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 {
30    SK_DECLARE_INST_COUNT(SkPDFGraphicState)
31public:
32    enum SkPDFSMaskMode {
33        kAlpha_SMaskMode,
34        kLuminosity_SMaskMode
35    };
36
37    virtual ~SkPDFGraphicState();
38
39    virtual void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,
40                              SkTSet<SkPDFObject*>* newResourceObjects);
41
42    // Override emitObject and getOutputSize so that we can populate
43    // the dictionary on demand.
44    virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog,
45                            bool indirect);
46    virtual size_t getOutputSize(SkPDFCatalog* catalog, bool indirect);
47
48    /** Get the graphic state for the passed SkPaint. The reference count of
49     *  the object is incremented and it is the caller's responsibility to
50     *  unreference it when done. This is needed to accommodate the weak
51     *  reference pattern used when the returned object is new and has no
52     *  other references.
53     *  @param paint  The SkPaint to emulate.
54     */
55    static SkPDFGraphicState* GetGraphicStateForPaint(const SkPaint& paint);
56
57    /** Make a graphic state that only sets the passed soft mask. The
58     *  reference count of the object is incremented and it is the caller's
59     *  responsibility to unreference it when done.
60     *  @param sMask     The form xobject to use as a soft mask.
61     *  @param invert    Indicates if the alpha of the sMask should be inverted.
62     *  @param sMaskMode Whether to use alpha or luminosity for the sMask.
63     */
64    static SkPDFGraphicState* GetSMaskGraphicState(SkPDFFormXObject* sMask,
65                                                   bool invert,
66                                                   SkPDFSMaskMode sMaskMode);
67
68    /** Get a graphic state that only unsets the soft mask. The reference
69     *  count of the object is incremented and it is the caller's responsibility
70     *  to unreference it when done. This is needed to accommodate the weak
71     *  reference pattern used when the returned object is new and has no
72     *  other references.
73     */
74    static SkPDFGraphicState* GetNoSMaskGraphicState();
75
76private:
77    const SkPaint fPaint;
78    SkTDArray<SkPDFObject*> fResources;
79    bool fPopulated;
80    bool fSMask;
81
82    class GSCanonicalEntry {
83    public:
84        SkPDFGraphicState* fGraphicState;
85        const SkPaint* fPaint;
86
87        bool operator==(const GSCanonicalEntry& b) const;
88        explicit GSCanonicalEntry(SkPDFGraphicState* gs)
89            : fGraphicState(gs),
90              fPaint(&gs->fPaint) {}
91        explicit GSCanonicalEntry(const SkPaint* paint)
92            : fGraphicState(NULL),
93              fPaint(paint) {}
94    };
95
96    // This should be made a hash table if performance is a problem.
97    static SkTDArray<GSCanonicalEntry>& CanonicalPaints();
98    static SkBaseMutex& CanonicalPaintsMutex();
99
100    SkPDFGraphicState();
101    explicit SkPDFGraphicState(const SkPaint& paint);
102
103    void populateDict();
104
105    static SkPDFObject* GetInvertFunction();
106
107    static int Find(const SkPaint& paint);
108    typedef SkPDFDict INHERITED;
109};
110
111#endif
112