CGContextAddLineToPoint

CGContextAddLineToPoint is a function in the Core Graphics framework that appends a straight line segment to the current path within a graphics context. It does not draw the line by itself; the line is created as part of the path and is rendered when the path is stroked or filled.

In C and Objective-C, the function signature is void CGContextAddLineToPoint(CGContextRef c, CGFloat x, CGFloat y). In Swift, the equivalent operation is context.addLine(to: CGPoint(x: x, y: y)) on a CGContext, or by using the corresponding CGPath methods. The function uses the context's current point as the starting point. It adds a line from the current point to (x, y) and then updates the current point to (x, y). If there is no current point, the call has no effect.

Usage generally follows establishing a starting point with CGContextMoveToPoint, then calling CGContextAddLineToPoint one or more times to build a polyline. After finishing the path, rendering is performed with CGContextStrokePath(ctx) or CGContextFillPath(ctx) as appropriate. This function is commonly used in immediate-mode drawing on iOS, macOS, and other platforms that support Quartz 2D.

See also: CGContextMoveToPoint, CGContextClosePath, CGContextStrokePath, CGContextFillPath.