From 22664ba0f83112edb93888aeda7b6635cf79c549 Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Sun, 1 Mar 2020 16:48:04 +0800
Subject: [PATCH] add slices param

---
 src/experimental/demo/loft_demo.scad | 11 ++++++-----
 src/experimental/loft.scad           | 20 ++++++++++++++++++--
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/experimental/demo/loft_demo.scad b/src/experimental/demo/loft_demo.scad
index efec5411..5f232e1f 100644
--- a/src/experimental/demo/loft_demo.scad
+++ b/src/experimental/demo/loft_demo.scad
@@ -1,12 +1,13 @@
 use <shape_starburst.scad>;
 use <rotate_p.scad>;
+use <util/reverse.scad>;
 use <experimental/loft.scad>;
     
 sects = [
-    for(i = [4:20])
-    [
-        for(p = shape_starburst(15, 12, i % 2 == 1 ? i : i - 1))    rotate_p([p[0], p[1], 3 * (i - 4)], i * 10)
-    ]
+    for(i = [4:10])
+    reverse([
+        for(p = shape_starburst(15, 12, i % 2 == 1 ? i : i - 1)) rotate_p([p[0], p[1], 5 * (i - 4)], i * 10)
+    ])
 ];
 
-loft(sects);
\ No newline at end of file
+loft(sects, slices = 3);
\ No newline at end of file
diff --git a/src/experimental/loft.scad b/src/experimental/loft.scad
index 1cedb51d..82bb3c2b 100644
--- a/src/experimental/loft.scad
+++ b/src/experimental/loft.scad
@@ -1,6 +1,6 @@
 use <experimental/sweep.scad>;
    
-module loft(sections) {
+module loft(sections, slices = 1) {
     function gcd(m, n) = n == 0 ? m : gcd(n, m % n);
 
     function lcm(m, n) = m * n / gcd(m, n);
@@ -30,11 +30,27 @@ module loft(sections) {
         n <= 1 ? sect : _interpolate(sect, len(sect), n);
         
     module _loft(sect1, sect2) {
+        function inter_sects(s1, s2, s_leng, slices) = 
+            slices == 1 ? [] : 
+                let(
+                    dps = [
+                        for(i = [0:lcm_n - 1])
+                        (s2[i] - s1[i]) / slices
+                    ]
+                )
+                [for(i = [1:slices - 1]) s1 + dps * i];
+
         lcm_n = lcm(len(sect1), len(sect2));
         new_sect1 = interpolate(sect1, lcm_n / len(sect1));
         new_sect2 = interpolate(sect2, lcm_n / len(sect2));
         
-        sweep([new_sect1, new_sect2]);
+        sweep(
+            concat(
+                [new_sect1],
+                inter_sects(new_sect1, new_sect2, lcm_n, slices),
+                [new_sect2]
+            )
+        );
     }
         
     for(i = [0:len(sections) - 2]) {