Screen Visualisations

[Arcane Wizard]

I want to make an application that applies a visual effect to the entire screen, no matter what application has focus (perhaps even in games).

Functional requirements:

• Be completely visually transparent.
  
• Be completely functionally transparent. (allow mouse events to pass through to other applications)
  
• Always fit the entire screen. Even when other applications have focus.
  
• Show graphics at specific alpha levels.
  
• Optional:
  
  
  • Get dynamic access to information about window elements on the screen. For example: see if an active title bar is at pixel ( 280, 420 ). Information such as: window type of the element, name of the parent window and application of the element, and bounding box (or shape) of the element.
    
  
  

I've written windows applications in Java and C++ before, but I was wondering if anybody could guide me to information on the specific topics above, for either language. Thanks. : )