From f51b5fe09c63e4b3c2ab5a4d06e162c43d38207d Mon Sep 17 00:00:00 2001 From: Eskil Abrahamsen Blomfeldt Date: Tue, 5 Jul 2011 10:33:59 +0200 Subject: Don't issue GL calls when the geometry is empty This works as a band-aid and optimization for QT-5104, because in the text in the example, which contains latin text and has a latin default font set, will think of all spaces between the cyrillic characters as latin characters, hence it will make separate text items for them and issue separate glDrawElements() calls. By cutting off if there are no glyphs to draw, we can avoid hitting the actual bug for this and several other use cases, making it less likely to happen. Task-number: QT-5104 Reviewed-by: Samuel --- src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp index 52450b6..5d2221f 100644 --- a/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp +++ b/src/opengl/gl2paintengineex/qpaintengineex_opengl2.cpp @@ -1696,6 +1696,8 @@ void QGL2PaintEngineExPrivate::drawCachedGlyphs(QFontEngineGlyphCache::Type glyp } int numGlyphs = vertexCoordinates->vertexCount() / 4; + if (numGlyphs == 0) + return; if (elementIndices.size() < numGlyphs*6) { Q_ASSERT(elementIndices.size() % 6 == 0); -- cgit v0.12