WIP on stroke rendering.

Author: chinmaygarde

impeller/aiks/aiks_unittests.cc

@@ -56,10 +56,10 @@ TEST_F(AiksTest, CanRenderImage) {
   auto image = std::make_shared<Image>(CreateTextureForFixture("kalimba.jpg"));
   paint.color = Color::Red();
   canvas.DrawImage(image, Point::MakeXY(100.0, 100.0), paint);
-  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
+  // ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
 
-TEST_F(AiksTest, CanRenderImageRect) {
+TEST_F(AiksTest, DISABLED_CanRenderImageRect) {
   Canvas canvas;
   Paint paint;
   auto image = std::make_shared<Image>(CreateTextureForFixture("kalimba.jpg"));
@@ -76,5 +76,14 @@ TEST_F(AiksTest, CanRenderImageRect) {
   // ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
 
+TEST_F(AiksTest, CanRenderStrokes) {
+  Canvas canvas;
+  Paint paint;
+  paint.color = Color::Red();
+  paint.stroke_width = 20.0;
+  canvas.DrawPath(PathBuilder{}.AddCircle({500, 500}, 250).CreatePath(), paint);
+  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
+}
+
 }  // namespace testing
 }  // namespace impeller

impeller/aiks/paint.cc

@@ -7,10 +7,18 @@
 namespace impeller {
 
 std::shared_ptr<Contents> Paint::CreateContentsForEntity() const {
-  if (!color.IsTransparent()) {
-    auto solid_color = std::make_shared<SolidColorContents>();
-    solid_color->SetColor(color);
-    return solid_color;
+  switch (style) {
+    case Style::kFill: {
+      auto solid_color = std::make_shared<SolidColorContents>();
+      solid_color->SetColor(color);
+      return solid_color;
+    }
+    case Style::kStroke: {
+      auto solid_stroke = std::make_shared<SolidStrokeContents>();
+      solid_stroke->SetColor(color);
+      solid_stroke->SetStrokeSize(stroke_width);
+      return solid_stroke;
+    }
   }
 
   return nullptr;

impeller/aiks/paint.h

@@ -4,16 +4,23 @@
 
 #pragma once
 
-#include "flutter/fml/macros.h"
+#include <memory>
 
+#include "flutter/fml/macros.h"
 #include "impeller/entity/contents.h"
 #include "impeller/geometry/color.h"
 
 namespace impeller {
 
 struct Paint {
+  enum class Style {
+    kFill,
+    kStroke,
+  };
+
   Color color;
   Scalar stroke_width = 0.0;
+  Style style = Style::kFill;
 
   std::shared_ptr<Contents> CreateContentsForEntity() const;
 };

impeller/entity/contents.cc

@@ -115,6 +115,10 @@ bool SolidColorContents::Render(const ContentRenderer& renderer,
                                 const Entity& entity,
                                 const Surface& surface,
                                 RenderPass& pass) const {
+  if (color_.IsTransparent()) {
+    return true;
+  }
+
   using VS = SolidFillPipeline::VertexShader;
 
   Command cmd;
@@ -165,18 +169,6 @@ std::unique_ptr<SolidColorContents> SolidColorContents::Make(Color color) {
   return contents;
 }
 
-/*******************************************************************************
- ******* SolidStrokeContents
- ******************************************************************************/
-
-void SolidStrokeContents::SetColor(Color color) {
-  color_ = color;
-}
-
-const Color& SolidStrokeContents::GetColor() const {
-  return color_;
-}
-
 /*******************************************************************************
  ******* TextureContents
  ******************************************************************************/
@@ -267,4 +259,39 @@ const IRect& TextureContents::GetSourceRect() const {
   return source_rect_;
 }
 
+/*******************************************************************************
+ ******* SolidStrokeContents
+ ******************************************************************************/
+
+SolidStrokeContents::SolidStrokeContents() = default;
+
+SolidStrokeContents::~SolidStrokeContents() = default;
+
+void SolidStrokeContents::SetColor(Color color) {
+  color_ = color;
+}
+
+const Color& SolidStrokeContents::GetColor() const {
+  return color_;
+}
+
+bool SolidStrokeContents::Render(const ContentRenderer& renderer,
+                                 const Entity& entity,
+                                 const Surface& surface,
+                                 RenderPass& pass) const {
+  if (color_.IsTransparent() || stroke_size_ <= 0.0) {
+    return true;
+  }
+
+  return false;
+}
+
+void SolidStrokeContents::SetStrokeSize(Scalar size) {
+  stroke_size_ = size;
+}
+
+Scalar SolidStrokeContents::GetStrokeSize() const {
+  return stroke_size_;
+}
+
 }  // namespace impeller

impeller/entity/contents.h

@@ -122,9 +122,9 @@ class SolidStrokeContents final : public Contents {
 
   const Color& GetColor() const;
 
-  void SetStrokeSize(Scalar size) { stroke_size_ = size; }
+  void SetStrokeSize(Scalar size);
 
-  Scalar GetStrokeSize() const { return stroke_size_; }
+  Scalar GetStrokeSize() const;
 
   // |Contents|
   bool Render(const ContentRenderer& renderer,