Hi. I am a total newbie to graphics on Core Graphics and OpenGL. I only had some experience with Windows graphics - bitblitz, metafile, and so on. So what is the most straight forward way to make a shape glow on a view? For instance, if I want to write an app where if you touch a spot on the screen, the spot would glow, and when you remove your finger, the spot would gradually dim and turn invisible. What is the most straight forward way to do that? I'm asking because I don't want to set off on the wrong track. Thank you!