Compute Shader for Drawing Lines

line.compute

// https://forum.unity.com/threads/compute-shader-for-line-drawing.599989/
#pragma kernel CSMain
RWTexture2D<float4> surface;

float Line( float2 p, float2 a, float2 b )
{
    float2 pa = p-a, ba = b-a;
    float h = saturate( dot(pa,ba)/dot(ba,ba) );
    float2 d = pa - ba * h;
    return dot(d,d);
}

[numthreads(8,8,1)]
void CSMain (uint2 id : SV_DispatchThreadID)
{
    float2 uv = float2 ((float)id.x/1024, (float)id.y/1024);
    float k = Line(uv,float2(0.3,0.1),float2(0.8,0.5));  
    float thickness = 0.00001;
    surface[id.xy] = lerp( float4(1,1,1,1), float4(0,0,0,1), smoothstep(0.0, thickness, k) );
}

Line.cs

// https://forum.unity.com/threads/compute-shader-for-line-drawing.599989/
using UnityEngine;

public class Line : MonoBehaviour
{
    public ComputeShader CS;

    void Start()
    {
        RenderTexture RT = new RenderTexture(1024, 1024, 0);
        RT.enableRandomWrite = true;
        RT.Create();
        CS.SetTexture(0, "surface", RT);  
        CS.Dispatch(0, RT.width / 8, RT.height / 8, 1);
        GetComponent<Renderer>().material.mainTexture = RT;      
    }
}

This is cool! Do you have any reference material on how you came up with this? I'm trying to learn how to be more exact in the drawing of the line, such as bresenham's algorithm for pixel lines