1 files changed, 31 insertions, 0 deletions
diff --git a/public/assets/javascripts/rectangles/models/vec3.js b/public/assets/javascripts/rectangles/models/vec3.js
new file mode 100644
index 0000000..4e00b0c
--- /dev/null
+++ b/public/assets/javascripts/rectangles/models/vec3.js
@@ -0,0 +1,31 @@
+function vec3(a,b,c){
+	this.a = a
+	this.b = b
+	this.c = c
+}
+vec3.prototype.add = function(v){
+	this.a += v.a
+	this.b += v.b
+	this.c += v.c
+	return this
+}
+vec3.prototype.sub = function(v){
+	this.a -= v.a
+	this.b -= v.b
+	this.c -= v.c
+	return this
+}
+
+// input: mat4 projection matrix
+vec3.prototype.apply_projection = function (m) {
+	var x = this.a, y = this.b, z = this.c;
+
+	var e = m.elements;
+	var d = 1 / ( e[3] * x + e[7] * y + e[11] * z + e[15] ); // perspective divide
+
+	this.x = ( e[0] * x + e[4] * y + e[8]  * z + e[12] ) * d;
+	this.y = ( e[1] * x + e[5] * y + e[9]  * z + e[13] ) * d;
+	this.z = ( e[2] * x + e[6] * y + e[10] * z + e[14] ) * d;
+
+	return this;
+}