1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/core/SkBBoxHierarchy.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,98 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2012 Google Inc.
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +#ifndef SkBBoxHierarchy_DEFINED
1.13 +#define SkBBoxHierarchy_DEFINED
1.14 +
1.15 +#include "SkRect.h"
1.16 +#include "SkTDArray.h"
1.17 +#include "SkRefCnt.h"
1.18 +
1.19 +/**
1.20 + * Interface for a client class that implements utility methods needed
1.21 + * by SkBBoxHierarchy that require intrinsic knowledge of the data
1.22 + * object type that is stored in the bounding box hierarchy.
1.23 + */
1.24 +class SkBBoxHierarchyClient {
1.25 +public:
1.26 + virtual ~SkBBoxHierarchyClient() {}
1.27 +
1.28 + /**
1.29 + * Implements a rewind stop condition used by rewindInserts
1.30 + * Must returns true if 'data' points to an object that should be re-wound
1.31 + * by rewinfInserts.
1.32 + */
1.33 + virtual bool shouldRewind(void* data) = 0;
1.34 +};
1.35 +
1.36 +/**
1.37 + * Interface for a spatial data structure that associates user data pointers with axis-aligned
1.38 + * bounding boxes, and allows efficient retrieval of intersections with query rectangles.
1.39 + */
1.40 +class SkBBoxHierarchy : public SkRefCnt {
1.41 +public:
1.42 + SK_DECLARE_INST_COUNT(SkBBoxHierarchy)
1.43 +
1.44 + SkBBoxHierarchy() : fClient(NULL) {}
1.45 +
1.46 + /**
1.47 + * Insert a data pointer and corresponding bounding box
1.48 + * @param data The data pointer, may be NULL
1.49 + * @param bounds The bounding box, should not be empty
1.50 + * @param defer Whether or not it is acceptable to delay insertion of this element (building up
1.51 + * an entire spatial data structure at once is often faster and produces better
1.52 + * structures than repeated inserts) until flushDeferredInserts is called or the first
1.53 + * search.
1.54 + */
1.55 + virtual void insert(void* data, const SkIRect& bounds, bool defer = false) = 0;
1.56 +
1.57 + /**
1.58 + * If any insertions have been deferred, this forces them to be inserted
1.59 + */
1.60 + virtual void flushDeferredInserts() = 0;
1.61 +
1.62 + /**
1.63 + * Populate 'results' with data pointers corresponding to bounding boxes that intersect 'query'
1.64 + */
1.65 + virtual void search(const SkIRect& query, SkTDArray<void*>* results) = 0;
1.66 +
1.67 + virtual void clear() = 0;
1.68 +
1.69 + /**
1.70 + * Gets the number of insertions actually made (does not include deferred insertions)
1.71 + */
1.72 + virtual int getCount() const = 0;
1.73 +
1.74 + /**
1.75 + * Returns the depth of the currently allocated tree. The root node counts for 1 level,
1.76 + * so it should be 1 or more if there's a root node. This information provides details
1.77 + * about the underlying structure, which is useful mainly for testing purposes.
1.78 + *
1.79 + * Returns 0 if there are currently no nodes in the tree.
1.80 + * Returns -1 if the structure isn't a tree.
1.81 + */
1.82 + virtual int getDepth() const = 0;
1.83 +
1.84 + /**
1.85 + * Rewinds all the most recently inserted data elements until an element
1.86 + * is encountered for which client->shouldRewind(data) returns false. May
1.87 + * not rewind elements that were inserted prior to the last call to
1.88 + * flushDeferredInserts.
1.89 + */
1.90 + virtual void rewindInserts() = 0;
1.91 +
1.92 + void setClient(SkBBoxHierarchyClient* client) { fClient = client; }
1.93 +
1.94 +protected:
1.95 + SkBBoxHierarchyClient* fClient;
1.96 +
1.97 +private:
1.98 + typedef SkRefCnt INHERITED;
1.99 +};
1.100 +
1.101 +#endif
