CGContextSetLineWidth
CGContextSetLineWidth is a function in the Core Graphics framework of Apple's operating systems that sets the width of the current line drawing operation. This function is part of the Quartz 2D drawing environment. When you draw lines, curves, or the outline of shapes using a Core Graphics context, the width specified by CGContextSetLineWidth determines how thick that stroke will be.
The function takes two arguments: a graphics port (CGContextRef) and a CGFloat value representing the line width.
This function is fundamental for controlling the visual appearance of stroked paths in applications built with