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      1 /*
      2  * Copyright 2016 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 SkSVGRenderContext_DEFINED
      9 #define SkSVGRenderContext_DEFINED
     10 
     11 #include "SkPaint.h"
     12 #include "SkPath.h"
     13 #include "SkRect.h"
     14 #include "SkSize.h"
     15 #include "SkSVGAttribute.h"
     16 #include "SkSVGIDMapper.h"
     17 #include "SkTLazy.h"
     18 #include "SkTypes.h"
     19 
     20 class SkCanvas;
     21 class SkSVGLength;
     22 
     23 class SkSVGLengthContext {
     24 public:
     25     SkSVGLengthContext(const SkSize& viewport, SkScalar dpi = 90)
     26         : fViewport(viewport), fDPI(dpi) {}
     27 
     28     enum class LengthType {
     29         kHorizontal,
     30         kVertical,
     31         kOther,
     32     };
     33 
     34     const SkSize& viewPort() const { return fViewport; }
     35     void setViewPort(const SkSize& viewport) { fViewport = viewport; }
     36 
     37     SkScalar resolve(const SkSVGLength&, LengthType) const;
     38     SkRect   resolveRect(const SkSVGLength& x, const SkSVGLength& y,
     39                          const SkSVGLength& w, const SkSVGLength& h) const;
     40 
     41 private:
     42     SkSize   fViewport;
     43     SkScalar fDPI;
     44 };
     45 
     46 struct SkSVGPresentationContext {
     47     SkSVGPresentationContext();
     48     SkSVGPresentationContext(const SkSVGPresentationContext&)            = default;
     49     SkSVGPresentationContext& operator=(const SkSVGPresentationContext&) = default;
     50 
     51     // Inherited presentation attributes, computed for the current node.
     52     SkSVGPresentationAttributes fInherited;
     53 
     54     // Cached paints, reflecting the current presentation attributes.
     55     SkPaint fFillPaint;
     56     SkPaint fStrokePaint;
     57 };
     58 
     59 class SkSVGRenderContext {
     60 public:
     61     SkSVGRenderContext(SkCanvas*, const SkSVGIDMapper&, const SkSVGLengthContext&,
     62                        const SkSVGPresentationContext&);
     63     SkSVGRenderContext(const SkSVGRenderContext&);
     64     SkSVGRenderContext(const SkSVGRenderContext&, SkCanvas*);
     65     ~SkSVGRenderContext();
     66 
     67     const SkSVGLengthContext& lengthContext() const { return *fLengthContext; }
     68     SkSVGLengthContext* writableLengthContext() { return fLengthContext.writable(); }
     69 
     70     const SkSVGPresentationContext& presentationContext() const { return *fPresentationContext; }
     71 
     72     SkCanvas* canvas() const { return fCanvas; }
     73     void saveOnce();
     74 
     75     enum ApplyFlags {
     76         kLeaf = 1 << 0, // the target node doesn't have descendants
     77     };
     78     void applyPresentationAttributes(const SkSVGPresentationAttributes&, uint32_t flags);
     79 
     80     const SkSVGNode* findNodeById(const SkString&) const;
     81 
     82     const SkPaint* fillPaint() const;
     83     const SkPaint* strokePaint() const;
     84 
     85     // The local computed clip path (not inherited).
     86     const SkPath* clipPath() const { return fClipPath.getMaybeNull(); }
     87 
     88 private:
     89     // Stack-only
     90     void* operator new(size_t)                               = delete;
     91     void* operator new(size_t, void*)                        = delete;
     92     SkSVGRenderContext& operator=(const SkSVGRenderContext&) = delete;
     93 
     94     void applyOpacity(SkScalar opacity, uint32_t flags);
     95     void applyClip(const SkSVGClip&);
     96 
     97     const SkSVGIDMapper&                          fIDMapper;
     98     SkTCopyOnFirstWrite<SkSVGLengthContext>       fLengthContext;
     99     SkTCopyOnFirstWrite<SkSVGPresentationContext> fPresentationContext;
    100     SkCanvas*                                     fCanvas;
    101     // The save count on 'fCanvas' at construction time.
    102     // A restoreToCount() will be issued on destruction.
    103     int                                           fCanvasSaveCount;
    104 
    105     // clipPath, if present for the current context (not inherited).
    106     SkTLazy<SkPath>                               fClipPath;
    107 };
    108 
    109 #endif // SkSVGRenderContext_DEFINED
    110