In this CGBitmapContextCreate, why is bytesPerRow 0?

Question

I\'ve noticed in Apple\'s sample code that they often provide a value of 0 in the bytesPerRow parameter of CGBitmapContextCreate. For example, this comes out of the Reflection s

Answer 1

My understanding is that if you pass in zero, it calculates the bytes-per-row based on the bitsPerComponent and width arguments. You might want additional padding at the end of each row of bytes (if your device required it, or some other constraint). In this case, you could pass a value that was more than just width * (bytes per pixel). I would imagine this is probably never needed in modern i/MacOS development, except for some weird edge-case optimizations.