mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
f2dbeb8aa7
This reverts commit 6ea69a0d4339dd153899bb6c299689f1dd43329d. On top of the revert, it reverted a commit in the PR: https://github.com/flutter/engine/pull/14024 This reverts commit ea67e5b0b930ebf552bc7dbd678a35ee6a129c39.
50 lines
1.8 KiB
C++
50 lines
1.8 KiB
C++
// 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/elevated_container_layer.h"
|
|
|
|
namespace flutter {
|
|
namespace {
|
|
|
|
float ClampElevation(float elevation,
|
|
float parent_elevation,
|
|
float max_elevation) {
|
|
// TODO(mklim): Deal with bounds overflow more elegantly. We'd like to be
|
|
// able to have developers specify the behavior here to alternatives besides
|
|
// clamping, like normalization on some arbitrary curve.
|
|
float clamped_elevation = elevation;
|
|
if (max_elevation > -1 && (parent_elevation + elevation) > max_elevation) {
|
|
// Clamp the local z coordinate at our max bound. Take into account the
|
|
// parent z position here to fix clamping in cases where the child is
|
|
// overflowing because of its parents.
|
|
clamped_elevation = max_elevation - parent_elevation;
|
|
}
|
|
|
|
return clamped_elevation;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
ElevatedContainerLayer::ElevatedContainerLayer(float elevation)
|
|
: elevation_(elevation), clamped_elevation_(elevation) {}
|
|
|
|
void ElevatedContainerLayer::Preroll(PrerollContext* context,
|
|
const SkMatrix& matrix) {
|
|
TRACE_EVENT0("flutter", "ElevatedContainerLayer::Preroll");
|
|
|
|
// Track total elevation as we walk the tree, in order to deal with bounds
|
|
// overflow in z.
|
|
parent_elevation_ = context->total_elevation;
|
|
clamped_elevation_ = ClampElevation(elevation_, parent_elevation_,
|
|
context->frame_physical_depth);
|
|
context->total_elevation += clamped_elevation_;
|
|
|
|
ContainerLayer::Preroll(context, matrix);
|
|
|
|
// Restore the elevation for our parent.
|
|
context->total_elevation = parent_elevation_;
|
|
}
|
|
|
|
} // namespace flutter
|