From 4706587abb57e5751ce6040b4fecb2041ff92356 Mon Sep 17 00:00:00 2001
From: Smie <smie.grin@gmail.com>
Date: Sat, 26 Nov 2016 19:16:46 -0700
Subject: [PATCH] Rewrites Circle drawing tool to behave better with large pen
 sizes.

---
 src/js/tools/drawing/Circle.js | 46 +++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/src/js/tools/drawing/Circle.js b/src/js/tools/drawing/Circle.js
index 05cfb1e..787ec70 100644
--- a/src/js/tools/drawing/Circle.js
+++ b/src/js/tools/drawing/Circle.js
@@ -20,35 +20,45 @@
    * @override
    */
   ns.Circle.prototype.draw = function (col, row, color, targetFrame, penSize) {
-    var circlePixels = this.getCirclePixels_(this.startCol, this.startRow, col, row);
-    pskl.PixelUtils.resizePixels(circlePixels, penSize).forEach(function (point) {
+    this.getCirclePixels_(this.startCol, this.startRow, col, row, penSize).forEach(function (point) {
       targetFrame.setPixel(point[0], point[1], color);
     });
   };
 
-  ns.Circle.prototype.getCirclePixels_ = function (x0, y0, x1, y1) {
+  ns.Circle.prototype.getCirclePixels_ = function (x0, y0, x1, y1, penSize) {
     var coords = pskl.PixelUtils.getOrderedRectangleCoordinates(x0, y0, x1, y1);
-    var xC = (coords.x0 + coords.x1) / 2;
-    var yC = (coords.y0 + coords.y1) / 2;
+    var xC = Math.round((coords.x0 + coords.x1) / 2);
+    var yC = Math.round((coords.y0 + coords.y1) / 2);
 
     var rX = coords.x1 - xC;
     var rY = coords.y1 - yC;
+    var iX = rX - penSize;
+    var iY = rY - penSize;
+    if (iX < 0) {
+      iX = 0;
+    }
+    if (iY < 0) {
+      iY = 0;
+    }
 
     var pixels = [];
 
-    var x, y, angle;
-    for (x = coords.x0 ; x < coords.x1 ; x++) {
-      angle = Math.acos((x - xC) / rX);
-      y = Math.round(rY * Math.sin(angle) + yC);
-      pixels.push({'col': x, 'row': y});
-      pixels.push({'col': 2 * xC - x, 'row': 2 * yC - y});
-    }
-
-    for (y = coords.y0 ; y < coords.y1 ; y++) {
-      angle = Math.asin((y - yC) / rY);
-      x = Math.round(rX * Math.cos(angle) + xC);
-      pixels.push({'col': x, 'row': y});
-      pixels.push({'col': 2 * xC - x, 'row': 2 * yC - y});
+    var x, y, angle, r;
+    for (x = 0 ; x <= rX ; x++) {
+      for (y = 0 ; y <= rY ; y++) {
+        angle = Math.atan(y / x);
+        r = Math.sqrt(x * x + y * y);
+        if ((rX <= penSize || rY <= penSize ||
+          r > iX * iY / Math.sqrt(iY * iY * Math.pow(Math.cos(angle), 2) + iX * iX * Math.pow(Math.sin(angle), 2)) +
+          0.5) &&
+          r < rX * rY / Math.sqrt(rY * rY * Math.pow(Math.cos(angle), 2) + rX * rX * Math.pow(Math.sin(angle), 2)) +
+          0.5) {
+          pixels.push([xC + x, yC + y]);
+          pixels.push([xC - x, yC + y]);
+          pixels.push([xC + x, yC - y]);
+          pixels.push([xC - x, yC - y]);
+        }
+      }
     }
 
     return pixels;