From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 20 Jan 2018 23:10:15 +0000 (+0000)
Subject: fairphone-case: Struts: support negative thickness for inverted objects (nfc)
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=014cfe33a525fcc820b5f91015bb9d569a61380b;p=reprap-play.git

fairphone-case: Struts: support negative thickness for inverted objects (nfc)

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/fairphone-case.scad b/fairphone-case.scad
index 5cd591e..52a9b31 100644
--- a/fairphone-case.scad
+++ b/fairphone-case.scad
@@ -246,14 +246,17 @@ module AroundEdges(fill_zstart, fill_th, fill_downwards=0){
 }
 
 module Struts(z_min, th){
+  // if th is negative, starts at z_min and works towards -ve z
+  // and object should then be printed other way up
   for (i= [1 : 1 : case_struts_count]) {
     translate([0,
 	       0,
 	       z_min])
+      mirror([0,0, th<0 ? 1 : 0])
       translate([0,
 	       -phone_height * i / (case_struts_count+1),
 	       case_struts_solid_below])
-      linear_extrude(height= th
+      linear_extrude(height= abs(th)
 		     -(case_struts_solid_below+case_struts_solid_above))
       rectfromto([               epp2i[0], -0.5 * case_struts_width ],
 		 [ phone_width - epp2i[0], +0.5 * case_struts_width ]);