Linux: calculate x-height from the outline of the glyph.

This allows us to pass css1/font_properties/font_size.html

Review URL: http://codereview.chromium.org/13076


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@6269 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 25 insertions, 9 deletions

diff --git a/webkit/port/platform/graphics/chromium/SimpleFontDataLinux.cpp b/webkit/port/platform/graphics/chromium/SimpleFontDataLinux.cpp
index c5080c9..2394c5e 100644
--- a/webkit/port/platform/graphics/chromium/SimpleFontDataLinux.cpp
+++ b/webkit/port/platform/graphics/chromium/SimpleFontDataLinux.cpp
@@ -39,26 +39,43 @@ void SimpleFontData::platformInit()
         m_descent = SkScalarCeil(metrics.fHeight) - m_ascent;
     }
 
-    m_xHeight = SkScalarToFloat(-metrics.fAscent) * 0.56f;   // hack I stole from the Windows port
+    GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
+    if (!glyphPageZero)
+      return;
+
+    static const UChar32 x_char = 'x';
+    const Glyph x_glyph = glyphPageZero->glyphDataForCharacter(x_char).glyph;
+
+    if (x_glyph) {
+      // If the face includes a glyph for x we measure its height exactly.
+      SkRect xbox;
+
+      paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+      paint.measureText(&x_glyph, 2, &xbox);
+
+      m_xHeight = -xbox.fTop;
+    } else {
+      // hack taken from the Windows port
+      m_xHeight = static_cast<float>(m_ascent) * 0.56;
+    }
+
     m_lineGap = SkScalarRound(metrics.fLeading);
     m_lineSpacing = m_ascent + m_descent + m_lineGap;
 
     // In WebKit/WebCore/platform/graphics/SimpleFontData.cpp, m_spaceWidth is
     // calculated for us, but we need to calculate m_maxCharWidth and
     // m_avgCharWidth in order for text entry widgets to be sized correctly.
-    // Skia doesn't expose either of these so we calculate them ourselves
-
-    GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
-    if (!glyphPageZero)
-      return;
 
     m_maxCharWidth = SkScalarRound(metrics.fXRange * SkScalarRound(m_font.size()));
 
     if (metrics.fAvgCharWidth) {
         m_avgCharWidth = SkScalarRound(metrics.fAvgCharWidth);
     } else {
-        static const UChar32 x_char = 'x';
-        m_avgCharWidth = widthForGlyph(glyphPageZero->glyphDataForCharacter(x_char).glyph);
+        if (x_glyph) {
+          m_avgCharWidth = widthForGlyph(x_glyph);
+        } else {
+          m_avgCharWidth = m_xHeight;
+        }
     }
 }
 
diff --git a/webkit/tools/layout_tests/test_lists/tests_fixable.txt b/webkit/tools/layout_tests/test_lists/tests_fixable.txt
index f6b812e..542a7ba 100644
--- a/webkit/tools/layout_tests/test_lists/tests_fixable.txt
+++ b/webkit/tools/layout_tests/test_lists/tests_fixable.txt
@@ -784,7 +784,6 @@ LayoutTests/http/tests/plugins/geturlnotify-from-npp-destroystream.html = FAIL P
 DEBUG : LayoutTests/svg/W3C-SVG-1.1/interact-dom-01-b.svg = CRASH
 
 // Tests that fail on linux but pass on windows.
-LINUX : LayoutTests/css1/font_properties/font_size.html = FAIL
 LINUX : LayoutTests/css1/pseudo/multiple_pseudo_elements.html = FAIL
 LINUX : LayoutTests/css1/text_properties/line_height.html = FAIL
 LINUX : LayoutTests/css1/text_properties/text_indent.html = FAIL