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 "include/core/SkRefCnt.h" 12 13 class SkData; 14 class SkImageGenerator; 15 class SkTraceMemoryDump; 16 17 class SK_API SkGraphics { 18 public: 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. Term()27 static void Term() {} 28 29 /** 30 * Return the max number of bytes that should be used by the font cache. 31 * If the cache needs to allocate more, it will purge previous entries. 32 * This max can be changed by calling SetFontCacheLimit(). 33 */ 34 static size_t GetFontCacheLimit(); 35 36 /** 37 * Specify the max number of bytes that should be used by the font cache. 38 * If the cache needs to allocate more, it will purge previous entries. 39 * 40 * This function returns the previous setting, as if GetFontCacheLimit() 41 * had be called before the new limit was set. 42 */ 43 static size_t SetFontCacheLimit(size_t bytes); 44 45 /** 46 * Return the number of bytes currently used by the font cache. 47 */ 48 static size_t GetFontCacheUsed(); 49 50 /** 51 * Return the number of entries in the font cache. 52 * A cache "entry" is associated with each typeface + pointSize + matrix. 53 */ 54 static int GetFontCacheCountUsed(); 55 56 /** 57 * Return the current limit to the number of entries in the font cache. 58 * A cache "entry" is associated with each typeface + pointSize + matrix. 59 */ 60 static int GetFontCacheCountLimit(); 61 62 /** 63 * Set the limit to the number of entries in the font cache, and return 64 * the previous value. If this new value is lower than the previous, 65 * it will automatically try to purge entries to meet the new limit. 66 */ 67 static int SetFontCacheCountLimit(int count); 68 69 /* 70 * Returns the maximum point size for text that may be cached. 71 * 72 * Sizes above this will be drawn directly from the font's outline. 73 * Setting this to a large value may speed up drawing larger text (repeatedly), 74 * but could cause the cache to purge other sizes more often. 75 * 76 * This value is a hint to the font engine, and the actual limit may be different due to 77 * implementation specific details. 78 */ 79 static int GetFontCachePointSizeLimit(); 80 81 /* 82 * Set the maximum point size for text that may be cached, returning the previous value. 83 * 84 * Sizes above this will be drawn directly from the font's outline. 85 * Setting this to a large value may speed up drawing larger text (repeatedly), 86 * but could cause the cache to purge other sizes more often. 87 * 88 * This value is a hint to the font engine, and the actual limit may be different due to 89 * implementation specific details. 90 */ 91 static int SetFontCachePointSizeLimit(int maxPointSize); 92 93 /** 94 * For debugging purposes, this will attempt to purge the font cache. It 95 * does not change the limit, but will cause subsequent font measures and 96 * draws to be recreated, since they will no longer be in the cache. 97 */ 98 static void PurgeFontCache(); 99 100 /** 101 * Scaling bitmaps with the kHigh_SkFilterQuality setting is 102 * expensive, so the result is saved in the global Scaled Image 103 * Cache. 104 * 105 * This function returns the memory usage of the Scaled Image Cache. 106 */ 107 static size_t GetResourceCacheTotalBytesUsed(); 108 109 /** 110 * These functions get/set the memory usage limit for the resource cache, used for temporary 111 * bitmaps and other resources. Entries are purged from the cache when the memory useage 112 * exceeds this limit. 113 */ 114 static size_t GetResourceCacheTotalByteLimit(); 115 static size_t SetResourceCacheTotalByteLimit(size_t newLimit); 116 117 /** 118 * For debugging purposes, this will attempt to purge the resource cache. It 119 * does not change the limit. 120 */ 121 static void PurgeResourceCache(); 122 123 /** 124 * When the cachable entry is very lage (e.g. a large scaled bitmap), adding it to the cache 125 * can cause most/all of the existing entries to be purged. To avoid the, the client can set 126 * a limit for a single allocation. If a cacheable entry would have been cached, but its size 127 * exceeds this limit, then we do not attempt to cache it at all. 128 * 129 * Zero is the default value, meaning we always attempt to cache entries. 130 */ 131 static size_t GetResourceCacheSingleAllocationByteLimit(); 132 static size_t SetResourceCacheSingleAllocationByteLimit(size_t newLimit); 133 134 /** 135 * Dumps memory usage of caches using the SkTraceMemoryDump interface. See SkTraceMemoryDump 136 * for usage of this method. 137 */ 138 static void DumpMemoryStatistics(SkTraceMemoryDump* dump); 139 140 /** 141 * Free as much globally cached memory as possible. This will purge all private caches in Skia, 142 * including font and image caches. 143 * 144 * If there are caches associated with GPU context, those will not be affected by this call. 145 */ 146 static void PurgeAllCaches(); 147 148 /** 149 * Applications with command line options may pass optional state, such 150 * as cache sizes, here, for instance: 151 * font-cache-limit=12345678 152 * 153 * The flags format is name=value[;name=value...] with no spaces. 154 * This format is subject to change. 155 */ 156 static void SetFlags(const char* flags); 157 158 typedef std::unique_ptr<SkImageGenerator> 159 (*ImageGeneratorFromEncodedDataFactory)(sk_sp<SkData>); 160 161 /** 162 * To instantiate images from encoded data, first looks at this runtime function-ptr. If it 163 * exists, it is called to create an SkImageGenerator from SkData. If there is no function-ptr 164 * or there is, but it returns NULL, then skia will call its internal default implementation. 165 * 166 * Returns the previous factory (which could be NULL). 167 */ 168 static ImageGeneratorFromEncodedDataFactory 169 SetImageGeneratorFromEncodedDataFactory(ImageGeneratorFromEncodedDataFactory); 170 }; 171 172 class SkAutoGraphics { 173 public: SkAutoGraphics()174 SkAutoGraphics() { 175 SkGraphics::Init(); 176 } 177 }; 178 179 #endif 180