How to know if a line intersects a rectangle

Question

I have checked out this question, but the answer is very large for me:

How to know if a line intersects a plane in C#? - Basic 2D geometry

Is there any .NET

Answer 1

There is no simple predefined .NET method you can call to accomplish that. However, using the Win32 API, there is a pretty easy way to do this (easy in the sense of implementation, performance is not the strong point): LineDDA

BOOL LineDDA(int nXStart,int nYStart,int nXEnd,int nYEnd,LINEDDAPROC lpLineFunc,LPARAM lpData)

This functions calls the callback function for every pixel of the line to be drawn. In this function, you can check if the pixel is within your rectangle - if you find one, then it intersects.

As I sais, this is not the fastest solution, but pretty easy to implement. To use it in C#, you will of course need to ddlimport it from gdi32.dll.

[DllImport("gdi32.dll")] public static extern int LineDDA(int n1,int n2,int n3,int n4,int lpLineDDAProc,int lParam);