Add example images of simulation of color deficiency

docs/crosssectionalcharts.jl

@@ -172,7 +172,7 @@ function write_png(io::IO, cs::AbstractArray{T}) where T <: Color
     u16(x) = (u8((x & 0xFFFF)>>8); u8(x))
     u32(x) = (u16((x & 0xFFFFFFFF)>>16); u16(x))
     b(bstr) = write(buf, bstr)
-    function pallet(c::Color)
+    function palette(c::Color)
         rgb24 = convert(RGB24,c)
         u8(rgb24.color>>16); u8(rgb24.color>>8); u8(rgb24.color)
     end
@@ -197,7 +197,7 @@ function write_png(io::IO, cs::AbstractArray{T}) where T <: Color
     u32(n * n * 3); flush();
     b(b"PLTE")
     for y = 1:n, x = 1:n
-        pallet(cs[y,x])
+        palette(cs[y,x])
     end
     crc32()
     # Image data

docs/make.jl

@@ -10,6 +10,7 @@ include("crosssectionalcharts.jl")
 include("colordiffcharts.jl")
 include("colormaps.jl")
 include("namedcolorcharts.jl")
+include("sampleimages.jl")
 
 
 makedocs(

docs/sampleimages.jl

@@ -0,0 +1,93 @@
+
+module SampleImages
+
+using Colors
+using Base64
+
+struct BeadsImageSVG <: Main.SVG
+    buf::IOBuffer
+end
+
+
+# The following code is ad-hoc and highly depends on "beads.svg".
+# Be careful when modifying the svg file or its code.
+function BeadsImageSVG(caption::String; filter=nothing, width="64mm", height="36mm")
+    io = IOBuffer()
+    id = string(hash(caption), base=16)
+
+    open(joinpath("assets", "figures", "beads.svg"), "r") do file
+        for line in eachline(file, keep=true)
+            occursin("<?xml", line) && continue
+            if occursin("<svg", line)
+                line = replace(line, ">"=>
+                    """width="$width" height="$height" style="display:inline; margin-left:1em; margin-bottom:1em">""")
+            elseif occursin("filter_beads_g", line)
+                line = replace(line, "filter_beads_g"=>"filter_"*id)
+            elseif occursin("</svg>", line)
+                text = """
+                       <text x="16" y="1000" style="fill:black;opacity:0.9;font-size:80px;">$caption</text>
+                       </svg>"""
+                line = replace(line, "</svg>"=>text)
+            end
+
+            m = match(r"data:image/png;base64,([^\"]+)", line)
+            if filter === nothing || m === nothing
+                write(io, line)
+                continue
+            end
+
+            head = m.offsets[1]
+            write(io, SubString(line, 1, head - 1))
+            src = IOBuffer(m.captures[1])
+            b64dec = Base64DecodePipe(src) # decode all for simplicity
+            b64enc = Base64EncodePipe(io)
+            write(b64enc, read(b64dec, 33)) # before the length of "PLTE"
+            replace_palette(b64enc, b64dec, filter)
+            n = write(b64enc, read(b64dec))
+            close(b64enc)
+            close(b64dec)
+            write(io, SubString(line, head + length(m.captures[1]), length(line)))
+        end
+    end
+    BeadsImageSVG(io)
+end
+
+
+function replace_palette(dest::IO, src::IO, filter)
+    buf = IOBuffer() # to calculate chunk CRCs
+
+    u8(x) = write(buf, UInt8(x & 0xFF))
+    u16(x) = (u8((x & 0xFFFF)>>8); u8(x))
+    u32(x) = (u16((x & 0xFFFFFFFF)>>16); u16(x))
+    function read_palette()
+        uint32 = (UInt32(read(src, UInt8)) << 16) |
+                 (UInt32(read(src, UInt8)) <<  8) | read(src, UInt8)
+        reinterpret(RGB24, uint32)
+    end
+    function write_palette(c::Color)
+        rgb24 = convert(RGB24,c)
+        u8(rgb24.color>>16); u8(rgb24.color>>8); u8(rgb24.color)
+    end
+    crct(x) = (for i = 1:8; x = x & 1==1 ? 0xEDB88320 ⊻ (x>>1) : x>>1 end; x)
+    table = UInt32[crct(i) for i = 0x00:0xFF]
+    function crc32()
+        seekstart(buf)
+        crc = 0xFFFFFFFF
+        while !eof(buf)
+            crc = (crc>>8) ⊻ table[(crc&0xFF) ⊻ read(buf, UInt8) + 1]
+        end
+        u32(crc ⊻ 0xFFFFFFFF)
+    end
+    lenbytes = read(src, 4)
+    len = (UInt32(lenbytes[3]) << 8) | lenbytes[4]
+    write(dest, lenbytes)
+    write(buf, read(src, 4)) # "PLTE"
+    for i = 1:(len÷3)
+        write_palette(filter(read_palette()))
+    end
+    read(src, 4) # CRC
+    crc32()
+    write(dest, take!(seekstart(buf)))
+end
+
+end

docs/src/advancedfunctions.md

@@ -48,7 +48,22 @@ deuteranopic(c::Color, p::Float64)
 tritanopic(c::Color, p::Float64)
 ```
 
-Also provided are versions of these functions with an extra parameter `p` in `[0, 1]`, giving the degree of photopigment loss, where 1.0 is a complete loss, and 0.0 is no loss at all.
+Also provided are versions of these functions with an extra parameter `p` in `[0, 1]`, giving the degree of photopigment loss, where `1.0` is a complete loss, and `0.0` is no loss at all. The partial loss simulates the anomalous trichromacy, i.e. *protanomaly*, *deuteranomaly* and *tritanomaly*.
+
+```@example deficiency
+using Colors #hide
+using Main: SampleImages # hide
+SampleImages.BeadsImageSVG("Normal") # hide
+```
+```@example deficiency
+SampleImages.BeadsImageSVG("Protanomaly (p=0.7)", filter=(c->protanopic(c, 0.7))) # hide
+```
+```@example deficiency
+SampleImages.BeadsImageSVG("Deuteranomaly (p=0.7)", filter=(c->deuteranopic(c, 0.7))) # hide
+```
+```@example deficiency
+SampleImages.BeadsImageSVG("Tritanomaly (p=0.7)", filter=(c->tritanopic(c, 0.7))) # hide
+```
 
 ```@docs
 protanopic