Add d4 and size to side util functions

3 files changed, 39 insertions, 6 deletions

diff --git a/designs/pips_d6.scad b/designs/pips_d6.scad
index 2f82ff4..8a5fe16 100644
--- a/designs/pips_d6.scad
+++ b/designs/pips_d6.scad
@@ -1,10 +1,12 @@
 use <../lib/dice.scad>
+use <../lib/utils.scad>
 use <../lib/faces/pips.scad>
 
-side = 14;
-size = 14;
+size = 16;
 
-rotate([180, 0, 0]) d6(side, size) {
+side = s2s_d6(size);
+
+rotate([180, 0, 0]) d6(size) {
     pips_1(side);
     pips_2(side);
     pips_3(side);
diff --git a/lib/dice.scad b/lib/dice.scad
index c3cab85..ed63d3f 100644
--- a/lib/dice.scad
+++ b/lib/dice.scad
@@ -1,9 +1,33 @@
-module d6(side=false, size=false) {
-    l = side ? side : size;
+use <utils.scad>
+
+module d4(size=false, side=false) {
+    l = side ? side : s2s_d4(size);
+    if (l == false) {
+        echo("ERROR: d6: one of side or size should be defined");
+    }
+    r = sqrt(6)/4*l;
+    c = r*2;
+    difference() {
+        intersection() {
+            sphere(r=r*0.79, $fn=64);
+            translate([0, 0, r-r/3]) cube(c, center=true);
+            intersection_for ( i = [0:2] ) {
+                rotate([0, 0, 120*i]) rotate([acos(1/3)+180, 0, 0]) 
+                    translate([0, 0, r-r/3]) cube(c, center=true);
+            }
+        }
+        rotate([180, 0, 0]) translate([0, 0, r/3]) child(0);
+        rotate([acos(1/3)+180, 0, 0]) rotate([180, 0, 0]) translate([0, 0, r/3]) child(1);
+        rotate([0, 0, 120]) rotate([acos(1/3)+180, 0, 0]) rotate([180, 0, 0]) translate([0, 0, r/3]) child(2);
+        rotate([0, 0, 240]) rotate([acos(1/3)+180, 0, 0]) rotate([180, 0, 0]) translate([0, 0, r/3]) child(3);
+    }
+}
+
+module d6(size=false, side=false) {
+    l = side ? side : s2s_d6(size);
     if (l == false) {
         echo("ERROR: d6: one of side or size should be defined");
     }
-    echo(l);
     difference() {
         intersection() {
             cube(l, center=true);
diff --git a/lib/utils.scad b/lib/utils.scad
new file mode 100644
index 0000000..d849636
--- /dev/null
+++ b/lib/utils.scad
@@ -0,0 +1,7 @@
+
+function circ_rad(size) = size / sqrt(2);
+
+function s2s_d4(size) = circ_rad(size)*2/sqrt(6);
+
+function s2s_d6(size) = size;
+