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 "SkChecksum.h"
16 
17 class SkPDFCanon;
18 class 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.
24 */
25 class SkPDFGraphicState final : public SkPDFObject {
26 
27 public:
28     enum SkPDFSMaskMode {
29         kAlpha_SMaskMode,
30         kLuminosity_SMaskMode
31     };
32 
33     // Override emitObject so that we can populate the dictionary on
34     // demand.
35     void emitObject(SkWStream* stream,
36                     const SkPDFObjNumMap& objNumMap,
37                     const SkPDFSubstituteMap& substitutes) const override;
38 
39     /** Get the graphic state for the passed SkPaint. The reference count of
40      *  the object is incremented and it is the caller's responsibility to
41      *  unreference it when done. This is needed to accommodate the weak
42      *  reference pattern used when the returned object is new and has no
43      *  other references.
44      *  @param paint  The SkPaint to emulate.
45      */
46     static SkPDFGraphicState* GetGraphicStateForPaint(SkPDFCanon* canon,
47                                                       const SkPaint& paint);
48 
49     /** Make a graphic state that only sets the passed soft mask. The
50      *  reference count of the object is incremented and it is the caller's
51      *  responsibility to unreference it when done.
52      *  @param sMask     The form xobject to use as a soft mask.
53      *  @param invert    Indicates if the alpha of the sMask should be inverted.
54      *  @param sMaskMode Whether to use alpha or luminosity for the sMask.
55      *
56      *  These are not de-duped.
57      */
58     static SkPDFDict* GetSMaskGraphicState(SkPDFFormXObject* sMask,
59                                            bool invert,
60                                            SkPDFSMaskMode sMaskMode);
61 
62     /** Get a graphic state that only unsets the soft mask. The reference
63      *  count of the object is incremented and it is the caller's responsibility
64      *  to unreference it when done. This is needed to accommodate the weak
65      *  reference pattern used when the returned object is new and has no
66      *  other references.
67      *
68      *  The returned object is a singleton.
69      */
70     static SkPDFDict* GetNoSMaskGraphicState();
71 
72     bool operator==(const SkPDFGraphicState& rhs) const {
73         return 0 == memcmp(&fStrokeWidth, &rhs.fStrokeWidth, 12);
74     }
hash()75     uint32_t hash() const { return SkChecksum::Murmur3(&fStrokeWidth, 12); }
76 
77 private:
78     const SkScalar fStrokeWidth;
79     const SkScalar fStrokeMiter;
80     const uint8_t fAlpha;
81     const uint8_t fStrokeCap;   // SkPaint::Cap
82     const uint8_t fStrokeJoin;  // SkPaint::Join
83     const uint8_t fMode;        // SkXfermode::Mode
84 
85     SkPDFGraphicState(const SkPaint&);
86 
87     typedef SkPDFDict INHERITED;
88 };
89 
90 #endif
91