Refactor non-UI code

README.md

@@ -60,4 +60,4 @@ Adjunctions:
 
 ## Thanks
 - [@cartesiancat](https://github.com/cartesiancat) for discussions about rendering aesthetic arrows.
-- [AndréC](https://tex.stackexchange.com/users/138900/andr%c3%a9c) for the custom TikZ `curve` setting.
+- [AndréC](https://tex.stackexchange.com/users/138900/andr%c3%a9c) for the custom TikZ `curve` style.

src/arrow.js

@@ -10,8 +10,7 @@ class QuiverSVG {
         // Create a top-level SVG. This will include all the edges and labels as children.
         // Note that we need to explicitly set the namespace attribute so that the SVG can be
         // treated as a standalone file, when we want to export it.
-        const xmlns = "http://www.w3.org/2000/svg";
-        this.element = new DOM.SVGElement("svg", { xmlns });
+        this.element = new DOM.SVGElement("svg", { xmlns: DOM.SVGElement.NAMESPACE });
     }
 }
 
@@ -474,12 +473,11 @@ class Arrow {
             fill: "none",
             stroke: "black",
             "stroke-width": stroke_width,
-            // We'd prefer to use `round`, especially for dashed and dotted lines, but unfortunately
-            // this doesn't work well with thicker edges. Ideally, we want a `round-butt` option,
-            // specifying edges do not extend farther than the path.
-            // We manually draw rounded ends for the overall path, but we avoid doing this for every
-            // dash, as this would be very expensive.
-            "stroke-linecap": "butt",
+            // We use the default `stroke-linecap` option of `butt`. We'd prefer to use `round`,
+            // especially for dashed and dotted lines, but unfortunately this doesn't work well with
+            // thicker edges. Ideally, we want a `round-butt` option, specifying edges do not extend
+            // farther than the path. We manually draw rounded ends for the overall path, but we
+            // avoid doing this for every dash, as this would be very expensive.
         });
 
         // When we draw squiggly arrows, we have straight line padding near the tail and head, which

src/bezier.js

@@ -99,6 +99,8 @@ class Bezier {
     /// number for the polygon with respect to the point. If the winding number is nonzero, then
     /// the point lies inside the polygon.
     /// This algorithm is based on the one at: http://geomalgorithms.com/a03-_inclusion.html.
+    /// Technically, this shouldn't really be a method on `Bezier`, but it is currently always used
+    /// for algorithms related to Bézier curves, so it's placed here for convenience.
     static point_inside_polygon(point, points) {
         // The displacement of a point from a line (calculated via the determinant of a 2x2 matrix).
         const displ = ([base, end], point) => {
@@ -254,7 +256,8 @@ class Bezier {
     }
 }
 
-/// A point on a quadratic Bézier curve, which also records the angle of the curve at the point.
+/// A point on a quadratic Bézier curve, which also records the parameter `t` and the `angle` of the
+/// curve at the point.
 class BezierPoint extends Point {
     constructor(point, t, angle) {
         super(point.x, point.y);

src/ui.js

@@ -2406,7 +2406,7 @@ class Panel {
             // and one for the unchecked version.
             const backgrounds = [];
 
-            const svg = new DOM.SVGElement("svg", { xmlns: "http://www.w3.org/2000/svg" }).element;
+            const svg = new DOM.SVGElement("svg", { xmlns: DOM.SVGElement.NAMESPACE }).element;
 
             const { shared, edge: { length, options, gap = null } } = properties(value, data);