source: trunk/src/gui/painting/qtextureglyphcache.cpp@ 262

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#include <qmath.h>

#include "qtextureglyphcache_p.h"

#include "private/qnumeric_p.h"
#include "private/qnativeimage_p.h"
#include "private/qfontengine_ft_p.h"

QT_BEGIN_NAMESPACE

// #define CACHE_DEBUG

void QTextureGlyphCache::populate(const QTextItemInt &ti,
                                  const QVarLengthArray<glyph_t> &glyphs,
                                  const QVarLengthArray<QFixedPoint> &)
{
#ifdef CACHE_DEBUG
    printf("Populating with '%s'\n", QString::fromRawData(ti.chars, ti.num_chars).toLatin1().data());
    qDebug() << " -> current transformation: " << m_transform;
#endif

    m_current_textitem = &ti;
    const int margin = glyphMargin();

    QHash<glyph_t, Coord> listItemCoordinates;
    int rowHeight = 0;

    // check each glyph for its metrics and get the required rowHeight.
    for (int i=0; i < glyphs.size(); ++i) {
        const glyph_t glyph = glyphs[i];
        if (coords.contains(glyph))
            continue;
        if (listItemCoordinates.contains(glyph))
            continue;
        glyph_metrics_t metrics = ti.fontEngine->boundingBox(glyph, m_transform);

#ifdef CACHE_DEBUG
        printf("'%c' (%4x): w=%.2f, h=%.2f, xoff=%.2f, yoff=%.2f, x=%.2f, y=%.2f, ti.ascent=%.2f, ti.descent=%.2f\n",
               ti.chars[i].toLatin1(),
               glyph,
               metrics.width.toReal(),
               metrics.height.toReal(),
               metrics.xoff.toReal(),
               metrics.yoff.toReal(),
               metrics.x.toReal(),
               metrics.y.toReal(),
               ti.ascent.toReal(),
               ti.descent.toReal());
#endif
        int glyph_width = metrics.width.ceil().toInt() + margin * 2;
        int glyph_height = metrics.height.ceil().toInt() + margin * 2;
        if (glyph_height == 0 || glyph_width == 0)
            continue;

        // align to 8-bit boundary
        if (m_type == QFontEngineGlyphCache::Raster_Mono)
            glyph_width = (glyph_width+7)&~7;

        Coord c = { 0, 0, // will be filled in later
                    glyph_width,
                    glyph_height, // texture coords
                    metrics.x.truncate(),
                    -metrics.y.truncate() }; // baseline for horizontal scripts

        listItemCoordinates.insert(glyph, c);
        rowHeight = qMax(rowHeight, glyph_height);
    }
    if (listItemCoordinates.isEmpty())
        return;

    rowHeight += margin * 2;
    if (isNull())
        createCache(256, rowHeight);

    // now actually use the coords and paint the wanted glyps into cache.
    QHash<glyph_t, Coord>::iterator iter = listItemCoordinates.begin();
    while (iter != listItemCoordinates.end()) {
        Coord c = iter.value();

        if (m_cx + c.w > m_w) {
            // no room on the current line, start new glyph strip
            m_cx = 0;
            m_cy = m_h;
        }
        if (m_cy + c.h > m_h) {
            int new_height;
            if (m_cx == 0) { // add a whole row
                new_height = m_h + rowHeight;
                m_cy = m_h;
            } else { // just extend row
                new_height = m_cy + rowHeight;
            }
            // if no room in the current texture - realloc a larger texture
            resizeTextureData(m_w, new_height);
            m_h = new_height;
        }

        c.x = m_cx;
        c.y = m_cy;

        fillTexture(c, iter.key());
        coords.insert(iter.key(), c);

        if (m_cx + c.w > m_w) {
            m_cx = 0;
            m_cy += rowHeight;
        } else {
            // for the Mono case, glyph_width is 8-bit aligned,
            // and therefore so will m_cx
            m_cx += c.w;
        }
        ++iter;
    }


}

/************************************************************************
 * QImageTextureGlyphCache
 */

void QImageTextureGlyphCache::resizeTextureData(int width, int height)
{
    m_image = m_image.copy(0, 0, width, height);
}

void QImageTextureGlyphCache::createTextureData(int width, int height)
{
    switch (m_type) {
    case QFontEngineGlyphCache::Raster_Mono:
        m_image = QImage(width, height, QImage::Format_Mono);
        break;
    case QFontEngineGlyphCache::Raster_A8: {
        m_image = QImage(width, height, QImage::Format_Indexed8);
        m_image.fill(0);
        QVector<QRgb> colors(256);
        QRgb *it = colors.data();
        for (int i=0; i<256; ++i, ++it)
            *it = 0xff000000 | i | (i<<8) | (i<<16);
        m_image.setColorTable(colors);
        break;   }
    case QFontEngineGlyphCache::Raster_RGBMask:
        m_image = QImage(width, height, QImage::Format_RGB32);
        break;
    }
}

int QImageTextureGlyphCache::glyphMargin() const
{
#ifdef Q_WS_MAC
    return 2;
#else
    return m_type == QFontEngineGlyphCache::Raster_RGBMask ? 2 : 0;
#endif