blob: 7899c31784b894a4bff187dc9b56a40bdcc21cba [file] [log] [blame]
// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "flutter/flow/layers/opacity_layer.h"
#include "flutter/fml/trace_event.h"
#include "third_party/skia/include/core/SkPaint.h"
namespace flutter {
OpacityLayer::OpacityLayer(SkAlpha alpha, const SkPoint& offset)
: alpha_(alpha), offset_(offset) {
// Ensure OpacityLayer has only one direct child.
//
// This is needed to ensure that retained rendering can always be applied to
// save the costly saveLayer.
//
// Any children will be actually added as children of this empty
// ContainerLayer.
ContainerLayer::Add(std::make_shared<ContainerLayer>());
}
void OpacityLayer::Add(std::shared_ptr<Layer> layer) {
GetChildContainer()->Add(std::move(layer));
}
void OpacityLayer::Preroll(PrerollContext* context, const SkMatrix& matrix) {
TRACE_EVENT0("flutter", "OpacityLayer::Preroll");
ContainerLayer* container = GetChildContainer();
FML_DCHECK(!container->layers().empty()); // OpacityLayer can't be a leaf.
const bool parent_is_opaque = context->is_opaque;
SkMatrix child_matrix = matrix;
child_matrix.postTranslate(offset_.fX, offset_.fY);
context->is_opaque = parent_is_opaque && (alpha_ == SK_AlphaOPAQUE);
context->mutators_stack.PushTransform(
SkMatrix::MakeTrans(offset_.fX, offset_.fY));
context->mutators_stack.PushOpacity(alpha_);
Layer::AutoPrerollSaveLayerState save =
Layer::AutoPrerollSaveLayerState::Create(context);
ContainerLayer::Preroll(context, child_matrix);
context->mutators_stack.Pop();
context->mutators_stack.Pop();
context->is_opaque = parent_is_opaque;
{
set_paint_bounds(paint_bounds().makeOffset(offset_.fX, offset_.fY));
if (!context->has_platform_view && context->raster_cache &&
SkRect::Intersects(context->cull_rect, paint_bounds())) {
SkMatrix ctm = child_matrix;
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
ctm = RasterCache::GetIntegralTransCTM(ctm);
#endif
context->raster_cache->Prepare(context, container, ctm);
}
}
}
void OpacityLayer::Paint(PaintContext& context) const {
TRACE_EVENT0("flutter", "OpacityLayer::Paint");
FML_DCHECK(needs_painting());
SkPaint paint;
paint.setAlpha(alpha_);
SkAutoCanvasRestore save(context.internal_nodes_canvas, true);
context.internal_nodes_canvas->translate(offset_.fX, offset_.fY);
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
context.internal_nodes_canvas->setMatrix(RasterCache::GetIntegralTransCTM(
context.leaf_nodes_canvas->getTotalMatrix()));
#endif
if (context.raster_cache) {
ContainerLayer* container = GetChildContainer();
const SkMatrix& ctm = context.leaf_nodes_canvas->getTotalMatrix();
RasterCacheResult child_cache = context.raster_cache->Get(container, ctm);
if (child_cache.is_valid()) {
child_cache.draw(*context.leaf_nodes_canvas, &paint);
return;
}
}
// Skia may clip the content with saveLayerBounds (although it's not a
// guaranteed clip). So we have to provide a big enough saveLayerBounds. To do
// so, we first remove the offset from paint bounds since it's already in the
// matrix. Then we round out the bounds because of our
// RasterCache::GetIntegralTransCTM optimization.
//
// Note that the following lines are only accessible when the raster cache is
// not available (e.g., when we're using the software backend in golden
// tests).
SkRect saveLayerBounds;
paint_bounds()
.makeOffset(-offset_.fX, -offset_.fY)
.roundOut(&saveLayerBounds);
Layer::AutoSaveLayer save_layer =
Layer::AutoSaveLayer::Create(context, saveLayerBounds, &paint);
PaintChildren(context);
}
#if defined(OS_FUCHSIA)
void OpacityLayer::UpdateScene(SceneUpdateContext& context) {
float saved_alpha = context.alphaf();
context.set_alphaf(context.alphaf() * (alpha_ / 255.f));
ContainerLayer::UpdateScene(context);
context.set_alphaf(saved_alpha);
}
#endif // defined(OS_FUCHSIA)
ContainerLayer* OpacityLayer::GetChildContainer() const {
FML_DCHECK(layers().size() == 1);
return static_cast<ContainerLayer*>(layers()[0].get());
}
} // namespace flutter