Merge pull request #136 from Kolaru/simply_fonts

Simplify changing fonts

Author: Kolaru

.github/workflows/ci.yml

@@ -20,10 +20,8 @@ jobs:
           - windows-latest
         arch:
           - x64
-          - x86
         exclude:
           - os: macOS-latest
-            arch: x86
     steps:
       - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v2

README.md

@@ -8,6 +8,63 @@ This is a package aimed at providing a pure Julia engine for LaTeX math mode. It
 - Equivalence between traditional LaTeX commands and their unicode input equivalent.
 - Pure julia.
 
+# Fonts
+
+The characters in a math expression come from a variety of fonts depending on their role (most notably italic for variable, regular for functions, math for the symbols).
+A set of such font forms a `FontFamily`, and several are predefined here (NewComputerModer, TeXGyreHeros, TeXGyrePagella, and LucioleMath)
+and can be access by `FontFamily(name)`.
+
+A font family is defined by a dictionary of the paths of the font files:
+```julia
+julia> FontFamily("NewComputerModern")
+FontFamily with 13.0° slant angle and 0.0375 line thickness
+  bold        =>  NewComputerModern\NewCM10-Bold.otf
+  bolditalic  =>  NewComputerModern\NewCM10-BoldItalic.otf
+  italic      =>  NewComputerModern\NewCM10-Italic.otf
+  math        =>  NewComputerModern\NewCMMath-Regular.otf
+  regular     =>  NewComputerModern\NewCMMath-Regular.otf
+```
+
+Currently, there are two ways to get the font information to Makie.
+
+First, change the global default font family using `set_texfont_family!`,
+which take either a font family as an argument or a list of (`Symbol`, path to the font file) pairs.
+```julia
+# Change to a different font familiy entirely
+julia> set_texfont_family!(FontFamily("LucioleMath"))
+FontFamily with 13.0° slant angle and 0.0375 line thickness
+  bold        =>  Luciole-Math\Luciole-Bold.ttf
+  bolditalic  =>  Luciole-Math\Luciole-Bold-Italic.ttf
+  italic      =>  Luciole-Math\Luciole-Regular-Italic.ttf
+  math        =>  Luciole-Math\Luciole-Math.otf
+  regular     =>  Luciole-Math\Luciole-Regular.ttf
+
+# Change just the regular and bold fonts, keep the default for the rest
+julia> set_texfont_family!(
+   regular = raw"C:\Users\Kolaru\.julia\dev\MathTeXEngine\experimental\utopia\Utopia-Regular.ttf",
+   bold = raw"C:\Users\Kolaru\.julia\dev\MathTeXEngine\experimental\utopia\Utopia-Bold.ttf")
+FontFamily with 13.0° slant angle and 0.0375 line thickness
+  bold        =>  C:\Users\Kolaru\.julia\dev\MathTeXEngine\experimental\utopia\Utopia-Bold.ttf
+  bolditalic  =>  NewComputerModern\NewCM10-BoldItalic.otf
+  italic      =>  NewComputerModern\NewCM10-Italic.otf
+  math        =>  NewComputerModern\NewCMMath-Regular.otf
+  regular     =>  C:\Users\Kolaru\.julia\dev\MathTeXEngine\experimental\utopia\Utopia-Regular.ttf
+
+# Switch back to the default
+julia> set_texfont_family!()
+FontFamily with 13.0° slant angle and 0.0375 line thickness
+  bold        =>  NewComputerModern\NewCM10-Bold.otf
+  bolditalic  =>  NewComputerModern\NewCM10-BoldItalic.otf
+  italic      =>  NewComputerModern\NewCM10-Italic.otf
+  math        =>  NewComputerModern\NewCMMath-Regular.otf
+  regular     =>  NewComputerModern\NewCMMath-Regular.otf
+```
+
+Alternatively, the special command `\fontfamily{FontName}` can be used in the LaTeX string itself
+to choose the font, for example `L"\fontfamily{TeXGyreHeros}x^2 + y^2 = 1"`.
+The font name must be in the global dictionary `MathTeXEngin.default_font_families`.
+If needed, it can be extended at runtime.
+
 # Engine
 
 The main use of the package is through `generate_tex_elements` taking a LaTeX string as input and return a list of tuples `(TeXElement, position, scale)` where `TeXElement` is one of the following:

src/MathTeXEngine.jl

@@ -22,7 +22,7 @@ import FreeTypeAbstraction:
 export TeXToken, tokenize
 export TeXExpr, texparse, TeXParseError, manual_texexpr
 export TeXElement, TeXChar, VLine, HLine, generate_tex_elements
-export texfont, FontFamily
+export texfont, FontFamily, set_texfont_family!, get_texfont_family
 export glyph_index
 
 # Reexport from LaTeXStrings

src/engine/fonts.jl

@@ -43,6 +43,14 @@ const _default_font_modifiers = Dict(
     :bf => Dict(:italic => :bolditalic, :regular => :bold)
 )
 
+const _default_fonts = Dict(
+    :regular => joinpath("NewComputerModern", "NewCMMath-Regular.otf"),
+    :italic => joinpath("NewComputerModern", "NewCM10-Italic.otf"),
+    :bold => joinpath("NewComputerModern", "NewCM10-Bold.otf"),
+    :bolditalic => joinpath("NewComputerModern", "NewCM10-BoldItalic.otf"),
+    :math => joinpath("NewComputerModern", "NewCMMath-Regular.otf")
+)
+
 """
     FontFamily(fonts ; font_mapping, font_modifiers, special_chars, slant_angle, thickness)
 
@@ -52,6 +60,7 @@ A set of font for LaTeX rendering.
   - `fonts` A with the path to 5 fonts (:regular, :italic, :bold, :bolditalic,
     and :math). The same font can be used for multiple entries, and unrelated
     fonts can be mixed.
+    Missing fields are completed with the default fonts from NewComputerModern.
 
 # Optional fields
   - `font_mapping` a dict mapping the different character types (`:digit`,
@@ -75,12 +84,14 @@ struct FontFamily
     thickness::Float64
 end
 
-function FontFamily(fonts::Dict ;
+function FontFamily(fonts ;
         font_mapping = _default_font_mapping,
         font_modifiers = _default_font_modifiers,
         special_chars = Dict{Char, Tuple{String, Int}}(),
         slant_angle = 13,
         thickness = 0.0375)
+
+    fonts = merge(_default_fonts, Dict(fonts))
 
     return FontFamily(
         fonts,
@@ -100,14 +111,26 @@ One of the default set of font for LaTeX rendering.
 Currently available are
 - NewComputerModern
 - TeXGyreHeros
+- TeXGyrePagella
+- LucioleMath
 
 These names can also be used in a LaTeXString directly,
+to set the font of a single string,
 with the command `\\fontfamily`,
 e.g. L"\\fontfamily{TeXGyreHeros}x^2_3".
 """
-FontFamily() = FontFamily("NewComputerModern")
+FontFamily() = get_texfont_family()
 FontFamily(fontname::AbstractString) = default_font_families[fontname]
 
+function Base.show(io::IO, family::FontFamily)
+    println(io, "FontFamily with $(family.slant_angle)° slant angle and $(family.thickness) line thickness")
+    for (key, font) in family.fonts
+        spaces = " "^(12 - length(string(key)))
+        println(io, "  $key$spaces=>  $font")
+    end
+end
+
+
 # These two fonts internals are very different, despite their similar names
 # We only try to fully support NewComputerModern, the other is here as it may
 # sometime provide quickfix solution to bug
@@ -150,6 +173,46 @@ const default_font_families = Dict(
     )
 )
 
+const current_texfont_family = Ref(default_font_families["NewComputerModern"])
+
+"""
+    get_texfont_family()
+
+Get the current default font family for the styling of LaTeXString.
+"""
+get_texfont_family() = current_texfont_family[]
+
+"""
+    set_texfont_family!([font_family::FontFamily])
+
+Set a font family for the styling of LaTeXString.
+
+See the documentaiton of `FontFamily` for more information.
+"""
+set_texfont_family!(font_family::FontFamily) = (current_texfont_family[] = font_family)
+
+"""
+    set_texfont_family!(; kwargs...)
+
+Set a font family for the styling of LaTeXString,
+using key-value to specify individual fonts.
+
+For example, the following sets the regular font
+(used for text and function names) to Utopia
+(assuming that the Utopia font can be found at the given path).
+
+```julia
+set_texfont_family!(regular = "Utopia-Regular.ttf")
+```
+
+See the documentation of `FontFamily` for more information.
+"""
+function set_texfont_family!(; kwargs...)
+    if length(kwargs) == 0
+        return current_texfont_family[] = default_font_families["NewComputerModern"]
+    end
+    return set_texfont_family!(FontFamily(kwargs))
+end
 
 """
     get_font([font_family=FontFamily()], fontstyle)