FontData.cpp   [plain text]

/*
 * Copyright (C) 2005 Apple Computer, Inc.  All rights reserved.
 * Copyright (C) 2006 Alexey Proskuryakov
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer. 
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution. 
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

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

#include <wtf/MathExtras.h>

namespace WebCore
{

FontData::FontData(const FontPlatformData& f)
:m_font(f), m_treatAsFixedPitch(false),
 m_smallCapsFontData(0)
 {    
    m_font = f;
    platformInit();
    
    // Nasty hack to determine if we should round or ceil space widths.
    // If the font is monospace or fake monospace we ceil to ensure that 
    // every character and the space are the same width.  Otherwise we round.
    m_spaceGlyph = m_characterToGlyphMap.glyphDataForCharacter(' ', this).glyph;
    float width = widthForGlyph(m_spaceGlyph);
    m_spaceWidth = width;
    determinePitch();
    m_adjustedSpaceWidth = m_treatAsFixedPitch ? ceilf(width) : roundf(width);
    
    // Force the glyph for ZERO WIDTH SPACE to have zero width, unless it is shared with SPACE.
    // Helvetica is an example of a non-zero width ZERO WIDTH SPACE glyph.
    // See <http://bugs.webkit.org/show_bug.cgi?id=13178>
    // Ask for the glyph for 0 to avoid paging in ZERO WIDTH SPACE. Control characters, including 0,
    // are mapped to the ZERO WIDTH SPACE glyph.
    Glyph zeroWidthSpaceGlyph = m_characterToGlyphMap.glyphDataForCharacter(0, this).glyph;
    if (zeroWidthSpaceGlyph) {
        if (zeroWidthSpaceGlyph != m_spaceGlyph)
            m_glyphToWidthMap.setWidthForGlyph(zeroWidthSpaceGlyph, 0);
        else
            LOG_ERROR("Font maps SPACE and ZERO WIDTH SPACE to the same glyph. Glyph width not overridden.");
    }
}

FontData::~FontData()
{
    platformDestroy();

    // We only get deleted when the cache gets cleared.  Since the smallCapsRenderer is also in that cache,
    // it will be deleted then, so we don't need to do anything here.
}

float FontData::widthForGlyph(Glyph glyph) const
{
    float width = m_glyphToWidthMap.widthForGlyph(glyph);
    if (width != cGlyphWidthUnknown)
        return width;
    
    width = platformWidthForGlyph(glyph);
    m_glyphToWidthMap.setWidthForGlyph(glyph, width);
    
    return width;
}

}