Merge branch 'release/2026.02' into maxim/flat-ui-fonts-update

# Conflicts:
#	indra/newview/skins/default/xui/en/panel_preferences_general.xml

3 files changed, 104 insertions, 26 deletions

diff --git a/indra/llprimitive/llgltfmaterial.cpp b/indra/llprimitive/llgltfmaterial.cpp
index 930222e3db..1c47001272 100644
--- a/indra/llprimitive/llgltfmaterial.cpp
+++ b/indra/llprimitive/llgltfmaterial.cpp
@@ -214,7 +214,7 @@ std::string LLGLTFMaterial::asJSON(bool prettyprint) const
     // to WriteGltfSceneToStream in the viewer.
     gltf.WriteGltfSceneToStream(&model_out, str, prettyprint, false);
 
-    return str.str();
+    return std::move(str).str();
 }
 
 void LLGLTFMaterial::setFromModel(const tinygltf::Model& model, S32 mat_index)
@@ -924,6 +924,25 @@ void LLGLTFMaterial::updateTextureTracking()
     // for material overrides editor will set it
 }
 
+// Test cases:
+// Case 1.
+// Input: scale 1.0,1.0; Offset horizontal 0.0, Offset vertical 0.0 Rotation 0.349066;
+// Expected output: scale 1.0,1.0; Offset horizontal 0.201, Offset vertical -0.141 Rotation -0.349066;
+// Case 2.
+// Input: scale 1.0,1.0; Offset horizontal 0.5, Offset vertical 0.1 Rotation 0;
+// Expected output: scale 1.0,1.0; Offset horizontal 0.5, Offset vertical -0.1 Rotation -0;
+// Case 3.
+// Input: scale 1.0,1.0; Offset horizontal 0.1, Offset vertical 0.2 Rotation 0.349066;
+// Expected output: scale 1.0,1.0; Offset horizontal 0.295, Offset vertical -0.345 Rotation -0.349066;
+// Case 4.
+// Input: scale 1.0,1.0; Offset horizontal 0.5, Offset vertical 0.0 Rotation 0.349066;
+// Expected output: scale 1.0,1.0; Offset horizontal 0.701, Offset vertical -0.141 Rotation -0.349066;
+//
+// Legacy offsets are right to left and top to bottom.
+// PBR offsets are right to left and bottom to top.
+//
+// Legacy rotation is relative to face's center counter clockwise,
+// PBR rotation is relative to top-left corner, clockwise
 void LLGLTFMaterial::convertTextureTransformToPBR(
     F32 tex_scale_s,
     F32 tex_scale_t,
@@ -935,22 +954,65 @@ void LLGLTFMaterial::convertTextureTransformToPBR(
     F32& pbr_rotation)
 {
     pbr_scale.set(tex_scale_s, tex_scale_t);
-    pbr_rotation = -(tex_rotation) / 2.f;
-    const F32 adjusted_offset_s = tex_offset_s;
-    const F32 adjusted_offset_t = -tex_offset_t;
+    pbr_rotation = -tex_rotation;
+
+    // Center of the tile
+    const F32 center_s = 0.5f;
+    const F32 center_t = 0.5f;
+
+    // Center adjustment for scale
     F32 center_adjust_s = 0.5f * (1.0f - tex_scale_s);
     F32 center_adjust_t = 0.5f * (1.0f - tex_scale_t);
 
-    if (pbr_rotation != 0.0f)
-    {
-        const F32 c = cosf(pbr_rotation);
-        const F32 s = sinf(pbr_rotation);
-        const F32 tmp_s = center_adjust_s * c - center_adjust_t * s;
-        const F32 tmp_t = center_adjust_s * s + center_adjust_t * c;
-        center_adjust_s = tmp_s;
-        center_adjust_t = tmp_t;
-    }
+    // 2. Offset from center
+    F32 pos_s = center_adjust_s - center_s;
+    F32 pos_t = center_adjust_t - center_t;
+
+    // 3. Rotate around center (clockwise, as per GLTF spec)
+    F32 c = cosf(pbr_rotation);
+    F32 s = sinf(pbr_rotation);
+    F32 rot_s = pos_s * c + pos_t * s;
+    F32 rot_t = -pos_s * s + pos_t * c;
+
+    // 4. Move back to top-left and apply offset
+    pbr_offset.set(rot_s + center_s + tex_offset_s, rot_t + center_t - tex_offset_t);
+}
+
+// Convert PBR transform values back to legacy TE transform values.
+// This is the reverse of convertTextureTransformToPBR.
+void LLGLTFMaterial::convertPBRTransformToTexture(
+    const LLVector2& pbr_scale,
+    const LLVector2& pbr_offset,
+    F32 pbr_rotation,
+    F32& tex_scale_s,
+    F32& tex_scale_t,
+    F32& tex_offset_s,
+    F32& tex_offset_t,
+    F32& tex_rotation)
+{
+    tex_scale_s = pbr_scale.mV[0];
+    tex_scale_t = pbr_scale.mV[1];
+    tex_rotation = -pbr_rotation;
+
+    // Center of the tile
+    const F32 center_s = 0.5f;
+    const F32 center_t = 0.5f;
+
+    // Center adjustment for scale
+    F32 center_adjust_s = 0.5f * (1.0f - tex_scale_s);
+    F32 center_adjust_t = 0.5f * (1.0f - tex_scale_t);
+
+    // 2. Offset from center
+    F32 pos_s = center_adjust_s - center_s;
+    F32 pos_t = center_adjust_t - center_t;
+
+    // 3. Rotate around center (clockwise, as per GLTF spec)
+    F32 c = cosf(pbr_rotation);
+    F32 s = sinf(pbr_rotation);
+    F32 rot_s = pos_s * c + pos_t * s;
+    F32 rot_t = -pos_s * s + pos_t * c;
 
-    pbr_offset.set(adjusted_offset_s + center_adjust_s,
-                   adjusted_offset_t + center_adjust_t);
+    // 3. Recover legacy offset
+    tex_offset_s = pbr_offset.mV[0] - rot_s - center_s;
+    tex_offset_t = -(pbr_offset.mV[1] - rot_t - center_t);
 }
diff --git a/indra/llprimitive/llgltfmaterial.h b/indra/llprimitive/llgltfmaterial.h
index 8d45cb6185..c37062e7d3 100644
--- a/indra/llprimitive/llgltfmaterial.h
+++ b/indra/llprimitive/llgltfmaterial.h
@@ -222,6 +222,14 @@ public:
                                              LLVector2& pbr_scale,
                                              LLVector2& pbr_offset,
                                              F32& pbr_rotation);
+
+    // Convert PBR transform values to legacy TE transform values.
+    static void convertPBRTransformToTexture(const LLVector2& pbr_scale,
+                                             const LLVector2& pbr_offset,
+                                             F32 pbr_rotation,
+                                             F32& tex_scale_s, F32& tex_scale_t,
+                                             F32& tex_offset_s, F32& tex_offset_t,
+                                             F32& tex_rotation);
 protected:
     static LLVector2 vec2FromJson(const std::map<std::string, tinygltf::Value>& object, const char* key, const LLVector2& default_value);
     static F32 floatFromJson(const std::map<std::string, tinygltf::Value>& object, const char* key, const F32 default_value);
diff --git a/indra/llprimitive/llmaterialid.h b/indra/llprimitive/llmaterialid.h
index bd6256d961..41dd5a8710 100644
--- a/indra/llprimitive/llmaterialid.h
+++ b/indra/llprimitive/llmaterialid.h
@@ -67,15 +67,11 @@ public:
 
     static const LLMaterialID null;
 
-    // Returns a 64 bits digest of the material Id, by XORing its two 64 bits
-    // long words. HB
-    inline U64 getDigest64() const
-    {
-        U64* tmp = (U64*)mID;
-        return tmp[0] ^ tmp[1];
-    }
-
 private:
+    // definitions follow class
+    friend std::hash<LLMaterialID>;
+    friend size_t hash_value(const LLMaterialID&) noexcept;
+
     void parseFromBinary(const LLSD::Binary& pMaterialID);
     void copyFromOtherMaterialID(const LLMaterialID& pOtherMaterialID);
     int  compareToOtherMaterialID(const LLMaterialID& pOtherMaterialID) const;
@@ -90,15 +86,27 @@ namespace std
     {
         inline size_t operator()(const LLMaterialID& id) const noexcept
         {
-            return (size_t)id.getDigest64();
+            size_t h = 0;
+            // Golden ratio hash with avalanche mixing
+            // Process 8 bytes at a time by manually constructing 64-bit values
+            // Shift by 31: mixes upper half into lower half for better bit distribution
+            // Shift by 47: ensures highest bits influence final hash output
+            for (int i = 0; i < MATERIAL_ID_SIZE; i += 8) {
+                size_t chunk = (size_t)id.mID[i] | ((size_t)id.mID[i + 1] << 8) |
+                               ((size_t)id.mID[i+2] << 16) | ((size_t)id.mID[i+3] << 24) |
+                               ((size_t)id.mID[i+4] << 32) | ((size_t)id.mID[i+5] << 40) |
+                               ((size_t)id.mID[i + 6] << 48) | ((size_t)id.mID[i + 7] << 56);
+                h ^= (chunk * 0x9e3779b97f4a7c15ULL) ^ (h >> 31) ^ (h >> 47);
+            }
+            return h;
         }
     };
 }
 
-// For use with boost containers.
+// For use with boost::container_hash
 inline size_t hash_value(const LLMaterialID& id) noexcept
 {
-    return (size_t)id.getDigest64();
+    return std::hash<LLMaterialID>{}(id);
 }
 
 #endif // LL_LLMATERIALID_H