From 3ed192760314dc976cd02f62ac49798daa89b4b1 Mon Sep 17 00:00:00 2001 From: Alexander Toresson Date: Wed, 28 Aug 2013 16:13:06 +0200 Subject: [PATCH] Fix for positioning of glyphs within a bitmap For positioning of glyphs within a bitmap, roundf(int + float) is used, where the float is the glyph position and the int is the text position. When the text position is varied, this may lead to the sum being rounded in different directions, due to floating point rounding, caused by that floating point numbers have different precision in different ranges. This may therefore lead to slightly different positioning for glyphs and therefore slightly different widths and heights for text strings, depending on the position they are rendered at. The solution in this patch is to use int + (int) roundf(float), which has consistent rounding, and also enables us to use the full range of ints. Change-Id: Id1143cdfcbdfa9915ced878ae04df589a3e03cee --- libs/hwui/font/Font.cpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/libs/hwui/font/Font.cpp b/libs/hwui/font/Font.cpp index 18983d8b6d32a..8f5beb8927325 100644 --- a/libs/hwui/font/Font.cpp +++ b/libs/hwui/font/Font.cpp @@ -404,10 +404,10 @@ void Font::render(SkPaint* paint, const char* text, uint32_t start, uint32_t len // If it's still not valid, we couldn't cache it, so we shouldn't // draw garbage; also skip empty glyphs (spaces) if (cachedGlyph->mIsValid && cachedGlyph->mCacheTexture) { - float penX = x + positions[(glyphsCount << 1)]; - float penY = y + positions[(glyphsCount << 1) + 1]; + int penX = x + (int) roundf(positions[(glyphsCount << 1)]); + int penY = y + (int) roundf(positions[(glyphsCount << 1) + 1]); - (*this.*render)(cachedGlyph, roundf(penX), roundf(penY), + (*this.*render)(cachedGlyph, penX, penY, bitmap, bitmapW, bitmapH, bounds, positions); }