1 files changed, 66 insertions, 0 deletions
diff --git a/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
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index 0000000000..6994a20b79
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+++ b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
@@ -0,0 +1,66 @@
+/** 
+ * @file exposureF.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
+ * $/LicenseInfo$
+ */
+ 
+#extension GL_ARB_texture_rectangle : enable
+
+/*[EXTRA_CODE_HERE]*/
+
+out vec4 frag_color;
+
+uniform sampler2D diffuseRect;
+uniform float dt;
+
+void main() 
+{
+    int samples = 16;
+    float step = 1.0/(samples-4);
+
+    float start = step;
+    float end = 1.0-step;
+
+    float w = 0.0;
+
+    vec3 col;
+
+    for (float x = start; x <= end; x += step)
+    {
+        for (float y = start; y <= end; y += step)
+        {
+            vec2 tc = vec2(x,y);
+            w += 1.0;
+            col += texture(diffuseRect, tc).rgb;
+        }
+    }
+
+    col /= w;
+
+    // calculate luminance the same way LLColor4::calcHSL does
+    float mx = max(max(col.r, col.g), col.b);
+    float mn = min(min(col.r, col.g), col.b);
+    float lum = (mx + mn) * 0.5;
+
+    frag_color = vec4(lum, lum, lum, dt);
+}
+