Merge changes I26f3edb0,Iba714851 into new_text

* changes:
  Removed a float equality comparision
  Merge remote-tracking branch 'origin/tizen' into new_text

diff --git a/dali-toolkit/internal/controls/text-controls/text-label-impl.cpp b/dali-toolkit/internal/controls/text-controls/text-label-impl.cpp
index 60ca46e..419d1c4 100644 (file)
--- a/dali-toolkit/internal/controls/text-controls/text-label-impl.cpp
+++ b/dali-toolkit/internal/controls/text-controls/text-label-impl.cpp
@@ -88,6 +88,7 @@ DALI_PROPERTY_REGISTRATION( TextLabel, "shadow-offset",        VECTOR2, SHADOW_O
 DALI_PROPERTY_REGISTRATION( TextLabel, "shadow-color",         VECTOR4, SHADOW_COLOR         )
 DALI_PROPERTY_REGISTRATION( TextLabel, "underline-enabled",    BOOLEAN, UNDERLINE_ENABLED    )
 DALI_PROPERTY_REGISTRATION( TextLabel, "underline-color",      VECTOR4, UNDERLINE_COLOR      )
+DALI_PROPERTY_REGISTRATION( TextLabel, "underline-height",     FLOAT,   UNDERLINE_HEIGHT       )
 DALI_TYPE_REGISTRATION_END()
 
 } // namespace
@@ -289,6 +290,20 @@ void TextLabel::SetProperty( BaseObject* object, Property::Index index, const Pr
         }
         break;
       }
+
+      case Toolkit::TextLabel::Property::UNDERLINE_HEIGHT:
+      {
+        if( impl.mController )
+        {
+          float height = value.Get< float >();
+          if ( impl.mController->GetUnderlineHeight() != height )
+          {
+            impl.mController->SetUnderlineHeight( height );
+            impl.RequestTextRelayout();
+          }
+        }
+        break;
+      }
     }
   }
 }
@@ -387,6 +402,14 @@ Property::Value TextLabel::GetProperty( BaseObject* object, Property::Index inde
         }
         break;
       }
+      case Toolkit::TextLabel::Property::UNDERLINE_HEIGHT:
+      {
+        if ( impl.mController )
+        {
+          value = impl.mController->GetUnderlineHeight();
+        }
+        break;
+      }
     }
   }
 

diff --git a/dali-toolkit/internal/text/rendering/atlas/text-atlas-renderer.cpp b/dali-toolkit/internal/text/rendering/atlas/text-atlas-renderer.cpp
index fda82f4..016284a 100644 (file)
--- a/dali-toolkit/internal/text/rendering/atlas/text-atlas-renderer.cpp
+++ b/dali-toolkit/internal/text/rendering/atlas/text-atlas-renderer.cpp
@@ -19,6 +19,7 @@
 #include <dali-toolkit/internal/text/rendering/atlas/text-atlas-renderer.h>
 
 // EXTERNAL INCLUDES
+#include <math.h>
 #include <dali/dali.h>
 #include <dali/integration-api/debug.h>
 
@@ -38,6 +39,10 @@ using namespace Dali::Toolkit::Text;
 
 namespace
 {
+  const float ZERO( 0.0f );
+  const float HALF( 0.5f );
+  const float ONE( 1.0f );
+  const float TWO( 2.0f );
   const Vector2 DEFAULT_ATLAS_SIZE( 512.0f, 512.0f );
   const Vector2 DEFAULT_BLOCK_SIZE( 16.0f, 16.0f );
   const Vector2 PADDING( 4.0f, 4.0f ); // Allow for variation in font glyphs
@@ -102,19 +107,21 @@ struct AtlasRenderer::Impl : public ConnectionTracker
                   const Vector4& textColor,
                   const Vector2& shadowOffset,
                   const Vector4& shadowColor,
-                  float underlineEnabled,
-                  const Vector4& underlineColor )
+                  bool underlineEnabled,
+                  const Vector4& underlineColor,
+                  float underlineHeight )
   {
     AtlasManager::AtlasSlot slot;
     std::vector< MeshRecord > meshContainer;
     Vector< Extent > extents;
 
-    float currentUnderlinePosition = 0.0f;
-    float currentUnderlineThickness = 0.0f;
+    float currentUnderlinePosition = ZERO;
+    float currentUnderlineThickness = underlineHeight;
+
     FontId lastFontId = 0;
     Style style = STYLE_NORMAL;
 
-    if ( shadowOffset.x != 0.0f || shadowOffset.y != 0.0f )
+    if ( fabsf( shadowOffset.x ) > Math::MACHINE_EPSILON_1 || fabsf( shadowOffset.y ) > Math::MACHINE_EPSILON_1 )
     {
       style = STYLE_DROP_SHADOW;
     }
@@ -140,13 +147,33 @@ struct AtlasRenderer::Impl : public ConnectionTracker
           // We need to fetch fresh font underline metrics
           FontMetrics fontMetrics;
           mFontClient.GetFontMetrics( glyph.fontId, fontMetrics );
-          currentUnderlinePosition = fontMetrics.underlinePosition;
-          currentUnderlineThickness = fontMetrics.underlineThickness;
+          currentUnderlinePosition = FontMetricsRoundUp( fabsf( fontMetrics.underlinePosition ) );
+          float descender = FontMetricsRoundUp( fabsf( fontMetrics.descender ) );
 
-          // Ensure that an underline is at least 1 pixel high
-          if ( currentUnderlineThickness < 1.0f )
+          if ( underlineHeight == ZERO )
           {
-            currentUnderlineThickness = 1.0f;
+            currentUnderlineThickness = fontMetrics.underlineThickness;
+
+            // Ensure underline will be at least a pixel high
+            if ( currentUnderlineThickness < ONE )
+            {
+              currentUnderlineThickness = ONE;
+            }
+            else
+            {
+              currentUnderlineThickness = FontMetricsRoundUp( currentUnderlineThickness );
+            }
+          }
+
+          // Clamp the underline position at the font descender and check for ( as EFL describes it ) a broken font
+          if ( currentUnderlinePosition > descender )
+          {
+            currentUnderlinePosition = descender;
+          }
+          if ( ZERO == currentUnderlinePosition )
+          {
+            // Move offset down by one ( EFL behavior )
+            currentUnderlinePosition = ONE;
           }
         }
 
@@ -173,7 +200,6 @@ struct AtlasRenderer::Impl : public ConnectionTracker
                 mGlyphManager.SetNewAtlasSize( DEFAULT_ATLAS_SIZE, mBlockSizes[ j ].mNeededBlockSize );
               }
             }
-            lastFontId = glyph.fontId;
           }
 
           // Glyph doesn't currently exist in atlas so upload
@@ -199,6 +225,7 @@ struct AtlasRenderer::Impl : public ConnectionTracker
                         currentUnderlineThickness,
                         slot );
       }
+      lastFontId = glyph.fontId;
     }
 
     if ( underlineEnabled )
@@ -289,14 +316,13 @@ struct AtlasRenderer::Impl : public ConnectionTracker
       uint32_t index = 0;
       for ( std::vector< MeshRecord >::iterator mIt = meshContainer.begin(); mIt != meshContainer.end(); ++mIt, ++index )
       {
-        if ( slot.mAtlasId == mIt->mAtlasId )
+        if ( slot.mAtlasId == mIt->mAtlasId && color == mIt->mColor )
         {
           // Stitch the mesh to the existing mesh and adjust any extents
           mGlyphManager.StitchMesh( mIt->mMeshData, newMeshData );
           AdjustExtents( extents,
                          meshContainer,
                          index,
-                         color,
                          left,
                          right,
                          baseLine,
@@ -318,7 +344,6 @@ struct AtlasRenderer::Impl : public ConnectionTracker
       AdjustExtents( extents,
                      meshContainer,
                      meshContainer.size() - 1u,
-                     color,
                      left,
                      right,
                      baseLine,
@@ -331,7 +356,6 @@ struct AtlasRenderer::Impl : public ConnectionTracker
   void AdjustExtents( Vector< Extent >& extents,
                       std::vector< MeshRecord>& meshRecords,
                       uint32_t index,
-                      const Vector4& color,
                       float left,
                       float right,
                       float baseLine,
@@ -343,21 +367,17 @@ struct AtlasRenderer::Impl : public ConnectionTracker
     {
       if ( Equals( baseLine, eIt->mBaseLine ) )
       {
-        // If we've found an extent with the same color then we don't need to create a new extent
-        if ( color == meshRecords[ index ].mColor )
+        foundExtent = true;
+        if ( left < eIt->mLeft )
         {
-          foundExtent = true;
-          if ( left < eIt->mLeft )
-          {
-            eIt->mLeft = left;
-          }
-          if ( right > eIt->mRight  )
-          {
-            eIt->mRight = right;
-          }
+          eIt->mLeft = left;
         }
-        // Font metrics use negative values for lower underline positions
-        if ( underlinePosition < eIt->mUnderlinePosition )
+        if ( right > eIt->mRight  )
+        {
+          eIt->mRight = right;
+        }
+
+        if ( underlinePosition > eIt->mUnderlinePosition )
         {
           eIt->mUnderlinePosition = underlinePosition;
         }
@@ -431,15 +451,25 @@ struct AtlasRenderer::Impl : public ConnectionTracker
     }
   }
 
+  float FontMetricsRoundUp( float value )
+  {
+    double integral_part;
+    if ( modf( value, &integral_part ) )
+    {
+      return ( static_cast< float >( integral_part ) + 1.0f );
+    }
+    else
+    {
+      return static_cast< float >( integral_part );
+    }
+  }
+
   void GenerateUnderlines( std::vector< MeshRecord>& meshRecords,
                            Vector< Extent >& extents,
                            const Vector4& underlineColor,
                            const Vector4& textColor )
   {
     MeshData newMeshData;
-    const float zero = 0.0f;
-    const float half = 0.5f;
-
     for ( Vector< Extent >::ConstIterator eIt = extents.Begin(); eIt != extents.End(); ++eIt )
     {
       MeshData::VertexContainer newVerts;
@@ -448,28 +478,28 @@ struct AtlasRenderer::Impl : public ConnectionTracker
       Vector2 uv = mGlyphManager.GetAtlasSize( meshRecords[ index ].mAtlasId );
 
       // Make sure we don't hit texture edge for single pixel texture ( filled pixel is in top left of every atlas )
-      float u = half / uv.x;
-      float v = half / uv.y;
+      float u = HALF / uv.x;
+      float v = HALF / uv.y;
       float thickness = eIt->mUnderlineThickness;
-      float baseLine = eIt->mBaseLine - eIt->mUnderlinePosition - ( thickness * 0.5f );
+      float baseLine = eIt->mBaseLine + eIt->mUnderlinePosition - ( thickness * HALF );
       float tlx = eIt->mLeft;
       float brx = eIt->mRight;
 
-      newVerts.push_back( MeshData::Vertex( Vector3( tlx, baseLine, zero ),
-                                            Vector2( zero, zero ),
-                                            Vector3( zero, zero, zero ) ) );
+      newVerts.push_back( MeshData::Vertex( Vector3( tlx, baseLine, ZERO ),
+                                            Vector2::ZERO,
+                                            Vector3::ZERO ) );
 
-      newVerts.push_back( MeshData::Vertex( Vector3( brx, baseLine, zero ),
-                                            Vector2( u, zero ),
-                                            Vector3( zero, zero, zero ) ) );
+      newVerts.push_back( MeshData::Vertex( Vector3( brx, baseLine, ZERO ),
+                                            Vector2( u, ZERO ),
+                                            Vector3::ZERO ) );
 
-      newVerts.push_back( MeshData::Vertex( Vector3( tlx, baseLine + thickness, zero ),
-                                            Vector2( zero, v ),
-                                            Vector3( zero, zero, zero ) ) );
+      newVerts.push_back( MeshData::Vertex( Vector3( tlx, baseLine + thickness, ZERO ),
+                                            Vector2( ZERO, v ),
+                                            Vector3::ZERO ) );
 
-      newVerts.push_back( MeshData::Vertex( Vector3( brx, baseLine + thickness, zero ),
+      newVerts.push_back( MeshData::Vertex( Vector3( brx, baseLine + thickness, ZERO ),
                                             Vector2( u, v ),
-                                            Vector3( zero, zero, zero ) ) );
+                                            Vector3::ZERO ) );
 
       newMeshData.SetVertices( newVerts );
       newMeshData.SetFaceIndices( mFace );
@@ -500,12 +530,10 @@ struct AtlasRenderer::Impl : public ConnectionTracker
   {
     // Scan vertex buffer to determine width and height of effect buffer needed
     MeshData::VertexContainer verts = meshRecord.mMeshData.GetVertices();
-    const float one = 1.0f;
-    const float zero = 0.0f;
     float tlx = verts[ 0 ].x;
     float tly = verts[ 0 ].y;
-    float brx = zero;
-    float bry = zero;
+    float brx = ZERO;
+    float bry = ZERO;
 
     for ( uint32_t i = 0; i < verts.size(); ++i )
     {
@@ -529,8 +557,8 @@ struct AtlasRenderer::Impl : public ConnectionTracker
 
     float width = brx - tlx;
     float height = bry - tly;
-    float divWidth = 2.0f / width;
-    float divHeight = 2.0f / height;
+    float divWidth = TWO / width;
+    float divHeight = TWO / height;
 
     // Create a buffer to render to
     meshRecord.mBuffer = FrameBufferImage::New( width, height );
@@ -539,21 +567,21 @@ struct AtlasRenderer::Impl : public ConnectionTracker
     MeshData::VertexContainer vertices;
     MeshData::FaceIndices face;
 
-    vertices.push_back( MeshData::Vertex( Vector3( tlx + shadowOffset.x, tly + shadowOffset.y, zero ),
-                                          Vector2( zero, zero ),
-                                          Vector3( zero, zero, zero ) ) );
+    vertices.push_back( MeshData::Vertex( Vector3( tlx + shadowOffset.x, tly + shadowOffset.y, ZERO ),
+                                          Vector2::ZERO,
+                                          Vector3::ZERO ) );
 
-    vertices.push_back( MeshData::Vertex( Vector3( brx + shadowOffset.x, tly + shadowOffset.y, zero ),
-                                          Vector2( one, zero ),
-                                          Vector3( zero, zero, zero ) ) );
+    vertices.push_back( MeshData::Vertex( Vector3( brx + shadowOffset.x, tly + shadowOffset.y, ZERO ),
+                                          Vector2( ONE, ZERO ),
+                                          Vector3::ZERO ) );
 
-    vertices.push_back( MeshData::Vertex( Vector3( tlx + shadowOffset.x, bry + shadowOffset.y, zero ),
-                                          Vector2( zero, one ),
-                                          Vector3( zero, zero, zero ) ) );
+    vertices.push_back( MeshData::Vertex( Vector3( tlx + shadowOffset.x, bry + shadowOffset.y, ZERO ),
+                                          Vector2( ZERO, ONE ),
+                                          Vector3::ZERO ) );
 
-    vertices.push_back( MeshData::Vertex( Vector3( brx + shadowOffset.x, bry + shadowOffset.y, zero ),
-                                          Vector2( one, one ),
-                                          Vector3( zero, zero, zero ) ) );
+    vertices.push_back( MeshData::Vertex( Vector3( brx + shadowOffset.x, bry + shadowOffset.y, ZERO ),
+                                          Vector2::ONE,
+                                          Vector3::ZERO ) );
 
     MeshData meshData;
     Material newMaterial = Material::New("effect buffer");
@@ -578,8 +606,8 @@ struct AtlasRenderer::Impl : public ConnectionTracker
     for ( uint32_t i = 0; i < verts.size(); ++i )
     {
       MeshData::Vertex vertex = verts[ i ];
-      vertex.x = ( ( vertex.x - tlx ) * divWidth ) - one;
-      vertex.y = ( ( vertex.y - tly ) * divHeight ) - one;
+      vertex.x = ( ( vertex.x - tlx ) * divWidth ) - ONE;
+      vertex.y = ( ( vertex.y - tly ) * divHeight ) - ONE;
       newVerts.push_back( vertex );
     }
 
@@ -676,7 +704,8 @@ RenderableActor AtlasRenderer::Render( Text::ViewInterface& view )
                       view.GetShadowOffset(),
                       view.GetShadowColor(),
                       view.IsUnderlineEnabled(),
-                      view.GetUnderlineColor() );
+                      view.GetUnderlineColor(),
+                      view.GetUnderlineHeight() );
   }
   return mImpl->mActor;
 }

diff --git a/dali-toolkit/internal/text/text-controller.cpp b/dali-toolkit/internal/text/text-controller.cpp
index 7d05f52..d86d4f5 100644 (file)
--- a/dali-toolkit/internal/text/text-controller.cpp
+++ b/dali-toolkit/internal/text/text-controller.cpp
@@ -987,6 +987,7 @@ struct Controller::Impl
     mVisualModel->SetShadowOffset( Vector2::ZERO );
     mVisualModel->SetShadowColor( Vector4::ZERO );
     mVisualModel->SetUnderlineEnabled( false );
+    mVisualModel->SetUnderlineHeight( 0.0f );
   }
 
   ~Impl()
@@ -1210,6 +1211,11 @@ bool Controller::IsUnderlineEnabled() const
   return mImpl->mVisualModel->IsUnderlineEnabled();
 }
 
+float Controller::GetUnderlineHeight() const
+{
+  return mImpl->mVisualModel->GetUnderlineHeight();
+}
+
 void Controller::SetTextColor( const Vector4& textColor )
 {
   mImpl->mVisualModel->SetTextColor( textColor );
@@ -1235,6 +1241,11 @@ void Controller::SetUnderlineEnabled( bool enabled )
   mImpl->mVisualModel->SetUnderlineEnabled( enabled );
 }
 
+void Controller::SetUnderlineHeight( float height )
+{
+  mImpl->mVisualModel->SetUnderlineHeight( height );
+}
+
 void Controller::EnableTextInput( DecoratorPtr decorator )
 {
   if( !mImpl->mTextInput )

diff --git a/dali-toolkit/internal/text/text-controller.h b/dali-toolkit/internal/text/text-controller.h
index 0234e7c..076897a 100644 (file)
--- a/dali-toolkit/internal/text/text-controller.h
+++ b/dali-toolkit/internal/text/text-controller.h
@@ -243,6 +243,20 @@ public:
   bool IsUnderlineEnabled() const;
 
   /**
+   * @brief Set the override used for underline height, 0 indicates height will be supplied by adaptor
+   *
+   * @param[in] height The height in pixels of the underline
+   */
+  void SetUnderlineHeight( float height );
+
+  /**
+   * @brief Retrieves the override height of an underline, 0 indicates height is supplied by adaptor
+   *
+   * @return The height of the underline, or 0 if height is not overrided.
+   */
+  float GetUnderlineHeight() const;
+
+  /**
    * @brief Called to enable text input.
    *
    * @note Only selectable or editable controls should calls this.

diff --git a/dali-toolkit/internal/text/text-view-interface.h b/dali-toolkit/internal/text/text-view-interface.h
index 116ad50..68d5e97 100644 (file)
--- a/dali-toolkit/internal/text/text-view-interface.h
+++ b/dali-toolkit/internal/text/text-view-interface.h
@@ -117,12 +117,19 @@ public:
   virtual const Vector4& GetUnderlineColor() const = 0;
 
   /**
-   * @brief Returns whether is underline is enabled or not.
+   * @brief Returns whether underline is enabled or not.
    *
    * @return The underline state.
    */
   virtual bool IsUnderlineEnabled() const = 0;
 
+  /**
+   * @brief Retrieves the underline height override
+   *
+   * @return Returns the override height for an underline, 0 indicates that adaptor will determine the height
+   */
+  virtual float GetUnderlineHeight() const = 0;
+
 };
 
 } // namespace Text

diff --git a/dali-toolkit/internal/text/text-view.cpp b/dali-toolkit/internal/text/text-view.cpp
index b0825f6..61073fe 100644 (file)
--- a/dali-toolkit/internal/text/text-view.cpp
+++ b/dali-toolkit/internal/text/text-view.cpp
@@ -101,6 +101,16 @@ bool View::IsUnderlineEnabled() const
   return false;
 }
 
+float View::GetUnderlineHeight() const
+{
+  if ( mImpl->mVisualModel )
+  {
+    VisualModel& model = *mImpl->mVisualModel;
+    return model.GetUnderlineHeight();
+  }
+  return 0.0f;
+}
+
 Length View::GetNumberOfGlyphs() const
 {
   if( mImpl->mVisualModel )

diff --git a/dali-toolkit/internal/text/text-view.h b/dali-toolkit/internal/text/text-view.h
index b9bd7fc..e611c3c 100644 (file)
--- a/dali-toolkit/internal/text/text-view.h
+++ b/dali-toolkit/internal/text/text-view.h
@@ -101,6 +101,11 @@ public:
    */
   virtual bool IsUnderlineEnabled() const;
 
+  /**
+   * @copydoc Dali::Toolkit::Text::ViewInterface::GetUnderlineHeight()
+   */
+  virtual float GetUnderlineHeight() const;
+
 private:
 
   // Undefined

diff --git a/dali-toolkit/internal/text/visual-model-impl.cpp b/dali-toolkit/internal/text/visual-model-impl.cpp
index c070179..a5fead4 100644 (file)
--- a/dali-toolkit/internal/text/visual-model-impl.cpp
+++ b/dali-toolkit/internal/text/visual-model-impl.cpp
@@ -441,6 +441,11 @@ void VisualModel::SetUnderlineEnabled( bool enabled )
   mUnderlineEnabled = enabled;
 }
 
+void VisualModel::SetUnderlineHeight( float height )
+{
+  mUnderlineHeight = height;
+}
+
 const Vector4& VisualModel::GetTextColor() const
 {
   return mTextColor;
@@ -466,6 +471,11 @@ bool VisualModel::IsUnderlineEnabled() const
   return mUnderlineEnabled;
 }
 
+float VisualModel::GetUnderlineHeight() const
+{
+  return mUnderlineHeight;
+}
+
 void VisualModel::ClearCaches()
 {
   mCachedLineIndex = 0u;
@@ -487,11 +497,12 @@ VisualModel::VisualModel()
   mShadowColor(),
   mUnderlineColor(),
   mShadowOffset(),
+  mUnderlineHeight( 0.0f ),
+  mUnderlineEnabled( false ),
+  mUnderlineColorSet( false ),
   mNaturalSize(),
   mActualSize(),
-  mCachedLineIndex( 0u ),
-  mUnderlineEnabled( false ),
-  mUnderlineColorSet( false )
+  mCachedLineIndex( 0u )
 {
 }
 

diff --git a/dali-toolkit/internal/text/visual-model-impl.h b/dali-toolkit/internal/text/visual-model-impl.h
index aa8a75f..292adc7 100644 (file)
--- a/dali-toolkit/internal/text/visual-model-impl.h
+++ b/dali-toolkit/internal/text/visual-model-impl.h
@@ -477,6 +477,20 @@ public:
    */
   void ClearCaches();
 
+  /**
+   * @brief Set the override used for underline height, 0 indicates height will be supplied by adaptor
+   *
+   * @param[in] height The height in pixels of the underline
+   */
+  void SetUnderlineHeight( float height );
+
+  /**
+   * @brief Retrieves the underline height override
+   *
+   * @return Returns the override height for an underline, 0 indicates that adaptor will determine the height
+   */
+  float GetUnderlineHeight() const;
+
 protected:
 
   /**
@@ -511,6 +525,10 @@ public:
   Vector4                mShadowColor;          ///< Color of drop shadow
   Vector4                mUnderlineColor;       ///< Color of underline
   Vector2                mShadowOffset;         ///< Offset for drop shadow, 0 indicates no shadow
+  float                  mUnderlineHeight;      ///< Fixed height for underline to override adaptor supplied settings.
+  bool                   mUnderlineEnabled:1;   ///< Underline enabled flag
+  bool                   mUnderlineColorSet:1;  ///< Has the underline color been explicitly set?
+
 
 private:
 
@@ -520,9 +538,6 @@ private:
   // Caches to increase performance in some consecutive operations.
   LineIndex mCachedLineIndex; ///< Used to increase performance in consecutive calls to GetLineOfGlyph() or GetLineOfCharacter() with consecutive glyphs or characters.
 
-public:
-  bool                   mUnderlineEnabled:1;   ///< Underline enabled flag
-  bool                   mUnderlineColorSet:1;  ///< Has the underline color been explicitly set?
 };
 
 } // namespace Text

diff --git a/dali-toolkit/public-api/controls/text-controls/text-label.h b/dali-toolkit/public-api/controls/text-controls/text-label.h
index 7ecb200..b11bd13 100644 (file)
--- a/dali-toolkit/public-api/controls/text-controls/text-label.h
+++ b/dali-toolkit/public-api/controls/text-controls/text-label.h
@@ -57,19 +57,20 @@ public:
   {
     enum
     {
-      RENDERING_BACKEND = PROPERTY_START_INDEX, ///< name "rendering-backend",    The type or rendering e.g. bitmap-based,      type INT
-      TEXT,                                     ///< name "text",                 The text to display in UTF-8 format,          type STRING
-      FONT_FAMILY,                              ///< name "font-family",          The requested font family,                    type STRING
-      FONT_STYLE,                               ///< name "font-style",           The requested font style e.g. Regular/Italic, type STRING
-      POINT_SIZE,                               ///< name "point-size",           The size of font in points,                   type FLOAT
-      MULTI_LINE,                               ///< name "multi-line",           The single-line or multi-line layout option,  type BOOLEAN
-      HORIZONTAL_ALIGNMENT,                     ///< name "horizontal-alignment", The line horizontal alignment,                type STRING,  values "BEGIN", "CENTER", "END"
-      VERTICAL_ALIGNMENT,                       ///< name "vertical-alignment",   The line vertical alignment,                  type STRING,  values   "TOP",   "CENTER",   "BOTTOM"
-      TEXT_COLOR,                               ///< name "text-color",           The text color,                               type VECTOR4
-      SHADOW_OFFSET,                            ///< name "shadow-offset",        The drop shadow offset 0 indicates no shadow, type VECTOR2
-      SHADOW_COLOR,                             ///< name "shadow-color",         The color of a drop shadow,                   type VECTOR4
-      UNDERLINE_ENABLED,                        ///< name "underline-enabled",    The underline enabled flag                    type BOOLEAN
-      UNDERLINE_COLOR,                          ///< name "underline-color",      The color of the underline                    type VECTOR4
+      RENDERING_BACKEND = PROPERTY_START_INDEX, ///< name "rendering-backend",    The type or rendering e.g. bitmap-based,          type INT
+      TEXT,                                     ///< name "text",                 The text to display in UTF-8 format,              type STRING
+      FONT_FAMILY,                              ///< name "font-family",          The requested font family,                        type STRING
+      FONT_STYLE,                               ///< name "font-style",           The requested font style e.g. Regular/Italic,     type STRING
+      POINT_SIZE,                               ///< name "point-size",           The size of font in points,                       type FLOAT
+      MULTI_LINE,                               ///< name "multi-line",           The single-line or multi-line layout option,      type BOOLEAN
+      HORIZONTAL_ALIGNMENT,                     ///< name "horizontal-alignment", The line horizontal alignment,                    type STRING,  values "BEGIN", "CENTER", "END"
+      VERTICAL_ALIGNMENT,                       ///< name "vertical-alignment",   The line vertical alignment,                      type STRING,  values   "TOP",   "CENTER",   "BOTTOM"
+      TEXT_COLOR,                               ///< name "text-color",           The text color,                                   type VECTOR4
+      SHADOW_OFFSET,                            ///< name "shadow-offset",        The drop shadow offset 0 indicates no shadow,     type VECTOR2
+      SHADOW_COLOR,                             ///< name "shadow-color",         The color of a drop shadow,                       type VECTOR4
+      UNDERLINE_ENABLED,                        ///< name "underline-enabled",    The underline enabled flag,                       type BOOLEAN
+      UNDERLINE_COLOR,                          ///< name "underline-color",      The color of the underline,                       type VECTOR4
+      UNDERLINE_HEIGHT                          ///< name "underline-height",     Overrides the underline height from font metrics, type FLOAT
     };
   };