go - How do I make a line at surface?

Question

I know there's a function to fill rectangles surface.FillRect(&Rect, uint32), but is there a way to draw a line in the surface, like a function for renderer renderer.DrawLine(x1, y1, x2, y2)?

question from:https://stackoverflow.com/questions/65872491/how-do-i-make-a-line-at-surface

Answer 1

In SDL2 Surface is just a structure that represents a bitmap (2D matrix of pixels) in driver agnostic format. In terms of drawing Surface API is limited to setting pixels or easily defined groups of them (rectangles) or blitting (copying) rectangles of one surface to the other. With that API you technically can draw a line by calculating coordinates of each pixel on that line between coords x1,y1 and x2,y2 and setting each pixel to the desired color. In SDL2 library itself there is no such utility function.

Renderer is much more advanced API that takes care of many underlying aspects of accelerated rendering. On top of single pixels and rectangles it offers also line primitives. Instead of Surface it uses Texture which stores pixels in an optimized format for underlying graphics driver (and thus provides higher performance when drawing). If you are working on something new you should stick with Renderer. If you need to plug code based on Surface to Renderer code, you can create Texture from Surface data using the Renderer.CreateTextureFromSurface() method.