[freetype2] GSoC-2019-moazin 0417321 13/28: Adds transform support for OT-SVG glyphs.

[Moazin Khatti]

branch: GSoC-2019-moazin
commit 04173214e96d7b1b689a444ab163a0302c47dc16
Author: Moazin Khatti <address@hidden>
Commit: Moazin Khatti <address@hidden>

    Adds transform support for OT-SVG glyphs.
---
 include/freetype/ftglyph.h |  9 ++++++++-
 include/freetype/otsvg.h   |  8 ++++++++
 src/base/ftglyph.c         | 32 +++++++++++++++++++++++++++++++-
 src/sfnt/ttsvg.c           |  7 +++++++
 src/svg/ftsvg.c            | 28 +++++++++++++++++++++++++++-
 5 files changed, 81 insertions(+), 3 deletions(-)

diff --git a/include/freetype/ftglyph.h b/include/freetype/ftglyph.h
index b29751e..e346444 100644
--- a/include/freetype/ftglyph.h
+++ b/include/freetype/ftglyph.h
@@ -268,6 +268,12 @@ FT_BEGIN_HEADER
    *   end_glyph_id ::
    *     The ending glyph ID for the glyph range that this document has.
    *
+   *   transform ::
+   *     Transformation matrix to apply on the glyph while rendering.
+   *
+   *   delta ::
+   *     Translation to apply on the glyph while rendering.
+   *
    * @note:
    *   `metrics` and `units_per_EM` might look like repetitions since both
    *   fields are stored in face objects.  However, the Glyph Management API
@@ -289,7 +295,8 @@ FT_BEGIN_HEADER
     FT_UShort           units_per_EM;
     FT_UShort           start_glyph_id;
     FT_UShort           end_glyph_id;
-    /* TODO: (OT-SVG) Maybe put a transformation matrix here */
+    FT_Matrix           transform;
+    FT_Vector           delta;
   } FT_SvgGlyphRec;
 
 
diff --git a/include/freetype/otsvg.h b/include/freetype/otsvg.h
index 62761c4..09039d5 100644
--- a/include/freetype/otsvg.h
+++ b/include/freetype/otsvg.h
@@ -147,6 +147,12 @@ FT_BEGIN_HEADER
    *   end_glyph_id ::
    *     The ending glyph ID for the glyph range that this document has.
    *
+   *   transform ::
+   *     Transformation matrix to apply on the glyph while rendering.
+   *
+   *   delta ::
+   *     Translation to apply on the glyph while rendering.
+   *
    * @note:
    *   `metrics` and `units_per_EM` might look like repetitions since both
    *   fields are stored in face object, but they are not; When the slot is
@@ -165,6 +171,8 @@ FT_BEGIN_HEADER
     FT_UShort        units_per_EM;
     FT_UShort        start_glyph_id;
     FT_UShort        end_glyph_id;
+    FT_Matrix        transform;
+    FT_Vector        delta;
   } FT_SVG_DocumentRec;
 
   /**************************************************************************
diff --git a/src/base/ftglyph.c b/src/base/ftglyph.c
index fa60ea1..300c05b 100644
--- a/src/base/ftglyph.c
+++ b/src/base/ftglyph.c
@@ -326,6 +326,9 @@
     glyph->units_per_EM        = document->units_per_EM;
     glyph->start_glyph_id      = document->start_glyph_id;
     glyph->end_glyph_id        = document->end_glyph_id;
+    glyph->transform           = document->transform;
+    glyph->delta               = document->delta;
+
     /* copy the document into glyph */
     FT_MEM_COPY( glyph->svg_document, document->svg_document, doc_length );
 
@@ -372,6 +375,8 @@
     target->units_per_EM        = source->units_per_EM;
     target->start_glyph_id      = source->start_glyph_id;
     target->end_glyph_id        = source->end_glyph_id;
+    target->transform           = source->transform;
+    target->delta               = source->delta;
 
     /* allocate space for the svg document */
     target->svg_document = memory->alloc( memory,
@@ -385,6 +390,29 @@
     return error;
   }
 
+  FT_CALLBACK_DEF( void )
+  ft_svg_glyph_transform( FT_Glyph          svg_glyph,
+                          const FT_Matrix*  matrix,
+                          const FT_Vector*  delta )
+  {
+    FT_SvgGlyph  glyph = (FT_SvgGlyph)svg_glyph;
+
+    if ( matrix )
+    {
+      FT_Matrix  a, b;
+      a = glyph->transform;
+      b = *matrix;
+      FT_Matrix_Multiply( &b, &a );
+      glyph->transform = a;
+    }
+
+    if ( delta )
+    {
+      glyph->delta.x = ADD_LONG( glyph->delta.x, delta->x );
+      glyph->delta.y = ADD_LONG( glyph->delta.y, delta->y );
+    }
+  }
+
   FT_CALLBACK_DEF( FT_Error )
   ft_svg_glyph_prepare( FT_Glyph     svg_glyph,
                         FT_GlyphSlot slot )
@@ -404,6 +432,8 @@
     document->units_per_EM        = glyph->units_per_EM;
     document->start_glyph_id      = glyph->start_glyph_id;
     document->end_glyph_id        = glyph->end_glyph_id;
+    document->transform           = glyph->transform;
+    document->delta               = glyph->delta;
 
     slot->format      = FT_GLYPH_FORMAT_SVG;
     slot->glyph_index = glyph->glyph_index;
@@ -421,7 +451,7 @@
     ft_svg_glyph_init,      /* FT_Glyph_InitFunc       glyph_init      */
     ft_svg_glyph_done,      /* FT_Glyph_DoneFunc       glyph_done      */
     ft_svg_glyph_copy,      /* FT_Glyph_CopyFunc       glyph_copy      */
-    NULL,                   /* FT_Glyph_TransformFunc  glyph_transform */
+    ft_svg_glyph_transform, /* FT_Glyph_TransformFunc  glyph_transform */
     NULL,                   /* FT_Glyph_GetBBoxFunc    glyph_bbox      */
     ft_svg_glyph_prepare    /* FT_Glyph_PrepareFunc    glyph_prepare   */
   )
diff --git a/src/sfnt/ttsvg.c b/src/sfnt/ttsvg.c
index 4607c1e..da83168 100644
--- a/src/sfnt/ttsvg.c
+++ b/src/sfnt/ttsvg.c
@@ -320,6 +320,13 @@
     svg_document->start_glyph_id      = start_glyph_id;
     svg_document->end_glyph_id        = end_glyph_id;
 
+    svg_document->transform.xx = 0x10000;
+    svg_document->transform.xy = 0;
+    svg_document->transform.yx = 0;
+    svg_document->transform.yy = 0x10000;
+    svg_document->delta.x      = 0;
+    svg_document->delta.y      = 0;
+
     FT_TRACE5(( "start_glyph_id: %d\n", start_glyph_id ));
     FT_TRACE5(( "end_glyph_id:   %d\n", end_glyph_id ));
     FT_TRACE5(( "svg_document:\n%.*s\n", doc_length, doc_list ));
diff --git a/src/svg/ftsvg.c b/src/svg/ftsvg.c
index 2f04758..2ba0a17 100644
--- a/src/svg/ftsvg.c
+++ b/src/svg/ftsvg.c
@@ -187,6 +187,32 @@
     return 0;
   }
 
+  static FT_Error
+  ft_svg_transform( FT_Renderer       renderer,
+                    FT_GlyphSlot      slot,
+                    const FT_Matrix*  matrix,
+                    const FT_Vector*  delta )
+  {
+    FT_SVG_Document  doc = (FT_SVG_Document)slot->other;
+
+    if ( matrix )
+    {
+      FT_Matrix  a, b;
+      a = doc->transform;
+      b = *matrix;
+      FT_Matrix_Multiply( &b, &a );
+      doc->transform = a;
+    }
+
+    if ( delta )
+    {
+      doc->delta.x = ADD_LONG( doc->delta.x, delta->x );
+      doc->delta.y = ADD_LONG( doc->delta.y, delta->y );
+    }
+
+    return FT_Err_Ok;
+  }
+
 #endif
 
 #ifdef FT_CONFIG_OPTION_SVG
@@ -213,7 +239,7 @@
       PUT_SVG_MODULE( ft_svg_get_interface ),                /* get_interface 
*/
       SVG_GLYPH_FORMAT,
       (FT_Renderer_RenderFunc)PUT_SVG_MODULE( ft_svg_render ),
-      NULL,
+      (FT_Renderer_TransformFunc)PUT_SVG_MODULE( ft_svg_transform ),
       NULL,
       NULL,
       NULL