| // 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 "impeller/entity/contents/filters/gaussian_blur_filter_contents.h" |
| |
| #include <valarray> |
| |
| #include "impeller/base/validation.h" |
| #include "impeller/entity/contents/content_context.h" |
| #include "impeller/entity/contents/filters/filter_contents.h" |
| #include "impeller/geometry/rect.h" |
| #include "impeller/geometry/scalar.h" |
| #include "impeller/renderer/formats.h" |
| #include "impeller/renderer/render_pass.h" |
| #include "impeller/renderer/sampler_descriptor.h" |
| #include "impeller/renderer/sampler_library.h" |
| |
| namespace impeller { |
| |
| DirectionalGaussianBlurFilterContents::DirectionalGaussianBlurFilterContents() = |
| default; |
| |
| DirectionalGaussianBlurFilterContents:: |
| ~DirectionalGaussianBlurFilterContents() = default; |
| |
| void DirectionalGaussianBlurFilterContents::SetSigma(Sigma sigma) { |
| if (sigma.sigma < kEhCloseEnough) { |
| // This cutoff is an implementation detail of the blur that's tied to the |
| // fragment shader. When the blur is set to 0, having a value slightly above |
| // zero makes the shader do 1 finite sample to pass the image through with |
| // no blur (while retaining correct alpha mask behavior). |
| blur_sigma_ = Sigma{kEhCloseEnough}; |
| return; |
| } |
| blur_sigma_ = sigma; |
| } |
| |
| void DirectionalGaussianBlurFilterContents::SetDirection(Vector2 direction) { |
| blur_direction_ = direction.Normalize(); |
| if (blur_direction_.IsZero()) { |
| blur_direction_ = Vector2(0, 1); |
| } |
| } |
| |
| void DirectionalGaussianBlurFilterContents::SetBlurStyle(BlurStyle blur_style) { |
| blur_style_ = blur_style; |
| |
| switch (blur_style) { |
| case FilterContents::BlurStyle::kNormal: |
| src_color_factor_ = false; |
| inner_blur_factor_ = true; |
| outer_blur_factor_ = true; |
| break; |
| case FilterContents::BlurStyle::kSolid: |
| src_color_factor_ = true; |
| inner_blur_factor_ = false; |
| outer_blur_factor_ = true; |
| break; |
| case FilterContents::BlurStyle::kOuter: |
| src_color_factor_ = false; |
| inner_blur_factor_ = false; |
| outer_blur_factor_ = true; |
| break; |
| case FilterContents::BlurStyle::kInner: |
| src_color_factor_ = false; |
| inner_blur_factor_ = true; |
| outer_blur_factor_ = false; |
| break; |
| } |
| } |
| |
| void DirectionalGaussianBlurFilterContents::SetTileMode( |
| Entity::TileMode tile_mode) { |
| tile_mode_ = tile_mode; |
| } |
| |
| void DirectionalGaussianBlurFilterContents::SetSourceOverride( |
| FilterInput::Ref source_override) { |
| source_override_ = source_override; |
| } |
| |
| bool DirectionalGaussianBlurFilterContents::RenderFilter( |
| const FilterInput::Vector& inputs, |
| const ContentContext& renderer, |
| const Entity& entity, |
| RenderPass& pass, |
| const Rect& coverage) const { |
| if (inputs.empty()) { |
| return true; |
| } |
| |
| using VS = GaussianBlurPipeline::VertexShader; |
| using FS = GaussianBlurPipeline::FragmentShader; |
| |
| auto& host_buffer = pass.GetTransientsBuffer(); |
| |
| // Input 0 snapshot and UV mapping. |
| |
| auto input_snapshot = inputs[0]->GetSnapshot(renderer, entity); |
| if (!input_snapshot.has_value()) { |
| return true; |
| } |
| auto maybe_input_uvs = input_snapshot->GetCoverageUVs(coverage); |
| if (!maybe_input_uvs.has_value()) { |
| return true; |
| } |
| auto input_uvs = maybe_input_uvs.value(); |
| |
| // Source override snapshot and UV mapping. |
| |
| auto source = source_override_ ? source_override_ : inputs[0]; |
| auto source_snapshot = source->GetSnapshot(renderer, entity); |
| if (!source_snapshot.has_value()) { |
| return true; |
| } |
| auto maybe_source_uvs = source_snapshot->GetCoverageUVs(coverage); |
| if (!maybe_source_uvs.has_value()) { |
| return true; |
| } |
| auto source_uvs = maybe_source_uvs.value(); |
| |
| VertexBufferBuilder<VS::PerVertexData> vtx_builder; |
| vtx_builder.AddVertices({ |
| {Point(0, 0), input_uvs[0], source_uvs[0]}, |
| {Point(1, 0), input_uvs[1], source_uvs[1]}, |
| {Point(1, 1), input_uvs[3], source_uvs[3]}, |
| {Point(0, 0), input_uvs[0], source_uvs[0]}, |
| {Point(1, 1), input_uvs[3], source_uvs[3]}, |
| {Point(0, 1), input_uvs[2], source_uvs[2]}, |
| }); |
| auto vtx_buffer = vtx_builder.CreateVertexBuffer(host_buffer); |
| |
| auto transformed_blur = entity.GetTransformation().TransformDirection( |
| blur_direction_ * blur_sigma_.sigma); |
| |
| VS::FrameInfo frame_info; |
| frame_info.mvp = Matrix::MakeOrthographic(ISize(1, 1)); |
| |
| FS::FragInfo frag_info; |
| frag_info.blur_sigma = transformed_blur.GetLength(); |
| frag_info.blur_radius = Radius{Sigma{frag_info.blur_sigma}}.radius; |
| frag_info.blur_direction = input_snapshot->transform.Invert() |
| .TransformDirection(transformed_blur) |
| .Normalize(); |
| frag_info.tile_mode = static_cast<Scalar>(tile_mode_); |
| frag_info.src_factor = src_color_factor_; |
| frag_info.inner_blur_factor = inner_blur_factor_; |
| frag_info.outer_blur_factor = outer_blur_factor_; |
| frag_info.texture_size = Point(input_snapshot->GetCoverage().value().size); |
| |
| SamplerDescriptor sampler_desc; |
| sampler_desc.min_filter = MinMagFilter::kLinear; |
| sampler_desc.mag_filter = MinMagFilter::kLinear; |
| auto sampler = |
| renderer.GetContext()->GetSamplerLibrary()->GetSampler(sampler_desc); |
| |
| Command cmd; |
| cmd.label = "Gaussian Blur Filter"; |
| auto options = OptionsFromPass(pass); |
| options.blend_mode = Entity::BlendMode::kSource; |
| cmd.pipeline = renderer.GetGaussianBlurPipeline(options); |
| cmd.BindVertices(vtx_buffer); |
| |
| FS::BindTextureSampler(cmd, input_snapshot->texture, sampler); |
| FS::BindAlphaMaskSampler(cmd, source_snapshot->texture, sampler); |
| VS::BindFrameInfo(cmd, host_buffer.EmplaceUniform(frame_info)); |
| FS::BindFragInfo(cmd, host_buffer.EmplaceUniform(frag_info)); |
| |
| return pass.AddCommand(cmd); |
| } |
| |
| std::optional<Rect> DirectionalGaussianBlurFilterContents::GetFilterCoverage( |
| const FilterInput::Vector& inputs, |
| const Entity& entity) const { |
| if (inputs.empty()) { |
| return std::nullopt; |
| } |
| |
| auto coverage = inputs[0]->GetCoverage(entity); |
| if (!coverage.has_value()) { |
| return std::nullopt; |
| } |
| |
| auto transformed_blur_vector = |
| inputs[0] |
| ->GetTransform(entity) |
| .TransformDirection(blur_direction_ * Radius{blur_sigma_}.radius) |
| .Abs(); |
| auto extent = coverage->size + transformed_blur_vector * 2; |
| return Rect(coverage->origin - transformed_blur_vector, |
| Size(extent.x, extent.y)); |
| } |
| |
| } // namespace impeller |