Merge pull request #17 from ricardozanini/master

Truncate Function on Vector Module

vector-light.lua

@@ -109,6 +109,19 @@ local function mirror(x,y, u,v)
 	return s*u - x, s*v - y
 end
 
+-- ref.: http://blog.signalsondisplay.com/?p=336
+local function truncate(maxLen)
+  local s
+    
+  s = maxLen / len()
+    
+  if s < 1 then s = 1 end
+  
+  x = x * s
+  y = y * s
+    
+  return x,y
+end
 
 -- the module
 return {

vector.lua

@@ -158,6 +158,24 @@ function vector:cross(v)
 	return self.x * v.y - self.y * v.x
 end
 
+-- ref.: http://blog.signalsondisplay.com/?p=336
+function vector:truncate_inplace(maxLen)
+  local s
+    
+  s = maxLen / self:len()
+    
+  if s < 1 then s = 1 end
+  
+  self.x = self.x * s
+  self.y = self.y * s
+    
+  return self
+end
+
+function vector:truncate(maxLen)
+  return self:clone():truncate_inplace(maxLen)
+end
+
 
 -- the module
 return setmetatable({new = new, isvector = isvector},