| // 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 |