Adds math commands, HTML rendering, and screenshotter tests.

This is part 2 of 3.  Part 1 added new fonts metrics.  Part 2 will add MathML support and unit tests.

src/Options.js

@@ -6,9 +6,9 @@
  */
 
 /**
- * This is the main options class. It contains the style, size, and color of the
- * current parse level. It also contains the style and size of the parent parse
- * level, so size changes can be handled efficiently.
+ * This is the main options class. It contains the style, size, color and font
+ * of the current parse level. It also contains the style and size of the parent
+ * parse level, so size changes can be handled efficiently.
  *
  * Each of the `.with*` and `.reset` functions passes its current style and size
  * as the parentStyle and parentSize of the new options class, so parent
@@ -19,6 +19,7 @@ function Options(data) {
     this.color = data.color;
     this.size = data.size;
     this.phantom = data.phantom;
+    this.font = data.font;
 
     if (data.parentStyle === undefined) {
         this.parentStyle = data.style;
@@ -44,7 +45,8 @@ Options.prototype.extend = function(extension) {
         color: this.color,
         parentStyle: this.style,
         parentSize: this.size,
-        phantom: this.phantom
+        phantom: this.phantom,
+        font: this.font
     };
 
     for (var key in extension) {
@@ -92,6 +94,15 @@ Options.prototype.withPhantom = function() {
     });
 };
 
+/**
+ * Create a new options objects with the give font.
+ */
+Options.prototype.withFont = function(font) {
+    return this.extend({
+        font: font
+    });
+};
+
 /**
  * Create a new options object with the same style, size, and color. This is
  * used so that parent style and size changes are handled correctly.

src/buildCommon.js

@@ -6,6 +6,26 @@
 var domTree = require("./domTree");
 var fontMetrics = require("./fontMetrics");
 var symbols = require("./symbols");
+var utils = require("./utils");
+
+var greekCapitals = [
+    "\\Gamma",
+    "\\Delta",
+    "\\Theta",
+    "\\Lambda",
+    "\\Xi",
+    "\\Pi",
+    "\\Sigma",
+    "\\Upsilon",
+    "\\Phi",
+    "\\Psi",
+    "\\Omega"
+];
+
+var dotlessLetters = [
+    "\u0131",   // dotless i, \imath
+    "\u0237"    // dotless j, \jmath
+];
 
 /**
  * Makes a symbolNode after translation via the list of symbols in symbols.js.
@@ -41,17 +61,10 @@ var makeSymbol = function(value, style, mode, color, classes) {
 };
 
 /**
- * Makes a symbol in the italic math font.
+ * Makes a symbol in Main-Regular or AMS-Regular.
+ * Used for rel, bin, open, close, inner, and punct.
  */
-var mathit = function(value, mode, color, classes) {
-    return makeSymbol(
-        value, "Math-Italic", mode, color, classes.concat(["mathit"]));
-};
-
-/**
- * Makes a symbol in the upright roman font.
- */
-var mathrm = function(value, mode, color, classes) {
+var mathsym = function(value, mode, color, classes) {
     // Decide what font to render the symbol in by its entry in the symbols
     // table.
     // Have a special case for when the value = \ because the \ is used as a
@@ -66,6 +79,67 @@ var mathrm = function(value, mode, color, classes) {
     }
 };
 
+/**
+ * Makes a symbol in the default font for mathords and textords.
+ */
+var mathDefault = function(value, mode, color, classes, type) {
+    if (type === "mathord") {
+        return mathit(value, mode, color, classes);
+    } else if (type === "textord") {
+        return makeSymbol(
+            value, "Main-Regular", mode, color, classes.concat(["mathrm"]));
+    } else {
+        throw new Error("unexpected type: " + type + " in mathDefault");
+    }
+};
+
+/**
+ * Makes a symbol in the italic math font.
+ */
+var mathit = function(value, mode, color, classes) {
+    if (/[0-9]/.test(value.charAt(0)) ||
+            // glyphs for \imath and \jmath do not exist in Math-Italic so we
+            // need to use Main-Italic instead
+            utils.contains(dotlessLetters, value) ||
+            utils.contains(greekCapitals, value)) {
+        return makeSymbol(
+            value, "Main-Italic", mode, color, classes.concat(["mainit"]));
+    } else {
+        return makeSymbol(
+            value, "Math-Italic", mode, color, classes.concat(["mathit"]));
+    }
+};
+
+/**
+ * Makes either a mathord or textord in the correct font and color.
+ */
+var makeOrd = function(group, options, type) {
+    var mode = group.mode;
+    var value = group.value;
+    if (symbols[mode][value] && symbols[mode][value].replace) {
+        value = symbols[mode][value].replace;
+    }
+
+    var classes = ["mord"];
+    var color = options.getColor();
+
+    var font = options.font;
+    if (font) {
+        if (font === "mathit" || utils.contains(dotlessLetters, value)) {
+            return mathit(value, mode, color, classes);
+        } else {
+            var fontName = fontMap[font].fontName;
+            if (fontMetrics.getCharacterMetrics(value, fontName)) {
+                return makeSymbol(value, fontName, mode, color, classes.concat([font]));
+            } else {
+                return mathDefault(value, mode, color, classes, type);
+            }
+        }
+    } else {
+        return mathDefault(value, mode, color, classes, type);
+    }
+};
+
 /**
  * Calculate the height, depth, and maxFontSize of an element based on its
  * children.
@@ -312,13 +386,61 @@ var spacingFunctions = {
     }
 };
 
+/**
+ * Maps TeX font commands to objects containing:
+ * - variant: string used for "mathvariant" attribute in buildMathML.js
+ * - fontName: the "style" parameter to fontMetrics.getCharacterMetrics
+ */
+// A map between tex font commands an MathML mathvariant attribute values
+var fontMap = {
+    // styles
+    "mathbf": {
+        variant: "bold",
+        fontName: "Main-Bold"
+    },
+    "mathrm": {
+        variant: "normal",
+        fontName: "Main-Regular"
+    },
+
+    // "mathit" is missing because it requires the use of two fonts: Main-Italic
+    // and Math-Italic.  This is handled by a special case in makeOrd which ends
+    // up calling mathit.
+
+    // families
+    "mathbb": {
+        variant: "double-struck",
+        fontName: "AMS-Regular"
+    },
+    "mathcal": {
+        variant: "script",
+        fontName: "Caligraphic-Regular"
+    },
+    "mathfrak": {
+        variant: "fraktur",
+        fontName: "Fraktur-Regular"
+    },
+    "mathscr": {
+        variant: "script",
+        fontName: "Script-Regular"
+    },
+    "mathsf": {
+        variant: "sans-serif",
+        fontName: "SansSerif-Regular"
+    },
+    "mathtt": {
+        variant: "monospace",
+        fontName: "Typewriter-Regular"
+    }
+};
+
 module.exports = {
     makeSymbol: makeSymbol,
-    mathit: mathit,
-    mathrm: mathrm,
+    mathsym: mathsym,
     makeSpan: makeSpan,
     makeFragment: makeFragment,
     makeVList: makeVList,
+    makeOrd: makeOrd,
     sizingMultiplier: sizingMultiplier,
     spacingFunctions: spacingFunctions
 };

src/buildHTML.js

@@ -171,13 +171,11 @@ var makeNullDelimiter = function(options) {
  */
 var groupTypes = {
     mathord: function(group, options, prev) {
-        return buildCommon.mathit(
-            group.value, group.mode, options.getColor(), ["mord"]);
+        return buildCommon.makeOrd(group, options, "mathord");
     },
 
     textord: function(group, options, prev) {
-        return buildCommon.mathrm(
-            group.value, group.mode, options.getColor(), ["mord"]);
+        return buildCommon.makeOrd(group, options, "textord");
     },
 
     bin: function(group, options, prev) {
@@ -199,32 +197,32 @@ var groupTypes = {
             className = "mord";
         }
 
-        return buildCommon.mathrm(
+        return buildCommon.mathsym(
             group.value, group.mode, options.getColor(), [className]);
     },
 
     rel: function(group, options, prev) {
-        return buildCommon.mathrm(
+        return buildCommon.mathsym(
             group.value, group.mode, options.getColor(), ["mrel"]);
     },
 
     open: function(group, options, prev) {
-        return buildCommon.mathrm(
+        return buildCommon.mathsym(
             group.value, group.mode, options.getColor(), ["mopen"]);
     },
 
     close: function(group, options, prev) {
-        return buildCommon.mathrm(
+        return buildCommon.mathsym(
             group.value, group.mode, options.getColor(), ["mclose"]);
     },
 
     inner: function(group, options, prev) {
-        return buildCommon.mathrm(
+        return buildCommon.mathsym(
             group.value, group.mode, options.getColor(), ["minner"]);
     },
 
     punct: function(group, options, prev) {
-        return buildCommon.mathrm(
+        return buildCommon.mathsym(
             group.value, group.mode, options.getColor(), ["mpunct"]);
     },
 
@@ -628,7 +626,7 @@ var groupTypes = {
             // into appropriate outputs.
             return makeSpan(
                 ["mord", "mspace"],
-                [buildCommon.mathrm(group.value, group.mode)]
+                [buildCommon.mathsym(group.value, group.mode)]
             );
         } else {
             // Other kinds of spaces are of arbitrary width. We use CSS to
@@ -712,7 +710,7 @@ var groupTypes = {
             // operators, like \limsup
             var output = [];
             for (var i = 1; i < group.value.body.length; i++) {
-                output.push(buildCommon.mathrm(group.value.body[i], group.mode));
+                output.push(buildCommon.mathsym(group.value.body[i], group.mode));
             }
             base = makeSpan(["mop"], output, options.getColor());
         }
@@ -819,26 +817,26 @@ var groupTypes = {
         // good, but the offsets for the T, E, and X were taken from the
         // definition of \TeX in TeX (see TeXbook pg. 356)
         var k = makeSpan(
-            ["k"], [buildCommon.mathrm("K", group.mode)]);
+            ["k"], [buildCommon.mathsym("K", group.mode)]);
         var a = makeSpan(
-            ["a"], [buildCommon.mathrm("A", group.mode)]);
+            ["a"], [buildCommon.mathsym("A", group.mode)]);
 
         a.height = (a.height + 0.2) * 0.75;
         a.depth = (a.height - 0.2) * 0.75;
 
         var t = makeSpan(
-            ["t"], [buildCommon.mathrm("T", group.mode)]);
+            ["t"], [buildCommon.mathsym("T", group.mode)]);
         var e = makeSpan(
-            ["e"], [buildCommon.mathrm("E", group.mode)]);
+            ["e"], [buildCommon.mathsym("E", group.mode)]);
 
         e.height = (e.height - 0.2155);
         e.depth = (e.depth + 0.2155);
 
         var x = makeSpan(
-            ["x"], [buildCommon.mathrm("X", group.mode)]);
+            ["x"], [buildCommon.mathsym("X", group.mode)]);
 
         return makeSpan(
-            ["katex-logo"], [k, a, t, e, x], options.getColor());
+            ["katex-logo", "mord"], [k, a, t, e, x], options.getColor());
     },
 
     overline: function(group, options, prev) {
@@ -1006,6 +1004,11 @@ var groupTypes = {
         return makeSpan([options.style.reset(), newStyle.cls()], inner);
     },
 
+    font: function(group, options, prev) {
+        var font = group.value.font;
+        return buildGroup(group.value.body, options.withFont(font), prev);
+    },
+
     delimsizing: function(group, options, prev) {
         var delim = group.value.value;
 

src/buildMathML.js

@@ -252,6 +252,11 @@ var groupTypes = {
 
         return node;
     },
+    
+    font: function(group) {
+        // pass through so we can render something without throwing
+        return buildGroup(group.value.body);
+    },
 
     spacing: function(group) {
         var node;

src/functions.js

@@ -215,6 +215,12 @@ var delimiters = [
     "."
 ];
 
+var fontAliases = {
+    "\\Bbb": "\\mathbb",
+    "\\bold": "\\mathbf",
+    "\\frak": "\\mathfrak"
+};
+
 /*
  * This is a list of functions which each have the same function but have
  * different names so that we don't have to duplicate the data a bunch of times.
@@ -476,6 +482,33 @@ var duplicatedFunctions = [
         }
     },
 
+    {
+        funcs: [
+            // styles
+            "\\mathrm", "\\mathit", "\\mathbf",
+
+            // families
+            "\\mathbb", "\\mathcal", "\\mathfrak", "\\mathscr", "\\mathsf",
+            "\\mathtt",
+
+            // aliases
+            "\\Bbb", "\\bold", "\\frak"
+        ],
+        data: {
+            numArgs: 1,
+            handler: function (func, body) {
+                if (func in fontAliases) {
+                    func = fontAliases[func];
+                }
+                return {
+                    type: "font",
+                    font: func.slice(1),
+                    body: body
+                };
+            }
+        }
+    },
+
     // Accents
     {
         funcs: [

src/symbols.js

@@ -2514,6 +2514,17 @@ var symbols = {
             font: "main",
             group: "accent",
             replace: "\u02d9"
+        },
+
+        "\\imath": {
+            font: "main",
+            group: "mathord",
+            replace: "\u0131"
+        },
+        "\\jmath": {
+            font: "main",
+            group: "mathord",
+            replace: "\u0237"
         }
     },
     "text": {