Add missing hash and convert methods for ScaledIsometry (#51)

Author: gpeairs

CHANGELOG.md

@@ -10,9 +10,10 @@ The format of this changelog is based on
 
 ### Fixed
 
-  - Rounding no longer fails when radius is less than `min_side_len` only due to numerical precision issues
+  - Rounding no longer fails when available length is less than `min_side_len` only due to numerical precision issues
   - Circular arcs in rounded polygons will no longer occasionally produce very short edges near the endpoints, and are instead now drawn with equally spaced points including the endpoints
   - `Turn` segments with `SimpleTrace` or `SimpleCPW` styles now use `atol` to determine the discretization; this is faster and in some cases more accurate than the fallback method using `adapted_grid`
+  - Added missing `hash` and `convert` methods for `ScaledIsometry`
 
 ## 1.1.1 (2025-04-16)
 

src/transform.jl

@@ -380,15 +380,33 @@ function Base.:(==)(t1::ScaledIsometry, t2::ScaledIsometry)
            t1.mag == t2.mag
 end
 
+function Base.hash(f::ScaledIsometry, h::UInt)
+    h = hash(ScaledIsometry, h)
+    # zero origin and nothing are == so should hash to the same thing
+    orig = (isnothing(f.origin) || iszero(f.origin)) ? nothing : f.origin
+    h = hash(orig, h)
+    h = hash(f.rotation % 360°, h)
+    h = hash(f.xrefl, h)
+    return hash(f.mag, h)
+end
+
+Base.convert(::Type{ScaledIsometry{Nothing}}, f::ScaledIsometry{Nothing}) = f
+Base.convert(::Type{ScaledIsometry{T}}, f::ScaledIsometry{T}) where {T <: Point} = f
+function Base.convert(
+    ::Type{ScaledIsometry{S}},
+    f::ScaledIsometry{T}
+) where {S <: Point, T <: Point}
+    return ScaledIsometry(convert(S, f.origin), f.rotation, f.xrefl, f.mag)
+end
 function Base.convert(
-    ::Type{ScaledIsometry{Point{S}}},
-    f::ScaledIsometry
-) where {S <: Coordinate}
-    orig = isnothing(f.origin) ? zero(Point{S}) : convert(Point{S}, f.origin)
-    return ScaledIsometry(orig, f.rotation, f.xrefl, f.mag)
+    ::Type{ScaledIsometry{S}},
+    f::ScaledIsometry{Nothing}
+) where {S <: Point}
+    return ScaledIsometry(zero(S), f.rotation, f.xrefl, f.mag)
 end
-Base.convert(::Type{ScaledIsometry{Point{S}}}, f::Transformation) where {S <: Coordinate} =
-    convert(ScaledIsometry{Point{S}}, ScaledIsometry(f))
+Base.convert(::Type{ScaledIsometry{S}}, f::Transformation) where {S <: Point} =
+    convert(ScaledIsometry{S}, ScaledIsometry(f))
+# Cannot convert *to* ScaledIsometry{Nothing} in general
 
 Base.isapprox(t1::Transformation, t2::ScaledIsometry; kwargs...) =
     isapprox(t1, affine(t2), kwargs...)

test/tests.jl

@@ -258,6 +258,11 @@ end
     @test !xrefl(trU)
     @test xrefl(rotFlt ∘ XReflection() ∘ rotDeg ∘ trU)
     @test !xrefl(rotFlt ∘ YReflection() ∘ trU ∘ XReflection() ∘ rotDeg)
+
+    tr = convert(ScaledIsometry{Nothing}, ScaledIsometry())
+    @test iszero(@allocated tr2 = convert(ScaledIsometry{Nothing}, tr))
+    @test convert(ScaledIsometry{Point{Int}}, tr).origin isa Point{Int}
+    @test hash(ScaledIsometry()) == hash(ScaledIsometry(Point(0, 0)))
 end
 
 @testset "Polygon rendering" begin