From 53e86a14fa8f8cc7badce28c5e1a5b96fcd4a010 Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Thu, 9 Apr 2020 14:31:08 +0800
Subject: [PATCH] symmetric

---
 examples/voronoi/voronoi_penholder.scad | 62 ++++++-------------------
 src/experimental/voronoi_square.scad    | 32 ++++++++-----
 2 files changed, 36 insertions(+), 58 deletions(-)

diff --git a/examples/voronoi/voronoi_penholder.scad b/examples/voronoi/voronoi_penholder.scad
index f79bacfa..26698c8e 100644
--- a/examples/voronoi/voronoi_penholder.scad
+++ b/examples/voronoi/voronoi_penholder.scad
@@ -1,53 +1,21 @@
-use <hull_polyline2d.scad>;
-use <shape_square.scad>;
-use <hollow_out.scad>;
+use <experimental/voronoi_square.scad>;
 use <bend_extrude.scad>;
-use <experimental/voronoi2d_cells.scad>;
+use <arc.scad>;
 
-xy = [100, 40];
-pt_nums = 20;
+size = [300, 120];
+grid_w = 30;
 thickness = 2;
+spacing = 3;
+seed = 5;
+$fn = 24;
 
-voronoi_penholder(xy, pt_nums, thickness);
+color("black")
+bend_extrude(size, thickness = thickness, angle = 360) 
+    voronoi_square(size, grid_w, seed, spacing);
 
-module voronoi_penholder(xy, pt_nums, thickness) {
-    xs1 = rands(0, xy[0], pt_nums);
-    ys1 = rands(0, xy[1], pt_nums);
-    points = [for(i = [0:len(xs1) - 1]) [xs1[i], ys1[i]]];
+r = size[0] / (2 * PI);
+linear_extrude(size[1])
+    arc(radius = r - thickness, angle = [0, 360], width = thickness / 2);
 
-    cpts = concat(
-        [for(p = points) if(p[0] > xy[0] - 10) p + [-xy[0], 0]],
-        points,
-        [for(p = points) if(p[0] < 10) p + [xy[0], 0]]
-    );
-
-    function default_region_size(points) = 
-        let(
-            xs = [for(p = points) p[0]],
-            ys = [for(p = points) abs(p[1])]
-        )
-        max([(max(xs) -  min(xs) / 2), (max(ys) -  min(ys)) / 2]);
-
-    size = default_region_size(cpts);  
-    region_shape = shape_square(size, corner_r = size / 5);
-
-    cells = voronoi2d_cells(cpts, region_shape);
-    bend_extrude(size = [xy[0], xy[1]], thickness = thickness, angle = 360, $fn = 48) 
-    {
-        for(i = [0:len(cpts) - 1]) {
-            cell = cells[i];
-            hull_polyline2d(concat(cell, [cell[0]]), width = thickness);
-            
-        }
-    }
-
-    r = 0.5 * xy[0] / PI;
-
-    linear_extrude(thickness)
-        circle(r, $fn = 48);
-
-    translate([0, 0, xy[1]])    
-    linear_extrude(thickness)
-    hollow_out(shell_thickness = thickness)
-        circle(r, $fn = 48);
-}
\ No newline at end of file
+linear_extrude(thickness)    
+    circle(r);    
\ No newline at end of file
diff --git a/src/experimental/voronoi_square.scad b/src/experimental/voronoi_square.scad
index c751746c..b393f9ec 100644
--- a/src/experimental/voronoi_square.scad
+++ b/src/experimental/voronoi_square.scad
@@ -3,28 +3,32 @@ module voronoi_square(size, grid_w, seed, spacing = 1, r = 0, delta = 0, chamfer
 
     function _lookup_noise_table(i) = _noise_table[i % 256];
 
-    function cell_pt(fcord, seed, x, y) = 
+    function cell_pt(fcord, seed, x, y, gw, gh) = 
         let(
             nx = fcord[0] + x,
             ny = fcord[1] + y,
-            sd_base = abs(nx + ny * grid_w),
+            sd_x = nx < 0 ? nx + gw : 
+                   nx >= gw ? nx % gw : nx,
+            sd_y = ny < 0 ? ny + gh : 
+                   ny >= gh ? ny % gh : ny,                   
+            sd_base = abs(sd_x + sd_y * grid_w),
             sd1 = _lookup_noise_table(seed + sd_base),
             sd2 = _lookup_noise_table(sd1 * 255 + sd_base)
         )
         [(nx + sd1) * grid_w, (ny + sd2) * grid_w];
 
     // 21-nearest-neighbor 
-    function _neighbors(fcord, seed, grid_w) = 
+    function _neighbors(fcord, seed, grid_w, gw, gh) = 
         concat(
             [
                 for(y = [-1:1])
                     for(x = [-1:1])
-                        cell_pt(fcord, seed, x, y)
+                        cell_pt(fcord, seed, x, y, gw, gh)
             ],
-            [for(x = [-1:1]) cell_pt(fcord, seed, x, -2)],
-            [for(x = [-1:1]) cell_pt(fcord, seed, x, 2)],
-            [for(y = [-1:1]) cell_pt(fcord, seed, -2, y)],
-            [for(y = [-1:1]) cell_pt(fcord, seed, 2, y)]
+            [for(x = [-1:1]) cell_pt(fcord, seed, x, -2, gw, gh)],
+            [for(x = [-1:1]) cell_pt(fcord, seed, x, 2, gw, gh)],
+            [for(y = [-1:1]) cell_pt(fcord, seed, -2, y, gw, gh)],
+            [for(y = [-1:1]) cell_pt(fcord, seed, 2, y, gw, gh)]
         );
 
     region_size = grid_w * 3;
@@ -44,13 +48,19 @@ module voronoi_square(size, grid_w, seed, spacing = 1, r = 0, delta = 0, chamfer
     
     sd = is_undef(seed) ? rands(0, 255, 1)[0] : seed; 
 
-    cell_nbrs_lt = [for(cy = [0:grid_w:size[1]]) 
-        for(cx = [0:grid_w:size[0]])
+
+    gw = size[0] / grid_w;
+    gh = size[1] / grid_w;
+
+    cell_nbrs_lt = [for(cy = [-grid_w:grid_w:size[1]]) 
+        for(cx = [-grid_w:grid_w:size[0]])
         let(
             nbrs = _neighbors(
                 [floor(cx / grid_w), floor(cy / grid_w)],
                 sd, 
-                grid_w
+                grid_w,
+                gw, 
+                gh
             ),
             p = nbrs[4],
             points = concat(