SL-19538 Followup -- fix for dynamic exposure having large gaps in it… (#157)

* SL-19538 Followup -- fix for dynamic exposure having large gaps in its luminance sampling.

* SL-19538 Followup -- review feedback changes.

9 files changed, 117 insertions, 50 deletions

diff --git a/indra/llrender/llrendertarget.cpp b/indra/llrender/llrendertarget.cpp
index 6dac614eea..7f507a0b58 100644
--- a/indra/llrender/llrendertarget.cpp
+++ b/indra/llrender/llrendertarget.cpp
@@ -483,7 +483,7 @@ U32 LLRenderTarget::getNumTextures() const
 
 void LLRenderTarget::bindTexture(U32 index, S32 channel, LLTexUnit::eTextureFilterOptions filter_options)
 {
-    gGL.getTexUnit(channel)->bindManual(mUsage, getTexture(index));
+    gGL.getTexUnit(channel)->bindManual(mUsage, getTexture(index), filter_options == LLTexUnit::TFO_TRILINEAR || filter_options == LLTexUnit::TFO_ANISOTROPIC);
 
     bool isSRGB = false;
     llassert(mInternalFormat.size() > index);
diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index 063f4fcf96..44a86dd22a 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -10500,7 +10500,7 @@
     <key>Type</key>
     <string>F32</string>
     <key>Value</key>
-    <real>0.3</real>
+    <real>0.175</real>
   </map>
     <key>RenderShaderLODThreshold</key>
     <map>
diff --git a/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
index 4c860cdde0..3eda2b9050 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
@@ -29,7 +29,6 @@
 
 out vec4 frag_color;
 
-uniform sampler2D diffuseRect;
 uniform sampler2D emissiveRect;
 uniform sampler2D exposureMap;
 
@@ -46,45 +45,12 @@ float lum(vec3 col)
 
 void main() 
 {
-    float step = 1.0/16.0;
+    vec2 tc = vec2(0.5,0.5);
 
-    float start = step;
-    float end = 1.0-step;
-
-    float w = 0.0;
-
-    vec3 col;
-
-    //vec2 nz = noiseVec * step * 0.5;
-
-    for (float x = start; x <= end; x += step)
-    {
-        for (float y = start; y <= end; y += step)
-        {
-            vec2 tc = vec2(x,y); // + nz;
-            vec3 c = texture(diffuseRect, tc).rgb + texture(emissiveRect, tc).rgb;
-            float L = max(lum(c), 0.25);
-
-            float d = length(vec2(0.5)-tc);
-            d = 1.0-d;
-            d *= d;
-            d *= d;
-            d *= d;
-            L *= d;
-
-            w += L;
-
-            col += c * L;
-        }
-    }
-
-    col /= w;
-
-    float L = lum(col);
+    float L = textureLod(emissiveRect, tc, 8).r;
 
     float s = clamp(dynamic_exposure_params.x/L, dynamic_exposure_params.y, dynamic_exposure_params.z);
 
-
     float prev = texture(exposureMap, vec2(0.5,0.5)).r;
 
     s = mix(prev, s, min(dt*2.0*abs(prev-s), 0.04));
diff --git a/indra/newview/app_settings/shaders/class1/deferred/luminanceF.glsl b/indra/newview/app_settings/shaders/class1/deferred/luminanceF.glsl
new file mode 100644
index 0000000000..e63e666778
--- /dev/null
+++ b/indra/newview/app_settings/shaders/class1/deferred/luminanceF.glsl
@@ -0,0 +1,52 @@
+/** 
+ * @file luminanceF.glsl
+ *
+ * $LicenseInfo:firstyear=2023&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2023, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+ 
+
+/*[EXTRA_CODE_HERE]*/
+
+// take a luminance sample of diffuseRect and emissiveRect 
+
+out vec4 frag_color;
+
+in vec2 vary_fragcoord;
+
+uniform sampler2D diffuseRect;
+uniform sampler2D emissiveRect;
+
+float lum(vec3 col)
+{
+    vec3 l = vec3(0.2126, 0.7152, 0.0722);
+    return dot(l, col);
+}
+
+void main() 
+{
+    vec2 tc = vary_fragcoord*0.6+0.2;
+    vec3 c = texture(diffuseRect, tc).rgb + texture(emissiveRect, tc).rgb;
+    float L = lum(c);
+
+    frag_color = vec4(L);
+}
+
diff --git a/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl b/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl
index 22e93496d2..49ff49fdd8 100644
--- a/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl
+++ b/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl
@@ -36,7 +36,9 @@ vec3 atmosFragLighting(vec3 light, vec3 additive, vec3 atten)
 { 
     light *= atten.r;
     additive = srgb_to_linear(additive*2.0);
-    additive *= sun_up_factor + 1.0;
+    // magic 3.0 here is to match the default RenderSkyHDRScale -- this parameter needs to be plumbed into sky settings or something
+    // so it's available to all shaders that call atmosFragLighting instead of just softenLightF.glsl
+    additive *= sun_up_factor*3.0 + 1.0; 
     light += additive;
     return light;
 }
diff --git a/indra/newview/llviewershadermgr.cpp b/indra/newview/llviewershadermgr.cpp
index 8b402e210d..4c34c6f6e5 100644
--- a/indra/newview/llviewershadermgr.cpp
+++ b/indra/newview/llviewershadermgr.cpp
@@ -188,6 +188,7 @@ LLGLSLShader			gDeferredCoFProgram;
 LLGLSLShader			gDeferredDoFCombineProgram;
 LLGLSLShader			gDeferredPostGammaCorrectProgram;
 LLGLSLShader			gExposureProgram;
+LLGLSLShader			gLuminanceProgram;
 LLGLSLShader			gFXAAProgram;
 LLGLSLShader			gDeferredPostNoDoFProgram;
 LLGLSLShader			gDeferredWLSkyProgram;
@@ -1002,6 +1003,7 @@ BOOL LLViewerShaderMgr::loadShadersDeferred()
 		gDeferredCoFProgram.unload();		
 		gDeferredDoFCombineProgram.unload();
         gExposureProgram.unload();
+        gLuminanceProgram.unload();
 		gDeferredPostGammaCorrectProgram.unload();
 		gFXAAProgram.unload();
 		gDeferredWLSkyProgram.unload();
@@ -2534,6 +2536,18 @@ BOOL LLViewerShaderMgr::loadShadersDeferred()
         llassert(success);
     }
 
+    if (success)
+    {
+        gLuminanceProgram.mName = "Luminance";
+        gLuminanceProgram.mShaderFiles.clear();
+        gLuminanceProgram.clearPermutations();
+        gLuminanceProgram.mShaderFiles.push_back(make_pair("deferred/postDeferredNoTCV.glsl", GL_VERTEX_SHADER));
+        gLuminanceProgram.mShaderFiles.push_back(make_pair("deferred/luminanceF.glsl", GL_FRAGMENT_SHADER));
+        gLuminanceProgram.mShaderLevel = mShaderLevel[SHADER_DEFERRED];
+        success = gLuminanceProgram.createShader(NULL, NULL);
+        llassert(success);
+    }
+
 	if (success)
 	{
 		gDeferredPostGammaCorrectProgram.mName = "Deferred Gamma Correction Post Process";
diff --git a/indra/newview/llviewershadermgr.h b/indra/newview/llviewershadermgr.h
index 6fb2bc3fec..0a23c33b78 100644
--- a/indra/newview/llviewershadermgr.h
+++ b/indra/newview/llviewershadermgr.h
@@ -236,6 +236,7 @@ extern LLGLSLShader			gFXAAProgram;
 extern LLGLSLShader			gDeferredPostNoDoFProgram;
 extern LLGLSLShader			gDeferredPostGammaCorrectProgram;
 extern LLGLSLShader			gExposureProgram;
+extern LLGLSLShader			gLuminanceProgram;
 extern LLGLSLShader			gDeferredAvatarShadowProgram;
 extern LLGLSLShader			gDeferredAvatarAlphaShadowProgram;
 extern LLGLSLShader			gDeferredAvatarAlphaMaskShadowProgram;
diff --git a/indra/newview/pipeline.cpp b/indra/newview/pipeline.cpp
index 1222613c66..4ab6483c88 100644
--- a/indra/newview/pipeline.cpp
+++ b/indra/newview/pipeline.cpp
@@ -1082,6 +1082,7 @@ void LLPipeline::releaseLUTBuffers()
     mPbrBrdfLut.release();
 
     mExposureMap.release();
+    mLuminanceMap.release();
     mLastExposure.release();
 
 }
@@ -1266,6 +1267,8 @@ void LLPipeline::createLUTBuffers()
     mExposureMap.clear();
     mExposureMap.flush();
 
+    mLuminanceMap.allocate(256, 256, GL_R16F);
+
     mLastExposure.allocate(1, 1, GL_R16F);
 }
 
@@ -7262,6 +7265,43 @@ void LLPipeline::renderFinalize()
             dst.flush();
         }
 
+        // luminance sample and mipmap generation
+        {
+            LL_PROFILE_GPU_ZONE("luminance sample");
+
+            mLuminanceMap.bindTarget();
+
+            LLGLDepthTest depth(GL_FALSE, GL_FALSE);
+
+            gLuminanceProgram.bind();
+
+
+            S32 channel = 0;
+            channel = gLuminanceProgram.enableTexture(LLShaderMgr::DEFERRED_DIFFUSE);
+            if (channel > -1)
+            {
+                screenTarget()->bindTexture(0, channel, LLTexUnit::TFO_POINT);
+            }
+
+            channel = gLuminanceProgram.enableTexture(LLShaderMgr::DEFERRED_EMISSIVE);
+            if (channel > -1)
+            {
+                mGlow[1].bindTexture(0, channel);
+            }
+
+
+            mScreenTriangleVB->setBuffer();
+            mScreenTriangleVB->drawArrays(LLRender::TRIANGLES, 0, 3);
+            mLuminanceMap.flush();
+
+            mLuminanceMap.bindTexture(0, 0, LLTexUnit::TFO_TRILINEAR);
+            glGenerateMipmap(GL_TEXTURE_2D);
+
+            // note -- unbind AFTER the glGenerateMipMap so time in generatemipmap can be profiled under "Luminance"
+            // also note -- keep an eye on the performance of glGenerateMipmap, might need to replace it with a mip generation shader
+            gLuminanceProgram.unbind();
+        }
+
         // exposure sample
         {
             LL_PROFILE_GPU_ZONE("exposure sample");
@@ -7278,25 +7318,16 @@ void LLPipeline::renderFinalize()
                 mLastExposure.flush();
             }
 
-
             mExposureMap.bindTarget();
 
             LLGLDepthTest depth(GL_FALSE, GL_FALSE);
             
             gExposureProgram.bind();
 
-
-            S32 channel = 0;
-            channel = gExposureProgram.enableTexture(LLShaderMgr::DEFERRED_DIFFUSE);
-            if (channel > -1)
-            {
-                screenTarget()->bindTexture(0, channel, LLTexUnit::TFO_POINT);
-            }
-
-            channel = gExposureProgram.enableTexture(LLShaderMgr::DEFERRED_EMISSIVE);
+            S32 channel = gExposureProgram.enableTexture(LLShaderMgr::DEFERRED_EMISSIVE);
             if (channel > -1)
             {
-                mGlow[1].bindTexture(0, channel);
+                mLuminanceMap.bindTexture(0, channel, LLTexUnit::TFO_TRILINEAR);
             }
 
             channel = gExposureProgram.enableTexture(LLShaderMgr::EXPOSURE_MAP);
diff --git a/indra/newview/pipeline.h b/indra/newview/pipeline.h
index eb30c85993..a231084e5c 100644
--- a/indra/newview/pipeline.h
+++ b/indra/newview/pipeline.h
@@ -678,6 +678,7 @@ public:
     LLRenderTarget          mSceneMap;
 
     // exposure map for getting average color in scene
+    LLRenderTarget          mLuminanceMap;
     LLRenderTarget          mExposureMap;
     LLRenderTarget          mLastExposure;