Correctly handle SkPath::kInverseWinding_FillType

Fix for http://code.google.com/p/skia/issues/detail?id=87

Even when SkPath::kInverseWinding_FillType is given, Skia left some
lines not filled(cleared) in one case.

Patch-by: morrita

http://codereview.appspot.com/3443041

git-svn-id: http://skia.googlecode.com/svn/trunk@630 2bbb7eff-a529-9590-31e7-b0007b416f81

src/core/SkScan_AntiPath.cpp

@@ -82,6 +82,7 @@ public:
     void flush();
 
     virtual void blitH(int x, int y, int width);
+    virtual void blitRect(int x, int y, int width, int height);
 
 private:
     SkAlphaRuns fRuns;
@@ -189,6 +190,15 @@ void SuperBlitter::blitH(int x, int y, int width)
 #endif
 }
 
+void SuperBlitter::blitRect(int x, int y, int width, int height)
+{
+    for (int i = 0; i < height; ++i) {
+        blitH(x, y + i, width);
+    }
+
+    flush();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 class MaskSuperBlitter : public BaseSuperBlitter {

src/core/SkScan_Path.cpp

@@ -508,6 +508,14 @@ void sk_fill_path(const SkPath& path, const SkIRect* clipRect, SkBlitter* blitte
 #endif
 
     if (count < 2) {
+        if (path.isInverseFillType()) {
+            const SkIRect& clipRect = clipRgn.getBounds();
+            blitter->blitRect(clipRect.fLeft << shiftEdgesUp,
+                              clipRect.fTop << shiftEdgesUp,
+                              clipRect.width() << shiftEdgesUp,
+                              clipRect.height() << shiftEdgesUp);
+        }
+
         return;
     }
 

tests/FillPathTest.cpp

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2010 The Chromium Authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Test.h"
+#include "SkRegion.h"
+#include "SkPath.h"
+#include "SkScan.h"
+#include "SkBlitter.h"
+
+namespace {
+
+struct FakeBlitter : public SkBlitter {
+  FakeBlitter()
+      : m_blitCount(0)
+  {}
+
+  virtual void blitH(int x, int y, int width) {
+    m_blitCount++;
+  }
+
+  int m_blitCount;
+};
+
+}
+
+// http://code.google.com/p/skia/issues/detail?id=87
+// Lines which is not clipped by boundary based clipping, 
+// but skipped after tessellation, should be cleared by the blitter.
+static void TestFillPathInverse(skiatest::Reporter* reporter) {
+  FakeBlitter blitter;
+  SkRegion clip;
+  SkPath path;
+  int height = 100;
+  int width  = 200;
+  int expected_lines = 5;
+  clip.setRect(0, height - expected_lines, width, height);
+  path.moveTo(0.0, 0.0);
+  path.quadTo(width/2, height, width, 0.0);
+  path.close();
+  path.setFillType(SkPath::kInverseWinding_FillType);
+  SkScan::FillPath(path, clip, &blitter);
+
+  REPORTER_ASSERT(reporter, blitter.m_blitCount == expected_lines);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("FillPath", FillPathTestClass, TestFillPathInverse)

tests/tests_files.mk

@@ -3,6 +3,7 @@ SOURCE := \
     BlitRowTest.cpp \
     ClipCubicTest.cpp \
     ClipperTest.cpp \
+    FillPathTest.cpp \
     FlateTest.cpp \
     GeometryTest.cpp \
     MathTest.cpp \