From 0eb499311b4fc3b823dea7b1f4fa999438b6caf8 Mon Sep 17 00:00:00 2001
From: JohnnyChen <johnnychen94@hotmail.com>
Date: Thu, 2 Dec 2021 02:15:47 +0800
Subject: [PATCH] unwrap rawview(::channelview) with one reshape reinterpret

---
 src/ImageCore.jl |  5 +++++
 test/show.jl     |  7 +++++--
 test/views.jl    | 13 +++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/ImageCore.jl b/src/ImageCore.jl
index f835c9c..a9caa4a 100644
--- a/src/ImageCore.jl
+++ b/src/ImageCore.jl
@@ -115,6 +115,11 @@ rawview(a::AbstractArray{T}) where {T<:FixedPoint} = mappedarray(reinterpret, y-
 rawview(a::Array{T}) where {T<:FixedPoint} = reinterpret(FixedPointNumbers.rawtype(T), a)
 rawview(a::AbstractArray{T}) where {T<:Real} = a
 
+if VERSION >= v"1.6.0-DEV.1083"
+    # does not use the slow `mappedarray` fallback for, typically, `rawview(channelview(img))`
+    rawview(a::Base.ReinterpretArray{T}) where {T<:FixedPoint} = reinterpret(reshape, FixedPointNumbers.rawtype(T), parent(a))
+end
+
 """
     normedview([T], img::AbstractArray{Unsigned})
 
diff --git a/test/show.jl b/test/show.jl
index c521b16..a997b7f 100644
--- a/test/show.jl
+++ b/test/show.jl
@@ -35,8 +35,11 @@ RGB_str = typestring(RGB)
     rgb8 = rand(RGB{N0f8}, 3, 5)
     c = rawview(channelview(rgb8))
     str = summary(c)
-    @test occursin("3×3×5 rawview(reinterpret($(rrstr)", str) && occursin("N0f8", str) &&
-          occursin("::Array{RGB{N0f8},$(rrdim(3))}", str) && occursin("with eltype UInt8", str)
+    if VERSION >= v"1.6.0-DEV.1083"
+        @test str == "3×3×5 reinterpret(reshape, UInt8, ::Array{RGB{N0f8},2}) with eltype UInt8"
+    else
+        @test str == "3×3×5 rawview(reinterpret(N0f8, ::Array{RGB{N0f8},3})) with eltype UInt8"
+    end
     @test summary(rgb8) == "3×5 Array{RGB{N0f8},2} with eltype $(RGB_str){$(N0f8_str)}"
     rand8 = rand(UInt8, 3, 5)
     d = normedview(PermutedDimsArray(rand8, (2,1)))
diff --git a/test/views.jl b/test/views.jl
index b488eb2..b3d4fd6 100644
--- a/test/views.jl
+++ b/test/views.jl
@@ -18,6 +18,19 @@ using PaddedViews: filltype
     v[2,2] = 0x0f
     @test a[2,2].i == 0x0f
     @test rawview(v) === v
+
+    if VERSION >= v"1.6.0-DEV.1083"
+        @testset "rawview(::AbstractArray)" begin
+            a = rand(RGB{N0f8}, 5, 5)
+            X1 = rawview(channelview(a))
+            X2 = rawview(collect(channelview(a)))
+            @test !isa(parent(X1), Base.ReinterpretArray)
+            @test typeof(X1) != typeof(X2)
+            @test axes(X1) == axes(X2)
+            @test eltype(X1) == eltype(X2)
+            @test X1 == X2
+        end
+    end
 end
 
 @testset "normedview" begin