1
2/*
3 * Copyright 2010 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkPDFGraphicState_DEFINED
11#define SkPDFGraphicState_DEFINED
12
13#include "SkPaint.h"
14#include "SkPDFTypes.h"
15#include "SkTemplates.h"
16#include "SkThread.h"
17
18class SkPDFFormXObject;
19
20/** \class SkPDFGraphicState
21    SkPaint objects roughly correspond to graphic state dictionaries that can
22    be installed. So that a given dictionary is only output to the pdf file
23    once, we want to canonicalize them. Static methods in this class manage
24    a weakly referenced set of SkPDFGraphicState objects: when the last
25    reference to a SkPDFGraphicState is removed, it removes itself from the
26    static set of objects.
27
28*/
29class SkPDFGraphicState : public SkPDFDict {
30public:
31    enum SkPDFSMaskMode {
32        kAlpha_SMaskMode,
33        kLuminosity_SMaskMode
34    };
35
36    virtual ~SkPDFGraphicState();
37
38    virtual void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,
39                              SkTSet<SkPDFObject*>* newResourceObjects);
40
41    // Override emitObject and getOutputSize so that we can populate
42    // the dictionary on demand.
43    virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog,
44                            bool indirect);
45    virtual size_t getOutputSize(SkPDFCatalog* catalog, bool indirect);
46
47    /** Get the graphic state for the passed SkPaint. The reference count of
48     *  the object is incremented and it is the caller's responsibility to
49     *  unreference it when done. This is needed to accommodate the weak
50     *  reference pattern used when the returned object is new and has no
51     *  other references.
52     *  @param paint  The SkPaint to emulate.
53     */
54    static SkPDFGraphicState* GetGraphicStateForPaint(const SkPaint& paint);
55
56    /** Make a graphic state that only sets the passed soft mask. The
57     *  reference count of the object is incremented and it is the caller's
58     *  responsibility to unreference it when done.
59     *  @param sMask     The form xobject to use as a soft mask.
60     *  @param invert    Indicates if the alpha of the sMask should be inverted.
61     *  @param sMaskMode Whether to use alpha or luminosity for the sMask.
62     */
63    static SkPDFGraphicState* GetSMaskGraphicState(SkPDFFormXObject* sMask,
64                                                   bool invert,
65                                                   SkPDFSMaskMode sMaskMode);
66
67    /** Get a graphic state that only unsets the soft mask. The reference
68     *  count of the object is incremented and it is the caller's responsibility
69     *  to unreference it when done. This is needed to accommodate the weak
70     *  reference pattern used when the returned object is new and has no
71     *  other references.
72     */
73    static SkPDFGraphicState* GetNoSMaskGraphicState();
74
75private:
76    const SkPaint fPaint;
77    SkTDArray<SkPDFObject*> fResources;
78    bool fPopulated;
79    bool fSMask;
80
81    class GSCanonicalEntry {
82    public:
83        SkPDFGraphicState* fGraphicState;
84        const SkPaint* fPaint;
85
86        bool operator==(const GSCanonicalEntry& b) const;
87        explicit GSCanonicalEntry(SkPDFGraphicState* gs)
88            : fGraphicState(gs),
89              fPaint(&gs->fPaint) {}
90        explicit GSCanonicalEntry(const SkPaint* paint)
91            : fGraphicState(NULL),
92              fPaint(paint) {}
93    };
94
95    // This should be made a hash table if performance is a problem.
96    static SkTDArray<GSCanonicalEntry>& CanonicalPaints();
97    static SkBaseMutex& CanonicalPaintsMutex();
98
99    SkPDFGraphicState();
100    explicit SkPDFGraphicState(const SkPaint& paint);
101
102    void populateDict();
103
104    static SkPDFObject* GetInvertFunction();
105
106    static int Find(const SkPaint& paint);
107};
108
109#endif
110