What is a good approach to implementing a markup tool for a paint program on an iPad?

Question

At a high level (or, if you want, at a low level), what is a good way to implement the blur effect for a paint program on an iPad using Quartz2D (Core Graphics)? Has anyone tried this?

_{(source: pixlr.com )}

Thank you in advance for your wisdom!

UPDATE I found this great article for anyone interested, check it out!

Link now at: http://losingfight.com/blog/2007/09/05/how-to-implement-smudge-and-stamp-tools/

Answer 1

, , OpenGL ES 2.0, .

• , -, , , . - .
• , , CAEAGLLayer
• 1 -touchesMoved, . , 2 "-" , .

, , . .., .

, CPU. :)