diff --git a/src/pixel/px_circle.scad b/src/pixel/px_circle.scad
index 99ae7cb4..281a3726 100644
--- a/src/pixel/px_circle.scad
+++ b/src/pixel/px_circle.scad
@@ -2,10 +2,8 @@ function _px_circle_y(f, y) = f >= 0 ? y - 1 : y;
 function _px_circle_ddf_y(f, ddf_y) = f >= 0 ? ddf_y + 2 : ddf_y;
 function _px_circle_f(f, ddf_y) = f >= 0 ? f + ddf_y : f;
 
-function _px_circle_sub(center, f, ddf_x, ddf_y, x, y, filled) = 
+function _px_circle_sub(f, ddf_x, ddf_y, x, y, filled) = 
     let(
-        x0 = center[0],
-        y0 = center[1],
         ny = _px_circle_y(f, y),
         nddf_y = _px_circle_ddf_y(f, ddf_y),
         nx = x + 1,
@@ -15,34 +13,32 @@ function _px_circle_sub(center, f, ddf_x, ddf_y, x, y, filled) =
     concat(
         filled ? 
             concat(
-               [for(xi = -nx; xi <= nx; xi = xi + 1) [x0 - xi, y0 + ny]],
-               [for(xi = -ny; xi <= ny; xi = xi + 1) [x0 - xi, y0 + nx]],
-               [for(xi = -ny; xi <= ny; xi = xi + 1) [x0 - xi, y0 - nx]],
-               [for(xi = -nx; xi <= nx; xi = xi + 1) [x0 - xi, y0 - ny]]
+               [for(xi = -nx; xi <= nx; xi = xi + 1) [-xi, ny]],
+               [for(xi = -ny; xi <= ny; xi = xi + 1) [-xi, nx]],
+               [for(xi = -ny; xi <= ny; xi = xi + 1) [-xi, -nx]],
+               [for(xi = -nx; xi <= nx; xi = xi + 1) [-xi, -ny]]
             )
             :
             [
-                [x0 - nx, y0 + ny],
-                [x0 + nx, y0 + ny],
-                [x0 - ny, y0 + nx],
-                [x0 + ny, y0 + nx],
+                [-nx, ny],
+                [nx, ny],
+                [-ny, nx],
+                [ny, nx],
 
-                [x0 - ny, y0 - nx],            
-                [x0 + ny, y0 - nx],
-                [x0 - nx, y0 - ny],
-                [x0 + nx, y0 - ny]        
+                [-ny, -nx],            
+                [ny, -nx],
+                [-nx, -ny],
+                [nx, -ny]        
             ],
-        _px_circle(center, nf, nddf_x, nddf_y, nx, ny, filled)
+        _px_circle(nf, nddf_x, nddf_y, nx, ny, filled)
     );
     
 
-function _px_circle(center, f, ddf_x, ddf_y, x, y, filled) = 
-    x >= y ? [] : _px_circle_sub(center, f, ddf_x, ddf_y, x, y, filled);
+function _px_circle(, f, ddf_x, ddf_y, x, y, filled) = 
+    x >= y ? [] : _px_circle_sub(f, ddf_x, ddf_y, x, y, filled);
     
-function px_circle(radius, center = [0, 0], filled = true) =
+function px_circle(radius, filled = true) =
     let(
-        x0 = center[0],
-        y0 = center[1],
         f = 1 - radius,
         ddf_x = 1,
         ddf_y = -2 * radius,
@@ -52,15 +48,15 @@ function px_circle(radius, center = [0, 0], filled = true) =
     concat(
         filled ? 
             concat(
-                [[x0, y0 + radius], [x0, y0 - radius]],
-                [for(xi = -radius; xi <= radius; xi = xi + 1) [x0 + xi, y0]]
+                [[0, radius], [0, -radius]],
+                [for(xi = -radius; xi <= radius; xi = xi + 1) [xi, 0]]
             )
             : 
             [
-                [x0, y0 + radius], 
-                [x0, y0 - radius], 
-                [x0 + radius, y0], 
-                [x0 -radius, y0]
+                [0, radius], 
+                [0, -radius], 
+                [radius, 0], 
+                [-radius, 0]
             ],
-        _px_circle(center, f, ddf_x, ddf_y, x, y, filled)
+        _px_circle(f, ddf_x, ddf_y, x, y, filled)
     );
\ No newline at end of file