Fix how subpixel positions are intepreted in an aliased grid.

With this change we break with the traditional X11 and GDI way of rasterzing
aliased polygons, but we become consistent across integer and sub-pixel
positions.

The new model uses the same rules as the antialised rasterizer which means
that a primitive edge on 0.4 becomes 0.0, 0.5 becomes 1 and 0.9 becomes one, which
is also in line with how one normally thinks of rounding rules.

1 files changed, 0 insertions, 9 deletions

diff --git a/src/gui/painting/qoutlinemapper.cpp b/src/gui/painting/qoutlinemapper.cpp
index bf03545..72e5833 100644
--- a/src/gui/painting/qoutlinemapper.cpp
+++ b/src/gui/painting/qoutlinemapper.cpp
@@ -47,8 +47,6 @@
 
 QT_BEGIN_NAMESPACE
 
-static const qreal aliasedCoordinateDelta = 0.5 - 0.015625;
-
 #define qreal_to_fixed_26_6(f) (int(f * 64))
 
 
@@ -216,13 +214,6 @@ void QOutlineMapper::endOutline()
         elements = m_elements_dev.data();
     }
 
-    if (m_round_coords) {
-        // round coordinates to match outlines drawn with drawLine_midpoint_i
-        for (int i = 0; i < m_elements.size(); ++i)
-            elements[i] = QPointF(qFloor(elements[i].x() + aliasedCoordinateDelta),
-                                  qFloor(elements[i].y() + aliasedCoordinateDelta));
-    }
-
     controlPointRect = boundingRect(elements, element_count);
 
 #ifdef QT_DEBUG_CONVERT