ImageCalc

This program displays an image which is being continuously updated. The image (which is calculated in a separate thread) is a black & white triangle that transforms into a random pattern of grey pixels. One of the calculation parameters is controlled via a slider and a key goal of this project was to have the calculation ongoing with the image continuously updating even while the user is moving the slider around. As this project was a test bed for a compute-intensive program where performance is important, I tried to make the image display as efficient as possible. Statistics on the update rates for the calculation ("model") and display ("view") are available in a drawer that can be opened via the Window menu.

download the ImageCalc project files
(Requires the Apple Developer Tools - I used the December 2002 release)

This project illustrates several aspects of programming for Mac OS X using the Cocoa API:

calculation in a separate thread
synchronizing use of shared variables via NSLock
image drawn via NSBitmapImageRep in a subclass of NSView
regular display updates via NSTimer
using NSEventTrackingRunLoopMode to get timer events while mouse is down
handling window resizing via inLiveResize
handling model size constraints when resizing
auxiliary information displayed in an NSDrawer