Merge SimpleFontData.cpp and SimpleFontDataSkia.cpp

Source/platform/fonts/SimpleFontData.cpp

Index: Source/platform/fonts/SimpleFontData.cpp
diff --git a/Source/platform/fonts/SimpleFontData.cpp b/Source/platform/fonts/SimpleFontData.cpp
index 275c57b71c52024623cddcf1bc291aabf350d116..f1290f955c6fe2ae36bbcc73332d4c52de91f346 100644
--- a/Source/platform/fonts/SimpleFontData.cpp
+++ b/Source/platform/fonts/SimpleFontData.cpp
@@ -30,13 +30,29 @@
 #include "config.h"
 #include "platform/fonts/SimpleFontData.h"
 
+#include "SkPaint.h"
+#include "SkPath.h"
+#include "SkTypeface.h"
+#include "SkTypes.h"
+#include "SkUtils.h"
+#include "platform/fonts/FontDescription.h"
+#include "platform/fonts/GlyphPage.h"
+#include "platform/fonts/VDMXParser.h"
+#include "platform/geometry/FloatRect.h"
 #include "wtf/MathExtras.h"
+#include "wtf/unicode/Unicode.h"
+#include <unicode/normlzr.h>
 
 namespace blink {
 
 const float smallCapsFontSizeMultiplier = 0.7f;
 const float emphasisMarkFontSizeMultiplier = 0.5f;
 
+#if OS(LINUX) || OS(ANDROID)
+// This is the largest VDMX table which we'll try to load and parse.
+static const size_t maxVDMXTableSize = 1024 * 1024; // 1 MB
+#endif
+
 SimpleFontData::SimpleFontData(const FontPlatformData& platformData, PassRefPtr<CustomFontData> customData, bool isTextOrientationFallback)
     : m_maxCharWidth(-1)
     , m_avgCharWidth(-1)
@@ -52,7 +68,6 @@ SimpleFontData::SimpleFontData(const FontPlatformData& platformData, PassRefPtr<
 {
     platformInit();
     platformGlyphInit();
-    platformCharWidthInit();
 #if ENABLE(OPENTYPE_VERTICAL)
     if (platformData.orientation() == Vertical && !isTextOrientationFallback) {
         m_verticalData = platformData.verticalData();
@@ -76,6 +91,142 @@ SimpleFontData::SimpleFontData(PassRefPtr<CustomFontData> customData, float font
         m_customFontData->initializeFontData(this, fontSize);
 }
 
+void SimpleFontData::platformInit()
+{
+    if (!m_platformData.size()) {
+        m_fontMetrics.reset();
+        m_avgCharWidth = 0;
+        m_maxCharWidth = 0;
+        return;
+    }
+
+    SkPaint paint;
+    SkPaint::FontMetrics metrics;
+
+    m_platformData.setupPaint(&paint);
+    paint.getFontMetrics(&metrics);
+    SkTypeface* face = paint.getTypeface();
+    ASSERT(face);
+
+    int vdmxAscent = 0, vdmxDescent = 0;
+    bool isVDMXValid = false;
+
+#if OS(LINUX) || OS(ANDROID)
+    // Manually digging up VDMX metrics is only applicable when bytecode hinting using FreeType.
+    // With GDI, the metrics will already have taken this into account (as needed).
+    // With DirectWrite or CoreText, no bytecode hinting is ever done.
+    // This code should be pushed into FreeType (hinted font metrics).
+    static const uint32_t vdmxTag = SkSetFourByteTag('V', 'D', 'M', 'X');
+    int pixelSize = m_platformData.size() + 0.5;
+    if (!paint.isAutohinted()
+        &&    (paint.getHinting() == SkPaint::kFull_Hinting
+            || paint.getHinting() == SkPaint::kNormal_Hinting))
+    {
+        size_t vdmxSize = face->getTableSize(vdmxTag);
+        if (vdmxSize && vdmxSize < maxVDMXTableSize) {
+            uint8_t* vdmxTable = (uint8_t*) fastMalloc(vdmxSize);
+            if (vdmxTable
+                && face->getTableData(vdmxTag, 0, vdmxSize, vdmxTable) == vdmxSize
+                && parseVDMX(&vdmxAscent, &vdmxDescent, vdmxTable, vdmxSize, pixelSize))
+                isVDMXValid = true;
+            fastFree(vdmxTable);
+        }
+    }
+#endif
+
+    float ascent;
+    float descent;
+
+    // Beware those who step here: This code is designed to match Win32 font
+    // metrics *exactly* (except the adjustment of ascent/descent on Linux/Android).
+    if (isVDMXValid) {
+        ascent = vdmxAscent;
+        descent = -vdmxDescent;
+    } else {
+        ascent = SkScalarRoundToInt(-metrics.fAscent);
+        descent = SkScalarRoundToInt(metrics.fDescent);
+#if OS(LINUX) || OS(ANDROID)
+        // When subpixel positioning is enabled, if the descent is rounded down, the descent part
+        // of the glyph may be truncated when displayed in a 'overflow: hidden' container.
+        // To avoid that, borrow 1 unit from the ascent when possible.
+        // FIXME: This can be removed if sub-pixel ascent/descent is supported.
+        if (platformData().fontRenderStyle().useSubpixelPositioning && descent < SkScalarToFloat(metrics.fDescent) && ascent >= 1) {
+            ++descent;
+            --ascent;
+        }
+#endif
+    }
+
+    m_fontMetrics.setAscent(ascent);
+    m_fontMetrics.setDescent(descent);
+
+    float xHeight;
+    if (metrics.fXHeight) {
+        xHeight = metrics.fXHeight;
+        m_fontMetrics.setXHeight(xHeight);
+    } else {
+        xHeight = ascent * 0.56; // Best guess from Windows font metrics.
+        m_fontMetrics.setXHeight(xHeight);
+        m_fontMetrics.setHasXHeight(false);
+    }
+
+    float lineGap = SkScalarToFloat(metrics.fLeading);
+    m_fontMetrics.setLineGap(lineGap);
+    m_fontMetrics.setLineSpacing(lroundf(ascent) + lroundf(descent) + lroundf(lineGap));
+
+    if (platformData().orientation() == Vertical && !isTextOrientationFallback()) {
+        static const uint32_t vheaTag = SkSetFourByteTag('v', 'h', 'e', 'a');
+        static const uint32_t vorgTag = SkSetFourByteTag('V', 'O', 'R', 'G');
+        size_t vheaSize = face->getTableSize(vheaTag);
+        size_t vorgSize = face->getTableSize(vorgTag);
+        if ((vheaSize > 0) || (vorgSize > 0))
+            m_hasVerticalGlyphs = true;
+    }
+
+    // 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.
+#if OS(WIN)
+    m_maxCharWidth = SkScalarRoundToInt(metrics.fMaxCharWidth);
+
+    // Older version of the DirectWrite API doesn't implement support for max
+    // char width. Fall back on a multiple of the ascent. This is entirely
+    // arbitrary but comes pretty close to the expected value in most cases.
+    if (m_maxCharWidth < 1)
+        m_maxCharWidth = ascent * 2;
+#else
+    // FIXME: This seems incorrect and should probably use fMaxCharWidth as
+    // the code path above.
+    SkScalar xRange = metrics.fXMax - metrics.fXMin;
+    m_maxCharWidth = SkScalarRoundToInt(xRange * SkScalarRoundToInt(m_platformData.size()));
+#endif
+
+    if (metrics.fAvgCharWidth) {
+        m_avgCharWidth = SkScalarRoundToInt(metrics.fAvgCharWidth);
+    } else {
+        m_avgCharWidth = xHeight;
+
+        GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
+
+        if (glyphPageZero) {
+            static const UChar32 xChar = 'x';
+            const Glyph xGlyph = glyphPageZero->glyphForCharacter(xChar);
+
+            if (xGlyph) {
+                // In widthForGlyph(), xGlyph will be compared with
+                // m_zeroWidthSpaceGlyph, which isn't initialized yet here.
+                // Initialize it with zero to make sure widthForGlyph() returns
+                // the right width.
+                m_zeroWidthSpaceGlyph = 0;
+                m_avgCharWidth = widthForGlyph(xGlyph);
+            }
+        }
+    }
+
+    if (int unitsPerEm = face->getUnitsPerEm())
+        m_fontMetrics.setUnitsPerEm(unitsPerEm);
+}
+
 void SimpleFontData::platformGlyphInit()
 {
     GlyphPage* glyphPageZero = GlyphPageTreeNode::getRootChild(this, 0)->page();
@@ -118,9 +269,6 @@ void SimpleFontData::platformGlyphInit()
 
 SimpleFontData::~SimpleFontData()
 {
-    if (!isSVGFont())
-        platformDestroy();
-
     if (isCustomFont())
         GlyphPageTreeNode::pruneTreeCustomFontData(this);
     else
@@ -227,4 +375,115 @@ PassRefPtr<SimpleFontData> SimpleFontData::createScaledFontData(const FontDescri
     return platformCreateScaledFontData(fontDescription, scaleFactor);
 }
 
+
+
+PassRefPtr<SimpleFontData> SimpleFontData::platformCreateScaledFontData(const FontDescription& fontDescription, float scaleFactor) const
+{
+    const float scaledSize = lroundf(fontDescription.computedSize() * scaleFactor);
+    return SimpleFontData::create(FontPlatformData(m_platformData, scaledSize), isCustomFont() ? CustomFontData::create() : nullptr);
+}
+
+void SimpleFontData::determinePitch()
+{
+    m_treatAsFixedPitch = platformData().isFixedPitch();
+}
+
+static inline void getSkiaBoundsForGlyph(SkPaint& paint, Glyph glyph, SkRect& bounds)
+{
+    paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+
+    SkPath path;
+    paint.getTextPath(&glyph, sizeof(glyph), 0, 0, &path);
+    bounds = path.getBounds();
+
+    if (!paint.isSubpixelText()) {
+        SkIRect ir;
+        bounds.round(&ir);
+        bounds.set(ir);
+    }
+}
+
+FloatRect SimpleFontData::platformBoundsForGlyph(Glyph glyph) const
+{
+    if (!m_platformData.size())
+        return FloatRect();
+
+    SkASSERT(sizeof(glyph) == 2); // compile-time assert
+
+    SkPaint paint;
+    m_platformData.setupPaint(&paint);
+
+    SkRect bounds;
+    getSkiaBoundsForGlyph(paint, glyph, bounds);
+    return FloatRect(bounds);
+}
+
+float SimpleFontData::platformWidthForGlyph(Glyph glyph) const
+{
+    if (!m_platformData.size())
+        return 0;
+
+    SkASSERT(sizeof(glyph) == 2); // compile-time assert
+
+    SkPaint paint;
+
+    m_platformData.setupPaint(&paint);
+
+    paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+    SkScalar width = paint.measureText(&glyph, 2);
+    if (!paint.isSubpixelText())
+        width = SkScalarRoundToInt(width);
+    return SkScalarToFloat(width);
+}
+
+bool SimpleFontData::canRenderCombiningCharacterSequence(const UChar* characters, size_t length) const
+{
+    if (!m_combiningCharacterSequenceSupport)
+        m_combiningCharacterSequenceSupport = adoptPtr(new HashMap<String, bool>);
+
+    WTF::HashMap<String, bool>::AddResult addResult = m_combiningCharacterSequenceSupport->add(String(characters, length), false);
+    if (!addResult.isNewEntry)
+        return addResult.storedValue->value;
+
+    UErrorCode error = U_ZERO_ERROR;
+    Vector<UChar, 4> normalizedCharacters(length);
+    int32_t normalizedLength = unorm_normalize(characters, length, UNORM_NFC, UNORM_UNICODE_3_2, &normalizedCharacters[0], length, &error);
+    // Can't render if we have an error or no composition occurred.
+    if (U_FAILURE(error) || (static_cast<size_t>(normalizedLength) == length))
+        return false;
+
+    SkPaint paint;
+    m_platformData.setupPaint(&paint);
+    paint.setTextEncoding(SkPaint::kUTF16_TextEncoding);
+    if (paint.textToGlyphs(&normalizedCharacters[0], normalizedLength * 2, 0)) {
+        addResult.storedValue->value = true;
+        return true;
+    }
+    return false;
+}
+
+bool SimpleFontData::fillGlyphPage(GlyphPage* pageToFill, unsigned offset, unsigned length, UChar* buffer, unsigned bufferLength) const
+{
+    if (SkUTF16_IsHighSurrogate(buffer[bufferLength-1])) {
+        SkDebugf("%s last char is high-surrogate", __FUNCTION__);
+        return false;
+    }
+
+    SkAutoSTMalloc<GlyphPage::size, uint16_t> glyphStorage(length);
+
+    uint16_t* glyphs = glyphStorage.get();
+    SkTypeface* typeface = platformData().typeface();
+    typeface->charsToGlyphs(buffer, SkTypeface::kUTF16_Encoding, glyphs, length);
+
+    bool haveGlyphs = false;
+    for (unsigned i = 0; i < length; i++) {
+        if (glyphs[i]) {
+            pageToFill->setGlyphDataForIndex(offset + i, glyphs[i], this);
+            haveGlyphs = true;
+        }
+    }
+
+    return haveGlyphs;
+}
+
 } // namespace blink