Brian Osman | e8e5458 | 2016-11-28 10:06:27 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016 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 GrTextureProducer_DEFINED |
| 9 | #define GrTextureProducer_DEFINED |
| 10 | |
| 11 | #include "GrSamplerParams.h" |
| 12 | #include "GrResourceKey.h" |
| 13 | |
| 14 | class GrColorSpaceXform; |
| 15 | class GrTexture; |
| 16 | |
| 17 | /** |
| 18 | * Different GPUs and API extensions have different requirements with respect to what texture |
| 19 | * sampling parameters may be used with textures of various types. This class facilitates making |
| 20 | * texture compatible with a given GrSamplerParams. There are two immediate subclasses defined |
| 21 | * below. One is a base class for sources that are inherently texture-backed (e.g. a texture-backed |
| 22 | * SkImage). It supports subsetting the original texture. The other is for use cases where the |
| 23 | * source can generate a texture that represents some content (e.g. cpu pixels, SkPicture, ...). |
| 24 | */ |
| 25 | class GrTextureProducer : public SkNoncopyable { |
| 26 | public: |
| 27 | struct CopyParams { |
| 28 | GrSamplerParams::FilterMode fFilter; |
| 29 | int fWidth; |
| 30 | int fHeight; |
| 31 | }; |
| 32 | |
| 33 | enum FilterConstraint { |
| 34 | kYes_FilterConstraint, |
| 35 | kNo_FilterConstraint, |
| 36 | }; |
| 37 | |
| 38 | /** |
| 39 | * Helper for creating a fragment processor to sample the texture with a given filtering mode. |
| 40 | * It attempts to avoid making texture copies or using domains whenever possible. |
| 41 | * |
| 42 | * @param textureMatrix Matrix used to access the texture. It is applied to |
| 43 | * the local coords. The post-transformed coords should |
| 44 | * be in texel units (rather than normalized) with |
| 45 | * respect to this Producer's bounds (width()/height()). |
| 46 | * @param constraintRect A rect that represents the area of the texture to be |
| 47 | * sampled. It must be contained in the Producer's |
| 48 | * bounds as defined by width()/height(). |
| 49 | * @param filterConstriant Indicates whether filtering is limited to |
| 50 | * constraintRect. |
| 51 | * @param coordsLimitedToConstraintRect Is it known that textureMatrix*localCoords is bound |
| 52 | * by the portion of the texture indicated by |
| 53 | * constraintRect (without consideration of filter |
| 54 | * width, just the raw coords). |
| 55 | * @param filterOrNullForBicubic If non-null indicates the filter mode. If null means |
| 56 | * use bicubic filtering. |
| 57 | **/ |
| 58 | virtual sk_sp<GrFragmentProcessor> createFragmentProcessor( |
| 59 | const SkMatrix& textureMatrix, |
| 60 | const SkRect& constraintRect, |
| 61 | FilterConstraint filterConstraint, |
| 62 | bool coordsLimitedToConstraintRect, |
| 63 | const GrSamplerParams::FilterMode* filterOrNullForBicubic, |
Brian Osman | 61624f0 | 2016-12-09 14:51:59 -0500 | [diff] [blame] | 64 | SkColorSpace* dstColorSpace) = 0; |
Brian Osman | e8e5458 | 2016-11-28 10:06:27 -0500 | [diff] [blame] | 65 | |
| 66 | virtual ~GrTextureProducer() {} |
| 67 | |
| 68 | int width() const { return fWidth; } |
| 69 | int height() const { return fHeight; } |
| 70 | bool isAlphaOnly() const { return fIsAlphaOnly; } |
| 71 | virtual SkAlphaType alphaType() const = 0; |
| 72 | |
| 73 | protected: |
| 74 | GrTextureProducer(int width, int height, bool isAlphaOnly) |
| 75 | : fWidth(width) |
| 76 | , fHeight(height) |
| 77 | , fIsAlphaOnly(isAlphaOnly) {} |
| 78 | |
| 79 | /** Helper for creating a key for a copy from an original key. */ |
| 80 | static void MakeCopyKeyFromOrigKey(const GrUniqueKey& origKey, |
| 81 | const CopyParams& copyParams, |
| 82 | GrUniqueKey* copyKey) { |
| 83 | SkASSERT(!copyKey->isValid()); |
| 84 | if (origKey.isValid()) { |
| 85 | static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain(); |
| 86 | GrUniqueKey::Builder builder(copyKey, origKey, kDomain, 3); |
| 87 | builder[0] = copyParams.fFilter; |
| 88 | builder[1] = copyParams.fWidth; |
| 89 | builder[2] = copyParams.fHeight; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * If we need to make a copy in order to be compatible with GrTextureParams producer is asked to |
| 95 | * return a key that identifies its original content + the CopyParms parameter. If the producer |
| 96 | * does not want to cache the stretched version (e.g. the producer is volatile), this should |
| 97 | * simply return without initializing the copyKey. If the texture generated by this producer |
Brian Osman | 61624f0 | 2016-12-09 14:51:59 -0500 | [diff] [blame] | 98 | * depends on the destination color space, then that information should also be incorporated |
| 99 | * in the key. |
Brian Osman | e8e5458 | 2016-11-28 10:06:27 -0500 | [diff] [blame] | 100 | */ |
| 101 | virtual void makeCopyKey(const CopyParams&, GrUniqueKey* copyKey, |
Brian Osman | 61624f0 | 2016-12-09 14:51:59 -0500 | [diff] [blame] | 102 | SkColorSpace* dstColorSpace) = 0; |
Brian Osman | e8e5458 | 2016-11-28 10:06:27 -0500 | [diff] [blame] | 103 | |
| 104 | /** |
| 105 | * If a stretched version of the texture is generated, it may be cached (assuming that |
| 106 | * makeCopyKey() returns true). In that case, the maker is notified in case it |
| 107 | * wants to note that for when the maker is destroyed. |
| 108 | */ |
| 109 | virtual void didCacheCopy(const GrUniqueKey& copyKey) = 0; |
| 110 | |
| 111 | |
| 112 | enum DomainMode { |
| 113 | kNoDomain_DomainMode, |
| 114 | kDomain_DomainMode, |
| 115 | kTightCopy_DomainMode |
| 116 | }; |
| 117 | |
| 118 | static GrTexture* CopyOnGpu(GrTexture* inputTexture, const SkIRect* subset, |
| 119 | const CopyParams& copyParams); |
| 120 | |
| 121 | static DomainMode DetermineDomainMode( |
| 122 | const SkRect& constraintRect, |
| 123 | FilterConstraint filterConstraint, |
| 124 | bool coordsLimitedToConstraintRect, |
| 125 | int texW, int texH, |
| 126 | const SkIRect* textureContentArea, |
| 127 | const GrSamplerParams::FilterMode* filterModeOrNullForBicubic, |
| 128 | SkRect* domainRect); |
| 129 | |
| 130 | static sk_sp<GrFragmentProcessor> CreateFragmentProcessorForDomainAndFilter( |
| 131 | GrTexture* texture, |
| 132 | sk_sp<GrColorSpaceXform> colorSpaceXform, |
| 133 | const SkMatrix& textureMatrix, |
| 134 | DomainMode domainMode, |
| 135 | const SkRect& domain, |
| 136 | const GrSamplerParams::FilterMode* filterOrNullForBicubic); |
| 137 | |
| 138 | private: |
| 139 | const int fWidth; |
| 140 | const int fHeight; |
| 141 | const bool fIsAlphaOnly; |
| 142 | |
| 143 | typedef SkNoncopyable INHERITED; |
| 144 | }; |
| 145 | |
| 146 | #endif |