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      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 #include "GrSDFMaskFilter.h"
      9 #include "SkDistanceFieldGen.h"
     10 #include "SkMaskFilterBase.h"
     11 #include "SkReadBuffer.h"
     12 #include "SkSafeMath.h"
     13 #include "SkWriteBuffer.h"
     14 #include "SkString.h"
     15 
     16 class SK_API GrSDFMaskFilterImpl : public SkMaskFilterBase {
     17 public:
     18     GrSDFMaskFilterImpl();
     19 
     20     // overrides from SkMaskFilterBase
     21     //  This method is not exported to java.
     22     SkMask::Format getFormat() const override;
     23     //  This method is not exported to java.
     24     bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix&,
     25                     SkIPoint* margin) const override;
     26 
     27     void computeFastBounds(const SkRect&, SkRect*) const override;
     28 
     29 protected:
     30 
     31 private:
     32     SK_FLATTENABLE_HOOKS(GrSDFMaskFilterImpl)
     33 
     34     typedef SkMaskFilter INHERITED;
     35     friend void gr_register_sdf_maskfilter_createproc();
     36 };
     37 
     38 ///////////////////////////////////////////////////////////////////////////////
     39 
     40 GrSDFMaskFilterImpl::GrSDFMaskFilterImpl() {}
     41 
     42 SkMask::Format GrSDFMaskFilterImpl::getFormat() const {
     43     return SkMask::kSDF_Format;
     44 }
     45 
     46 bool GrSDFMaskFilterImpl::filterMask(SkMask* dst, const SkMask& src,
     47                                      const SkMatrix& matrix, SkIPoint* margin) const {
     48     if (src.fFormat != SkMask::kA8_Format
     49         && src.fFormat != SkMask::kBW_Format
     50         && src.fFormat != SkMask::kLCD16_Format) {
     51         return false;
     52     }
     53 
     54     *dst = SkMask::PrepareDestination(SK_DistanceFieldPad, SK_DistanceFieldPad, src);
     55     dst->fFormat = SkMask::kSDF_Format;
     56 
     57     if (margin) {
     58         margin->set(SK_DistanceFieldPad, SK_DistanceFieldPad);
     59     }
     60 
     61     if (src.fImage == nullptr) {
     62         return true;
     63     }
     64     if (dst->fImage == nullptr) {
     65         dst->fBounds.setEmpty();
     66         return false;
     67     }
     68 
     69     if (src.fFormat == SkMask::kA8_Format) {
     70         return SkGenerateDistanceFieldFromA8Image(dst->fImage, src.fImage,
     71                                                   src.fBounds.width(), src.fBounds.height(),
     72                                                   src.fRowBytes);
     73     } else if (src.fFormat == SkMask::kLCD16_Format) {
     74         return SkGenerateDistanceFieldFromLCD16Mask(dst->fImage, src.fImage,
     75                                                      src.fBounds.width(), src.fBounds.height(),
     76                                                      src.fRowBytes);
     77     } else {
     78         return SkGenerateDistanceFieldFromBWImage(dst->fImage, src.fImage,
     79                                                   src.fBounds.width(), src.fBounds.height(),
     80                                                   src.fRowBytes);
     81     }
     82 }
     83 
     84 void GrSDFMaskFilterImpl::computeFastBounds(const SkRect& src,
     85                                             SkRect* dst) const {
     86     dst->set(src.fLeft  - SK_DistanceFieldPad, src.fTop    - SK_DistanceFieldPad,
     87              src.fRight + SK_DistanceFieldPad, src.fBottom + SK_DistanceFieldPad);
     88 }
     89 
     90 sk_sp<SkFlattenable> GrSDFMaskFilterImpl::CreateProc(SkReadBuffer& buffer) {
     91     return GrSDFMaskFilter::Make();
     92 }
     93 
     94 void gr_register_sdf_maskfilter_createproc() { SK_REGISTER_FLATTENABLE(GrSDFMaskFilterImpl); }
     95 
     96 ///////////////////////////////////////////////////////////////////////////////
     97 
     98 sk_sp<SkMaskFilter> GrSDFMaskFilter::Make() {
     99     return sk_sp<SkMaskFilter>(new GrSDFMaskFilterImpl());
    100 }
    101