qt/qtsvg/src/svg/qsvgfont.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:significant reason:default
#include "qsvgfont_p.h"
#include "qpainter.h"
#include "qpen.h"
#include "qdebug.h"
QT_BEGIN_NAMESPACE
QSvgGlyph::QSvgGlyph(const QString &unicode, const QPainterPath &path, qreal horizAdvX)
: m_unicode(unicode), m_path(path), m_horizAdvX(horizAdvX)
{
}
QSvgFont::QSvgFont(qreal horizAdvX)
: m_horizAdvX(horizAdvX)
{
}
QSvgFont::~QSvgFont()
= default;
void QSvgFont::addGlyph(const QString &unicode, const QPainterPath &path, qreal horizAdvX)
{
m_glyphs.emplaceBack(unicode, path, (horizAdvX == -1) ? m_horizAdvX : horizAdvX);
}
bool QSvgFont::addMissingGlyph(const QPainterPath &path, qreal horizAdvX)
{
if (m_missingGlyph) {
qWarning("The font already has a 'missing-glyph' element.");
return false;
}
m_missingGlyph.reset(new QSvgGlyph(QChar(), path, (horizAdvX == -1) ? m_horizAdvX : horizAdvX));
return true;
}
void QSvgFont::draw(QPainter *p, const QPointF &point, const QList<const QSvgGlyph *> &glyphs,
qreal pixelSize, Qt::Alignment alignment) const
{
draw_helper(p, point, glyphs, pixelSize, alignment, nullptr);
}
QRectF QSvgFont::boundingRect(QPainter *p, const QPointF &point,
const QList<const QSvgGlyph *> &glyphs,
qreal pixelSize, Qt::Alignment alignment) const
{
QRectF bounds;
draw_helper(p, point, glyphs, pixelSize, alignment, &bounds);
return bounds;
}
// text must not be empty
char32_t firstUcs4(QStringView text)
{
if (text.size() > 1 && text.at(0).isHighSurrogate() && text.at(1).isLowSurrogate())
return QChar::surrogateToUcs4(text.at(0), text.at(1));
return text.first().unicode();
}
// returns a pointer to the first QSvgGlyph to be used in the text
// or nullptr if none can be found
const QSvgGlyph *QSvgFont::findFirstGlyphFor(QStringView text) const
{
const auto possibleIndices = m_possibleGlyphIndicesForChar.value(firstUcs4(text));
for (const qsizetype i : possibleIndices) {
const QSvgGlyph &currentGlyph = m_glyphs.at(i);
if (text.startsWith(currentGlyph.m_unicode)) {
return &currentGlyph;
}
}
for (; m_firstUnscannedGlyphIdx < m_glyphs.size(); ++m_firstUnscannedGlyphIdx) {
const QSvgGlyph &currentGlyph = m_glyphs.at(m_firstUnscannedGlyphIdx);
m_possibleGlyphIndicesForChar[firstUcs4(currentGlyph.m_unicode)].push_back(m_firstUnscannedGlyphIdx);
if (text.startsWith(currentGlyph.m_unicode)) {
++m_firstUnscannedGlyphIdx;
return &currentGlyph;
}
}
return nullptr;
}
QList<const QSvgGlyph *> QSvgFont::toGlyphs(QStringView text) const
{
QList<const QSvgGlyph *> glyphs;
glyphs.reserve(text.length());
while (text.length()) {
const QSvgGlyph *foundGlyph = findFirstGlyphFor(text);
if (foundGlyph) {
glyphs.append(foundGlyph);
text.slice(foundGlyph->m_unicode.length());
} else {
if (m_missingGlyph)
glyphs.append(m_missingGlyph.get());
if (text.size() > 1
&& text.at(0).isHighSurrogate() && text.at(1).isLowSurrogate()) {
text.slice(2);
} else {
text.slice(1);
}
}
}
return glyphs;
}
void QSvgFont::draw_helper(QPainter *p, const QPointF &point,
const QList<const QSvgGlyph *> &glyphs, qreal pixelSize,
Qt::Alignment alignment, QRectF *boundingRect) const
{
const bool isPainting = (boundingRect == nullptr);
p->save();
p->translate(point);
p->scale(pixelSize / m_unitsPerEm, -pixelSize / m_unitsPerEm);
// Calculate the text width to be used for alignment
int textWidth = 0;
for (const auto *glyph : glyphs)
textWidth += static_cast<int>(glyph->m_horizAdvX);
QPoint alignmentOffset(0, 0);
if (alignment == Qt::AlignHCenter) {
alignmentOffset.setX(-textWidth / 2);
} else if (alignment == Qt::AlignRight) {
alignmentOffset.setX(-textWidth);
}
p->translate(alignmentOffset);
// since in SVG the embedded font ain't really a path
// the outline has got to stay untransformed...
qreal penWidth = p->pen().widthF();
penWidth /= (pixelSize/m_unitsPerEm);
QPen pen = p->pen();
pen.setWidthF(penWidth);
p->setPen(pen);
for (const auto *glyph : glyphs) {
if (isPainting)
p->drawPath(glyph->m_path);
if (boundingRect) {
QPainterPathStroker stroker;
stroker.setWidth(penWidth);
stroker.setJoinStyle(p->pen().joinStyle());
stroker.setMiterLimit(p->pen().miterLimit());
QPainterPath stroke = stroker.createStroke(glyph->m_path);
*boundingRect |= p->transform().map(stroke).boundingRect();
}
p->translate(glyph->m_horizAdvX, 0);
}
p->restore();
}
void QSvgFont::setUnitsPerEm(qreal upem)
{
m_unitsPerEm = upem;
}
QT_END_NAMESPACE