Changeset 148582 in webkit

Timestamp:

Apr 16, 2013 5:09:49 PM (11 years ago)

Author:

hmuller@adobe.com

Message:

[CSS Exclusions] polygon shape-inside layout fails
​https://bugs.webkit.org/show_bug.cgi?id=114402

Source/WebCore:

Reviewed by Dirk Schulze.

The firstIncludedIntervalLogicalTop() method's implementation relied on optimistic
assumptions about floating point accuracy which, in rare cases, caused it to discard
first-fit locations based on the intersection of the minLogicalIntervalTop offset edge
and a polygon offset edge. Now: we do not verify that first-fit locations based on the
intersection of an offset edge and the minLogicalIntervalTop offset edge are below
the horizontal minLogicalIntervalTop line. They're essentially below the line "by definition".

Test: fast/exclusions/shape-inside/shape-inside-polygon-layout.html

• rendering/ExclusionPolygon.cpp:

(WebCore::ExclusionPolygon::firstIncludedIntervalLogicalTop): Avoid floating point problems

when checking intersections with the offset edge based on minLogicalIntervalTop.

• rendering/ExclusionPolygon.h:

(WebCore::OffsetPolygonEdge::OffsetPolygonEdge): Initialize the basis field.
(WebCore::OffsetPolygonEdge::basis): Report what the offset edge is "based on": a polygon

edge, the top of the line, or a (reflex) vertex.

(OffsetPolygonEdge): Added the Basis enum to enable tracking what the geometry of

an offset edge is based on.

LayoutTests:

Verify that subsequent polygon shape-inside lines are vertically adjacent.

Reviewed by Dirk Schulze.

• fast/exclusions/shape-inside/shape-inside-polygon-layout-expected.txt: Added.
• fast/exclusions/shape-inside/shape-inside-polygon-layout.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/exclusions/shape-inside/shape-inside-polygon-layout-expected.txt (added)
• LayoutTests/fast/exclusions/shape-inside/shape-inside-polygon-layout.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/ExclusionPolygon.cpp (modified) (1 diff)
• Source/WebCore/rendering/ExclusionPolygon.h (modified) (5 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2013-04-16  Hans Muller  <hmuller@adobe.com>
+
+        [CSS Exclusions] polygon shape-inside layout fails
+        https://bugs.webkit.org/show_bug.cgi?id=114402
+
+        Verify that subsequent polygon shape-inside lines are vertically adjacent.
+
+        Reviewed by Dirk Schulze.
+
+        * fast/exclusions/shape-inside/shape-inside-polygon-layout-expected.txt: Added.
+        * fast/exclusions/shape-inside/shape-inside-polygon-layout.html: Added.
+
 2013-04-16  Michelangelo De Simone  <michelangelo@webkit.org>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2013-04-16  Hans Muller  <hmuller@adobe.com>
+
+        [CSS Exclusions] polygon shape-inside layout fails
+        https://bugs.webkit.org/show_bug.cgi?id=114402
+
+        Reviewed by Dirk Schulze.
+
+        The firstIncludedIntervalLogicalTop() method's implementation relied on optimistic
+        assumptions about floating point accuracy which, in rare cases, caused it to discard
+        first-fit locations based on the intersection of the minLogicalIntervalTop offset edge
+        and a polygon offset edge. Now: we do not verify that first-fit locations based on the
+        intersection of an offset edge and the minLogicalIntervalTop offset edge are below
+        the horizontal minLogicalIntervalTop line. They're essentially below the line "by definition".
+
+        Test: fast/exclusions/shape-inside/shape-inside-polygon-layout.html
+
+        * rendering/ExclusionPolygon.cpp:
+        (WebCore::ExclusionPolygon::firstIncludedIntervalLogicalTop): Avoid floating point problems
+            when checking intersections with the offset edge based on minLogicalIntervalTop.
+        * rendering/ExclusionPolygon.h:
+        (WebCore::OffsetPolygonEdge::OffsetPolygonEdge): Initialize the basis field.
+        (WebCore::OffsetPolygonEdge::basis): Report what the offset edge is "based on": a polygon
+            edge, the top of the line, or a (reflex) vertex.
+        (OffsetPolygonEdge): Added the Basis enum to enable tracking what the geometry of
+            an offset edge is based on.
+
 2013-04-16  Jer Noble  <jer.noble@apple.com>
 

trunk/Source/WebCore/rendering/ExclusionPolygon.cpp

@@ -488 +488 @@
                 FloatPoint potentialFirstFitLocation(offsetEdgesIntersection.x() - dx, offsetEdgesIntersection.y() - dy);
                 FloatRect potentialFirstFitRect(potentialFirstFitLocation, minLogicalIntervalSize);
-                if ((potentialFirstFitLocation.y() >= minLogicalIntervalTop)
+                if ((offsetEdges[i].basis() == OffsetPolygonEdge::LineTop
+                    || offsetEdges[j].basis() == OffsetPolygonEdge::LineTop
+                    || potentialFirstFitLocation.y() >= minLogicalIntervalTop)
                     && (!firstFitFound || aboveOrToTheLeft(potentialFirstFitRect, firstFitRect))
                     && polygon.contains(offsetEdgesIntersection)

trunk/Source/WebCore/rendering/ExclusionPolygon.h

@@ -39 +39 @@
 class OffsetPolygonEdge : public VertexPair {
 public:
+    enum Basis {
+        Edge,
+        Vertex,
+        LineTop
+    };
+
     OffsetPolygonEdge(const FloatPolygonEdge& edge, const FloatSize& offset)
         : m_vertex1(edge.vertex1() + offset)
         , m_vertex2(edge.vertex2() + offset)
         , m_edgeIndex(edge.edgeIndex())
+        , m_basis(Edge)
     {
     }
@@ -50 +57 @@
         , m_vertex2(reflexVertex + offset2)
         , m_edgeIndex(-1)
+        , m_basis(Vertex)
     {
     }
@@ -57 +65 @@
         , m_vertex2(FloatPoint(polygon.boundingBox().maxX(), minLogicalIntervalTop) + offset)
         , m_edgeIndex(-1)
+        , m_basis(LineTop)
     {
     }
@@ -63 +72 @@
     virtual const FloatPoint& vertex2() const OVERRIDE { return m_vertex2; }
     int edgeIndex() const { return m_edgeIndex; }
+    Basis basis() const { return m_basis; }
 
 private:
@@ -68 +78 @@
     FloatPoint m_vertex2;
     int m_edgeIndex;
+    Basis m_basis;
 };