diff --git a/src/pixel/_impl/_px_line_impl.scad b/src/pixel/_impl/_px_line_impl.scad
new file mode 100644
index 00000000..9b6d046a
--- /dev/null
+++ b/src/pixel/_impl/_px_line_impl.scad
@@ -0,0 +1,202 @@
+
+use <__comm__/__to3d.scad>;
+use <__comm__/__to2d.scad>;
+
+function _px_line_zsgn(a) = a == 0 ? a : a / abs(a);
+    
+// x-dominant
+function _px_line_xdominant_y(y, yd, sy) = yd >= 0 ? y + sy : y;
+function _px_line_xdominant_yd(yd, ax, ay) = (yd >= 0 ? yd - ax : yd) + ay;
+function _px_line_xdominant_z(z, zd, sz) = zd >= 0 ? z + sz : z;
+function _px_line_xdominant_zd(zd, ax, az) = (zd >= 0 ? zd - ax : zd) + az;
+
+function _px_line_xdominant(start, end, a, s) = 
+    let(
+        x = start[0],
+        y = start[1],
+        z = start[2],
+        ax = a[0],
+        ay = a[1],
+        az = a[2],
+        sx = s[0],
+        sy = s[1],
+        sz = s[2],        
+        shrx = floor(ax / 2),
+        yd = ay - shrx,
+        zd = az - shrx,
+        endx = end[0]
+    )
+    concat(
+        [start], 
+        _px_line_xdominant_sub(
+            x + sx, 
+            _px_line_xdominant_y(y, yd, sy), 
+            _px_line_xdominant_z(z, zd, sz), 
+            endx, 
+            a, 
+            s, 
+            _px_line_xdominant_yd(yd, ax, ay), 
+            _px_line_xdominant_zd(zd, ax, az)
+        )
+    );
+
+function _px_line_xdominant_sub(x, y, z, endx, a, s, yd, zd) = 
+    let(
+        ax = a[0],
+        ay = a[1],
+        az = a[2],
+        sx = s[0],
+        sy = s[1],
+        sz = s[2]
+    )
+    x == endx ? [] : 
+        concat([[x, y, z]], 
+            _px_line_xdominant_sub(
+                x + sx, 
+                _px_line_xdominant_y(y, yd, sy), 
+                _px_line_xdominant_z(z, zd, sz), 
+                endx, 
+                a, 
+                s, 
+                _px_line_xdominant_yd(yd, ax, ay), 
+                _px_line_xdominant_zd(zd, ax, az)
+            )
+        );
+        
+// y-dominant
+function _px_line_ydominant_x(x, xd, sx) = xd >= 0 ? x + sx : x;
+function _px_line_ydominant_xd(xd, ax, ay) = (xd >= 0 ? xd - ay : xd) + ax;
+function _px_line_ydominant_z(z, zd, sz) = zd >= 0 ? z + sz : z;
+function _px_line_ydominant_zd(zd, ay, az) = (zd >= 0 ? zd - ay : zd) + az;
+        
+function _px_line_ydominant(start, end, a, s) = 
+    let(
+        x = start[0],
+        y = start[1],
+        z = start[2],
+        ax = a[0],
+        ay = a[1],
+        az = a[2],
+        sx = s[0],
+        sy = s[1],
+        sz = s[2],        
+        shry = floor(ay / 2),
+        xd = ax - shry,
+        zd = az - shry,
+        endy = end[1]
+    )
+    concat(
+        [start], 
+        _px_line_ydominant_sub(
+            _px_line_ydominant_x(x, xd, sx), 
+            y + sy,
+            _px_line_ydominant_z(z, zd, sz), 
+            endy, 
+            a, 
+            s, 
+            _px_line_ydominant_xd(xd, ax, ay), 
+            _px_line_ydominant_zd(zd, ay, az)
+        )
+    );
+
+function _px_line_ydominant_sub(x, y, z, endy, a, s, xd, zd) = 
+    let(
+        ax = a[0],
+        ay = a[1],
+        az = a[2],
+        sx = s[0],
+        sy = s[1],
+        sz = s[2]
+    )
+    y == endy ? [] : 
+        concat([[x, y, z]], 
+            _px_line_ydominant_sub(
+                _px_line_ydominant_x(x, xd, sx), 
+                y + sy,
+                _px_line_ydominant_z(z, zd, sz), 
+                endy, 
+                a, 
+                s, 
+                _px_line_ydominant_xd(xd, ax, ay), 
+                _px_line_ydominant_zd(zd, ay, az)
+            )
+        );
+
+// z-dominant
+function _px_line_zdominant_x(x, xd, sx) = xd >= 0 ? x + sx : x;
+function _px_line_zdominant_xd(xd, ax, az) = (xd >= 0 ? xd - az : xd) + ax;
+
+function _px_line_zdominant_y(y, yd, sy) = yd >= 0 ? y + sy : y;
+function _px_line_zdominant_yd(yd, ay, az) = (yd >= 0 ? yd - az : yd) + ay;
+        
+function _px_line_zdominant(start, end, a, s) = 
+    let(
+        x = start[0],
+        y = start[1],
+        z = start[2],
+        ax = a[0],
+        ay = a[1],
+        az = a[2],
+        sx = s[0],
+        sy = s[1],
+        sz = s[2],        
+        shrz = floor(az / 2),
+        xd = ax - shrz,
+        yd = ay - shrz,
+        endz = end[2]
+    )
+    concat(
+        [start], 
+        _px_line_zdominant_sub(
+            _px_line_zdominant_x(x, xd, sx), 
+            _px_line_zdominant_y(y, yd, sy), 
+            z + sz,
+            endz, 
+            a, 
+            s, 
+            _px_line_zdominant_xd(xd, ax, az), 
+            _px_line_zdominant_yd(yd, ay, az)
+        )
+    );
+
+function _px_line_zdominant_sub(x, y, z, endz, a, s, xd, yd) = 
+    let(
+        ax = a[0],
+        ay = a[1],
+        az = a[2],
+        sx = s[0],
+        sy = s[1],
+        sz = s[2]
+    )
+    z == endz ? [] : 
+        concat([[x, y, z]], 
+            _px_line_zdominant_sub(
+                _px_line_zdominant_x(x, xd, sx), 
+                _px_line_zdominant_y(y, yd, sy), 
+                z + sz,
+                endz, 
+                a, 
+                s, 
+                _px_line_zdominant_xd(xd, ax, az), 
+                _px_line_zdominant_yd(yd, ay, az)
+            )
+        );
+        
+function _px_line_impl(p1, p2) = 
+    let(
+        is_2d = len(p1) == 2,
+        start_pt = is_2d ? __to3d(p1) : p1,
+        end_pt = is_2d ? __to3d(p2) : p2,
+        dt = end_pt - start_pt,
+        ax = floor(abs(dt[0]) * 2),
+        ay = floor(abs(dt[1]) * 2),
+        az = floor(abs(dt[2]) * 2),
+        sx = _px_line_zsgn(dt[0]),
+        sy = _px_line_zsgn(dt[1]),
+        sz = _px_line_zsgn(dt[2]),
+        points = ax >= max(ay, az) ? _px_line_xdominant(start_pt, end_pt, [ax, ay, az], [sx, sy, sz]) : (
+            ay >= max(ax, az) ? _px_line_ydominant(start_pt, end_pt, [ax, ay, az], [sx, sy, sz]) :
+                _px_line_zdominant(start_pt, end_pt, [ax, ay, az], [sx, sy, sz])
+        )
+    )   
+    is_2d ? [for(pt = points) __to2d(pt)] : points;
\ No newline at end of file
diff --git a/src/pixel/px_line.scad b/src/pixel/px_line.scad
index ccb5cb36..d8b75167 100644
--- a/src/pixel/px_line.scad
+++ b/src/pixel/px_line.scad
@@ -8,204 +8,6 @@
 *
 **/ 
 
-include <__comm__/__to3d.scad>;
-include <__comm__/__to2d.scad>;
+use <pixel/_impl/_px_line_impl.scad>;
 
-function _px_line_zsgn(a) = a == 0 ? a : a / abs(a);
-    
-// x-dominant
-function _px_line_xdominant_y(y, yd, sy) = yd >= 0 ? y + sy : y;
-function _px_line_xdominant_yd(yd, ax, ay) = (yd >= 0 ? yd - ax : yd) + ay;
-function _px_line_xdominant_z(z, zd, sz) = zd >= 0 ? z + sz : z;
-function _px_line_xdominant_zd(zd, ax, az) = (zd >= 0 ? zd - ax : zd) + az;
-
-function _px_line_xdominant(start, end, a, s) = 
-    let(
-        x = start[0],
-        y = start[1],
-        z = start[2],
-        ax = a[0],
-        ay = a[1],
-        az = a[2],
-        sx = s[0],
-        sy = s[1],
-        sz = s[2],        
-        shrx = floor(ax / 2),
-        yd = ay - shrx,
-        zd = az - shrx,
-        endx = end[0]
-    )
-    concat(
-        [start], 
-        _px_line_xdominant_sub(
-            x + sx, 
-            _px_line_xdominant_y(y, yd, sy), 
-            _px_line_xdominant_z(z, zd, sz), 
-            endx, 
-            a, 
-            s, 
-            _px_line_xdominant_yd(yd, ax, ay), 
-            _px_line_xdominant_zd(zd, ax, az)
-        )
-    );
-
-function _px_line_xdominant_sub(x, y, z, endx, a, s, yd, zd) = 
-    let(
-        ax = a[0],
-        ay = a[1],
-        az = a[2],
-        sx = s[0],
-        sy = s[1],
-        sz = s[2]
-    )
-    x == endx ? [] : 
-        concat([[x, y, z]], 
-            _px_line_xdominant_sub(
-                x + sx, 
-                _px_line_xdominant_y(y, yd, sy), 
-                _px_line_xdominant_z(z, zd, sz), 
-                endx, 
-                a, 
-                s, 
-                _px_line_xdominant_yd(yd, ax, ay), 
-                _px_line_xdominant_zd(zd, ax, az)
-            )
-        );
-        
-// y-dominant
-function _px_line_ydominant_x(x, xd, sx) = xd >= 0 ? x + sx : x;
-function _px_line_ydominant_xd(xd, ax, ay) = (xd >= 0 ? xd - ay : xd) + ax;
-function _px_line_ydominant_z(z, zd, sz) = zd >= 0 ? z + sz : z;
-function _px_line_ydominant_zd(zd, ay, az) = (zd >= 0 ? zd - ay : zd) + az;
-        
-function _px_line_ydominant(start, end, a, s) = 
-    let(
-        x = start[0],
-        y = start[1],
-        z = start[2],
-        ax = a[0],
-        ay = a[1],
-        az = a[2],
-        sx = s[0],
-        sy = s[1],
-        sz = s[2],        
-        shry = floor(ay / 2),
-        xd = ax - shry,
-        zd = az - shry,
-        endy = end[1]
-    )
-    concat(
-        [start], 
-        _px_line_ydominant_sub(
-            _px_line_ydominant_x(x, xd, sx), 
-            y + sy,
-            _px_line_ydominant_z(z, zd, sz), 
-            endy, 
-            a, 
-            s, 
-            _px_line_ydominant_xd(xd, ax, ay), 
-            _px_line_ydominant_zd(zd, ay, az)
-        )
-    );
-
-function _px_line_ydominant_sub(x, y, z, endy, a, s, xd, zd) = 
-    let(
-        ax = a[0],
-        ay = a[1],
-        az = a[2],
-        sx = s[0],
-        sy = s[1],
-        sz = s[2]
-    )
-    y == endy ? [] : 
-        concat([[x, y, z]], 
-            _px_line_ydominant_sub(
-                _px_line_ydominant_x(x, xd, sx), 
-                y + sy,
-                _px_line_ydominant_z(z, zd, sz), 
-                endy, 
-                a, 
-                s, 
-                _px_line_ydominant_xd(xd, ax, ay), 
-                _px_line_ydominant_zd(zd, ay, az)
-            )
-        );
-
-// z-dominant
-function _px_line_zdominant_x(x, xd, sx) = xd >= 0 ? x + sx : x;
-function _px_line_zdominant_xd(xd, ax, az) = (xd >= 0 ? xd - az : xd) + ax;
-
-function _px_line_zdominant_y(y, yd, sy) = yd >= 0 ? y + sy : y;
-function _px_line_zdominant_yd(yd, ay, az) = (yd >= 0 ? yd - az : yd) + ay;
-        
-function _px_line_zdominant(start, end, a, s) = 
-    let(
-        x = start[0],
-        y = start[1],
-        z = start[2],
-        ax = a[0],
-        ay = a[1],
-        az = a[2],
-        sx = s[0],
-        sy = s[1],
-        sz = s[2],        
-        shrz = floor(az / 2),
-        xd = ax - shrz,
-        yd = ay - shrz,
-        endz = end[2]
-    )
-    concat(
-        [start], 
-        _px_line_zdominant_sub(
-            _px_line_zdominant_x(x, xd, sx), 
-            _px_line_zdominant_y(y, yd, sy), 
-            z + sz,
-            endz, 
-            a, 
-            s, 
-            _px_line_zdominant_xd(xd, ax, az), 
-            _px_line_zdominant_yd(yd, ay, az)
-        )
-    );
-
-function _px_line_zdominant_sub(x, y, z, endz, a, s, xd, yd) = 
-    let(
-        ax = a[0],
-        ay = a[1],
-        az = a[2],
-        sx = s[0],
-        sy = s[1],
-        sz = s[2]
-    )
-    z == endz ? [] : 
-        concat([[x, y, z]], 
-            _px_line_zdominant_sub(
-                _px_line_zdominant_x(x, xd, sx), 
-                _px_line_zdominant_y(y, yd, sy), 
-                z + sz,
-                endz, 
-                a, 
-                s, 
-                _px_line_zdominant_xd(xd, ax, az), 
-                _px_line_zdominant_yd(yd, ay, az)
-            )
-        );
-        
-function px_line(p1, p2) = 
-    let(
-        is_2d = len(p1) == 2,
-        start_pt = is_2d ? __to3d(p1) : p1,
-        end_pt = is_2d ? __to3d(p2) : p2,
-        dt = end_pt - start_pt,
-        ax = floor(abs(dt[0]) * 2),
-        ay = floor(abs(dt[1]) * 2),
-        az = floor(abs(dt[2]) * 2),
-        sx = _px_line_zsgn(dt[0]),
-        sy = _px_line_zsgn(dt[1]),
-        sz = _px_line_zsgn(dt[2]),
-        points = ax >= max(ay, az) ? _px_line_xdominant(start_pt, end_pt, [ax, ay, az], [sx, sy, sz]) : (
-            ay >= max(ax, az) ? _px_line_ydominant(start_pt, end_pt, [ax, ay, az], [sx, sy, sz]) :
-                _px_line_zdominant(start_pt, end_pt, [ax, ay, az], [sx, sy, sz])
-        )
-    )   
-    is_2d ? [for(pt = points) __to2d(pt)] : points;
\ No newline at end of file
+function px_line(p1, p2) = _px_line_impl(p1, p2);
\ No newline at end of file
diff --git a/test/pixel/test_px_line.scad b/test/pixel/test_px_line.scad
index 8440ba21..7f1f47d0 100644
--- a/test/pixel/test_px_line.scad
+++ b/test/pixel/test_px_line.scad
@@ -1,5 +1,5 @@
-include <unittest.scad>;
-include <pixel/px_line.scad>;
+use <unittest.scad>;
+use <pixel/px_line.scad>;
 
 module test_px_line() {
     echo("==== test_px_line ====");