Fix math spacing, delimiters, radicals, and script fractions

reference/data/basics.jl

@@ -0,0 +1,97 @@
+BASICS = Dict()
+
+BASICS["accents"] = [
+    L"\dot{Q} \dot{q}",
+    L"\vec{A} \vec{a}",
+    L"\bar{L} \bar{l}",
+    L"\hat{\Phi} \bar{\varphi}"
+]
+
+BASICS["delimiters"] = [
+    L"(1 + 2) (\frac{1}{2})",
+    L"\left(1 + 2\right) \left(\frac{1}{2}\right)",
+    L"\left[a + b\right] \left[\frac{a}{b}\right]",
+    L"\left{A + B \right} + \left{\frac{A}{B}\right}",
+    L"\left{\alpha + \beta \right} + \left{\frac{\alpha}{\beta}\right}",
+    L"\left{1 + \left[2 + \left(3 + 4\right)\right]\right}"
+]
+
+BASICS["fonts"] = [
+    L"\mathrm{bonjour}",
+    L"\mathbb{R} \mathbb{Q} \mathbb{C}",
+    L"\mathcal{N} \mathcal{K}"
+]
+
+BASICS["fractions"] = [
+    L"\frac{a + b + c}{c + b + a}",
+    L"\frac{a}{A + B + C}",
+    L"\frac{j - f}{f - j}"
+]
+
+BASICS["functions"] = [
+    L"\sin{\omega} + \cos{\theta}",
+    L"\exp{\log{2}} = 2",
+    L"\inf_{x} \tan(x) \leq \sup_{x} \tan(x)" 
+]
+
+BASICS["infix"] = [
+    L"T + V",
+    L"7 - 2",
+    L"v \cdot w",
+    L"E = m c^2"
+]
+
+BASICS["integrals"] = [
+    L"\int_a^b",
+    L"\int \int \int"
+]
+
+BASICS["linebreaks"] = [
+    L"we clearly see $x = 22$\\and $y > x^2$"
+]
+
+BASICS["punctuation"] = [
+    L"x!",
+    L"23.17",
+    L"10,000"
+]
+
+BASICS["spaces"] = [
+    L"a \! b",
+    L"a \; b",
+    L"a \quad b",
+    L"a \qquad b"
+]
+
+BASICS["square_roots"] = [
+    L"\sqrt{2}",
+    L"\sqrt{\frac{1}{2}}",
+    L"\sqrt{b^2 - 4ac}",
+    L"\sqrt{1 + \frac{A + B}{J + U}}"
+]
+
+BASICS["subsuper"] = [
+    L"V^1_2",
+    L"U_{ij}",
+    L"W^{(i + j)}",
+    L"x_L x_y x_{y \rightarrow 0}",
+    L"N_\nu L_\nu A_\nu J_\nu",
+    L"N^\nu L^\nu A^\nu J^\nu",
+    L"^{87} Rb"
+]
+
+BASICS["symbols"] = [
+    L"k\xi",
+    L"\alpha \beta \gamma \delta \epsilon \omega \theta \phi \varphi \psi",
+    L"\Gamma \Delta \Omega \Theta \Phi \Psi",
+    L"\nabla \rightarrow \neq \leq \hbar",
+    L"\text{phi} \rightarrow \phi \quad \text{varphi} \rightarrow \varphi",
+    L"\text{epsilon} \rightarrow \epsilon \quad \text{varepsilon} \rightarrow \varepsilon"
+]
+
+BASICS["underover"] = [
+    L"\sum_{n = 1}^{m^2}",
+    L"\sum_{N = 1}^{M^2}",
+    L"\prod_{n \neq m}",
+    L"\prod_{N \neq M}"
+]

reference/data/spacing.jl

@@ -0,0 +1,94 @@
+const SPACING = Dict(
+    "Issue #142 italic roman boundaries" => [
+        raw"f(t)",
+        raw"g(x)",
+        raw"(f)x",
+        raw"(t)",
+        raw"\eta(t)",
+        raw"\alpha(t)",
+        raw"g(f(x))",
+        raw"\mathrm{y}(x)",
+        raw"\mathrm{g}t",
+    ],
+    "Issue #95 lower-case Greek and subscript spacing" => [
+        raw"\eta(t)",
+        raw"\alpha_k",
+        raw"\omega_k",
+        raw"k\xi",
+        raw"\nu(k)",
+        raw"N_\nu L_\nu A_\nu J_\nu",
+        raw"x_{\alpha(k)}",
+        raw"v_{(a + b)_k}^i",
+        raw"\partial_i u_j",
+        raw"\phi_\varphi \rho_\sigma",
+    ],
+    "Subscript and superscript combinations" => [
+        raw"x_i",
+        raw"x^i",
+        raw"x_i^j",
+        raw"V^i_j",
+        raw"x_{i_j}",
+        raw"x^{i^j}",
+        raw"x_{(a+b)_k}^i",
+        raw"T_{\alpha\beta}^{ij}",
+        raw"\Gamma^\mu_{\nu\rho}",
+        raw"\psi^\dagger_i\psi_i",
+    ],
+    "PR #151 primes and deep scripts" => [
+        raw"x' f'",
+        raw"x'' f''",
+        raw"x′ f′",
+        raw"x\prime f\prime",
+        raw"x^\prime f^\prime",
+        raw"x'_y f_g'",
+        raw"A^{B^{C^{D^E}}}_{F_{G_{H_I}}}",
+        raw"f^{A'}",
+    ],
+    "Roman upright and capital boundaries" => [
+        raw"\mathrm{d}x",
+        raw"\mathrm{e}^{-x}",
+        raw"\mathrm{Re}\,z",
+        raw"\mathrm{Im}\,z",
+        raw"\mathrm{Tr}\,A_i^j",
+        raw"\mathrm{Cov}(X,Y)",
+        raw"A_\nu B_\nu C_\nu D_\nu",
+        raw"M\mathrm{M}M",
+    ],
+    "Issue #129 math operator spacing" => [
+        raw"\log x",
+        raw"\log(x)",
+        raw"\sin x",
+        raw"\sin(x)",
+        raw"\exp t",
+        raw"\exp(t)",
+        raw"\max_{t \in \{1,...,5\}}",
+    ],
+    "Operators, delimiters, and fractions" => [
+        raw"-1,\ 2-1,\ (-1)",
+        raw"\alpha^*",
+        raw"\psi^* \psi",
+        raw"\frac{1}{2}\pm\sqrt{3}",
+        raw"\frac{1}{2}{}\pm\sqrt{3}",
+        raw"\left(\frac{1}{2}\right)f(t)",
+        raw"\sqrt{x_i^2+y_i^2}",
+        raw"\sum_{k=0}^n a_k x^k",
+        raw"\int_0^{2\pi}\sin(x)\,dx",
+    ],
+    "Script layout issues #93, #105, #110, #126" => [
+        raw"\left(\frac{dy}{dx}\right)_0",
+        raw"\left(\frac{A^{xy}}{B}\right)^{1/4}",
+        raw"(\frac{A^{xy}}{B})^{1/4}",
+        raw"\left\langle\left|\int\right|\right\rangle",
+        raw"\left\langle\left|\left\langle\left|\int\right|\right\rangle\right|\right\rangle",
+        raw"x^{\frac{1}{1+2}}",
+        raw"x_{\frac{1}{1+2}}",
+    ],
+    "Nested expressions" => [
+        raw"\frac{\alpha_i+\beta_i}{\gamma_i+\delta_i}",
+        raw"\sqrt{\frac{1+\alpha_k}{1+\beta_k}}",
+        raw"F_{\mu\nu}F^{\mu\nu}",
+        raw"\overline{z}_i",
+        raw"\left(\alpha_{(i+j)_k}\right)^2",
+        raw"\frac{\partial^2 f}{\partial x_i\partial x_j}",
+    ],
+)

reference/references.jl

@@ -1,128 +1,59 @@
 using CairoMakie
 using MathTeXEngine
+using LaTeXStrings
 
-inputs = Dict()
+include("data/basics.jl")
+include("data/spacing.jl")
 
-inputs["accents"] = [
-    L"\dot{Q} \dot{q}",
-    L"\vec{A} \vec{a}",
-    L"\bar{L} \bar{l}",
-    L"\hat{\Phi} \bar{\varphi}"
-]
-
-inputs["delimiters"] = [
-    L"(1 + 2) (\frac{1}{2})",
-    L"\left(1 + 2\right) \left(\frac{1}{2}\right)",
-    L"\left[a + b\right] \left[\frac{a}{b}\right]",
-    L"\left{A + B \right} + \left{\frac{A}{B}\right}",
-    L"\left{\alpha + \beta \right} + \left{\frac{\alpha}{\beta}\right}",
-    L"\left{1 + \left[2 + \left(3 + 4\right)\right]\right}"
-]
+with_font(font_name, expr) = latexstring("\\fontfamily{$font_name}$expr")
 
-inputs["fonts"] = [
-    L"\mathrm{bonjour}",
-    L"\mathbb{R} \mathbb{Q} \mathbb{C}",
-    L"\mathcal{N} \mathcal{K}"
-]
+const REFERENCES = Dict(
+    "basics" => BASICS,
+    "spacing" => SPACING
+)
 
-inputs["fractions"] = [
-    L"\frac{a + b + c}{c + b + a}",
-    L"\frac{a}{A + B + C}",
-    L"\frac{j - f}{f - j}"
+const SUPPORTED_FONTS = [
+    "NewComputerModern",
+    "TeXGyreHeros",
+    "TeXGyrePagella",
+    "LucioleMath"
 ]
 
-inputs["functions"] = [
-    L"\sin{\omega} + \cos{\theta}",
-    L"\exp{\log{2}} = 2",
-    L"\inf_{x} \tan(x) \leq \sup_{x} \tan(x)" 
-]
-
-inputs["infix"] = [
-    L"T + V",
-    L"7 - 2",
-    L"v \cdot w",
-    L"E = m c^2"
-]
-
-inputs["integrals"] = [
-    L"\int_a^b",
-    L"\int \int \int"
-]
-
-inputs["linebreaks"] = [
-    L"we clearly see $x = 22$\\and $y > x^2$"
-]
-
-inputs["punctuation"] = [
-    L"x!",
-    L"23.17",
-    L"10,000"
-]
+function generate(destination_folder, references = REFERENCES, fonts = SUPPORTED_FONTS)
+    @info "Generating reference images in folder $destination_folder"
 
-inputs["spaces"] = [
-    L"a \! b",
-    L"a \; b",
-    L"a \quad b",
-    L"a \qquad b"
-]
-
-inputs["square_roots"] = [
-    L"\sqrt{2}",
-    L"\sqrt{\frac{1}{2}}",
-    L"\sqrt{b^2 - 4ac}",
-    L"\sqrt{1 + \frac{A + B}{J + U}}"
-]
-
-inputs["subsuper"] = [
-    L"V^1_2",
-    L"U_{ij}",
-    L"W^{(i + j)}",
-    L"x_L x_y x_{y \rightarrow 0}",
-    L"N_\nu L_\nu A_\nu J_\nu",
-    L"N^\nu L^\nu A^\nu J^\nu",
-    L"^{87} Rb"
-]
-
-inputs["symbols"] = [
-    L"\alpha \beta \gamma \delta \epsilon \omega \theta \phi \varphi \psi",
-    L"\Gamma \Delta \Omega \Theta \Phi \Psi",
-    L"\nabla \rightarrow \neq \leq \hbar",
-    L"\text{phi} \rightarrow \phi \quad \text{varphi} \rightarrow \varphi",
-    L"\text{epsilon} \rightarrow \epsilon \quad \text{varepsilon} \rightarrow \varepsilon"
-]
+    path = mkpath(destination_folder)
+    failures = Dict()
+    for (group, data) in references
+        if data isa AbstractDict
+            generate(joinpath(destination_folder, group), data)
+        else
+            fig, fails = reference_figure(data, fonts)
 
-inputs["underover"] = [
-    L"\sum_{n = 1}^{m^2}",
-    L"\sum_{N = 1}^{M^2}",
-    L"\prod_{n \neq m}",
-    L"\prod_{N \neq M}"
-]
+            if !isempty(fails)
+                failures[group] = fails
+            end
 
-function generate(name)
-    @info "Generating reference image at $name"
-    path = mkpath(name)
-    failures = Dict()
-    for (group, exprs) in inputs
-        fig, fails = single_figure(exprs)
-        if !isempty(fails)
-            failures[group] = fails
+            save(joinpath(path, "$group.png"), fig, px_per_unit=3)
         end
-
-        save(joinpath(path, "$group.png"), fig, px_per_unit=3)
     end
 
     return failures
 end
 
-function single_figure(exprs)
-    fig = Figure(size=(200, length(exprs)*60))
+function reference_figure(exprs, fonts = SUPPORTED_FONTS)
+    fig = Figure()
     failures = Dict()
-    for (i, expr) in enumerate(exprs)
-        try
-            Label(fig[i, 1], expr)
-        catch e
-            failures[expr] = e
-        end 
+    for (j, font) in enumerate(fonts)
+        Label(fig[0, j], font)
+        for (i, expr) in enumerate(exprs)
+            try
+                Label(fig[i, j], with_font(font, expr))
+            catch e
+                failures[expr] = e
+            end 
+        end
     end
+    resize_to_layout!(fig)
     return fig, failures
 end

src/MathTeXEngine.jl

@@ -28,6 +28,11 @@ export glyph_index
 # Reexport from LaTeXStrings
 export @L_str
 
+# Advanced layout/parser knobs. These are intentionally not exported, but may
+# be toggled by qualified access when debugging regressions.
+const italic_correction_enabled = Ref(true)
+const unspace_binary_operators_heuristic_enabled = Ref(true)
+
 include("parser/tokenizer.jl")
 include("parser/texexpr.jl")
 include("parser/commands_data.jl")

src/engine/fonts.jl

@@ -255,10 +255,8 @@ object.
 get_fontpath(font_family::FontFamily, fontstyle::Symbol) = full_fontpath(font_family.fonts[fontstyle])
 get_fontpath(fontstyle::Symbol) = get_fontpath(FontFamily(), fontstyle)
 
-function is_slanted(font_family, char_type)
-    font_id = font_family.font_mapping[char_type]
-    return font_id == :italic
-end
+is_slanted_font(font_id) = font_id in (:italic, :bolditalic)
+is_slanted(font_family, char_type) = is_slanted_font(font_family.font_mapping[char_type])
 
 slant_angle(font_family) = font_family.slant_angle * π / 180