I need a better name for this, but I have software, so I shall release it with a dumb name. Thingie has just been uploaded to hackage. It is a library for creating 2D visualizations in a purely functional manner. It supports static visualizations and animation, and like most vis libraries, can probably do games as well as simple viz graphics. The backend uses Cairo for rendering, but I'm looking to port it to OpenGL/GLUT for systems where Gtk/Cairo is hard to get working (i.e. OS/X). The idea is that you create a graph of objects or function that return objects and the library renders them for you in 2D. Right now, there's one thing I would like to add to the system above all other things: The interactive system has the concept of a tracked program state that is threaded through the graph. This state is defined by a UIState class, and any state (which is a record object) must be an instance of UIState and provide the system with a certain number of getters and setters for basic bits of state. I would like to use Template Haskell to help create/derive these structures. Does anyone on the list want to help with that? Here are two examples. Each draws a smiley face, and the interactive one tracks your mouse with a little red ball. First the non-interactive: module Main where import Graphics.Rendering.Thingie.Primitives import Graphics.Rendering.Thingie.Cairo import qualified Graphics.Rendering.Cairo as Cairo smiley = Context [FillRGBA 0 0 0 0, Operator Cairo.OperatorClear] $ Group [Draw rectangleFilled{ topleft=Point2D 0 0, width=200, height=200 } ,Context [FillRGBA 1 1 0 1, OutlineRGBA 0 0 0 1, Translate 100 100, Operator Cairo.OperatorOver] $ Group [Draw arc{ radius=100, filled=True } ,Context [FillRGBA 0 0 0 1] $ Group [Draw arc{ center=Point2D (-33) (-33), radius=10, filled=True } ,Draw arc{ center=Point2D 33 (-33), radius=10, filled=True } ,Draw arc{ angle1=degrees 30, angle2=degrees 150, radius=70 }]]] main = renderObjectToPNG "smiley.png" 200 200 smiley ----- Now the interactive: import Graphics.Rendering.Thingie.Interactive import Graphics.Rendering.Thingie.BasicUIState import Graphics.Rendering.Thingie.Cairo import Graphics.Rendering.Thingie.Primitives import qualified Graphics.Rendering.Cairo as Cairo smiley = Context [FillRGBA 0 0 0 0, Operator Cairo.OperatorClear] $ Group [Draw rectangleFilled{ topleft=Point2D 0 0, width=200, height=200 } ,Context [FillRGBA 1 1 0 1, OutlineRGBA 0 0 0 1, Translate 100 100, Operator Cairo.OperatorOver] $ Group [Draw arc{ radius=100, filled=True } ,Context [FillRGBA 0 0 0 1] $ Group [Draw arc{ center=Point2D (-33) (-33), radius=10, filled=True } ,Draw arc{ center=Point2D 33 (-33), radius=10, filled=True } ,Draw arc{ angle1=degrees 30, angle2=degrees 150, radius=70 }]]] undercursor uistate = Context [FillRGBA 1 0 0 1] $ Draw arcFilled{ center=mousePosition uistate, radius=5 } scene = [StaticElement smiley (Rect2D 0 0 0 0) ,UnboundedElement undercursor] main = simpleMotionSensitiveGui defaultBasicUIState scene "smiley face"