| // 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/image_filter_layer.h" |
| #include "flutter/display_list/display_list_comparable.h" |
| #include "flutter/flow/layers/layer.h" |
| #include "flutter/flow/raster_cache_util.h" |
| |
| namespace flutter { |
| |
| ImageFilterLayer::ImageFilterLayer(std::shared_ptr<const DlImageFilter> filter) |
| : CacheableContainerLayer( |
| RasterCacheUtil::kMinimumRendersBeforeCachingFilterLayer), |
| filter_(std::move(filter)), |
| transformed_filter_(nullptr) {} |
| |
| void ImageFilterLayer::Diff(DiffContext* context, const Layer* old_layer) { |
| DiffContext::AutoSubtreeRestore subtree(context); |
| auto* prev = static_cast<const ImageFilterLayer*>(old_layer); |
| if (!context->IsSubtreeDirty()) { |
| FML_DCHECK(prev); |
| if (NotEquals(filter_, prev->filter_)) { |
| context->MarkSubtreeDirty(context->GetOldLayerPaintRegion(old_layer)); |
| } |
| } |
| |
| if (context->has_raster_cache()) { |
| context->SetTransform( |
| RasterCacheUtil::GetIntegralTransCTM(context->GetTransform())); |
| } |
| |
| if (filter_) { |
| auto filter = filter_->makeWithLocalMatrix(context->GetTransform()); |
| if (filter) { |
| // This transform will be applied to every child rect in the subtree |
| context->PushFilterBoundsAdjustment([filter](SkRect rect) { |
| SkIRect filter_out_bounds; |
| filter->map_device_bounds(rect.roundOut(), SkMatrix::I(), |
| filter_out_bounds); |
| return SkRect::Make(filter_out_bounds); |
| }); |
| } |
| } |
| DiffChildren(context, prev); |
| context->SetLayerPaintRegion(this, context->CurrentSubtreeRegion()); |
| } |
| |
| void ImageFilterLayer::Preroll(PrerollContext* context) { |
| Layer::AutoPrerollSaveLayerState save = |
| Layer::AutoPrerollSaveLayerState::Create(context); |
| |
| AutoCache cache = AutoCache(layer_raster_cache_item_.get(), context, |
| context->state_stack.transform_3x3()); |
| |
| SkRect child_bounds = SkRect::MakeEmpty(); |
| |
| PrerollChildren(context, &child_bounds); |
| |
| if (!filter_) { |
| set_paint_bounds(child_bounds); |
| return; |
| } |
| |
| // Our saveLayer would apply any outstanding opacity or any outstanding |
| // color filter after it applies our image filter. So we can apply either |
| // of those attributes with our saveLayer. |
| context->renderable_state_flags = |
| (LayerStateStack::kCallerCanApplyOpacity | |
| LayerStateStack::kCallerCanApplyColorFilter); |
| |
| const SkIRect filter_in_bounds = child_bounds.roundOut(); |
| SkIRect filter_out_bounds; |
| filter_->map_device_bounds(filter_in_bounds, SkMatrix::I(), |
| filter_out_bounds); |
| child_bounds = SkRect::Make(filter_out_bounds); |
| |
| set_paint_bounds(child_bounds); |
| |
| // CacheChildren only when the transformed_filter_ doesn't equal null. |
| // So in here we reset the LayerRasterCacheItem cache state. |
| layer_raster_cache_item_->MarkNotCacheChildren(); |
| |
| transformed_filter_ = |
| filter_->makeWithLocalMatrix(context->state_stack.transform_3x3()); |
| if (transformed_filter_) { |
| layer_raster_cache_item_->MarkCacheChildren(); |
| } |
| } |
| |
| void ImageFilterLayer::Paint(PaintContext& context) const { |
| FML_DCHECK(needs_painting(context)); |
| |
| auto mutator = context.state_stack.save(); |
| |
| if (context.raster_cache) { |
| // Always apply the integral transform in the presence of a raster cache |
| // whether or not we will draw from the cache |
| mutator.integralTransform(); |
| |
| // Try drawing the layer cache item from the cache before applying the |
| // image filter if it was cached with the filter applied. |
| if (!layer_raster_cache_item_->IsCacheChildren()) { |
| SkPaint sk_paint; |
| if (layer_raster_cache_item_->Draw(context, |
| context.state_stack.fill(sk_paint))) { |
| return; |
| } |
| } |
| } |
| |
| if (context.raster_cache && layer_raster_cache_item_->IsCacheChildren()) { |
| // If we render the children from cache then we need the special |
| // transformed version of the filter so we must process it into the |
| // cache paint object manually. |
| FML_DCHECK(transformed_filter_ != nullptr); |
| SkPaint sk_paint; |
| context.state_stack.fill(sk_paint); |
| sk_paint.setImageFilter(transformed_filter_->skia_object()); |
| if (layer_raster_cache_item_->Draw(context, &sk_paint)) { |
| return; |
| } |
| } |
| |
| // Now apply the image filter and then try rendering the children. |
| mutator.applyImageFilter(child_paint_bounds(), filter_); |
| |
| PaintChildren(context); |
| } |
| |
| } // namespace flutter |