QImage QWindowsFontEngineDirectWrite::alphaRGBMapForGlyph(glyph_t t,
QFixed subPixelPosition,
const QTransform &xform)
{
QImage mask = imageForGlyph(t,
subPixelPosition,
glyphMargin(QFontEngineGlyphCache::Raster_RGBMask),
xform);
return mask.depth() == 32
? mask
: mask.convertToFormat(QImage::Format_RGB32);
}
bool QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const glyph_t *glyphs,
const QFixedPoint *positions)
{
#ifdef CACHE_DEBUG
printf("Populating with %d glyphs\n", numGlyphs);
qDebug() << " -> current transformation: " << m_transform;
#endif
m_current_fontengine = fontEngine;
const int margin = glyphMargin();
const int paddingDoubled = glyphPadding() * 2;
bool supportsSubPixelPositions = fontEngine->supportsSubPixelPositions();
if (fontEngine->m_subPixelPositionCount == 0) {
if (!supportsSubPixelPositions) {
fontEngine->m_subPixelPositionCount = 1;
} else {
int i = 0;
while (fontEngine->m_subPixelPositionCount == 0 && i < numGlyphs)
fontEngine->m_subPixelPositionCount = calculateSubPixelPositionCount(glyphs[i++]);
}
}
QHash<GlyphAndSubPixelPosition, Coord> listItemCoordinates;
int rowHeight = 0;
QFontEngine::GlyphFormat format;
switch (m_type) {
case Raster_A8: format = QFontEngine::Format_A8; break;
case Raster_RGBMask: format = QFontEngine::Format_A32; break;
default: format = QFontEngine::Format_Mono; break;
}
// check each glyph for its metrics and get the required rowHeight.
for (int i=0; i < numGlyphs; ++i) {
const glyph_t glyph = glyphs[i];
QFixed subPixelPosition;
if (supportsSubPixelPositions) {
QFixed x = positions != 0 ? positions[i].x : QFixed();
subPixelPosition = fontEngine->subPixelPositionForX(x);
}
if (coords.contains(GlyphAndSubPixelPosition(glyph, subPixelPosition)))
continue;
if (listItemCoordinates.contains(GlyphAndSubPixelPosition(glyph, subPixelPosition)))
continue;
glyph_metrics_t metrics = fontEngine->alphaMapBoundingBox(glyph, subPixelPosition, m_transform, format);
#ifdef CACHE_DEBUG
printf("(%4x): w=%.2f, h=%.2f, xoff=%.2f, yoff=%.2f, x=%.2f, y=%.2f\n",
glyph,
metrics.width.toReal(),
metrics.height.toReal(),
metrics.xoff.toReal(),
metrics.yoff.toReal(),
metrics.x.toReal(),
metrics.y.toReal());
#endif
GlyphAndSubPixelPosition key(glyph, subPixelPosition);
int glyph_width = metrics.width.ceil().toInt();
int glyph_height = metrics.height.ceil().toInt();
if (glyph_height == 0 || glyph_width == 0) {
// Avoid multiple calls to boundingBox() for non-printable characters
Coord c = { 0, 0, 0, 0, 0, 0 };
coords.insert(key, c);
continue;
}
glyph_width += margin * 2 + 4;
glyph_height += margin * 2 + 4;
// 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(key, c);
rowHeight = qMax(rowHeight, glyph_height);
}
if (listItemCoordinates.isEmpty())
return true;
rowHeight += margin * 2 + paddingDoubled;
if (m_w == 0) {
if (fontEngine->maxCharWidth() <= QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH)
m_w = QT_DEFAULT_TEXTURE_GLYPH_CACHE_WIDTH;
else
m_w = qt_next_power_of_two(fontEngine->maxCharWidth());
}
// now actually use the coords and paint the wanted glyps into cache.
QHash<GlyphAndSubPixelPosition, Coord>::iterator iter = listItemCoordinates.begin();
int requiredWidth = m_w;
while (iter != listItemCoordinates.end()) {
Coord c = iter.value();
m_currentRowHeight = qMax(m_currentRowHeight, c.h + margin * 2);
if (m_cx + c.w > requiredWidth) {
int new_width = requiredWidth*2;
while (new_width < m_cx + c.w)
new_width *= 2;
if (new_width <= maxTextureWidth()) {
requiredWidth = new_width;
} else {
// no room on the current line, start new glyph strip
m_cx = 0;
m_cy += m_currentRowHeight + paddingDoubled;
m_currentRowHeight = c.h + margin * 2; // New row
}
}
if (maxTextureHeight() > 0 && m_cy + c.h > maxTextureHeight()) {
// We can't make a cache of the required size, so we bail out
return false;
}
c.x = m_cx;
c.y = m_cy;
coords.insert(iter.key(), c);
m_pendingGlyphs.insert(iter.key(), c);
m_cx += c.w + paddingDoubled;
++iter;
}
return true;
}
