWidth() < mGLTexturep->getWidth() || mRawImage->getHeight() < mGLTexturep->getHeight() ))
     {
         mRawImage = new LLImageRaw();
         if (!mGLTexturep->readBackRaw(-1, mRawImage, false))
diff --git a/indra/newview/llviewertexturelist.cpp b/indra/newview/llviewertexturelist.cpp
index 2df60dbf6c..7b89ae4e44 100644
--- a/indra/newview/llviewertexturelist.cpp
+++ b/indra/newview/llviewertexturelist.cpp
@@ -964,7 +964,7 @@ void LLViewerTextureList::updateImageDecodePriority(LLViewerFetchedTexture* imag
           // this is an alternative to decaying mMaxVirtualSize over time
           // that keeps textures from continously downrezzing and uprezzing in the background
 
-            if (LLViewerTexture::sDesiredDiscardBias > 2.f ||
+            if (LLViewerTexture::sDesiredDiscardBias > 1.5f ||
                 (!on_screen && LLViewerTexture::sDesiredDiscardBias > 1.f))
             {
                 imagep->mMaxVirtualSize = 0.f;
diff --git a/indra/newview/llvovolume.cpp b/indra/newview/llvovolume.cpp
index 7d85b2b7da..28a7be6569 100644
--- a/indra/newview/llvovolume.cpp
+++ b/indra/newview/llvovolume.cpp
@@ -1149,7 +1149,7 @@ void LLVOVolume::updateSculptTexture()
         {
             mSculptTexture = LLViewerTextureManager::getFetchedTexture(id, FTT_DEFAULT, true, LLGLTexture::BOOST_SCULPTED, LLViewerTexture::LOD_TEXTURE);
             mSculptTexture->forceToSaveRawImage(0, F32_MAX);
-            mSculptTexture->addTextureStats(256.f*256.f);
+            mSculptTexture->setKnownDrawSize(256, 256);
         }
 
         mSkinInfoUnavaliable = false;
@@ -1251,7 +1251,7 @@ void LLVOVolume::sculpt()
             discard_level = mSculptTexture->getSavedRawImageLevel();
         }
 
-        if (!raw_image)
+        if (!raw_image || raw_image->getWidth() < mSculptTexture->getWidth() || raw_image->getHeight() < mSculptTexture->getHeight())
         {
             // last resort, read back from GL
             mSculptTexture->readbackRawImage();
@@ -1338,17 +1338,8 @@ void LLVOVolume::sculpt()
                 mSculptTexture->updateBindStatsForTester() ;
             }
         }
-        getVolume()->sculpt(sculpt_width, sculpt_height, sculpt_components, sculpt_data, discard_level, mSculptTexture->isMissingAsset());
 
-        //notify rebuild any other VOVolumes that reference this sculpty volume
-        for (S32 i = 0; i < mSculptTexture->getNumVolumes(LLRender::SCULPT_TEX); ++i)
-        {
-            LLVOVolume* volume = (*(mSculptTexture->getVolumeList(LLRender::SCULPT_TEX)))[i];
-            if (volume != this && volume->getVolume() == getVolume())
-            {
-                gPipeline.markRebuild(volume->mDrawable, LLDrawable::REBUILD_GEOMETRY);
-            }
-        }
+        getVolume()->sculpt(sculpt_width, sculpt_height, sculpt_components, sculpt_data, discard_level, mSculptTexture->isMissingAsset());
     }
 }
 
diff --git a/indra/newview/llvovolume.h b/indra/newview/llvovolume.h
index 6241bf42d6..97a5131260 100644
--- a/indra/newview/llvovolume.h
+++ b/indra/newview/llvovolume.h
@@ -451,6 +451,7 @@ public:
 private:
     friend class LLDrawable;
     friend class LLFace;
+    friend class LLViewerFetchedTexture;
 
     bool        mFaceMappingChanged;
     LLFrameTimer mTextureUpdateTimer;
diff --git a/indra/newview/llwearablelist.cpp b/indra/newview/llwearablelist.cpp
index 76348d4ea1..2d59712142 100644
--- a/indra/newview/llwearablelist.cpp
+++ b/indra/newview/llwearablelist.cpp
@@ -36,6 +36,7 @@
 #include "llnotificationsutil.h"
 #include "llinventorymodel.h"
 #include "lltrans.h"
+#include "llappviewer.h"
 
 // Callback struct
 struct LLWearableArrivedData
@@ -97,6 +98,22 @@ void LLWearableList::getAsset(const LLAssetID& assetID, const std::string& weara
 // static
 void LLWearableList::processGetAssetReply( const char* filename, const LLAssetID& uuid, void* userdata, S32 status, LLExtStat ext_status )
 {
+    if (!LLCoros::on_main_coro())
+    {
+        // if triggered from a coroutine, dispatch to main thread before accessing app state
+        std::string filename_in = filename;
+        LLUUID uuid_in = uuid;
+
+        LLAppViewer::instance()->postToMainCoro([=]()
+            {
+                processGetAssetReply(filename_in.c_str(), uuid_in, userdata, status, ext_status);
+            });
+
+        return;
+    }
+
+    LL_PROFILE_ZONE_SCOPED_CATEGORY_AVATAR;
+
     bool isNewWearable = false;
     LLWearableArrivedData* data = (LLWearableArrivedData*) userdata;
     LLViewerWearable* wearable = NULL; // NULL indicates failure
diff --git a/indra/newview/skins/default/xui/en/menu_viewer.xml b/indra/newview/skins/default/xui/en/menu_viewer.xml
index 25ad9da5ea..fb556a6587 100644
--- a/indra/newview/skins/default/xui/en/menu_viewer.xml
+++ b/indra/newview/skins/default/xui/en/menu_viewer.xml
@@ -3672,9 +3672,10 @@ function="World.EnvPreset"
             <menu_item_separator/>
 
             <menu_item_call
-              enabled="true"
               label="Create Local Paintmap"
               name="Create Local Paintmap">
+              <menu_item_call.on_enable
+               function="EnableTerrainLocalPaintMap"/>
               <menu_item_call.on_click
                function="Advanced.TerrainCreateLocalPaintMap" />
             </menu_item_call>