Re-land: RenderTextHarfBuzz: Set font render parameters in font data functions

ui/gfx/render_text_harfbuzz.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #include <map>
 
 #include "base/i18n/bidi_line_iterator.h"
 #include "base/i18n/break_iterator.h"
@@ skipping 250 matching lines @@
 
   hb_face_t* get() {
     return face_;
   }
 
  private:
   hb_face_t* face_;
 };
 
 // Creates a HarfBuzz font from the given Skia face and text size.
-hb_font_t* CreateHarfBuzzFont(SkTypeface* skia_face, int text_size) {
+hb_font_t* CreateHarfBuzzFont(SkTypeface* skia_face,
+                              int text_size,
+                              const FontRenderParams& params,
+                              bool background_is_transparent) {
   typedef std::pair<HarfBuzzFace, GlyphCache> FaceCache;
 
   // TODO(ckocagil): This shouldn't grow indefinitely. Maybe use base::MRUCache?
   static std::map<SkFontID, FaceCache> face_caches;
 
   FaceCache* face_cache = &face_caches[skia_face->uniqueID()];
   if (face_cache->first.get() == NULL)
     face_cache->first.Init(skia_face);
 
   hb_font_t* harfbuzz_font = hb_font_create(face_cache->first.get());
   const int scale = SkScalarToFixed(text_size);
   hb_font_set_scale(harfbuzz_font, scale, scale);
   FontData* hb_font_data = new FontData(&face_cache->second);
   hb_font_data->paint_.setTypeface(skia_face);
   hb_font_data->paint_.setTextSize(text_size);
+  // TODO(ckocagil): Do we need to update these params later?
+  internal::ApplyRenderParams(params, background_is_transparent,
+                              &hb_font_data->paint_);
   hb_font_set_funcs(harfbuzz_font, g_font_funcs.Get().get(), hb_font_data,
                     DeleteByType<FontData>);
   hb_font_make_immutable(harfbuzz_font);
   return harfbuzz_font;
 }
 
 // Returns true if characters of |block_code| may trigger font fallback.
 bool IsUnusualBlockCode(UBlockCode block_code) {
   return block_code == UBLOCK_GEOMETRIC_SHAPES ||
          block_code == UBLOCK_MISCELLANEOUS_SYMBOLS;
@@ skipping 566 matching lines @@
 
     set_lines(&lines);
   }
 }
 
 void RenderTextHarfBuzz::DrawVisualText(Canvas* canvas) {
   DCHECK(!needs_layout_);
   internal::SkiaTextRenderer renderer(canvas);
   ApplyFadeEffects(&renderer);
   ApplyTextShadows(&renderer);
-
-#if defined(OS_WIN) || defined(OS_LINUX)
-  renderer.SetFontRenderParams(
-      font_list().GetPrimaryFont().GetFontRenderParams(),
-      background_is_transparent());
-#endif
-
   ApplyCompositionAndSelectionStyles();
 
   int current_x = 0;
   const Vector2d line_offset = GetLineOffset(0);
   for (size_t i = 0; i < runs_.size(); ++i) {
     const internal::TextRunHarfBuzz& run = *runs_[visual_to_logical_[i]];
     renderer.SetTypeface(run.skia_face.get());
     renderer.SetTextSize(run.font_size);
+    renderer.SetFontRenderParams(run.render_params,
+                                 background_is_transparent());
 
     Vector2d origin = line_offset + Vector2d(current_x, lines()[0].baseline);
     scoped_ptr<SkPoint[]> positions(new SkPoint[run.glyph_count]);
     for (size_t j = 0; j < run.glyph_count; ++j) {
       positions[j] = run.positions[j];
       positions[j].offset(SkIntToScalar(origin.x()), SkIntToScalar(origin.y()));
     }
 
     for (BreakList<SkColor>::const_iterator it =
              colors().GetBreak(run.range.start());
@@ skipping 207 matching lines @@
 }
 
 bool RenderTextHarfBuzz::ShapeRunWithFont(internal::TextRunHarfBuzz* run,
                                           const std::string& font_family) {
   const base::string16& text = GetLayoutText();
   skia::RefPtr<SkTypeface> skia_face =
       internal::CreateSkiaTypeface(font_family, run->font_style);
   if (skia_face == NULL)
     return false;
   run->skia_face = skia_face;
+  FontRenderParamsQuery query(false);
+  query.families.push_back(font_family);
+  query.pixel_size = run->font_size;
+  query.style = run->font_style;
+  run->render_params = GetFontRenderParams(query, NULL);
   hb_font_t* harfbuzz_font = CreateHarfBuzzFont(run->skia_face.get(),
-                                                run->font_size);
+      run->font_size, run->render_params, background_is_transparent());
 
   // Create a HarfBuzz buffer and add the string to be shaped. The HarfBuzz
   // buffer holds our text, run information to be used by the shaping engine,
   // and the resulting glyph data.
   hb_buffer_t* buffer = hb_buffer_create();
   hb_buffer_add_utf16(buffer, reinterpret_cast<const uint16*>(text.c_str()),
                       text.length(), run->range.start(), run->range.length());
   hb_buffer_set_script(buffer, ICUScriptToHBScript(run->script));
   hb_buffer_set_direction(buffer,
       run->is_rtl ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
@@ skipping 13 matching lines @@
   run->glyph_to_char.resize(run->glyph_count);
   run->positions.reset(new SkPoint[run->glyph_count]);
   run->width = 0.0f;
   for (size_t i = 0; i < run->glyph_count; ++i) {
     run->glyphs[i] = infos[i].codepoint;
     run->glyph_to_char[i] = infos[i].cluster;
     const int x_offset = SkFixedToScalar(hb_positions[i].x_offset);
     const int y_offset = SkFixedToScalar(hb_positions[i].y_offset);
     run->positions[i].set(run->width + x_offset, -y_offset);
     run->width += SkFixedToScalar(hb_positions[i].x_advance);
+#if defined(OS_LINUX)
+    // Match Pango's glyph rounding logic on Linux.
+    run->width = std::floor(run->width + 0.5f);

[msw, 2014/08/22 21:59:36]

I wonder if this should still be contingent on if
(!run->render_params.subpixel_positioning).

[ckocagil, 2014/08/22 22:22:40]

Done. Subpixel positioning on Linux seems to be working when you enable it with
--enable-browser-text-subpixel-positioning.

+#endif
   }
 
   hb_buffer_destroy(buffer);
   hb_font_destroy(harfbuzz_font);
   return true;
 }
 
 }  // namespace gfx