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      1 /*
      2  * Copyright 2012 The Android Open Source Project
      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 "SkMergeImageFilter.h"
      9 
     10 #include "SkCanvas.h"
     11 #include "SkColorSpaceXformer.h"
     12 #include "SkReadBuffer.h"
     13 #include "SkSpecialImage.h"
     14 #include "SkSpecialSurface.h"
     15 #include "SkWriteBuffer.h"
     16 #include "SkValidationUtils.h"
     17 
     18 sk_sp<SkImageFilter> SkMergeImageFilter::Make(sk_sp<SkImageFilter>* const filters, int count,
     19                                                const CropRect* cropRect) {
     20     return sk_sp<SkImageFilter>(new SkMergeImageFilter(filters, count, cropRect));
     21 }
     22 
     23 ///////////////////////////////////////////////////////////////////////////////
     24 
     25 SkMergeImageFilter::SkMergeImageFilter(sk_sp<SkImageFilter>* const filters, int count,
     26                                        const CropRect* cropRect)
     27     : INHERITED(filters, count, cropRect) {
     28     SkASSERT(count >= 0);
     29 }
     30 
     31 sk_sp<SkSpecialImage> SkMergeImageFilter::onFilterImage(SkSpecialImage* source, const Context& ctx,
     32                                                         SkIPoint* offset) const {
     33     int inputCount = this->countInputs();
     34     if (inputCount < 1) {
     35         return nullptr;
     36     }
     37 
     38     SkIRect bounds;
     39     bounds.setEmpty();
     40 
     41     std::unique_ptr<sk_sp<SkSpecialImage>[]> inputs(new sk_sp<SkSpecialImage>[inputCount]);
     42     std::unique_ptr<SkIPoint[]> offsets(new SkIPoint[inputCount]);
     43 
     44     // Filter all of the inputs.
     45     for (int i = 0; i < inputCount; ++i) {
     46         offsets[i] = { 0, 0 };
     47         inputs[i] = this->filterInput(i, source, ctx, &offsets[i]);
     48         if (!inputs[i]) {
     49             continue;
     50         }
     51         const SkIRect inputBounds = SkIRect::MakeXYWH(offsets[i].fX, offsets[i].fY,
     52                                                       inputs[i]->width(), inputs[i]->height());
     53         bounds.join(inputBounds);
     54     }
     55     if (bounds.isEmpty()) {
     56         return nullptr;
     57     }
     58 
     59     // Apply the crop rect to the union of the inputs' bounds.
     60     // Note that the crop rect can only reduce the bounds, since this
     61     // filter does not affect transparent black.
     62     bool embiggen = false;
     63     this->getCropRect().applyTo(bounds, ctx.ctm(), embiggen, &bounds);
     64     if (!bounds.intersect(ctx.clipBounds())) {
     65         return nullptr;
     66     }
     67 
     68     const int x0 = bounds.left();
     69     const int y0 = bounds.top();
     70 
     71     sk_sp<SkSpecialSurface> surf(source->makeSurface(ctx.outputProperties(), bounds.size()));
     72     if (!surf) {
     73         return nullptr;
     74     }
     75 
     76     SkCanvas* canvas = surf->getCanvas();
     77     SkASSERT(canvas);
     78 
     79     canvas->clear(0x0);
     80 
     81     // Composite all of the filter inputs.
     82     for (int i = 0; i < inputCount; ++i) {
     83         if (!inputs[i]) {
     84             continue;
     85         }
     86 
     87         inputs[i]->draw(canvas,
     88                         SkIntToScalar(offsets[i].x() - x0), SkIntToScalar(offsets[i].y() - y0),
     89                         nullptr);
     90     }
     91 
     92     offset->fX = bounds.left();
     93     offset->fY = bounds.top();
     94     return surf->makeImageSnapshot();
     95 }
     96 
     97 sk_sp<SkImageFilter> SkMergeImageFilter::onMakeColorSpace(SkColorSpaceXformer* xformer) const {
     98     SkSTArray<5, sk_sp<SkImageFilter>> inputs(this->countInputs());
     99     bool changed = false;
    100     for (int i = 0; i < this->countInputs(); i++) {
    101         inputs.push_back(xformer->apply(this->getInput(i)));
    102         changed |= (inputs[i].get() != this->getInput(i));
    103     }
    104 
    105     if (changed) {
    106         return SkMergeImageFilter::Make(inputs.begin(), this->countInputs(),
    107                                         this->getCropRectIfSet());
    108     }
    109     return this->refMe();
    110 }
    111 
    112 sk_sp<SkFlattenable> SkMergeImageFilter::CreateProc(SkReadBuffer& buffer) {
    113     Common common;
    114     if (!common.unflatten(buffer, -1) || !buffer.isValid()) {
    115         return nullptr;
    116     }
    117     return Make(common.inputs(), common.inputCount(), &common.cropRect());
    118 }
    119 
    120 void SkMergeImageFilter::flatten(SkWriteBuffer& buffer) const {
    121     this->INHERITED::flatten(buffer);
    122 }
    123 
    124 #ifndef SK_IGNORE_TO_STRING
    125 void SkMergeImageFilter::toString(SkString* str) const {
    126     str->appendf("SkMergeImageFilter: (");
    127 
    128     for (int i = 0; i < this->countInputs(); ++i) {
    129         SkImageFilter* filter = this->getInput(i);
    130         str->appendf("%d: (", i);
    131         filter->toString(str);
    132         str->appendf(")");
    133     }
    134 
    135     str->append(")");
    136 }
    137 #endif
    138