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