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 
14 class SK_API GrReducedClip {
15 public:
16     typedef SkTLList<SkClipStack::Element> 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 NULL, 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-NULL 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 = NULL,
46                                 bool* requiresAA = NULL);
47 };
48 
49 #endif
50