circle brush algo

1 files changed, 18 insertions, 3 deletions

diff --git a/js/blit.js b/js/blit.js
index 367d67b..16c62a5 100644
--- a/js/blit.js
+++ b/js/blit.js
@@ -47,11 +47,26 @@ var blit = (function(){
       }
     })
   }
+  var distance_rect = function(x, y, ratio){
+    return Math.sqrt((Math.pow(y * ratio, 2)) + Math.pow(x, 2))
+  }
+  var distance_square = function(x, y, ratio){
+    return Math.sqrt((Math.pow(y * ratio, 2)) + Math.pow(x * ratio, 2))
+  }
   blit.circle = function(A, lex){
-    var hw = brush.w/2|0, hh = brush.h/2|0
+    var hw = brush.w/2, hh = brush.h/2
+    var ratio, distance
+    
+    if (brush.w === brush.h){
+      distance = distance_square
+      ratio = hw / hh * (brush.w === 3 || brush.w === 5 ? 1.2 : 1.05)
+    } else {
+      distance = distance_rect
+      ratio = hw / hh
+    }
+
     A.forEach(function(lex,x,y) {
-      var len = Math.sqrt(Math.pow(x-hw,2)+Math.pow(y-hh,2))
-      if (len > Math.abs(hw)) {
+      if (distance(x - hw + 0.5, y - hh + 0.5, ratio) > hw){
         lex.clear()
       }
     })