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      1 /*
      2  * Copyright 2017 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 "SkSGRenderNode.h"
      9 
     10 #include "SkCanvas.h"
     11 #include "SkPaint.h"
     12 
     13 namespace sksg {
     14 
     15 RenderNode::RenderNode() : INHERITED(0) {}
     16 
     17 void RenderNode::render(SkCanvas* canvas, const RenderContext* ctx) const {
     18     SkASSERT(!this->hasInval());
     19     this->onRender(canvas, ctx);
     20 }
     21 
     22 bool RenderNode::RenderContext::modulatePaint(SkPaint* paint) const {
     23     const auto initial_alpha = paint->getAlpha(),
     24                        alpha = SkToU8(sk_float_round2int(initial_alpha * fOpacity));
     25 
     26     if (alpha != initial_alpha || fColorFilter) {
     27         paint->setAlpha(alpha);
     28         paint->setColorFilter(SkColorFilter::MakeComposeFilter(fColorFilter,
     29                                                                paint->refColorFilter()));
     30         return true;
     31     }
     32 
     33     return false;
     34 }
     35 
     36 RenderNode::ScopedRenderContext::ScopedRenderContext(SkCanvas* canvas, const RenderContext* ctx)
     37     : fCanvas(canvas)
     38     , fCtx(ctx ? *ctx : RenderContext())
     39     , fRestoreCount(canvas->getSaveCount()) {}
     40 
     41 RenderNode::ScopedRenderContext::~ScopedRenderContext() {
     42     if (fRestoreCount >= 0) {
     43         fCanvas->restoreToCount(fRestoreCount);
     44     }
     45 }
     46 
     47 RenderNode::ScopedRenderContext&&
     48 RenderNode::ScopedRenderContext::modulateOpacity(float opacity) {
     49     SkASSERT(opacity >= 0 && opacity <= 1);
     50     fCtx.fOpacity *= opacity;
     51     return std::move(*this);
     52 }
     53 
     54 RenderNode::ScopedRenderContext&&
     55 RenderNode::ScopedRenderContext::modulateColorFilter(sk_sp<SkColorFilter> cf) {
     56     fCtx.fColorFilter = SkColorFilter::MakeComposeFilter(std::move(fCtx.fColorFilter),
     57                                                          std::move(cf));
     58     return std::move(*this);
     59 }
     60 
     61 RenderNode::ScopedRenderContext&&
     62 RenderNode::ScopedRenderContext::setIsolation(const SkRect& bounds, bool isolation) {
     63     if (isolation) {
     64         SkPaint layer_paint;
     65         if (fCtx.modulatePaint(&layer_paint)) {
     66             fCanvas->saveLayer(bounds, &layer_paint);
     67             fCtx = RenderContext();
     68         }
     69     }
     70     return std::move(*this);
     71 }
     72 
     73 } // namespace sksg
     74