fontlinux.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

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 * met:
 * 
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 * notice, this list of conditions and the following disclaimer.
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 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "Font.h"

#include "FloatRect.h"
#include "GlyphBuffer.h"
#include "GraphicsContext.h"
#include "NotImplemented.h"
#include "PlatformContextSkia.h"
#include "SimpleFontData.h"

#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkTemplates.h"
#include "SkTypeface.h"
#include "SkUtils.h"

namespace WebCore {

void Font::drawGlyphs(GraphicsContext* gc, const SimpleFontData* font,
                      const GlyphBuffer& glyphBuffer,  int from, int numGlyphs,
                      const FloatPoint& point) const {
    SkASSERT(sizeof(GlyphBufferGlyph) == sizeof(uint16_t));  // compile-time assert

    const GlyphBufferGlyph* glyphs = glyphBuffer.glyphs(from);
    SkScalar x = SkFloatToScalar(point.x());
    SkScalar y = SkFloatToScalar(point.y());

    // FIXME: text rendering speed:
    // Android has code in their WebCore fork to special case when the
    // GlyphBuffer has no advances other than the defaults. In that case the
    // text drawing can proceed faster. However, it's unclear when those
    // patches may be upstreamed to WebKit so we always use the slower path
    // here.
    const GlyphBufferAdvance* adv = glyphBuffer.advances(from);
    SkAutoSTMalloc<32, SkPoint> storage(numGlyphs);
    SkPoint* pos = storage.get();

    for (int i = 0; i < numGlyphs; i++) {
        pos[i].set(x, y);
        x += SkFloatToScalar(adv[i].width());
        y += SkFloatToScalar(adv[i].height());
    }

    SkCanvas* canvas = gc->platformContext()->canvas();
    int textMode = gc->platformContext()->getTextDrawingMode();

    // We draw text up to two times (once for fill, once for stroke).
    if (textMode & cTextFill) {
        SkPaint paint;
        gc->platformContext()->setupPaintForFilling(&paint);
        font->platformData().setupPaint(&paint);
        paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
        paint.setColor(gc->fillColor().rgb());
        canvas->drawPosText(glyphs, numGlyphs << 1, pos, paint);
    }

    if ((textMode & cTextStroke)
        && gc->platformContext()->getStrokeStyle() != NoStroke
        && gc->platformContext()->getStrokeThickness() > 0) {

        SkPaint paint;
        gc->platformContext()->setupPaintForStroking(&paint, 0, 0);
        font->platformData().setupPaint(&paint);
        paint.setFlags(SkPaint::kAntiAlias_Flag);
        paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
        paint.setColor(gc->strokeColor().rgb());

        if (textMode & cTextFill) {
            // If we also filled, we don't want to draw shadows twice.
            // See comment in FontChromiumWin.cpp::paintSkiaText() for more details.
            paint.setLooper(0)->safeUnref();
        }

        canvas->drawPosText(glyphs, numGlyphs << 1, pos, paint);
    }
}

void Font::drawComplexText(GraphicsContext* context, const TextRun& run,
                           const FloatPoint& point, int from, int to) const
{
    notImplemented();
}

float Font::floatWidthForComplexText(const TextRun& run) const
{
    notImplemented();
    return 0;
}

int Font::offsetForPositionForComplexText(const TextRun& run, int x,
                                          bool includePartialGlyphs) const
{
    notImplemented();
    return 0;
}

FloatRect Font::selectionRectForComplexText(const TextRun& run,
                                            const IntPoint& point, int h,
                                            int from, int to) const
{
    notImplemented();
    return FloatRect();
}

}  // namespace WebCore