43 lines
1.1 KiB
C++
43 lines
1.1 KiB
C++
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/*
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* Copyright 2018 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "SkSGOpacityEffect.h"
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#include "SkCanvas.h"
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#include <math.h>
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namespace sksg {
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OpacityEffect::OpacityEffect(sk_sp<RenderNode> child, float opacity)
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: INHERITED(std::move(child))
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, fOpacity(opacity) {}
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void OpacityEffect::onRender(SkCanvas* canvas) const {
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// opacity <= 0 disables rendering
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if (fOpacity <= 0)
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return;
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// TODO: we could avoid savelayer if there is no more than one drawing primitive
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// in the sub-DAG.
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SkAutoCanvasRestore acr(canvas, false);
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if (fOpacity < 1) {
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canvas->saveLayerAlpha(&this->bounds(), roundf(fOpacity * 255));
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}
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this->INHERITED::onRender(canvas);
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}
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SkRect OpacityEffect::onRevalidate(InvalidationController* ic, const SkMatrix& ctm) {
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SkASSERT(this->hasInval());
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// opacity <= 0 disables rendering AND revalidation for the sub-DAG
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return fOpacity > 0 ? this->INHERITED::onRevalidate(ic, ctm) : SkRect::MakeEmpty();
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}
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} // namespace sksg
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