Triangle fans

[nt3d] / nt3d.js

diff --git a/nt3d.js b/nt3d.js
index 9d45486c32095235f9c423453b78b28acd193247..623c0f1b3756940087c0bcc07f0a364891a1a532 100644 (file)
--- a/nt3d.js
+++ b/nt3d.js
@@ -23,6 +23,26 @@ nt3d = {
                return this.triangle(a, b, c).concat(
                       this.triangle(c, d, a));
        },
+       trianglefan: function(fan) {
+               var result = [];
+               for (var i = 2; i < fan.length; i++) {
+                       result.push(fan[0], fan[i-1], fan[i]);
+               }
+               return result;
+       },
+       quadstrip: function(strip) {
+               if (strip.length % 2 != 0) {
+                       alert("quadstrip length not divisble by 2!");
+               }
+               var result = [];
+               for (var i = 2; i < strip.length; i += 2) {
+                       result = result.concat(nt3d.quad(strip[i-2], strip[i-1], strip[i+1], strip[i]));
+               }
+               return result;
+       },
+       closed_quadstrip: function(strip) {
+               return nt3d.quadstrip(strip).concat(nt3d.quad(strip[strip.length-2], strip[strip.length-1], strip[1], strip[0]));
+       },
        sub: function(a, b) {
                return [a[0] - b[0],
                        a[1] - b[1],