Question

when the user draws over the stencil of alphabets using GLpaint how to detect the character is drawn completely.. what is the way to do doing this…
here is the link for the app doing this…pls check this out and help me soon…
http://itunes.apple.com/in/app/toddlers-alphabets-numbers/id408187201?mt=8

thanks in advance….

Answer 1

I think that this application knows beforehand what is the number or letter to guess, and that there is no word-detection.
If you notice, there is no need to draw exactly the letter or number, just that the child fills at least part of the image to jump to the next level.

So, you could (given an image that initially has only one color) calculate what is the amount of pixels drawn by the user with a different color from the initial one, and then you can act according to a certain percentage of pixels that have been drawn.
See this answer to play with the raw data of an UIImage.
I think you could just use CoreGraphics to do this.