From 8b5ac36284d73b70036dd9a74742ef8fcdd23a80 Mon Sep 17 00:00:00 2001
From: Tanner Collin <git@tannercollin.com>
Date: Sat, 14 Mar 2026 13:30:51 -0600
Subject: [PATCH] feat: Add angle mode toggle and apply to trig functions

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>
---
 calculator/calculator.app.js | 55 +++++++++++++++++++++++++++++-------
 1 file changed, 45 insertions(+), 10 deletions(-)

diff --git a/calculator/calculator.app.js b/calculator/calculator.app.js
index b49f8c8..6f18bb0 100644
--- a/calculator/calculator.app.js
+++ b/calculator/calculator.app.js
@@ -64,10 +64,11 @@ var scientificOperators = {
   'sin': {grid: [0, 0], val: 'sin'},
   'cos': {grid: [1, 0], val: 'cos'},
   'tan': {grid: [0, 1], val: 'tan'},
-  'log': {grid: [1, 1], val: 'log'},
-  'tenpow': {grid: [0, 2], val: '10^x'},
-  'ln': {grid: [1, 2], val: 'ln'},
-  'epow': {grid: [0, 3], val: 'e^x'},
+  'angleMode': {grid: [1, 1], val: 'rad'},
+  'log': {grid: [0, 2], val: 'log'},
+  'tenpow': {grid: [1, 2], val: '10^x'},
+  'ln': {grid: [0, 3], val: 'ln'},
+  'epow': {grid: [1, 3], val: 'e^x'},
 };
 
 var specialsGrid = [2, 2];
@@ -85,6 +86,7 @@ var operator = null;
 var results = null;
 var isDecimal = false;
 var hasPressedEquals = false;
+var angleMode = 'rad';
 
 function prepareScreen(screen, grid, defaultColor) {
   for (var k in screen) {
@@ -360,30 +362,54 @@ function buttonPress(val) {
       break;
     case 'sin':
       if (results != null) {
-        results = Math.sin(results);
+        let angle = results;
+        if (angleMode === 'deg') {
+          angle = angle * Math.PI / 180;
+        }
+        results = Math.sin(angle);
         displayOutput(results);
       } else if (currNumber != null) {
-        currNumber = Math.sin(currNumber);
+        let angle = currNumber;
+        if (angleMode === 'deg') {
+          angle = angle * Math.PI / 180;
+        }
+        currNumber = Math.sin(angle);
         displayOutput(currNumber);
       }
       hasPressedNumber = false;
       break;
     case 'cos':
       if (results != null) {
-        results = Math.cos(results);
+        let angle = results;
+        if (angleMode === 'deg') {
+          angle = angle * Math.PI / 180;
+        }
+        results = Math.cos(angle);
         displayOutput(results);
       } else if (currNumber != null) {
-        currNumber = Math.cos(currNumber);
+        let angle = currNumber;
+        if (angleMode === 'deg') {
+          angle = angle * Math.PI / 180;
+        }
+        currNumber = Math.cos(angle);
         displayOutput(currNumber);
       }
       hasPressedNumber = false;
       break;
     case 'tan':
       if (results != null) {
-        results = Math.tan(results);
+        let angle = results;
+        if (angleMode === 'deg') {
+          angle = angle * Math.PI / 180;
+        }
+        results = Math.tan(angle);
         displayOutput(results);
       } else if (currNumber != null) {
-        currNumber = Math.tan(currNumber);
+        let angle = currNumber;
+        if (angleMode === 'deg') {
+          angle = angle * Math.PI / 180;
+        }
+        currNumber = Math.tan(angle);
         displayOutput(currNumber);
       }
       hasPressedNumber = false;
@@ -428,6 +454,15 @@ function buttonPress(val) {
       }
       hasPressedNumber = false;
       break;
+    case 'angleMode':
+      if (angleMode === 'rad') {
+        angleMode = 'deg';
+      } else {
+        angleMode = 'rad';
+      }
+      scientificOperators.angleMode.val = angleMode;
+      drawKey('angleMode', scientificOperators.angleMode);
+      break;
     case 'i':
       if (results != null) {
         results = divide(1, results);