filled contourplot

src/UnicodePlots.jl

@@ -25,6 +25,7 @@ export Plot,
     BrailleCanvas,
     DensityCanvas,
     HeatmapCanvas,
+    FilledCanvas,
     BlockCanvas,
     AsciiCanvas,
     DotCanvas,
@@ -89,6 +90,7 @@ include("canvas/blockcanvas.jl")
 include("canvas/asciicanvas.jl")
 include("canvas/dotcanvas.jl")
 include("canvas/heatmapcanvas.jl")
+include("canvas/filledcanvas.jl")
 
 include("description.jl")
 include("volume.jl")

src/canvas/asciicanvas.jl

@@ -26,7 +26,7 @@ struct AsciiCanvas{YS<:Function,XS<:Function} <: LookupCanvas
 end
 
 const N_ASCII = grid_type(AsciiCanvas)(512)
-const ASCII_SIGNS = [
+const ASCII_ENCODE = [
     0b100_000_000 0b010_000_000 0b001_000_000
     0b000_100_000 0b000_010_000 0b000_001_000
     0b000_000_100 0b000_000_010 0b000_000_001
@@ -123,7 +123,7 @@ ASCII_DECODE[(N_ASCII + 1):typemax(N_ASCII)] = UNICODE_TABLE[1:(typemax(N_ASCII)
 @inline y_pixel_per_char(::Type{<:AsciiCanvas}) = 3
 @inline x_pixel_per_char(::Type{<:AsciiCanvas}) = 3
 
-@inline lookup_encode(::AsciiCanvas) = ASCII_SIGNS
+@inline lookup_encode(::AsciiCanvas) = ASCII_ENCODE
 @inline lookup_decode(::AsciiCanvas) = ASCII_DECODE
 @inline lookup_offset(::AsciiCanvas) = N_ASCII
 

src/canvas/blockcanvas.jl

@@ -22,12 +22,11 @@ struct BlockCanvas{YS<:Function,XS<:Function} <: LookupCanvas
     xscale::XS
 end
 
-const BLOCK_SIGNS = [
+const N_BLOCK = grid_type(BlockCanvas)(16)
+const BLOCK_ENCODE = [
     0b1000 0b0100
     0b0010 0b0001
 ]
-
-const N_BLOCK = grid_type(BlockCanvas)(16)
 const BLOCK_DECODE = Vector{Char}(undef, typemax(N_BLOCK))
 
 BLOCK_DECODE[1] = ' '
@@ -51,7 +50,7 @@ BLOCK_DECODE[(N_BLOCK + 1):typemax(N_BLOCK)] = UNICODE_TABLE[1:(typemax(N_BLOCK)
 @inline x_pixel_per_char(::Type{<:BlockCanvas}) = 2
 @inline y_pixel_per_char(::Type{<:BlockCanvas}) = 2
 
-@inline lookup_encode(::BlockCanvas) = BLOCK_SIGNS
+@inline lookup_encode(::BlockCanvas) = BLOCK_ENCODE
 @inline lookup_decode(::BlockCanvas) = BLOCK_DECODE
 @inline lookup_offset(::BlockCanvas) = N_BLOCK
 

src/canvas/braillecanvas.jl

@@ -1,11 +1,3 @@
-# braille dots composing ⣿
-const BRAILLE_SIGNS = UnicodeType.([
-    '⠁' '⠈'
-    '⠂' '⠐'
-    '⠄' '⠠'
-    '⡀' '⢀'
-])
-
 """
 The type of canvas with the highest resolution for Unicode-based plotting.
 It uses the Unicode characters for the Braille symbols to represent individual pixel.
@@ -28,6 +20,14 @@ struct BrailleCanvas{YS<:Function,XS<:Function} <: Canvas
     xscale::XS
 end
 
+# braille dots composing ⣿
+const BRAILLE_ENCODE = UnicodeType.([
+    '⠁' '⠈'
+    '⠂' '⠐'
+    '⠄' '⠠'
+    '⡀' '⢀'
+])
+
 @inline blank(c::BrailleCanvas) = Char(BLANK_BRAILLE)
 
 @inline y_pixel_per_char(::Type{<:BrailleCanvas}) = 4
@@ -85,7 +85,7 @@ function pixel!(
     char_x, char_y, char_x_off, char_y_off = pixel_to_char_point_off(c, pixel_x, pixel_y)
     if checkbounds(Bool, c.grid, char_y, char_x)
         if BLANK_BRAILLE ≤ (val = c.grid[char_y, char_x]) ≤ FULL_BRAILLE
-            c.grid[char_y, char_x] = val | BRAILLE_SIGNS[char_y_off, char_x_off]
+            c.grid[char_y, char_x] = val | BRAILLE_ENCODE[char_y_off, char_x_off]
         end
         set_color!(c, char_x, char_y, color, blend)
     end

src/canvas/densitycanvas.jl

@@ -1,5 +1,3 @@
-const DEN_SIGNS = Ref((' ', '░', '▒', '▓', '█'))
-
 """
 Unlike the `BrailleCanvas`, the density canvas does not simply mark a "pixel" as set.
 Instead it increments a counter per character that keeps track of the frequency of pixels drawn in that character.
@@ -24,6 +22,8 @@ struct DensityCanvas{YS<:Function,XS<:Function,DS<:Function} <: Canvas
     dscale::DS
 end
 
+const DEN_DECODE = Ref((' ', '░', '▒', '▓', '█'))
+
 @inline y_pixel_per_char(::Type{<:DensityCanvas}) = 2
 @inline x_pixel_per_char(::Type{<:DensityCanvas}) = 1
 
@@ -94,11 +94,11 @@ end
 
 function print_row(io::IO, _, print_color, c::DensityCanvas, row::Integer)
     1 ≤ row ≤ nrows(c) || throw(ArgumentError("`row` out of bounds: $row"))
-    signs = DEN_SIGNS[]
-    fact = (length(signs) - 1) / c.max_density[]
+    decoder = DEN_DECODE[]
+    fact = (length(decoder) - 1) / c.max_density[]
     for col ∈ 1:ncols(c)
         val = fact * c.dscale(c.grid[row, col])
-        print_color(io, c.colors[row, col], signs[round(Int, val, RoundNearestTiesUp) + 1])
+        print_color(io, c.colors[row, col], decoder[round(Int, val, RoundNearestTiesUp) + 1])
     end
     nothing
 end

src/canvas/dotcanvas.jl

@@ -26,8 +26,9 @@ struct DotCanvas{YS<:Function,XS<:Function} <: LookupCanvas
 end
 
 const N_DOT = grid_type(DotCanvas)(4)
-const DOT_SIGNS = [0b10; 0b01]
+const DOT_ENCODE = [0b10; 0b01]
 const DOT_DECODE = Array{Char}(undef, typemax(N_DOT))
+
 DOT_DECODE[1] = ' '
 DOT_DECODE[2] = '.'
 DOT_DECODE[3] = '\''
@@ -37,7 +38,7 @@ DOT_DECODE[(N_DOT + 1):typemax(N_DOT)] = UNICODE_TABLE[1:(typemax(N_DOT) - N_DOT
 @inline y_pixel_per_char(::Type{<:DotCanvas}) = 2
 @inline x_pixel_per_char(::Type{<:DotCanvas}) = 1
 
-@inline lookup_encode(::DotCanvas) = DOT_SIGNS
+@inline lookup_encode(::DotCanvas) = DOT_ENCODE
 @inline lookup_decode(::DotCanvas) = DOT_DECODE
 @inline lookup_offset(::DotCanvas) = N_DOT
 

src/canvas/filledcanvas.jl

@@ -0,0 +1,99 @@
+"""
+FilledCanvas uses the Unicode [Symbols for Legacy Computing](https://en.wikipedia.org/wiki/Symbols_for_Legacy_Computing)
+to draw boundary segments. This is used for filled contour plots.
+"""
+
+struct FilledCanvas{YS<:Function,XS<:Function} <: LookupCanvas
+    grid::Transpose{UInt16,Matrix{UInt16}}
+    colors::Transpose{ColorType,Matrix{ColorType}}
+    visible::Bool
+    blend::Bool
+    yflip::Bool
+    xflip::Bool
+    pixel_height::Int
+    pixel_width::Int
+    origin_y::Float64
+    origin_x::Float64
+    height::Float64
+    width::Float64
+    min_max::NTuple{2,UnicodeType}
+    yscale::YS
+    xscale::XS
+end
+
+const FILLED_LOOKUP = Dict{NTuple{2, Int},Char}()
+
+FILLED_LOOKUP[(1, 4)]= '🭍'
+FILLED_LOOKUP[(1, 5)]= '🭏'
+FILLED_LOOKUP[(1, 6)]= '◣'
+FILLED_LOOKUP[(1, 7)]= '🭀'
+FILLED_LOOKUP[(2, 4)]= '🭌'
+FILLED_LOOKUP[(2, 5)]= '🭎'
+FILLED_LOOKUP[(2, 6)]= '🭐'
+FILLED_LOOKUP[(2, 7)]= '▌'
+FILLED_LOOKUP[(2, 8)]= '🭛'
+FILLED_LOOKUP[(2, 9)]= '🭙'
+FILLED_LOOKUP[(2, 10)]= '🭗'
+FILLED_LOOKUP[(3, 7)]= '🭡'
+FILLED_LOOKUP[(3, 8)]= '◤'
+FILLED_LOOKUP[(3, 9)]= '🭚'
+FILLED_LOOKUP[(3, 10)]= '🭘'
+FILLED_LOOKUP[(4, 1)]= '🭣'
+FILLED_LOOKUP[(4, 2)]= '🭢'
+FILLED_LOOKUP[(4, 7)]= '🭟'
+FILLED_LOOKUP[(4, 8)]= '🭠'
+FILLED_LOOKUP[(4, 9)]= '🭜'
+FILLED_LOOKUP[(4, 10)]= '🬂'
+FILLED_LOOKUP[(5, 1)]= '🭥'
+FILLED_LOOKUP[(5, 2)]= '🭤'
+FILLED_LOOKUP[(5, 7)]= '🭝'
+FILLED_LOOKUP[(5, 8)]= '🭞'
+FILLED_LOOKUP[(5, 9)]= '🬎'
+FILLED_LOOKUP[(5, 10)]= '🭧'
+FILLED_LOOKUP[(6, 1)]= '◥'
+FILLED_LOOKUP[(6, 2)]= '🭦'
+FILLED_LOOKUP[(6, 9)]= '🭓'
+FILLED_LOOKUP[(6, 10)]= '🭕'
+FILLED_LOOKUP[(7, 1)]= '🭖'
+FILLED_LOOKUP[(7, 2)]= '▐'
+FILLED_LOOKUP[(7, 3)]= '🭋'
+FILLED_LOOKUP[(7, 4)]= '🭉'
+FILLED_LOOKUP[(7, 5)]= '🭇'
+FILLED_LOOKUP[(7, 9)]= '🭒'
+FILLED_LOOKUP[(7, 10)]= '🭔'
+FILLED_LOOKUP[(8, 2)]= '🭅'
+FILLED_LOOKUP[(8, 3)]= '◢'
+FILLED_LOOKUP[(8, 4)]= '🭊'
+FILLED_LOOKUP[(8, 5)]= '🭈'
+FILLED_LOOKUP[(9, 2)]= '🭃'
+FILLED_LOOKUP[(9, 3)]= '🭄'
+FILLED_LOOKUP[(9, 4)]= '🭆'
+FILLED_LOOKUP[(9, 5)]= '🬭'
+FILLED_LOOKUP[(9, 6)]= '🬽'
+FILLED_LOOKUP[(9, 7)]= '🬼'
+FILLED_LOOKUP[(10, 2)]= '🭁'
+FILLED_LOOKUP[(10, 3)]= '🭂'
+FILLED_LOOKUP[(10, 4)]= '🬹'
+FILLED_LOOKUP[(10, 5)]= '🭑'
+FILLED_LOOKUP[(10, 6)]= '🬿'
+FILLED_LOOKUP[(10, 7)]= '🬾'
+
+const N_FILLED = grid_type(FilledCanvas)(56)
+const FILLED_DECODE = Vector{Char}(undef, typemax(N_FILLED))
+
+FILLED_DECODE[1] = EMPTY_BLOCK   # replaced during rendering, not to overdraw lower layers
+FILLED_DECODE[2] = FULL_BLOCK
+let n = 0
+    for (_, v) ∈ sort(collect(FILLED_LOOKUP))
+        FILLED_DECODE[(n += 1)+2] = v
+    end
+end
+
+@inline x_pixel_per_char(::Type{<:FilledCanvas}) = 1
+@inline y_pixel_per_char(::Type{<:FilledCanvas}) = 1
+
+@inline lookup_encode(::FilledCanvas) = FILLED_ENCODE
+@inline lookup_decode(::FilledCanvas) = FILLED_DECODE
+@inline lookup_offset(::FilledCanvas) = N_FILLED
+
+FilledCanvas(args...; kw...) = CreateLookupCanvas(FilledCanvas, (0, 56), args...; kw...)

src/canvas/heatmapcanvas.jl

@@ -1,6 +1,3 @@
-const HEATMAP_SIGNS = [0 1; 0 1]
-const HEATMAP_DECODE = [HALF_BLOCK; HALF_BLOCK]
-
 """
 The `HeatmapCanvas` is also Unicode-based.
 It has a half the resolution of the `BlockCanvas`.
@@ -24,12 +21,15 @@ struct HeatmapCanvas{YS<:Function,XS<:Function} <: LookupCanvas
     xscale::XS
 end
 
+const HEATMAP_ENCODE = [0 1; 0 1]
+const HEATMAP_DECODE = [HALF_BLOCK; HALF_BLOCK]
+
 @inline nrows(c::HeatmapCanvas) = div(size(c.grid, 1) + 1, 2)
 
 @inline y_pixel_per_char(::Type{<:HeatmapCanvas}) = 2
 @inline x_pixel_per_char(::Type{<:HeatmapCanvas}) = 1
 
-@inline lookup_encode(::HeatmapCanvas) = HEATMAP_SIGNS
+@inline lookup_encode(::HeatmapCanvas) = HEATMAP_ENCODE
 @inline lookup_decode(::HeatmapCanvas) = HEATMAP_DECODE
 
 function HeatmapCanvas(args...; kw...)

src/common.jl

@@ -227,6 +227,7 @@ const BASES = (identity = nothing, ln = "ℯ", log2 = "2", log10 = "10")
 
 const FULL_BLOCK = '█'
 const HALF_BLOCK = '▄'
+const EMPTY_BLOCK = '\0'
 
 # standard terminals seem to respect a 4:3 aspect ratio
 # unix.stackexchange.com/questions/148569/standard-terminal-font-aspect-ratio

src/interface/contourplot.jl

@@ -13,7 +13,7 @@ Draws a contour plot on a new canvas.
 $(arguments(
     (
         A = "`Matrix` of interest for which contours are extracted, or `Function` evaluated as `f(x, y)`",
-        levels = "the number of contour levels",
+        levels = "the number of contour levels or a vector of levels",
     ); add = (Z_DESCRIPTION..., :x, :y, :canvas), remove = (:blend, :grid)
 ))
 
@@ -70,7 +70,22 @@ function contourplot(
         pkw...,
     )
     A isa Function && (A = A.(x', y))
-    contourplot!(plot, x, y, A; colormap, okw...)
+    if canvas === FilledCanvas
+        # TODO: process levels, and fill the canvas
+
+       # Note that displaying the characters is not done here (delayed to using `show`, `display` or `savefig` on the plot)
+       # and that is handled in `src/show.jl`: https://github.com/JuliaPlots/UnicodePlots.jl/blob/master/src/show.jl#L301
+
+       # There, each canvas row is printed: since `FilledCanvas` is a subtype of the abstract type `LookupCanvas`,
+       # `lookup_decode` must be implemented such that decoding can occur in here:
+       # https://github.com/JuliaPlots/UnicodePlots.jl/blob/master/src/canvas/lookupcanvas.jl#L75
+
+       # I would suggest taking inspiration from `src/interface/heatmap.jl` for filling the grid and colors:
+       # https://github.com/JuliaPlots/UnicodePlots.jl/blob/master/src/interface/heatmap.jl#L192-L196
+        println("unimplemented")
+    else
+        contourplot!(plot, x, y, A; colormap, okw...)
+    end
 end
 
 @doc (@doc contourplot) function contourplot!(
@@ -81,11 +96,11 @@ end
     name::AbstractString = KEYWORDS.name,
     colormap = KEYWORDS.colormap,
     zlim = KEYWORDS.zlim,
-    levels::Integer = 3,
+    levels::Union{Integer,AbstractVector{<:Real}} = 3,
 )
     isempty(name) || label!(plot, :r, string(name))
 
-    mA, MA = nanless_extrema(A)
+    mA, MA = nanless_extrema(levels isa Integer ? A : levels)
     plot.cmap.lim = (mh, Mh) = is_auto(zlim) ? (mA, MA) : zlim
     plot.cmap.callback = callback = colormap_callback(colormap)
 

test/tst_contourplot.jl

@@ -30,6 +30,11 @@ end
     test_ref("contourplot/gauss_$(levels)levels.txt", @show_col(p))
 end
 
+@testset "custom levels" begin
+    p = @binf contourplot(gaussian_2d()...; levels = [0.2, 0.5, 0.6, 0.8])
+    test_ref("contourplot/gauss_customlevels.txt", @show_col(p))
+end
+
 @testset "update contourplot" begin
     p = @binf contourplot(gaussian_2d()...; levels = 2)
     # mutate the colormap & number of levels
@@ -53,3 +58,10 @@ end
     p = contourplot(x, y, z; levels = 10)
     test_ref("contourplot/consistency.txt", @show_col(p))
 end
+
+@testset "filled `contourplot`" begin
+    himmelblau(x, y) = (x^2 + y - 11)^2 + (x + y^2 - 7)^2
+    x = y = range(-5, 5; length = 25)
+    p = contourplot(x, y, himmelblau; levels = [30, 80, 150, 400], canvas = FilledCanvas)
+    test_ref("contourplot/filled_himmelblau.txt", @show_col(p))
+end