[ui] MathEvaluator : Fix issues in the expression evaluation

Author: Alxiice

meshroom/ui/qml/Controls/ExpressionTextField.qml

@@ -29,6 +29,9 @@ TextField {
             var result = MathEvaluator.eval(root.text)
             if (isInt) {
                 result = parseInt(result)
+            } else {
+                // Probably useless
+                result = parseFloat(result)
             }
             root.text = result
             hasExprError = false

meshroom/ui/qml/Controls/mathEvaluator.js

@@ -4,6 +4,9 @@
 var symbols = {
     pi: Math.PI,
     e: Math.E,
+};
+
+var functions = {
     abs: Math.abs,
     min: Math.min,
     max: Math.max,
@@ -24,20 +27,22 @@ var symbols = {
  * @returns        float or int
  */
 function eval(expr) {
-    // Replace symbols
-    for (var symbol in symbols) {
-        // Match each symbol only if they are at the beginning or end of the word
-        expr = expr.replace(new RegExp("\\b" + symbol + "\\b", "g"), symbols[symbol]);
-    }
-    
     // Additionally replace the "," to "."
-    expr = expr.replace(',','.')
-    
+    expr = expr.replace(",", ".").replace(" ", "")
+
     // Only allow numbers, operators, parentheses, and function names
-    if (!/^[0-9+\-*/^().,\s]*$/.test(expr.replace(/\b[a-zA-Z]+\b/g, ""))) {
+    if (!/^[0-9+\-*/^()e.,\s]*$/.test(expr.replace(/\b[a-zA-Z]+\b/g, ""))) {
         throw "Invalid characters in expression";
     }
 
+    // Replace symbols and functions
+    for (var symbol in symbols) {
+        expr = expr.replace(new RegExp("\\b" + symbol + "\\b", "g"), symbols[symbol]);
+    }
+    for (var func in functions) {  // Warning : not really a map
+        expr = expr.replace(new RegExp("\\b" + func + "\\b", "g"), "Math." + func);
+    }
+
     // Eval with function to avoid issues with undeclared variables
     return Function('"use strict"; return (' + expr + ')')();
 }