[ot-color] Preparation for setting PNG width/height in extents

src/dump-emoji.cc

@@ -69,12 +69,13 @@ sbix_dump (hb_face_t *face)
     for (unsigned int glyph_id = 0; glyph_id < num_glyphs; glyph_id++)
     {
       hb_blob_t *blob;
-      blob = sbix.reference_blob_for_glyph (glyph_id, 0, available_ppems[group],
-					    HB_TAG('p','n','g',' '));
+      unsigned int ppem = available_ppems[group];
+      blob = sbix.reference_blob_for_glyph (glyph_id, ppem, ppem,
+					    HB_TAG('p','n','g',' '), nullptr, nullptr);
       if (hb_blob_get_length (blob) == 0) continue;
 
       char output_path[255];
-      sprintf (output_path, "out/sbix-%d-%d.png", available_ppems[group], glyph_id);
+      sprintf (output_path, "out/sbix-%d-%d.png", ppem, glyph_id);
       FILE *f = fopen (output_path, "wb");
       unsigned int length;
       const char* data = hb_blob_get_data (blob, &length);

src/hb-ot-color-sbix-table.hh

@@ -75,7 +75,7 @@ struct SBIXStrike
   inline unsigned int get_resolution () const
   { return resolution; }
 
-  inline unsigned int blob_size (unsigned int glyph_id) const
+  inline unsigned int calculate_blob_size (unsigned int glyph_id) const
   {
     return imageOffsetsZ[glyph_id + 1] - imageOffsetsZ[glyph_id] - SBIXGlyph::min_size;
   }
@@ -84,6 +84,8 @@ struct SBIXStrike
 				    hb_blob_t    *sbix_blob,
 				    unsigned int  sbix_len,
 				    unsigned int  strike_offset,
+				    int          *x_offset,
+				    int          *y_offset,
 				    hb_tag_t      file_type,
 				    unsigned int  num_glyphs) const
   {
@@ -95,7 +97,7 @@ struct SBIXStrike
 
     const SBIXGlyph *glyph = &(this+imageOffsetsZ[glyph_id]);
     if (unlikely (glyph->graphicType == HB_TAG ('d','u','p','e') &&
-		  blob_size (glyph_id) >= 2))
+		  calculate_blob_size (glyph_id) >= 2))
     {
       unsigned int new_glyph_id = *((HBUINT16 *) &glyph->data);
       if (new_glyph_id < num_glyphs)
@@ -108,9 +110,15 @@ struct SBIXStrike
     }
     if (unlikely (file_type != glyph->graphicType))
       return hb_blob_get_empty ();
+    unsigned int blob_size = calculate_blob_size (glyph_id);
+    if (unlikely (blob_size == 0))
+      return hb_blob_get_empty ();
+
+    if (x_offset) *x_offset = glyph->xOffset;
+    if (y_offset) *y_offset = glyph->yOffset;
     unsigned int offset = strike_offset + SBIXGlyph::min_size;
     offset += imageOffsetsZ[glyph_id];
-    return hb_blob_create_sub_blob (sbix_blob, offset, blob_size (glyph_id));
+    return hb_blob_create_sub_blob (sbix_blob, offset, blob_size);
   }
 
   protected:
@@ -163,25 +171,51 @@ struct sbix
     }
 
     inline hb_blob_t *reference_blob_for_glyph (hb_codepoint_t  glyph_id,
-						unsigned int    ptem HB_UNUSED,
-						unsigned int    requested_ppem,
-						unsigned int    requested_file_type) const
+						unsigned int    x_ppem,
+						unsigned int    y_ppem,
+						unsigned int    file_type,
+						int            *x_offset,
+						int            *y_offset) const
     {
       if (unlikely (sbix_len == 0 || sbix_table->strikes.len == 0))
         return hb_blob_get_empty ();
 
       /* TODO: Does spec guarantee strikes are ascended sorted? */
       unsigned int group = sbix_table->strikes.len - 1;
-      if (requested_ppem != 0)
+      unsigned int ppem = MAX (x_ppem, y_ppem);
+      if (ppem != 0)
 	/* TODO: Use bsearch maybe or doesn't worth it? */
         for (group = 0; group < sbix_table->strikes.len; group++)
-	  if ((sbix_table+sbix_table->strikes[group]).get_ppem () >= requested_ppem)
+	  if ((sbix_table+sbix_table->strikes[group]).get_ppem () >= ppem)
 	    break;
 
       const SBIXStrike &strike = sbix_table+sbix_table->strikes[group];
       return strike.get_glyph_blob (glyph_id, sbix_blob, sbix_len,
 				    sbix_table->strikes[group],
-				    requested_file_type, num_glyphs);
+				    x_offset, y_offset,
+				    file_type, num_glyphs);
+    }
+
+    inline bool get_png_extents (hb_codepoint_t      glyph,
+				 unsigned int        x_ppem,
+				 unsigned int        y_ppem,
+				 hb_glyph_extents_t *extents) const
+    {
+      int x_offset, y_offset;
+      hb_blob_t *blob = reference_blob_for_glyph (glyph, x_ppem, y_ppem,
+						  HB_TAG ('P','N','G',' '),
+						  &x_offset, &y_offset);
+      if (hb_blob_get_length (blob) == 0)
+        return false;
+
+      extents->x_bearing = x_offset;
+      extents->y_bearing = y_offset;
+      /* XXX: Help me please! */
+      extents->width     = 0;
+      extents->height    = 0;
+      hb_blob_destroy (blob);
+
+      return true;
     }
 
     inline bool has_data () const

src/hb-ot-color.cc

@@ -316,16 +316,14 @@ hb_blob_t *
 hb_ot_color_glyph_reference_png (hb_font_t *font, hb_codepoint_t  glyph)
 {
   hb_blob_t *blob = hb_blob_get_empty ();
-  /* don't run cbdt first if aat is set */
-  if (!hb_options ().aat && _get_cbdt (font->face).has_data ())
-    blob = _get_cbdt (font->face).reference_blob_for_glyph (glyph, font->x_ppem, font->y_ppem);
 
-  if (_get_sbix (font->face).has_data () && !hb_blob_get_length (blob))
-    blob = _get_sbix (font->face).reference_blob_for_glyph (glyph, font->ptem,
-							    MAX (font->x_ppem, font->y_ppem),
-							    HB_TAG('p','n','g',' '));
+  if (_get_sbix (font->face).has_data ())
+    blob = _get_sbix (font->face).reference_blob_for_glyph (glyph,
+							    font->x_ppem, font->y_ppem,
+							    HB_TAG('p','n','g',' '),
+							    nullptr, nullptr);
 
-  if (hb_options ().aat && _get_cbdt (font->face).has_data () && !hb_blob_get_length (blob))
+  if (hb_blob_get_length (blob) == 0 && _get_cbdt (font->face).has_data ())
     blob = _get_cbdt (font->face).reference_blob_for_glyph (glyph, font->x_ppem, font->y_ppem);
 
   return blob;

src/hb-ot-font.cc

@@ -39,6 +39,7 @@
 #include "hb-ot-glyf-table.hh"
 #include "hb-ot-vorg-table.hh"
 #include "hb-ot-color-cbdt-table.hh"
+#include "hb-ot-color-sbix-table.hh"
 
 
 /**
@@ -182,7 +183,11 @@ hb_ot_get_glyph_extents (hb_font_t *font,
 			 void *user_data HB_UNUSED)
 {
   const hb_ot_face_data_t *ot_face = (const hb_ot_face_data_t *) font_data;
-  bool ret = ot_face->glyf->get_extents (glyph, extents);
+  bool ret = false;
+  if (ot_face->sbix->has_data ())
+    ret = ot_face->sbix->get_png_extents (glyph, font->x_ppem, font->y_ppem, extents);
+  if (!ret)
+    ret = ot_face->glyf->get_extents (glyph, extents);
   if (!ret)
     ret = ot_face->CBDT->get_extents (glyph, extents);
   // TODO Hook up side-bearings variations.