1/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef GrReducedClip_DEFINED
9#define GrReducedClip_DEFINED
10
11#include "SkClipStack.h"
12#include "SkTLList.h"
13
14class SK_API GrReducedClip {
15public:
16    typedef SkTLList<SkClipStack::Element, 16> ElementList;
17
18    enum InitialState {
19        kAllIn_InitialState,
20        kAllOut_InitialState,
21    };
22
23    /**
24     * This function takes a clip stack and a query rectangle and it produces a
25     * reduced set of SkClipStack::Elements that are equivalent to applying the
26     * full stack to the rectangle. The clip stack generation id that represents
27     * the list of elements is returned in resultGenID. The initial state of the
28     * query rectangle before the first clip element is applied is returned via
29     * initialState. Optionally, the caller can request a tighter bounds on the
30     * clip be returned via tighterBounds. If not nullptr, tighterBounds will
31     * always be contained by queryBounds after return. If tighterBounds is
32     * specified then it is assumed that the caller will implicitly clip against
33     * it. If the caller specifies non-nullptr for requiresAA then it will indicate
34     * whether anti-aliasing is required to process any of the elements in the
35     * result.
36     *
37     * This may become a member function of SkClipStack when its interface is
38     * determined to be stable.
39     */
40    static void ReduceClipStack(const SkClipStack& stack,
41                                const SkIRect& queryBounds,
42                                ElementList* result,
43                                int32_t* resultGenID,
44                                InitialState* initialState,
45                                SkIRect* tighterBounds = nullptr,
46                                bool* requiresAA = nullptr);
47};
48
49#endif
50