Programming offers new opportunities for visual art creation, but understanding and manipulating the abstract representations that make programming powerful can pose challenges for artists who are accustomed to manual tools and concrete visual interaction. We hypothesize that we can reduce these barriers through programming environments that link state to visual artwork output.
We created Demystified Dynamic Brushes (DDB), a tool that bidirectionally links code, numerical data, and artwork across the programming interface and the execution environment---i.e., the artist's in-progress artwork. DDB automatically records stylus input as artists draw, and stores a history of brush state and output in relation to the input. This structure enables artists to inspect current and past numerical input, state, and output and control program execution through the direct selection of visual geometric elements in the drawing canvas. An observational study suggests that artists engage in program inspection when they can visually access geometric state information on the drawing canvas in the process of manual drawing.