Merge pull request #42 from Kolaru/hotfix_only

Fix layouting issues with super and sum

Author: Kolaru

Project.toml

@@ -1,7 +1,7 @@
 name = "MathTeXEngine"
 uuid = "0a4f8689-d25c-4efe-a92b-7142dfc1aa53"
 authors = ["Benoît Richard <kolaru@hotmail.com>"]
-version = "0.3.1"
+version = "0.3.2"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"

src/engine/layout.jl

@@ -1,3 +1,12 @@
+"""
+Return the y value needed for the element to be vertically centered in the
+middle of the xheight.
+"""
+function y_for_centered(font_family, elem)
+    h = inkheight(elem)
+    return h/2 + xheight(font_family)/2
+end
+
 """
     tex_layout(mathexpr::TeXExpr, font_family)
 
@@ -48,7 +57,7 @@ function tex_layout(expr, state)
                 Point2f[
                     (0, 0),
                     (core_width, -0.2),
-                    (core_width, xheight(core) - 0.5 * descender(super))],
+                    (core_width, 0.8 * xheight(core))],
                 [1, shrink, shrink]
             )
         elseif head == :delimited
@@ -100,7 +109,7 @@ function tex_layout(expr, state)
 
             return Group(
                 [line, numerator, denominator],
-                Point2f[(0,y0), (x1, ytop), (x2, ybottom)]
+                Point2f[(0, y0), (x1, ytop), (x2, ybottom)]
             )
         elseif head == :function
             name = args[1]
@@ -123,7 +132,7 @@ function tex_layout(expr, state)
             return Group(
                 [int, sub, super],
                 Point2f[
-                    (0, h/2 + xheight(font_family)/2),
+                    (0, y_for_centered(font_family, int)),
                     (
                         0.15 - inkwidth(sub)*shrink/2,
                         -h/2 + xheight(font_family)/2 - topinkbound(sub)*shrink - pad
@@ -155,23 +164,22 @@ function tex_layout(expr, state)
                 h = inkheight(sqrt)
                 y0 = (topinkbound(sqrt) - bottominkbound(sqrt))/2 + xheight(font_family)/2
             else
-                y0 = bottominkbound(content) - bottominkbound(sqrt) - 0.2
+                y0 = bottominkbound(content) - bottominkbound(sqrt) - 0.1
             end
 
             lw = thickness(font_family)
 
             y = y0 + topinkbound(sqrt) - lw
-            xpad = advance(sqrt) - inkwidth(sqrt)
-            w =  inkwidth(content) + 2xpad
 
-            hline = HLine(w, lw)
+            hline = HLine(inkwidth(content) + 0.1, lw)
 
             return Group(
-                [sqrt, hline, content],
+                [sqrt, hline, content, Space(1.2)],
                 Point2f[
                     (0, y0),
                     (rightinkbound(sqrt) - lw/2, y - lw/2),
-                    (advance(sqrt), 0)
+                    (rightinkbound(sqrt), 0),
+                    (rightinkbound(content), 0)
                 ]
             )
 
@@ -188,12 +196,20 @@ function tex_layout(expr, state)
             # The leftmost element must have x = 0
             x0 = -min(0, dxsub, dxsuper)
 
+            # Special case to deal with sum symbols and the like that do not
+            # have their baseline properly set in the font
+            if core isa TeXChar
+                y0 = y_for_centered(font_family, core)
+            else
+                y0 = 0.0
+            end
+
             return Group(
                 [core, sub, super],
                 Point2f[
-                    (x0, 0),
-                    (x0 + dxsub, under_offset),
-                    (x0 + dxsuper, over_offset)
+                    (x0, y0),
+                    (x0 + dxsub, y0 + under_offset),
+                    (x0 + dxsuper, y0 + over_offset)
                 ],
                 [1, shrink, shrink]
             )

src/prototype.jl

@@ -23,15 +23,15 @@ function draw_texelement!(ax, line::VLine, position, scale ; size=64)
     xmid, y0 = position
     x0 = xmid - lw
     x1 = xmid + lw
-    y1 = y0 + line.height
+    y1 = y0 + line.height * scale
     points = Point2f[(x0, y0), (x0, y1), (x1, y1), (x1, y0)]
     poly!(ax, points .* size, color=:black, shading=false, linewidth=0)
 end
 
 function draw_texelement!(ax, line::HLine, position, scale ; size=64)
     lw = line.thickness * scale / 2
     x0, ymid = position
-    x1 = x0 + line.width
+    x1 = x0 + line.width * scale
     y0 = ymid - lw
     y1 = ymid + lw
     points = Point2f[(x0, y0), (x0, y1), (x1, y1), (x1, y0)]
@@ -116,7 +116,7 @@ begin  # Quick test
     fig[1, 1] = Label(fig, "LaTeX in Makie.jl", tellwidth=false, textsize=64)
     ax = Axis(fig[2, 1])
     ax.aspect = DataAspect()
-    tex = L"\lim_{L →\infty} \gamma A^j = \vec{v}_{(a + \bar{a})_k} + \sqrt{2T} x! \quad \mathrm{when} \quad \sqrt{\frac{\Omega-2}{4+a+x}} < \int_{0}^{2π} |\sin(\mu x)| dx"
+    tex = L"\lim_{L →\infty} \gamma A^\sqrt{2 + 3 + 2} z^2 = \sum_{k = 1}^N \vec{v}_{(a + \bar{a})_k} + \sqrt{j} x! \quad \mathrm{when} \quad \sqrt{\frac{\Omega-2}{4+a+x}} < \int_{0}^{2π} |\sin(\mu x)| dx"
 
     makie_tex!(ax, tex, debug=false, size=300)
     fig