/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrContextOptions_DEFINED
#define GrContextOptions_DEFINED
#include "SkData.h"
#include "SkTypes.h"
#include "GrTypes.h"
#include "../private/GrTypesPriv.h"
#include "GrDriverBugWorkarounds.h"
#include <vector>
class SkExecutor;
#if SK_SUPPORT_GPU
struct SK_API GrContextOptions {
enum class Enable {
/** Forces an option to be disabled. */
kNo,
/** Forces an option to be enabled. */
kYes,
/**
* Uses Skia's default behavior, which may use runtime properties (e.g. driver version).
*/
kDefault
};
/**
* Abstract class which stores Skia data in a cache that persists between sessions. Currently,
* Skia stores compiled shader binaries (only when glProgramBinary / glGetProgramBinary are
* supported) when provided a persistent cache, but this may extend to other data in the future.
*/
class SK_API PersistentCache {
public:
virtual ~PersistentCache() {}
/**
* Returns the data for the key if it exists in the cache, otherwise returns null.
*/
virtual sk_sp<SkData> load(const SkData& key) = 0;
virtual void store(const SkData& key, const SkData& data) = 0;
};
GrContextOptions() {}
// Suppress prints for the GrContext.
bool fSuppressPrints = false;
/** Overrides: These options override feature detection using backend API queries. These
overrides can only reduce the feature set or limits, never increase them beyond the
detected values. */
int fMaxTextureSizeOverride = SK_MaxS32;
/** the threshold in bytes above which we will use a buffer mapping API to map vertex and index
buffers to CPU memory in order to update them. A value of -1 means the GrContext should
deduce the optimal value for this platform. */
int fBufferMapThreshold = -1;
/**
* Executor to handle threaded work within Ganesh. If this is nullptr, then all work will be
* done serially on the main thread. To have worker threads assist with various tasks, set this
* to a valid SkExecutor instance. Currently, used for software path rendering, but may be used
* for other tasks.
*/
SkExecutor* fExecutor = nullptr;
/** Construct mipmaps manually, via repeated downsampling draw-calls. This is used when
the driver's implementation (glGenerateMipmap) contains bugs. This requires mipmap
level and LOD control (ie desktop or ES3). */
bool fDoManualMipmapping = false;
/**
* Disables the coverage counting path renderer. Coverage counting can sometimes cause new
* rendering artifacts along shared edges if care isn't taken to ensure both contours wind in
* the same direction.
*/
bool fDisableCoverageCountingPaths = false;
/**
* Disables distance field rendering for paths. Distance field computation can be expensive,
* and yields no benefit if a path is not rendered multiple times with different transforms.
*/
bool fDisableDistanceFieldPaths = false;
/**
* If true this allows path mask textures to be cached. This is only really useful if paths
* are commonly rendered at the same scale and fractional translation.
*/
bool fAllowPathMaskCaching = true;
/**
* If true, the GPU will not be used to perform YUV -> RGB conversion when generating
* textures from codec-backed images.
*/
bool fDisableGpuYUVConversion = false;
/**
* The maximum size of cache textures used for Skia's Glyph cache.
*/
size_t fGlyphCacheTextureMaximumBytes = 2048 * 1024 * 4;
/**
* Below this threshold size in device space distance field fonts won't be used. Distance field
* fonts don't support hinting which is more important at smaller sizes. A negative value means
* use the default threshold.
*/
float fMinDistanceFieldFontSize = -1.f;
/**
* Above this threshold size in device space glyphs are drawn as individual paths. A negative
* value means use the default threshold.
*/
float fGlyphsAsPathsFontSize = -1.f;
/**
* Can the glyph atlas use multiple textures. If allowed, the each texture's size is bound by
* fGlypheCacheTextureMaximumBytes.
*/
Enable fAllowMultipleGlyphCacheTextures = Enable::kDefault;
/**
* Bugs on certain drivers cause stencil buffers to leak. This flag causes Skia to avoid
* allocating stencil buffers and use alternate rasterization paths, avoiding the leak.
*/
bool fAvoidStencilBuffers = false;
/**
* If true, texture fetches from mip-mapped textures will be biased to read larger MIP levels.
* This has the effect of sharpening those textures, at the cost of some aliasing, and possible
* performance impact.
*/
bool fSharpenMipmappedTextures = false;
/**
* Enables driver workaround to use draws instead of HW clears, e.g. glClear on the GL backend.
*/
Enable fUseDrawInsteadOfClear = Enable::kDefault;
/**
* Allow Ganesh to explicitly allocate resources at flush time rather than incrementally while
* drawing. This will eventually just be the way it is but, for now, it is optional.
*/
Enable fExplicitlyAllocateGPUResources = Enable::kDefault;
/**
* Allow Ganesh to sort the opLists prior to allocating resources. This is an optional
* behavior that is only relevant when 'fExplicitlyAllocateGPUResources' is enabled.
* Eventually this will just be what is done and will not be optional.
*/
Enable fSortRenderTargets = Enable::kDefault;
/**
* Allow Ganesh to more aggressively reorder operations. This is an optional
* behavior that is only relevant when 'fSortRenderTargets' is enabled.
* Eventually this will just be what is done and will not be optional.
*/
Enable fReduceOpListSplitting = Enable::kDefault;
/**
* Some ES3 contexts report the ES2 external image extension, but not the ES3 version.
* If support for external images is critical, enabling this option will cause Ganesh to limit
* shaders to the ES2 shading language in that situation.
*/
bool fPreferExternalImagesOverES3 = false;
/**
* Disables correctness workarounds that are enabled for particular GPUs, OSes, or drivers.
* This does not affect code path choices that are made for perfomance reasons nor does it
* override other GrContextOption settings.
*/
bool fDisableDriverCorrectnessWorkarounds = false;
/**
* Cache in which to store compiled shader binaries between runs.
*/
PersistentCache* fPersistentCache = nullptr;
/**
* This affects the usage of the PersistentCache. If this is set to true GLSL shader strings
* rather than GL program binaries will be cached. It is intended to be used when the driver's
* binary loading/storing is believed to have bugs. Caching GLSL strings still saves a
* significant amount of CPU work when a GL program is created.
*/
bool fDisallowGLSLBinaryCaching = false;
#if GR_TEST_UTILS
/**
* Private options that are only meant for testing within Skia's tools.
*/
/**
* If non-zero, overrides the maximum size of a tile for sw-backed images and bitmaps rendered
* by SkGpuDevice.
*/
int fMaxTileSizeOverride = 0;
/**
* Prevents use of dual source blending, to test that all xfer modes work correctly without it.
*/
bool fSuppressDualSourceBlending = false;
/**
* If true, the caps will never report driver support for path rendering.
*/
bool fSuppressPathRendering = false;
/**
* If true, the caps will never support geometry shaders.
*/
bool fSuppressGeometryShaders = false;
/**
* Render everything in wireframe
*/
bool fWireframeMode = false;
/**
* Include or exclude specific GPU path renderers.
*/
GpuPathRenderers fGpuPathRenderers = GpuPathRenderers::kAll;
#endif
#if SK_SUPPORT_ATLAS_TEXT
/**
* Controls whether distance field glyph vertices always have 3 components even when the view
* matrix does not have perspective.
*/
Enable fDistanceFieldGlyphVerticesAlwaysHaveW = Enable::kDefault;
#endif
GrDriverBugWorkarounds fDriverBugWorkarounds;
};
#else
struct GrContextOptions {
struct PersistentCache {};
};
#endif
#endif