fix console errors when changing expressions

1 files changed, 13 insertions, 5 deletions

diff --git a/level.js b/level.js
index e2018e2..17ccee7 100644
--- a/level.js
+++ b/level.js
@@ -55,7 +55,9 @@ export function setupLevelUi(level, root, audio) {
   ui.xeq = document.createElement('input');
   ui.xeq.value = X_START;
   ui.xeq.onchange = (e) => {
-    level.equations.x = math.compile(e.target.value);
+    try {
+      level.equations.x = math.compile(e.target.value);
+    } catch(err) { }
     level.running = false;
     level.path = computePath(level.equations);
     render(ui.ctx, level, 0);
@@ -66,7 +68,9 @@ export function setupLevelUi(level, root, audio) {
   ui.yeq = document.createElement('input');
   ui.yeq.value = Y_START;
   ui.yeq.onchange = (e) => {
-    level.equations.y = math.compile(e.target.value);
+    try {
+      level.equations.y = math.compile(e.target.value);
+    } catch(err) { }
     level.running = false;
     level.path = computePath(level.equations);
     render(ui.ctx, level, 0);
@@ -74,7 +78,7 @@ export function setupLevelUi(level, root, audio) {
   ui.yeq.onkeydown = ui.yeq.onchange;
   ui.yeq.onkeyup = ui.yeq.onchange;
 
-  ui.message = document.createElement('h1');
+  ui.message = document.createElement('div');
   ui.id = "level-message";
 
   root.appendChild(ui.launchButton);
@@ -128,8 +132,12 @@ function stepLevel(ui, level, index) {
 
 
 function computePath(equations, start, end, step) {
-  const ts = [...Array(Math.floor((PATH_LEN)/PATH_STEP)).keys()].map(k => PATH_STEP * k);
-  return ts.map(t => [ equations.x.eval({t}), equations.y.eval({t}) ]);
+  try {
+    const ts = [...Array(Math.floor((PATH_LEN)/PATH_STEP)).keys()].map(k => PATH_STEP * k);
+    return ts.map(t => [ equations.x.eval({t}), equations.y.eval({t}) ]);
+  } catch (err) {
+    return [ [0, 0] ];
+  }
 }