QRawFont: improve performance and safety of glyphIndexesForString()

As of 98c1eb1750498cdff9d3b26658e5e5be9c026c92, partially initialized
QGlyphLayout is ok for stringToCMap() if GlyphIndicesOnly flag is set,
thus we can use the glyphIndexes buffer directly and avoid copying.
Also add some checks to guarantee we're not falling into an undefined behavior
for the empty text or NULL buffer.

Change-Id: I662953703e4c65edbebabbe4b753972417d963f3
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/tests/auto/gui/text/qrawfont/tst_qrawfont.cpp b/tests/auto/gui/text/qrawfont/tst_qrawfont.cpp
index 7a254546fe..c26964e764 100644
--- a/tests/auto/gui/text/qrawfont/tst_qrawfont.cpp
+++ b/tests/auto/gui/text/qrawfont/tst_qrawfont.cpp
@@ -267,6 +267,24 @@ void tst_QRawFont::glyphIndices()
     expectedGlyphIndices << 44 << 83 << 83 << 70 << 69 << 86;
 
     QCOMPARE(glyphIndices, expectedGlyphIndices);
+
+    glyphIndices = font.glyphIndexesForString(QString());
+    QVERIFY(glyphIndices.isEmpty());
+
+    QString str(QLatin1String("Foobar"));
+    int numGlyphs = str.size();
+    glyphIndices.resize(numGlyphs);
+
+    QVERIFY(!font.glyphIndexesForChars(str.constData(), 0, glyphIndices.data(), &numGlyphs));
+    QCOMPARE(numGlyphs, 0);
+
+    QVERIFY(!font.glyphIndexesForChars(str.constData(), str.size(), glyphIndices.data(), &numGlyphs));
+    QCOMPARE(numGlyphs, str.size());
+
+    QVERIFY(font.glyphIndexesForChars(str.constData(), str.size(), glyphIndices.data(), &numGlyphs));
+    QCOMPARE(numGlyphs, str.size());
+
+    QCOMPARE(glyphIndices, expectedGlyphIndices);
 }
 
 void tst_QRawFont::advances_data()
@@ -310,6 +328,33 @@ void tst_QRawFont::advances()
 
         QVERIFY(qFuzzyIsNull(advances.at(i).y()));
     }
+
+    advances = font.advancesForGlyphIndexes(QVector<quint32>());
+    QVERIFY(advances.isEmpty());
+
+    int numGlyphs = glyphIndices.size();
+    advances.resize(numGlyphs);
+
+    QVERIFY(!font.advancesForGlyphIndexes(glyphIndices.constData(), advances.data(), 0));
+
+    QVERIFY(font.advancesForGlyphIndexes(glyphIndices.constData(), advances.data(), numGlyphs));
+
+    for (int i=0; i<glyphIndices.size(); ++i) {
+#ifdef Q_OS_WIN
+        // In Windows, freetype engine returns advance of 9 when full hinting is used (default) for
+        // some of the glyphs.
+        if (font_d->fontEngine->type() == QFontEngine::Freetype
+            && (hintingPreference == QFont::PreferFullHinting || hintingPreference == QFont::PreferDefaultHinting)
+            && (i == 0 || i == 5)) {
+            QEXPECT_FAIL("", "Advance for some glyphs is not the expected with Windows Freetype engine (9 instead of 8)", Continue);
+        }
+#endif
+        QVERIFY(qFuzzyCompare(qRound(advances.at(i).x()), 8.0));
+        if (supportsSubPixelPositions)
+            QVERIFY(advances.at(i).x() > 8.0);
+
+        QVERIFY(qFuzzyIsNull(advances.at(i).y()));
+    }
 }
 
 void tst_QRawFont::textLayout()