Move GrReducedClip to its own files.
R=robertphillips@google.com
Review URL: https://codereview.appspot.com/6891045
git-svn-id: http://skia.googlecode.com/svn/trunk@6686 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrReducedClip.h b/src/gpu/GrReducedClip.h
new file mode 100644
index 0000000..6b6725f
--- /dev/null
+++ b/src/gpu/GrReducedClip.h
@@ -0,0 +1,33 @@
+
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkClipStack.h"
+#include "SkTLList.h"
+
+namespace GrReducedClip {
+
+typedef SkTLList<SkClipStack::Element> ElementList;
+
+enum InitialState {
+ kAllIn_InitialState,
+ kAllOut_InitialState,
+};
+
+/**
+ * This function takes a clip stack and a query rectangle and it produces a reduced set of
+ * SkClipStack::Elements that are equivalent to applying the full stack to the rectangle. The
+ * initial state of the query rectangle before the first clip element is applied is returned via
+ * initialState. This function is declared here so that it can be unit-tested. It may become a
+ * member function of SkClipStack when its interface is determined to be stable.
+ */
+void GrReduceClipStack(const SkClipStack& stack,
+ const SkRect& queryBounds,
+ ElementList* result,
+ InitialState* initialState);
+
+} // namespace GrReducedClip