Shape::{union, subtraction, intersection, smooth_min};

Added more shapes

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "space-filling"
-version = "0.3.0"
+version = "0.3.1"
 description = "Generalized 2D space filling"
 readme = "readme.md"
 authors = ["Frederica Bernkastel <bernkastel.frederica@protonmail.com>"]

src/argmax2d.rs

@@ -96,8 +96,8 @@ fn offset_to_xy(offset: u64, width: u64) -> Point2D<u64, PixelSpace> {
   ].into()
 }
 
-fn xy_to_offset(xy: Point2D<i64, PixelSpace>, width: u64) -> u64 {
-  xy.y as u64 * width + xy.x as u64
+fn xy_to_offset(xy: Point2D<u64, PixelSpace>, width: u64) -> u64 {
+  xy.y * width + xy.x
 }
 
 impl Argmax2D {
@@ -168,7 +168,7 @@ impl Argmax2D {
     ) * self.resolution as f32;
     let chunk_span = (domain / self.chunk_size as f32)
       .round_out()
-      .to_i64();
+      .cast::<u64>();
 
     (chunk_span.min.y .. chunk_span.max.y)
       .into_par_iter()

src/drawing/impl_draw_rgbaimage.rs

@@ -125,14 +125,14 @@ fn rescale_texture(texture: &DynamicImage, size: Size2D<u32, PixelSpace>) -> Dyn
   ).resize_exact(size.width, size.height, FilterType::Triangle)
 }
 
-fn sdf_overlay_aa(sdf: f32, Δp: f32, col1: Rgba<u8>, mut col2: Rgba<u8>) -> Rgba<u8> {
+fn sdf_overlay_aa(sdf: f32, Δp: f32, mut col1: Rgba<u8>, mut col2: Rgba<u8>) -> Rgba<u8> {
   let Δf = (0.5 * Δp - sdf) // antialias
     .clamp(0.0, Δp);
   let alpha = Δf / Δp;
   // overlay blending with premultiplied alpha
   col2.0[3] = ((col2.0[3] as f32) * alpha) as u8;
-  col2.blend(&col1);
-  col2
+  col1.blend(&col2);
+  col1
 }
 
 /// Draw shapes, parallel.

src/geometry/mod.rs

@@ -1,22 +1,22 @@
 //! .
 //!
-//! The origin of coordinate system is in top-left corner. All shapes are represented in the
-//! interval [-1, 1], and center in the origin.
+//! The origin of coordinate system is in top-left corner. Most of shapes are represented in the
+//! interval `[-1, 1]`, and center in the origin.
 
 use {
   std::ops::Mul,
   euclid::{Point2D, Box2D, Vector2D as V2, Size2D, Rotation2D, Angle},
   num_traits::NumCast,
-  crate::sdf::SDF
+  crate::sdf::{SDF, Union, Subtraction, Intersection, SmoothMin}
 };
 
 pub mod shapes;
 pub use shapes::*;
 
-/// Pixel coordinate system
+/// Pixel coordinate basis
 #[derive(Debug, Copy, Clone)]
 pub struct PixelSpace;
-/// Normalized coordinate system
+/// Normalized coordinate basis
 #[derive(Debug, Copy, Clone)]
 pub struct WorldSpace;
 
@@ -29,12 +29,33 @@ pub trait Shape: SDF<f32> + BoundingBox<f32, WorldSpace> {
   fn translate<T>(self, offset: V2<T, WorldSpace>) -> Translation<Self, T> where Self: Sized {
     Translation { shape: self, offset }
   }
+  /// Rotate around the center of shape's bounding box
   fn rotate<T>(self, angle: Angle<T>) -> Rotation<Self, T> where Self: Sized {
     Rotation { shape: self, angle }
   }
+  /// Scale around the center of shape's bounding box
   fn scale<T>(self, scale: V2<T, WorldSpace>) -> Scale<Self, T> where Self: Sized {
     Scale { shape: self, scale }
   }
+  /// Union of two SDFs.
+  fn union<U>(self, other: U) -> Union<Self, U> where Self: Sized {
+    Union { s1: self, s2: other }
+  }
+  /// Subtracion of two SDFs. Note that this operation is *not* commutative,
+  /// i.e. `Subtraction {a, b} =/= Subtraction {b, a}`.
+  fn subtraction<U>(self, other: U) -> Subtraction<Self, U> where Self: Sized {
+    Subtraction { s1: self, s2: other }
+  }
+  /// Intersection of two SDFs.
+  fn intersection<U>(self, other: U) -> Intersection<Self, U> where Self: Sized {
+    Intersection { s1: self, s2: other }
+  }
+  /// Takes the minimum of two SDFs, smoothing between them when they are close.
+  ///
+  /// `k` controls the radius/distance of the smoothing. 32 is a good default value.
+  fn smooth_min<T, U>(self, other: U, k: T) -> SmoothMin<T, Self, U> where Self: Sized {
+    SmoothMin { s1: self, s2: other, k }
+  }
   #[cfg(feature = "drawing")]
   #[cfg_attr(doc, doc(cfg(feature = "drawing")))]
   fn texture<T>(self, texture: T) -> crate::drawing::Texture<Self, T> where Self: Sized {
@@ -55,6 +76,7 @@ impl <S> BoundingBox<f32, WorldSpace> for Translation<S, f32>
   }
 }
 
+/// Rotate around the center of shape's bounding box
 #[derive(Debug, Copy, Clone)]
 pub struct Rotation<S, T> {
   pub shape: S,
@@ -72,6 +94,7 @@ impl <S> BoundingBox<f32, WorldSpace> for Rotation<S, f32>
   }
 }
 
+/// Scale around the center of shape's bounding box
 #[derive(Debug, Copy, Clone)]
 pub struct Scale<S, T> {
   pub shape: S,