AutoFlowchart is a excellent source code flowcharting tool to generate flowchart from source code 
Its flowchart can expand and shrink. and you can pre-define the the width , height,Horizontal spacing and vertical spacing. Move and zoom is also very easy. It can export the flowchart as a Microsoft Word file or a bitmap file. It can help programmers understand, document and visualize source code.
It supports C,C++,Pascal!