Stop rounding the baseline to use subpixels

Signed-off-by: MURAOKA Taro <koron.kaoriya@gmail.com>

diff --git a/src/gui_dwrite.cpp b/src/gui_dwrite.cpp
index c71358717..4461b2b89 100644
--- a/src/gui_dwrite.cpp
+++ b/src/gui_dwrite.cpp
@@ -1092,7 +1092,9 @@ DWriteContext::DrawText(const WCHAR *text, int len,
 	// font fallback, the metrics change).
 	// Use the pre-calculated font ascent for all text to prevent
 	// vertical shifts during redraw.
-	FLOAT baselineY = roundf(FLOAT(y) + FLOAT(h) * mFontAscent + 0.5);
+	// The baseline should not be rounded to take floating point values
+	// into account.
+	FLOAT baselineY = FLOAT(y) + FLOAT(h) * mFontAscent;
 
 	TextRenderer renderer(this);
 	TextRendererContext context = { color, FLOAT(cellWidth), lpDx, len,
