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 "SkSGMaskEffect.h"
9
10#include "SkCanvas.h"
11
12namespace sksg {
13
14MaskEffect::MaskEffect(sk_sp<RenderNode> child, sk_sp<RenderNode> mask)
15    : INHERITED(std::move(child))
16    , fMaskNode(std::move(mask)) {
17    this->observeInval(fMaskNode);
18}
19
20MaskEffect::~MaskEffect() {
21    this->unobserveInval(fMaskNode);
22}
23
24void MaskEffect::onRender(SkCanvas* canvas) const {
25    if (this->bounds().isEmpty())
26        return;
27
28    SkAutoCanvasRestore acr(canvas, false);
29
30    canvas->saveLayer(this->bounds(), nullptr);
31    fMaskNode->render(canvas);
32
33
34    SkPaint p;
35    p.setBlendMode(SkBlendMode::kSrcIn);
36    canvas->saveLayer(this->bounds(), &p);
37
38    this->INHERITED::onRender(canvas);
39}
40
41
42SkRect MaskEffect::onRevalidate(InvalidationController* ic, const SkMatrix& ctm) {
43    SkASSERT(this->hasInval());
44
45    const auto maskBounds = fMaskNode->revalidate(ic, ctm);
46    auto childBounds = this->INHERITED::onRevalidate(ic, ctm);
47
48    return childBounds.intersect(maskBounds) ? childBounds : SkRect::MakeEmpty();
49}
50
51} // namespace sksg
52