Add the Spiral operation and associated enums.

gegl/source/operations/enums.rs

@@ -90,6 +90,20 @@ gegl_enum!(
   WhiteOnBlack => "white-on-black",
 );
 
+gegl_enum!(
+  /// The spiral swirl direction for [`Spiral`][super::Spiral]
+  SpiralDirection,
+  Clockwise => "cw",
+  CounterClockwise => "ccw",
+);
+
+gegl_enum!(
+  /// The spiral type for [`Spiral`][super::Spiral]
+  SpiralType,
+  Linear => "linear",
+  Logarithmic => "logarithmic",
+);
+
 gegl_enum!(
   /// The sampler type for [`StereographicProjection`][super::StereographicProjection].
   StereographicProjectionSamplerType,

gegl/source/operations/mod.rs

@@ -415,6 +415,38 @@ gegl_operation!(
   ),
 );
 
+gegl_operation!(
+  struct_name: Spiral,
+  gegl_name: "spiral",
+  append_crop: true,
+  values: (
+    /// The area balance between the two colors.
+    balance: f64, 0.0,
+    /// The logarithmic spiral base.
+    base: f64, 2.0,
+    /// The primary color.
+    color1: String, "#000".to_string(),
+    /// The secondary color.
+    color2: String, "#fff".to_string(),
+    /// The spiral swirl direction.
+    direction: SpiralDirection, SpiralDirection::Clockwise,
+    /// The height of the generated buffer.
+    height: i64, 768,
+    /// The spiral radius.
+    radius: f64, 100.0,
+    /// The spiral rotation.
+    rotation: f64, 0.0,
+    /// The spiral type.
+    spiral_type: SpiralType, SpiralType::Linear,
+    /// The X origin coordinate.
+    x: f64, 0.5,
+    /// The Y origin coordinate.
+    y: f64, 0.5,
+    /// The width of the generated buffer.
+    width: i64, 1024,
+  ),
+);
+
 gegl_operation!(
   struct_name: StereographicProjection,
   gegl_name: "stereographic-projection",