Updated Text Rendering Overview (markdown)

Text-Rendering-Overview.md

@@ -20,7 +20,6 @@ _(Abstract class)_
 This object handles the management of all TextSymbolizer properties. It can be used as a base class for own objects which implement new processing semantics. Basically this class just makes sure a pointer of the right class is returned by the ```get_placement_info``` call.
 
 ## Functions
-* ```get_all_expressions```: Get a list of all expressions used in any placement. This function is used to collect attributes.
 * ```get_placement_info```: _(Abstract function)_ Get a text_ placement_info object to use in rendering. The returned object creates a list of settings which is used to try to find a placement and stores all information that is generated by the placement finder. 
 
 This function usually is implemented as
@@ -29,6 +28,9 @@ This function usually is implemented as
      return text_placement_info_ptr(new text_placement_info_XXX(this));
 }
 ```
+
+* ```get_all_expressions```: Get a list of all expressions used in any placement. This function is used to collect attributes.
+
 ## Members
 All properties are grouped into a class ```text_symbolizer_properties``` accessible via public member ```properties```. They are used by subclasses as their default settings.
 
@@ -63,6 +65,15 @@ List of all characters and their positions and formats for a placement.
 
 
 
+# text_processor
+Stores formating information and uses this to produce formated text for a given feature.
+
+# Functions
+* ```process```: Takes a feature and produces formated text as output. The output ```processed_text``` object has to be created by the caller and passed in for thread safety.
+* ```get_all_expressions```: Get a list of all expressions used in any placement. This function is used to collect attributes.
+* ```from_xml```:  Construct object from XML.
+* ```to_xml```: Write object to XML ptree.
+
 
 # text_symbolizer_properties
 Contains all text symbolizer properties which are not directly related to text formating.