Write code that pulls saturated moving colors from a web cam… that is… if you move a red coffee cup across the screen your code should capture the color red.
A few hints: frame differencing, hsb and get/setVector.
I’ll post my working version tomorrow or the next day… this is a challenging one so I may give an extra day before I post my solution….
Difficulty : Medium
I’ve had many requests to add a donate button to this site, finally added one today….
This quiz jumps around a bit from MovieClips to OOP.
Number of Questions : 7
Difficulty : Medium
Topic : MovieClips and OOP
Today's quiz is not multiple choice. Instead, your task is to write a lisp style math parser. This may sound tricky, but it's surprisingly simple. (well... not simple exactly, it's just simple compared to what one might assume).
Lisp uses prefix notation... where the operator is placed before the operands:
10 * 10
becomes:
* 10 10
You could think of this as a function "*" with two arguments (10, 10). In Lisp this is enclosed with parens:
(* 10 10)
Let's see a few more examples:
100 / 2 + 10
becomes:
(+ (/ 100 2) 10)
...
2 * 4 * 6 * 7
becomes:
(* 2 4 6 7)
...
(2 + 2) * (10 - 2) * 2
becomes
(* (+ 2 2) (- 10 2) 2)
Remember, thinking "functions" really helps. The above can be though of as:
multiply( add(2, 2), subtract(10 , 2), 2)
You should create a function called parsePrefix() that takes a string and returns a number:
Here is some code to test if your parser works properly:
I highly recommend giving this a try, it was one of those cases where I assumed it would be much trickier than it was.
I've posted my solution here.