[Impeller] remove tessellation from texture (flutter/engine#40570)

[Impeller] remove tessellation from texture contents

engine/src/flutter/impeller/entity/contents/texture_contents.cc

@@ -17,7 +17,6 @@
 #include "impeller/renderer/formats.h"
 #include "impeller/renderer/render_pass.h"
 #include "impeller/renderer/sampler_library.h"
-#include "impeller/tessellator/tessellator.h"
 
 namespace impeller {
 
@@ -27,7 +26,6 @@ TextureContents::~TextureContents() = default;
 
 std::shared_ptr<TextureContents> TextureContents::MakeRect(Rect destination) {
   auto contents = std::make_shared<TextureContents>();
-  contents->path_ = PathBuilder{}.AddRect(destination).TakePath();
   contents->rect_ = destination;
   return contents;
 }
@@ -36,9 +34,8 @@ void TextureContents::SetLabel(std::string label) {
   label_ = std::move(label);
 }
 
-void TextureContents::SetPath(const Path& path) {
-  path_ = path;
-  rect_ = std::nullopt;
+void TextureContents::SetRect(Rect rect) {
+  rect_ = rect;
 }
 
 void TextureContents::SetTexture(std::shared_ptr<Texture> texture) {
@@ -73,7 +70,7 @@ std::optional<Rect> TextureContents::GetCoverage(const Entity& entity) const {
   if (opacity_ == 0) {
     return std::nullopt;
   }
-  return path_.GetTransformedBoundingBox(entity.GetTransformation());
+  return rect_.TransformBounds(entity.GetTransformation());
 };
 
 std::optional<Snapshot> TextureContents::RenderToSnapshot(
@@ -81,21 +78,16 @@ std::optional<Snapshot> TextureContents::RenderToSnapshot(
     const Entity& entity,
     const std::optional<SamplerDescriptor>& sampler_descriptor,
     bool msaa_enabled) const {
-  auto bounds = path_.GetBoundingBox();
-  if (!bounds.has_value()) {
-    return std::nullopt;
-  }
-
   // Passthrough textures that have simple rectangle paths and complete source
   // rects.
-  if (rect_.has_value() &&
-      source_rect_ == Rect::MakeSize(texture_->GetSize()) &&
+  auto bounds = rect_;
+  if (source_rect_ == Rect::MakeSize(texture_->GetSize()) &&
       (opacity_ >= 1 - kEhCloseEnough || defer_applying_opacity_)) {
-    auto scale = Vector2(bounds->size / Size(texture_->GetSize()));
+    auto scale = Vector2(bounds.size / Size(texture_->GetSize()));
     return Snapshot{
         .texture = texture_,
         .transform = entity.GetTransformation() *
-                     Matrix::MakeTranslation(bounds->origin) *
+                     Matrix::MakeTranslation(bounds.origin) *
                      Matrix::MakeScale(scale),
         .sampler_descriptor = sampler_descriptor.value_or(sampler_descriptor_),
         .opacity = opacity_};
@@ -120,66 +112,20 @@ static TextureFillVertexShader::PerVertexData ComputeVertexData(
 bool TextureContents::Render(const ContentContext& renderer,
                              const Entity& entity,
                              RenderPass& pass) const {
-  if (texture_ == nullptr) {
-    return true;
-  }
-
   using VS = TextureFillVertexShader;
   using FS = TextureFillFragmentShader;
 
-  const auto coverage_rect = path_.GetBoundingBox();
+  const auto coverage_rect = rect_;
 
-  if (!coverage_rect.has_value()) {
-    return true;
-  }
-
-  if (coverage_rect->size.IsEmpty()) {
-    return true;
-  }
-
-  const auto texture_size = texture_->GetSize();
-  if (texture_size.IsEmpty()) {
-    return true;
-  }
-
-  if (source_rect_.IsEmpty()) {
+  if (coverage_rect.size.IsEmpty() || source_rect_.IsEmpty() ||
+      texture_ == nullptr || texture_->GetSize().IsEmpty()) {
     return true;
   }
 
   VertexBufferBuilder<VS::PerVertexData> vertex_builder;
-  if (!rect_.has_value()) {
-    const auto tess_result = renderer.GetTessellator()->Tessellate(
-        path_.GetFillType(), path_.CreatePolyline(1.0f),
-        [this, &vertex_builder, &coverage_rect, &texture_size](
-            const float* vertices, size_t vertices_size,
-            const uint16_t* indices, size_t indices_size) {
-          for (auto i = 0u; i < vertices_size; i += 2) {
-            vertex_builder.AppendVertex(ComputeVertexData(
-                {vertices[i], vertices[i + 1]}, coverage_rect.value(),
-                texture_size, source_rect_));
-          }
-          FML_DCHECK(vertex_builder.GetVertexCount() == vertices_size / 2);
-          for (auto i = 0u; i < indices_size; i++) {
-            vertex_builder.AppendIndex(indices[i]);
-          }
-          return true;
-        });
-
-    if (tess_result == Tessellator::Result::kInputError) {
-      return true;
-    }
-    if (tess_result == Tessellator::Result::kTessellationError) {
-      return false;
-    }
-  } else {
-    for (const auto vtx : rect_->GetPoints()) {
-      vertex_builder.AppendVertex(ComputeVertexData(
-          vtx, coverage_rect.value(), texture_size, source_rect_));
-    }
-  }
-
-  if (!vertex_builder.HasVertices()) {
-    return true;
+  for (const auto vtx : rect_.GetPoints()) {
+    vertex_builder.AppendVertex(ComputeVertexData(
+        vtx, coverage_rect, texture_->GetSize(), source_rect_));
   }
 
   auto& host_buffer = pass.GetTransientsBuffer();
@@ -202,9 +148,8 @@ bool TextureContents::Render(const ContentContext& renderer,
   if (!stencil_enabled_) {
     pipeline_options.stencil_compare = CompareFunction::kAlways;
   }
-  if (rect_.has_value()) {
-    pipeline_options.primitive_type = PrimitiveType::kTriangleStrip;
-  }
+  pipeline_options.primitive_type = PrimitiveType::kTriangleStrip;
+
   cmd.pipeline = renderer.GetTexturePipeline(pipeline_options);
   cmd.stencil_reference = entity.GetStencilDepth();
   cmd.BindVertices(vertex_builder.CreateVertexBuffer(host_buffer));

engine/src/flutter/impeller/entity/contents/texture_contents.h

@@ -30,7 +30,7 @@ class TextureContents final : public Contents {
 
   void SetLabel(std::string label);
 
-  void SetPath(const Path& path);
+  void SetRect(Rect rect);
 
   void SetTexture(std::shared_ptr<Texture> texture);
 
@@ -76,8 +76,7 @@ class TextureContents final : public Contents {
  private:
   std::string label_;
 
-  Path path_;
-  std::optional<Rect> rect_;
+  Rect rect_;
   bool stencil_enabled_ = true;
 
   std::shared_ptr<Texture> texture_;

engine/src/flutter/impeller/entity/entity_unittests.cc

@@ -1052,7 +1052,7 @@ TEST_P(EntityTest, GaussianBlurFilter) {
     if (selected_input_type == 0) {
       auto texture = std::make_shared<TextureContents>();
       texture->SetSourceRect(Rect::MakeSize(boston->GetSize()));
-      texture->SetPath(PathBuilder{}.AddRect(input_rect).TakePath());
+      texture->SetRect(input_rect);
       texture->SetTexture(boston);
       texture->SetOpacity(input_color.alpha);
 
@@ -1176,7 +1176,7 @@ TEST_P(EntityTest, MorphologyFilter) {
         Rect::MakeXYWH(path_rect[0], path_rect[1], path_rect[2], path_rect[3]);
     auto texture = std::make_shared<TextureContents>();
     texture->SetSourceRect(Rect::MakeSize(boston->GetSize()));
-    texture->SetPath(PathBuilder{}.AddRect(input_rect).TakePath());
+    texture->SetRect(input_rect);
     texture->SetTexture(boston);
     texture->SetOpacity(input_color.alpha);