RendererSupport Radial Gradient

Author: swhitty

SwiftDraw/LayerTree.CommandGenerator.swift

@@ -218,7 +218,7 @@ extension LayerTree {
         let apha = provider.createFloat(from: fill.opacity)
         commands.append(.setAlpha(apha))
 
-        commands.append(.drawGradient(gradient, from: start, to: end))
+        commands.append(.drawLinearGradient(gradient, from: start, to: end))
         commands.append(.popState)
       }
 

SwiftDraw/Renderer.CGText.swift

@@ -510,7 +510,7 @@ public final class CGTextRenderer: Renderer {
     lines.append("ctx.draw(image, in: CGRect(x: 0, y: 0, width: image.width, height: image.height)")
   }
 
-  func draw(gradient: LayerTree.Gradient, from start: String, to end: String) {
+  func draw(linear gradient: LayerTree.Gradient, from start: String, to end: String) {
     let identifier = createOrGetGradient(gradient)
     lines.append("""
     ctx.drawLinearGradient(\(identifier),
@@ -520,6 +520,18 @@ public final class CGTextRenderer: Renderer {
     """)
   }
 
+  func draw(radial gradient: LayerTree.Gradient, at center: String, radius: LayerTree.Float) {
+    let identifier = createOrGetGradient(gradient)
+    lines.append("""
+    ctx.drawLinearGradient(\(identifier),
+                           startCenter: \(center),
+                           startRadius: 0,
+                           endCenter: \(center),
+                           endRadius: radius,
+                           options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+    """)
+  }
+
   func makeText() -> String {
     var template = """
     extension UIImage {

SwiftDraw/Renderer.CoreGraphics.swift

@@ -416,11 +416,22 @@ struct CGRenderer: Renderer {
     ctx.draw(image, in: rect)
   }
 
-  func draw(gradient: CGGradient, from start: CGPoint, to end: CGPoint) {
+  func draw(linear gradient: CGGradient, from start: CGPoint, to end: CGPoint) {
     ctx.drawLinearGradient(gradient,
                            start: start,
                            end: end,
-                           options: [.drawsAfterEndLocation, .drawsBeforeStartLocation])
+                           options: [.drawsAfterEndLocation, .drawsBeforeStartLocation]
+    )
+  }
+
+  func draw(radial gradient: CGGradient, at center: CGPoint, radius: CGFloat) {
+    ctx.drawRadialGradient(gradient,
+      startCenter: center,
+      startRadius: 0,
+      endCenter: center,
+      endRadius: radius,
+      options: [.drawsAfterEndLocation, .drawsBeforeStartLocation]
+    )
   }
 }
 

SwiftDraw/Renderer.swift

@@ -102,7 +102,8 @@ protocol Renderer {
   func stroke(path: Types.Path)
   func fill(path: Types.Path, rule: Types.FillRule)
   func draw(image: Types.Image)
-  func draw(gradient: Types.Gradient, from start: Types.Point, to end: Types.Point)
+  func draw(linear gradient: Types.Gradient, from start: Types.Point, to end: Types.Point)
+  func draw(radial gradient: Types.Gradient, at center: Types.Point, radius: Types.Float)
 }
 
 extension Renderer {
@@ -152,11 +153,13 @@ extension Renderer {
       fill(path: p, rule: r)
     case .draw(image: let i):
       draw(image: i)
-    case .drawGradient(let g, let start, let end):
-      draw(gradient: g, from: start, to: end)
+    case .drawLinearGradient(let g, let start, let end):
+      draw(linear: g, from: start, to: end)
+    case .drawRadialGradient(let g, center: let center, radius: let radius):
+      draw(radial: g, at: center, radius: radius)
     }
   }
-  
+
   func perform(_ commands: [RendererCommand<Types>]) {
     for cmd in commands {
       perform(cmd)
@@ -189,8 +192,9 @@ enum RendererCommand<Types: RendererTypes> {
   case fill(Types.Path, rule: Types.FillRule)
 
   case draw(image: Types.Image)
-  case drawGradient(Types.Gradient, from: Types.Point, to: Types.Point)
-  
+  case drawLinearGradient(Types.Gradient, from: Types.Point, to: Types.Point)
+  case drawRadialGradient(Types.Gradient, center: Types.Point, radius: Types.Float)
+
   case pushTransparencyLayer
   case popTransparencyLayer
 }

SwiftDrawTests/MockRenderer.swift

@@ -126,7 +126,11 @@ final class MockRenderer: Renderer {
     operations.append("drawImage")
   }
 
-  func draw(gradient: LayerTree.Gradient, from start: LayerTree.Point, to end: LayerTree.Point) {
-    operations.append("drawGradient")
+  func draw(linear gradient: LayerTree.Gradient, from start: LayerTree.Point, to end: LayerTree.Point) {
+    operations.append("drawLinearGradient")
+  }
+
+  func draw(radial gradient: LayerTree.Gradient, at center: LayerTree.Point, radius: LayerTree.Float) {
+    operations.append("drawRadialGradient")
   }
 }

SwiftDrawTests/RendererTests.swift

@@ -59,7 +59,8 @@ final class RendererTests: XCTestCase {
       .setAlpha(0.5),
       .setBlend(mode: .sourceIn),
       .draw(image: .mock),
-      .drawGradient(.mock, from: .zero, to: .zero),
+      .drawLinearGradient(.mock, from: .zero, to: .zero),
+      .drawRadialGradient(.mock, center: .zero, radius: 100)
     ])
 
     XCTAssertEqual(renderer.operations, [
@@ -85,7 +86,8 @@ final class RendererTests: XCTestCase {
       "setAlpha",
       "setBlendMode",
       "drawImage",
-      "drawGradient"
+      "drawLinearGradient",
+      "drawRadialGradient"
     ])
   }
 }