Added tranform.centered_cosine(...).

doc/files/utils/transform.html

@@ -132,6 +132,16 @@
     <td class="summary">Performs a linear transform on the given value to transform the value from the range -10/10 to 0/1.</td>
     </tr>
 
+    <tr>
+    <td class="name" nowrap><a href="#transform.centered">transform.centered</a>&nbsp;(value, transformation, min, max, new_min, new_max)</td>
+    <td class="summary">Performs the given transformation on the given value with the peak in center of the min and max values.</td>
+    </tr>
+
+    <tr>
+    <td class="name" nowrap><a href="#transform.centered_cosine">transform.centered_cosine</a>&nbsp;(value, min, max, new_min, new_max)</td>
+    <td class="summary">Performs a cosine transformation on the given value with the peak in center of the min and max values.</td>
+    </tr>
+
     <tr>
     <td class="name" nowrap><a href="#transform.centered_linear">transform.centered_linear</a>&nbsp;(value, min, max, new_min, new_max)</td>
     <td class="summary">Performs a linear transformation on the given value with the peak in center of the min and max values.</td>
@@ -197,6 +207,100 @@ Performs a linear transform on the given value to transform the value from the r
 
 
 
+<h3>Return value:</h3>
+The transformed value.
+
+
+
+</dd>
+
+
+
+
+<dt><a name="transform.centered"></a><strong>transform.centered</strong>&nbsp;(value, transformation, min, max, new_min, new_max)</dt>
+<dd>
+Performs the given transformation on the given value with the peak in center of the min and max values. 
+
+
+<h3>Parameters</h3>
+<ul>
+	
+	<li>
+	  value: The value to transform.
+	</li>
+	
+	<li>
+	  transformation: The transformation function, assumed to accept five values.
+	</li>
+	
+	<li>
+	  min: Optional. The original minimum value, defaults to -1.
+	</li>
+	
+	<li>
+	  max: Optional. The original maximum value, default to 1.
+	</li>
+	
+	<li>
+	  new_min: Optional. The minimum value for the new range, defaults to 0.
+	</li>
+	
+	<li>
+	  new_max: Optional. The maximum value for the new range, defaults to 1.
+	</li>
+	
+</ul>
+
+
+
+
+
+
+<h3>Return value:</h3>
+The transformed value.
+
+
+
+</dd>
+
+
+
+
+<dt><a name="transform.centered_cosine"></a><strong>transform.centered_cosine</strong>&nbsp;(value, min, max, new_min, new_max)</dt>
+<dd>
+Performs a cosine transformation on the given value with the peak in center of the min and max values. 
+
+
+<h3>Parameters</h3>
+<ul>
+	
+	<li>
+	  value: The value to transform.
+	</li>
+	
+	<li>
+	  min: Optional. The original minimum value, defaults to -1.
+	</li>
+	
+	<li>
+	  max: Optional. The original maximum value, default to 1.
+	</li>
+	
+	<li>
+	  new_min: Optional. The minimum value for the new range, defaults to 0.
+	</li>
+	
+	<li>
+	  new_max: Optional. The maximum value for the new range, defaults to 1.
+	</li>
+	
+</ul>
+
+
+
+
+
+
 <h3>Return value:</h3>
 The transformed value.
 

test/transform.lua

@@ -3,6 +3,7 @@
 dofile("./utils/test.lua")
 
 -- Load the file for testing.
+dofile("./utils/interpolate.lua")
 dofile("./utils/transform.lua")
 dofile("./utils/mathutil.lua")
 

utils/transform.lua

@@ -40,6 +40,43 @@ function transform.big_linear(value, new_min, new_max)
 	return transform.linear(value, -10, 10, new_min, new_max)
 end
 
+--- Performs the given transformation on the given value with the peak in center
+-- of the min and max values.
+--
+-- @param value The value to transform.
+-- @param transformation The transformation function, assumed to accept five
+--                       values.
+-- @param min Optional. The original minimum value, defaults to -1.
+-- @param max Optional. The original maximum value, default to 1.
+-- @param new_min Optional. The minimum value for the new range, defaults to 0.
+-- @param new_max Optional. The maximum value for the new range, defaults to 1.
+-- @return The transformed value.
+function transform.centered(value, transformation, min, max, new_min, new_max)
+	min = min or -1
+	max = max or 1
+	
+	local center = (min + max) / 2
+	
+	if value < center then
+		return transformation(value, min, center, new_min, new_max)
+	else
+		return transformation(value, max, center, new_min, new_max)
+	end
+end
+
+--- Performs a cosine transformation on the given value with the peak in center
+-- of the min and max values.
+--
+-- @param value The value to transform.
+-- @param min Optional. The original minimum value, defaults to -1.
+-- @param max Optional. The original maximum value, default to 1.
+-- @param new_min Optional. The minimum value for the new range, defaults to 0.
+-- @param new_max Optional. The maximum value for the new range, defaults to 1.
+-- @return The transformed value.
+function transform.centered_cosine(value, min, max, new_min, new_max)
+	return transform.centered(value, transform.cosine, min, max, new_min, new_max)
+end
+
 --- Performs a linear transformation on the given value with the peak in center
 -- of the min and max values.
 --
@@ -49,16 +86,7 @@ end
 -- @param new_min Optional. The minimum value for the new range, defaults to 0.
 -- @param new_max Optional. The maximum value for the new range, defaults to 1.
 function transform.centered_linear(value, min, max, new_min, new_max)
-	min = min or -1
+	return transform.centered(value, transform.linear, min, max, new_min, new_max)
-	max = max or 1
-	
-	local center = (min + max) / 2
-	
-	if value < center then
-		return transform.linear(value, min, center, new_min, new_max)
-	else
-		return transform.linear(value, max, center, new_min, new_max)
-	end
 end
 
 --- Performs a cosine transform on the given value to transform the value