256b-winter-2011/hw2

Homework #2: SonicSlingShot (SSS)

Due date: 2011.2.2 11:59:59pm (or thereabout), Wednesday.

The goals of this assignment:

• set up a flip view (one for real-time graphics, one for UI elements)
• using the Synthesis Toolkit for iPhone
• real-time graphics via OpenGL ES
• basic physical simulation + interaction
• musical mapping

Specification (part 1 of 3): Setup: Flip View, OpenGL ES, STK

• create a project containing a flip view
• this should be covered in class, and reviewed from the tutorial.
• get graphics set up with a orthographic projection, using mo_gfx
• compile in STK, make some sounds via mo_audio

Specification (part 2 of 3): The Slingshot Interaction

The slingshot in this assignment operates as follows:

• initial state: empty screen
• two point multitouch: creates a "rubber band" (rendered as some type of line)
• third point: the rubber band maybe gently plucked (should see some wave forms, may even be the actual waveform)
  • should sounds like a plucked string, pitch determined by length!
• thrid point: pulling and holding in any direction on the rubber band stretches it
  • release: restores the rubber band, while shooting a projectile into the space
  • the direction and velocity of the projectile should be determined by angle and how far the rubber band is stretched

Specification (part 3 of 3): Collision Detection + Mapping

• check for collision:
  • against the boundaries of the screen
  • against other projectiles
• collision detection should generate a visual cue somehow
  • use texture mapping to create an animation
• collision detection should generate events that gets sonified (you choose the sonification)
• think about how to map the collisions to sound parameters
• add a few options to the flip view, here are some to implement and some suggestions:
  • enable accelerometer and introduce gravity into the system (a toggle)
  • shake to clear the space (a toggle)
  • add damping to the system, i.e., projectiles loss energy and slow down over time (a slide for amount of damping)
  • a mapping of your own
  • (optional) reverberation / panning

Tips

• do things in chunks, unit test when possible!
• make things as simple as possible...Global variables are fine for now.

Note

• have fun with it!!!
• comment your code!
• choose your own coding conventions - but be consistent
• you are welcome to work together, but you must do/turn in your own work

Deliverables

turn in all files by putting them in your Library/Web/256b/hw2/ directory, and concise online documentation + readme + email ge + jieun + nick

• 1) source code to the project(s) (*.h, *.cpp, *.m *.mm *.c makefile, project files, etc.)
• 2) online page for your project (should be viewable at http://ccrma.stanford.edu/~YOURID/256b/hw2). It should include:
  • links to your files of various kinds (or to a zip/tar archive)
  • instructions on building the project (for example, anyone in the class should be able to download and run)
  • a short README text section that:
    • conveys your ideas/comments in constructing each program
    • describes any difficulties you encountered in the process
    • lists any collaborators
• 3) email Ge, Jieun, and Nick with the link to your web page, as a confirmation that you are submitting the assignment