1/*
2 * Copyright 2006 The Android Open Source Project
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 SkGraphics_DEFINED
9#define SkGraphics_DEFINED
10
11#include "SkRefCnt.h"
12
13class SkData;
14class SkImageGenerator;
15class SkTraceMemoryDump;
16
17class SK_API SkGraphics {
18public:
19    /**
20     *  Call this at process initialization time if your environment does not
21     *  permit static global initializers that execute code.
22     *  Init() is thread-safe and idempotent.
23     */
24    static void Init();
25
26    // We're in the middle of cleaning this up.
27    static void Term() {}
28
29    /**
30     *  Return the version numbers for the library. If the parameter is not
31     *  null, it is set to the version number.
32     */
33    static void GetVersion(int32_t* major, int32_t* minor, int32_t* patch);
34
35    /**
36     *  Return the max number of bytes that should be used by the font cache.
37     *  If the cache needs to allocate more, it will purge previous entries.
38     *  This max can be changed by calling SetFontCacheLimit().
39     */
40    static size_t GetFontCacheLimit();
41
42    /**
43     *  Specify the max number of bytes that should be used by the font cache.
44     *  If the cache needs to allocate more, it will purge previous entries.
45     *
46     *  This function returns the previous setting, as if GetFontCacheLimit()
47     *  had be called before the new limit was set.
48     */
49    static size_t SetFontCacheLimit(size_t bytes);
50
51    /**
52     *  Return the number of bytes currently used by the font cache.
53     */
54    static size_t GetFontCacheUsed();
55
56    /**
57     *  Return the number of entries in the font cache.
58     *  A cache "entry" is associated with each typeface + pointSize + matrix.
59     */
60    static int GetFontCacheCountUsed();
61
62    /**
63     *  Return the current limit to the number of entries in the font cache.
64     *  A cache "entry" is associated with each typeface + pointSize + matrix.
65     */
66    static int GetFontCacheCountLimit();
67
68    /**
69     *  Set the limit to the number of entries in the font cache, and return
70     *  the previous value. If this new value is lower than the previous,
71     *  it will automatically try to purge entries to meet the new limit.
72     */
73    static int SetFontCacheCountLimit(int count);
74
75    /*
76     *  Returns the maximum point size for text that may be cached.
77     *
78     *  Sizes above this will be drawn directly from the font's outline.
79     *  Setting this to a large value may speed up drawing larger text (repeatedly),
80     *  but could cause the cache to purge other sizes more often.
81     *
82     *  This value is a hint to the font engine, and the actual limit may be different due to
83     *  implementation specific details.
84     */
85    static int GetFontCachePointSizeLimit();
86
87    /*
88     *  Set the maximum point size for text that may be cached, returning the previous value.
89     *
90     *  Sizes above this will be drawn directly from the font's outline.
91     *  Setting this to a large value may speed up drawing larger text (repeatedly),
92     *  but could cause the cache to purge other sizes more often.
93     *
94     *  This value is a hint to the font engine, and the actual limit may be different due to
95     *  implementation specific details.
96     */
97    static int SetFontCachePointSizeLimit(int maxPointSize);
98
99    /**
100     *  For debugging purposes, this will attempt to purge the font cache. It
101     *  does not change the limit, but will cause subsequent font measures and
102     *  draws to be recreated, since they will no longer be in the cache.
103     */
104    static void PurgeFontCache();
105
106    /**
107     *  Scaling bitmaps with the kHigh_SkFilterQuality setting is
108     *  expensive, so the result is saved in the global Scaled Image
109     *  Cache.
110     *
111     *  This function returns the memory usage of the Scaled Image Cache.
112     */
113    static size_t GetResourceCacheTotalBytesUsed();
114
115    /**
116     *  These functions get/set the memory usage limit for the resource cache, used for temporary
117     *  bitmaps and other resources. Entries are purged from the cache when the memory useage
118     *  exceeds this limit.
119     */
120    static size_t GetResourceCacheTotalByteLimit();
121    static size_t SetResourceCacheTotalByteLimit(size_t newLimit);
122
123    /**
124     *  For debugging purposes, this will attempt to purge the resource cache. It
125     *  does not change the limit.
126     */
127    static void PurgeResourceCache();
128
129    /**
130     *  When the cachable entry is very lage (e.g. a large scaled bitmap), adding it to the cache
131     *  can cause most/all of the existing entries to be purged. To avoid the, the client can set
132     *  a limit for a single allocation. If a cacheable entry would have been cached, but its size
133     *  exceeds this limit, then we do not attempt to cache it at all.
134     *
135     *  Zero is the default value, meaning we always attempt to cache entries.
136     */
137    static size_t GetResourceCacheSingleAllocationByteLimit();
138    static size_t SetResourceCacheSingleAllocationByteLimit(size_t newLimit);
139
140    /**
141     *  Dumps memory usage of caches using the SkTraceMemoryDump interface. See SkTraceMemoryDump
142     *  for usage of this method.
143     */
144    static void DumpMemoryStatistics(SkTraceMemoryDump* dump);
145
146    /**
147     *  Free as much globally cached memory as possible. This will purge all private caches in Skia,
148     *  including font and image caches.
149     *
150     *  If there are caches associated with GPU context, those will not be affected by this call.
151     */
152    static void PurgeAllCaches();
153
154    /**
155     *  Applications with command line options may pass optional state, such
156     *  as cache sizes, here, for instance:
157     *  font-cache-limit=12345678
158     *
159     *  The flags format is name=value[;name=value...] with no spaces.
160     *  This format is subject to change.
161     */
162    static void SetFlags(const char* flags);
163
164    /**
165     *  Return the max number of bytes that should be used by the thread-local
166     *  font cache.
167     *  If the cache needs to allocate more, it will purge previous entries.
168     *  This max can be changed by calling SetFontCacheLimit().
169     *
170     *  If this thread has never called SetTLSFontCacheLimit, or has called it
171     *  with 0, then this thread is using the shared font cache. In that case,
172     *  this function will always return 0, and the caller may want to call
173     *  GetFontCacheLimit.
174     */
175    static size_t GetTLSFontCacheLimit();
176
177    /**
178     *  Specify the max number of bytes that should be used by the thread-local
179     *  font cache. If this value is 0, then this thread will use the shared
180     *  global font cache.
181     */
182    static void SetTLSFontCacheLimit(size_t bytes);
183
184    typedef std::unique_ptr<SkImageGenerator>
185                                            (*ImageGeneratorFromEncodedDataFactory)(sk_sp<SkData>);
186
187    /**
188     *  To instantiate images from encoded data, first looks at this runtime function-ptr. If it
189     *  exists, it is called to create an SkImageGenerator from SkData. If there is no function-ptr
190     *  or there is, but it returns NULL, then skia will call its internal default implementation.
191     *
192     *  Returns the previous factory (which could be NULL).
193     */
194    static ImageGeneratorFromEncodedDataFactory
195                    SetImageGeneratorFromEncodedDataFactory(ImageGeneratorFromEncodedDataFactory);
196};
197
198class SkAutoGraphics {
199public:
200    SkAutoGraphics() {
201        SkGraphics::Init();
202    }
203};
204
205#endif
206