SkPDF: SkPDFGraphicState Lookup hashtabled

src/pdf/SkPDFGraphicState.h

 
 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPDFGraphicState_DEFINED
 #define SkPDFGraphicState_DEFINED
 
 #include "SkPaint.h"
 #include "SkPDFTypes.h"
 #include "SkTemplates.h"
+#include "SkChecksum.h"
 
+class SkPDFCanon;
 class SkPDFFormXObject;
 
 /** \class SkPDFGraphicState
     SkPaint objects roughly correspond to graphic state dictionaries that can
     be installed. So that a given dictionary is only output to the pdf file
-    once, we want to canonicalize them. Static methods in this class manage
-    a weakly referenced set of SkPDFGraphicState objects: when the last
-    reference to a SkPDFGraphicState is removed, it removes itself from the
-    static set of objects.
-
+    once, we want to canonicalize them.
 */
-class SkPDFGraphicState : public SkPDFDict {
+class SkPDFGraphicState : public SkPDFObject {
     SK_DECLARE_INST_COUNT(SkPDFGraphicState)
 public:
     enum SkPDFSMaskMode {
         kAlpha_SMaskMode,
         kLuminosity_SMaskMode
     };
 
-    virtual ~SkPDFGraphicState();
-
     // Override emitObject so that we can populate the dictionary on
     // demand.
     virtual void emitObject(SkWStream* stream,
                             const SkPDFObjNumMap& objNumMap,
                             const SkPDFSubstituteMap& substitutes);
 
     /** Get the graphic state for the passed SkPaint. The reference count of
      *  the object is incremented and it is the caller's responsibility to
      *  unreference it when done. This is needed to accommodate the weak
      *  reference pattern used when the returned object is new and has no
      *  other references.
      *  @param paint  The SkPaint to emulate.
      */
     static SkPDFGraphicState* GetGraphicStateForPaint(SkPDFCanon* canon,
                                                       const SkPaint& paint);
 
     /** Make a graphic state that only sets the passed soft mask. The
      *  reference count of the object is incremented and it is the caller's
      *  responsibility to unreference it when done.
      *  @param sMask     The form xobject to use as a soft mask.
      *  @param invert    Indicates if the alpha of the sMask should be inverted.
      *  @param sMaskMode Whether to use alpha or luminosity for the sMask.
+     *
+     *  These are not de-duped.
      */
-    static SkPDFGraphicState* GetSMaskGraphicState(SkPDFFormXObject* sMask,
-                                                   bool invert,
-                                                   SkPDFSMaskMode sMaskMode);
+    static SkPDFDict* GetSMaskGraphicState(SkPDFFormXObject* sMask,
+                                           bool invert,
+                                           SkPDFSMaskMode sMaskMode);
 
     /** Get a graphic state that only unsets the soft mask. The reference
      *  count of the object is incremented and it is the caller's responsibility
      *  to unreference it when done. This is needed to accommodate the weak
      *  reference pattern used when the returned object is new and has no
      *  other references.
+     *
+     *  The returned object is a singleton.
      */
-    static SkPDFGraphicState* GetNoSMaskGraphicState();
+    static SkPDFDict* GetNoSMaskGraphicState();
 
-    bool equals(const SkPaint&) const;
-
-    // Only public for SK_DECLARE_STATIC_LAZY_PTR
-    static SkPDFGraphicState* CreateNoSMaskGraphicState();
+    bool operator==(const SkPDFGraphicState& rhs) const {
+        return 0 == memcmp(&fStrokeWidth, &rhs.fStrokeWidth, 12);
+    }
+    uint32_t hash() const { return SkChecksum::Murmur3(&fStrokeWidth, 12); }
 
 private:
-    const SkPaint fPaint;
-    bool fPopulated;
+    const SkScalar fStrokeWidth;
+    const SkScalar fStrokeMiter;
+    const uint8_t fAlpha;
+    const uint8_t fStrokeCap;   // SkPaint::Cap
+    const uint8_t fStrokeJoin;  // SkPaint::Join
+    const uint8_t fMode;        // SkXfermode::Mode
 
-    SkPDFGraphicState();
-    SkPDFGraphicState(const SkPaint& paint);
-
-    void populateDict();
+    SkPDFGraphicState(const SkPaint&);
 
     typedef SkPDFDict INHERITED;
 };
 
 #endif