Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2018 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 SkMaskFilterBase_DEFINED |
| 9 | #define SkMaskFilterBase_DEFINED |
| 10 | |
| 11 | #include "SkBlurTypes.h" |
| 12 | #include "SkFlattenable.h" |
| 13 | #include "SkMask.h" |
| 14 | #include "SkMaskFilter.h" |
Ben Wagner | d5148e3 | 2018-07-16 17:44:06 -0400 | [diff] [blame] | 15 | #include "SkNoncopyable.h" |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 16 | #include "SkPaint.h" |
| 17 | #include "SkStrokeRec.h" |
| 18 | |
| 19 | class GrClip; |
| 20 | class GrContext; |
| 21 | struct GrFPArgs; |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 22 | class GrFragmentProcessor; |
Robert Phillips | 20390c3 | 2018-08-17 11:01:03 -0400 | [diff] [blame^] | 23 | class GrPaint; |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 24 | class GrRenderTarget; |
Robert Phillips | 20390c3 | 2018-08-17 11:01:03 -0400 | [diff] [blame^] | 25 | class GrRenderTargetContext; |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 26 | class GrResourceProvider; |
| 27 | class GrTexture; |
| 28 | class GrTextureProxy; |
Robert Phillips | 20390c3 | 2018-08-17 11:01:03 -0400 | [diff] [blame^] | 29 | |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 30 | class SkBitmap; |
| 31 | class SkBlitter; |
| 32 | class SkCachedData; |
| 33 | class SkMatrix; |
| 34 | class SkPath; |
| 35 | class SkRasterClip; |
| 36 | class SkRRect; |
| 37 | |
| 38 | class SkMaskFilterBase : public SkMaskFilter { |
| 39 | public: |
| 40 | /** Returns the format of the resulting mask that this subclass will return |
| 41 | when its filterMask() method is called. |
| 42 | */ |
| 43 | virtual SkMask::Format getFormat() const = 0; |
| 44 | |
| 45 | /** Create a new mask by filter the src mask. |
| 46 | If src.fImage == null, then do not allocate or create the dst image |
| 47 | but do fill out the other fields in dstMask. |
| 48 | If you do allocate a dst image, use SkMask::AllocImage() |
| 49 | If this returns false, dst mask is ignored. |
| 50 | @param dst the result of the filter. If src.fImage == null, dst should not allocate its image |
| 51 | @param src the original image to be filtered. |
| 52 | @param matrix the CTM |
| 53 | @param margin if not null, return the buffer dx/dy need when calculating the effect. Used when |
| 54 | drawing a clipped object to know how much larger to allocate the src before |
| 55 | applying the filter. If returning false, ignore this parameter. |
| 56 | @return true if the dst mask was correctly created. |
| 57 | */ |
| 58 | virtual bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix&, |
Ben Wagner | 275df2e | 2018-04-25 15:27:40 -0400 | [diff] [blame] | 59 | SkIPoint* margin) const = 0; |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 60 | |
| 61 | #if SK_SUPPORT_GPU |
| 62 | /** |
| 63 | * Returns a processor if the filter can be expressed a single-pass GrProcessor without |
| 64 | * requiring an explicit input mask. Per-pixel, the effect receives the incoming mask's |
| 65 | * coverage as the input color and outputs the filtered covereage value. This means that each |
| 66 | * pixel's filtered coverage must only depend on the unfiltered mask value for that pixel and |
| 67 | * not on surrounding values. |
| 68 | */ |
| 69 | std::unique_ptr<GrFragmentProcessor> asFragmentProcessor(const GrFPArgs& args) const; |
| 70 | |
| 71 | /** |
| 72 | * Returns true iff asFragmentProcessor() will return a processor |
| 73 | */ |
| 74 | bool hasFragmentProcessor() const; |
| 75 | |
| 76 | /** |
| 77 | * If asFragmentProcessor() fails the filter may be implemented on the GPU by a subclass |
| 78 | * overriding filterMaskGPU (declared below). That code path requires constructing a |
| 79 | * src mask as input. Since that is a potentially expensive operation, the subclass must also |
| 80 | * override this function to indicate whether filterTextureMaskGPU would succeeed if the mask |
| 81 | * were to be created. |
| 82 | * |
| 83 | * 'maskRect' returns the device space portion of the mask that the filter needs. The mask |
| 84 | * passed into 'filterMaskGPU' should have the same extent as 'maskRect' but be |
| 85 | * translated to the upper-left corner of the mask (i.e., (maskRect.fLeft, maskRect.fTop) |
| 86 | * appears at (0, 0) in the mask). |
| 87 | * |
| 88 | * Logically, how this works is: |
| 89 | * canFilterMaskGPU is called |
| 90 | * if (it returns true) |
| 91 | * the returned mask rect is used for quick rejecting |
| 92 | * either directFilterMaskGPU or directFilterRRectMaskGPU is then called |
| 93 | * if (neither of them handle the blur) |
| 94 | * the mask rect is used to generate the mask |
| 95 | * filterMaskGPU is called to filter the mask |
| 96 | * |
| 97 | * TODO: this should work as: |
| 98 | * if (canFilterMaskGPU(devShape, ...)) // rect, rrect, drrect, path |
| 99 | * filterMaskGPU(devShape, ...) |
| 100 | * this would hide the RRect special case and the mask generation |
| 101 | */ |
| 102 | virtual bool canFilterMaskGPU(const SkRRect& devRRect, |
| 103 | const SkIRect& clipBounds, |
| 104 | const SkMatrix& ctm, |
| 105 | SkRect* maskRect) const; |
| 106 | |
| 107 | /** |
| 108 | * Try to directly render the mask filter into the target. Returns true if drawing was |
| 109 | * successful. If false is returned then paint is unmodified. |
| 110 | */ |
| 111 | virtual bool directFilterMaskGPU(GrContext*, |
Robert Phillips | 20390c3 | 2018-08-17 11:01:03 -0400 | [diff] [blame^] | 112 | GrRenderTargetContext*, |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 113 | GrPaint&& paint, |
| 114 | const GrClip&, |
| 115 | const SkMatrix& viewMatrix, |
| 116 | const SkStrokeRec& strokeRec, |
| 117 | const SkPath& path) const; |
| 118 | /** |
| 119 | * Try to directly render a rounded rect mask filter into the target. Returns |
| 120 | * true if drawing was successful. If false is returned then paint is unmodified. |
| 121 | */ |
| 122 | virtual bool directFilterRRectMaskGPU(GrContext*, |
Robert Phillips | 20390c3 | 2018-08-17 11:01:03 -0400 | [diff] [blame^] | 123 | GrRenderTargetContext*, |
| 124 | GrPaint&&, |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 125 | const GrClip&, |
| 126 | const SkMatrix& viewMatrix, |
Robert Phillips | 20390c3 | 2018-08-17 11:01:03 -0400 | [diff] [blame^] | 127 | const SkStrokeRec&, |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 128 | const SkRRect& rrect, |
| 129 | const SkRRect& devRRect) const; |
| 130 | |
| 131 | /** |
| 132 | * This function is used to implement filters that require an explicit src mask. It should only |
| 133 | * be called if canFilterMaskGPU returned true and the maskRect param should be the output from |
| 134 | * that call. |
| 135 | * Implementations are free to get the GrContext from the src texture in order to create |
| 136 | * additional textures and perform multiple passes. |
| 137 | */ |
| 138 | virtual sk_sp<GrTextureProxy> filterMaskGPU(GrContext*, |
| 139 | sk_sp<GrTextureProxy> srcProxy, |
| 140 | const SkMatrix& ctm, |
| 141 | const SkIRect& maskRect) const; |
| 142 | #endif |
| 143 | |
| 144 | /** |
| 145 | * The fast bounds function is used to enable the paint to be culled early |
| 146 | * in the drawing pipeline. This function accepts the current bounds of the |
| 147 | * paint as its src param and the filter adjust those bounds using its |
| 148 | * current mask and returns the result using the dest param. Callers are |
| 149 | * allowed to provide the same struct for both src and dest so each |
| 150 | * implementation must accomodate that behavior. |
| 151 | * |
| 152 | * The default impl calls filterMask with the src mask having no image, |
| 153 | * but subclasses may override this if they can compute the rect faster. |
| 154 | */ |
| 155 | virtual void computeFastBounds(const SkRect& src, SkRect* dest) const; |
| 156 | |
| 157 | struct BlurRec { |
| 158 | SkScalar fSigma; |
| 159 | SkBlurStyle fStyle; |
Mike Reed | 80747ef | 2018-01-23 15:29:32 -0500 | [diff] [blame] | 160 | }; |
| 161 | /** |
| 162 | * If this filter can be represented by a BlurRec, return true and (if not null) fill in the |
| 163 | * provided BlurRec parameter. If this effect cannot be represented as a BlurRec, return false |
| 164 | * and ignore the BlurRec parameter. |
| 165 | */ |
| 166 | virtual bool asABlur(BlurRec*) const; |
| 167 | |
| 168 | protected: |
| 169 | SkMaskFilterBase() {} |
| 170 | |
| 171 | #if SK_SUPPORT_GPU |
| 172 | virtual std::unique_ptr<GrFragmentProcessor> onAsFragmentProcessor(const GrFPArgs&) const; |
| 173 | virtual bool onHasFragmentProcessor() const; |
| 174 | #endif |
| 175 | |
| 176 | enum FilterReturn { |
| 177 | kFalse_FilterReturn, |
| 178 | kTrue_FilterReturn, |
| 179 | kUnimplemented_FilterReturn |
| 180 | }; |
| 181 | |
| 182 | class NinePatch : ::SkNoncopyable { |
| 183 | public: |
| 184 | NinePatch() : fCache(nullptr) { } |
| 185 | ~NinePatch(); |
| 186 | |
| 187 | SkMask fMask; // fBounds must have [0,0] in its top-left |
| 188 | SkIRect fOuterRect; // width/height must be >= fMask.fBounds' |
| 189 | SkIPoint fCenter; // identifies center row/col for stretching |
| 190 | SkCachedData* fCache; |
| 191 | }; |
| 192 | |
| 193 | /** |
| 194 | * Override if your subclass can filter a rect, and return the answer as |
| 195 | * a ninepatch mask to be stretched over the returned outerRect. On success |
| 196 | * return kTrue_FilterReturn. On failure (e.g. out of memory) return |
| 197 | * kFalse_FilterReturn. If the normal filterMask() entry-point should be |
| 198 | * called (the default) return kUnimplemented_FilterReturn. |
| 199 | * |
| 200 | * By convention, the caller will take the center rol/col from the returned |
| 201 | * mask as the slice it can replicate horizontally and vertically as we |
| 202 | * stretch the mask to fit inside outerRect. It is an error for outerRect |
| 203 | * to be smaller than the mask's bounds. This would imply that the width |
| 204 | * and height of the mask should be odd. This is not required, just that |
| 205 | * the caller will call mask.fBounds.centerX() and centerY() to find the |
| 206 | * strips that will be replicated. |
| 207 | */ |
| 208 | virtual FilterReturn filterRectsToNine(const SkRect[], int count, |
| 209 | const SkMatrix&, |
| 210 | const SkIRect& clipBounds, |
| 211 | NinePatch*) const; |
| 212 | /** |
| 213 | * Similar to filterRectsToNine, except it performs the work on a round rect. |
| 214 | */ |
| 215 | virtual FilterReturn filterRRectToNine(const SkRRect&, const SkMatrix&, |
| 216 | const SkIRect& clipBounds, |
| 217 | NinePatch*) const; |
| 218 | |
| 219 | private: |
| 220 | friend class SkDraw; |
| 221 | |
| 222 | /** Helper method that, given a path in device space, will rasterize it into a kA8_Format mask |
| 223 | and then call filterMask(). If this returns true, the specified blitter will be called |
| 224 | to render that mask. Returns false if filterMask() returned false. |
| 225 | This method is not exported to java. |
| 226 | */ |
| 227 | bool filterPath(const SkPath& devPath, const SkMatrix& ctm, const SkRasterClip&, SkBlitter*, |
| 228 | SkStrokeRec::InitStyle) const; |
| 229 | |
| 230 | /** Helper method that, given a roundRect in device space, will rasterize it into a kA8_Format |
| 231 | mask and then call filterMask(). If this returns true, the specified blitter will be called |
| 232 | to render that mask. Returns false if filterMask() returned false. |
| 233 | */ |
| 234 | bool filterRRect(const SkRRect& devRRect, const SkMatrix& ctm, const SkRasterClip&, |
| 235 | SkBlitter*) const; |
| 236 | |
| 237 | typedef SkFlattenable INHERITED; |
| 238 | }; |
| 239 | |
| 240 | inline SkMaskFilterBase* as_MFB(SkMaskFilter* mf) { |
| 241 | return static_cast<SkMaskFilterBase*>(mf); |
| 242 | } |
| 243 | |
| 244 | inline const SkMaskFilterBase* as_MFB(const SkMaskFilter* mf) { |
| 245 | return static_cast<const SkMaskFilterBase*>(mf); |
| 246 | } |
| 247 | |
| 248 | inline const SkMaskFilterBase* as_MFB(const sk_sp<SkMaskFilter>& mf) { |
| 249 | return static_cast<SkMaskFilterBase*>(mf.get()); |
| 250 | } |
| 251 | |
| 252 | #endif |