blob: dea9b8f18ebd3483eaa24d0035d31536b531fc0e [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/transform_layer.h"
namespace flutter {
TransformLayer::TransformLayer(const SkMatrix& transform)
: transform_(transform) {
// Checks (in some degree) that SkMatrix transform_ is valid and initialized.
//
// If transform_ is uninitialized, this assert may look flaky as it doesn't
// fail all the time, and some rerun may make it pass. But don't ignore it and
// just rerun the test if this is triggered, since even a flaky failure here
// may signify a potentially big problem in the code.
//
// We have to write this flaky test because there is no reliable way to test
// whether a variable is initialized or not in C++.
FML_DCHECK(transform_.isFinite());
if (!transform_.isFinite()) {
FML_LOG(ERROR) << "TransformLayer is constructed with an invalid matrix.";
transform_.setIdentity();
}
}
void TransformLayer::Preroll(PrerollContext* context, const SkMatrix& matrix) {
TRACE_EVENT0("flutter", "TransformLayer::Preroll");
SkMatrix child_matrix;
child_matrix.setConcat(matrix, transform_);
context->mutators_stack.PushTransform(transform_);
SkRect previous_cull_rect = context->cull_rect;
SkMatrix inverse_transform_;
// Perspective projections don't produce rectangles that are useful for
// culling for some reason.
if (!transform_.hasPerspective() && transform_.invert(&inverse_transform_)) {
inverse_transform_.mapRect(&context->cull_rect);
} else {
context->cull_rect = kGiantRect;
}
SkRect child_paint_bounds = SkRect::MakeEmpty();
PrerollChildren(context, child_matrix, &child_paint_bounds);
transform_.mapRect(&child_paint_bounds);
set_paint_bounds(child_paint_bounds);
context->cull_rect = previous_cull_rect;
context->mutators_stack.Pop();
}
#if defined(OS_FUCHSIA)
void TransformLayer::UpdateScene(SceneUpdateContext& context) {
TRACE_EVENT0("flutter", "TransformLayer::UpdateScene");
FML_DCHECK(needs_system_composite());
if (!transform_.isIdentity()) {
SceneUpdateContext::Transform transform(context, transform_);
UpdateSceneChildren(context);
} else {
UpdateSceneChildren(context);
}
}
#endif // defined(OS_FUCHSIA)
void TransformLayer::Paint(PaintContext& context) const {
TRACE_EVENT0("flutter", "TransformLayer::Paint");
FML_DCHECK(needs_painting());
SkAutoCanvasRestore save(context.internal_nodes_canvas, true);
context.internal_nodes_canvas->concat(transform_);
PaintChildren(context);
}
} // namespace flutter