1 /* 2 * Copyright 2015 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 GrContextOptions_DEFINED 9 #define GrContextOptions_DEFINED 10 11 #include "include/core/SkData.h" 12 #include "include/core/SkTypes.h" 13 #include "include/gpu/GrDriverBugWorkarounds.h" 14 #include "include/gpu/GrTypes.h" 15 #include "include/private/GrTypesPriv.h" 16 17 #include <vector> 18 19 class SkExecutor; 20 21 #if SK_SUPPORT_GPU 22 struct SK_API GrContextOptions { 23 enum class Enable { 24 /** Forces an option to be disabled. */ 25 kNo, 26 /** Forces an option to be enabled. */ 27 kYes, 28 /** 29 * Uses Skia's default behavior, which may use runtime properties (e.g. driver version). 30 */ 31 kDefault 32 }; 33 34 /** 35 * Abstract class which stores Skia data in a cache that persists between sessions. Currently, 36 * Skia stores compiled shader binaries (only when glProgramBinary / glGetProgramBinary are 37 * supported) when provided a persistent cache, but this may extend to other data in the future. 38 */ 39 class SK_API PersistentCache { 40 public: ~PersistentCacheGrContextOptions41 virtual ~PersistentCache() {} 42 43 /** 44 * Returns the data for the key if it exists in the cache, otherwise returns null. 45 */ 46 virtual sk_sp<SkData> load(const SkData& key) = 0; 47 48 virtual void store(const SkData& key, const SkData& data) = 0; 49 }; 50 51 /** 52 * Abstract class to report errors when compiling shaders. If fShaderErrorHandler is present, 53 * it will be called to report any compilation failures. Otherwise, failures will be reported 54 * via SkDebugf and asserts. 55 */ 56 class SK_API ShaderErrorHandler { 57 public: ~ShaderErrorHandlerGrContextOptions58 virtual ~ShaderErrorHandler() {} 59 virtual void compileError(const char* shader, const char* errors) = 0; 60 }; 61 GrContextOptionsGrContextOptions62 GrContextOptions() {} 63 64 // Suppress prints for the GrContext. 65 bool fSuppressPrints = false; 66 67 /** Overrides: These options override feature detection using backend API queries. These 68 overrides can only reduce the feature set or limits, never increase them beyond the 69 detected values. */ 70 71 int fMaxTextureSizeOverride = SK_MaxS32; 72 73 /** the threshold in bytes above which we will use a buffer mapping API to map vertex and index 74 buffers to CPU memory in order to update them. A value of -1 means the GrContext should 75 deduce the optimal value for this platform. */ 76 int fBufferMapThreshold = -1; 77 78 /** 79 * Executor to handle threaded work within Ganesh. If this is nullptr, then all work will be 80 * done serially on the main thread. To have worker threads assist with various tasks, set this 81 * to a valid SkExecutor instance. Currently, used for software path rendering, but may be used 82 * for other tasks. 83 */ 84 SkExecutor* fExecutor = nullptr; 85 86 /** Construct mipmaps manually, via repeated downsampling draw-calls. This is used when 87 the driver's implementation (glGenerateMipmap) contains bugs. This requires mipmap 88 level and LOD control (ie desktop or ES3). */ 89 bool fDoManualMipmapping = false; 90 91 /** 92 * Disables the use of coverage counting shortcuts to render paths. Coverage counting can cause 93 * artifacts along shared edges if care isn't taken to ensure both contours wind in the same 94 * direction. 95 */ 96 // FIXME: Once this is removed from Chrome and Android, rename to fEnable"". 97 bool fDisableCoverageCountingPaths = true; 98 99 /** 100 * Disables distance field rendering for paths. Distance field computation can be expensive, 101 * and yields no benefit if a path is not rendered multiple times with different transforms. 102 */ 103 bool fDisableDistanceFieldPaths = false; 104 105 /** 106 * If true this allows path mask textures to be cached. This is only really useful if paths 107 * are commonly rendered at the same scale and fractional translation. 108 */ 109 bool fAllowPathMaskCaching = true; 110 111 /** 112 * If true, the GPU will not be used to perform YUV -> RGB conversion when generating 113 * textures from codec-backed images. 114 */ 115 bool fDisableGpuYUVConversion = false; 116 117 /** 118 * The maximum size of cache textures used for Skia's Glyph cache. 119 */ 120 size_t fGlyphCacheTextureMaximumBytes = 2048 * 1024 * 4; 121 122 /** 123 * Below this threshold size in device space distance field fonts won't be used. Distance field 124 * fonts don't support hinting which is more important at smaller sizes. A negative value means 125 * use the default threshold. 126 */ 127 float fMinDistanceFieldFontSize = -1.f; 128 129 /** 130 * Above this threshold size in device space glyphs are drawn as individual paths. A negative 131 * value means use the default threshold. 132 */ 133 float fGlyphsAsPathsFontSize = -1.f; 134 135 /** 136 * Can the glyph atlas use multiple textures. If allowed, the each texture's size is bound by 137 * fGlypheCacheTextureMaximumBytes. 138 */ 139 Enable fAllowMultipleGlyphCacheTextures = Enable::kDefault; 140 141 /** 142 * Bugs on certain drivers cause stencil buffers to leak. This flag causes Skia to avoid 143 * allocating stencil buffers and use alternate rasterization paths, avoiding the leak. 144 */ 145 bool fAvoidStencilBuffers = false; 146 147 /** 148 * If true, texture fetches from mip-mapped textures will be biased to read larger MIP levels. 149 * This has the effect of sharpening those textures, at the cost of some aliasing, and possible 150 * performance impact. 151 */ 152 bool fSharpenMipmappedTextures = false; 153 154 /** 155 * Enables driver workaround to use draws instead of HW clears, e.g. glClear on the GL backend. 156 */ 157 Enable fUseDrawInsteadOfClear = Enable::kDefault; 158 159 /** 160 * Allow Ganesh to more aggressively reorder operations. 161 * Eventually this will just be what is done and will not be optional. 162 */ 163 Enable fReduceOpListSplitting = Enable::kDefault; 164 165 /** 166 * Some ES3 contexts report the ES2 external image extension, but not the ES3 version. 167 * If support for external images is critical, enabling this option will cause Ganesh to limit 168 * shaders to the ES2 shading language in that situation. 169 */ 170 bool fPreferExternalImagesOverES3 = false; 171 172 /** 173 * Disables correctness workarounds that are enabled for particular GPUs, OSes, or drivers. 174 * This does not affect code path choices that are made for perfomance reasons nor does it 175 * override other GrContextOption settings. 176 */ 177 bool fDisableDriverCorrectnessWorkarounds = false; 178 179 /** 180 * Cache in which to store compiled shader binaries between runs. 181 */ 182 PersistentCache* fPersistentCache = nullptr; 183 184 /** 185 * This affects the usage of the PersistentCache. If this is set to true GLSL shader strings 186 * rather than GL program binaries will be cached. It is intended to be used when the driver's 187 * binary loading/storing is believed to have bugs. Caching GLSL strings still saves a 188 * significant amount of CPU work when a GL program is created. 189 */ 190 bool fDisallowGLSLBinaryCaching = false; 191 192 /** 193 * If present, use this object to report shader compilation failures. If not, report failures 194 * via SkDebugf and assert. 195 */ 196 ShaderErrorHandler* fShaderErrorHandler = nullptr; 197 198 /** 199 * Specifies the number of samples Ganesh should use when performing internal draws with MSAA or 200 * mixed samples (hardware capabilities permitting). 201 * 202 * If 0, Ganesh will disable internal code paths that use multisampling. 203 */ 204 int fInternalMultisampleCount = 4; 205 206 #if GR_TEST_UTILS 207 /** 208 * Private options that are only meant for testing within Skia's tools. 209 */ 210 211 /** 212 * If non-zero, overrides the maximum size of a tile for sw-backed images and bitmaps rendered 213 * by SkGpuDevice. 214 */ 215 int fMaxTileSizeOverride = 0; 216 217 /** 218 * Prevents use of dual source blending, to test that all xfer modes work correctly without it. 219 */ 220 bool fSuppressDualSourceBlending = false; 221 222 /** 223 * If true, the caps will never support geometry shaders. 224 */ 225 bool fSuppressGeometryShaders = false; 226 227 /** 228 * Render everything in wireframe 229 */ 230 bool fWireframeMode = false; 231 232 /** 233 * Similar to fDisallowGLSLBinaryCaching. If set to true, SkSL shader strings will be cached. 234 */ 235 bool fCacheSKSL = false; 236 237 /** 238 * Enforces clearing of all textures when they're created. 239 */ 240 bool fClearAllTextures = false; 241 242 /** 243 * Include or exclude specific GPU path renderers. 244 */ 245 GpuPathRenderers fGpuPathRenderers = GpuPathRenderers::kAll; 246 #endif 247 248 #if SK_SUPPORT_ATLAS_TEXT 249 /** 250 * Controls whether distance field glyph vertices always have 3 components even when the view 251 * matrix does not have perspective. 252 */ 253 Enable fDistanceFieldGlyphVerticesAlwaysHaveW = Enable::kDefault; 254 #endif 255 256 GrDriverBugWorkarounds fDriverBugWorkarounds; 257 }; 258 #else 259 struct GrContextOptions { 260 struct PersistentCache {}; 261 }; 262 #endif 263 264 #endif 265