C# comparison of two different implementations of the Bresenham's Line Algorithm.

BresenhamLineAlgorithm.cs

// Compares the speed of two different implementations of Bresenham's Line Algorithm.
// Draws the resulting lines on a user defined canvas.

using System.Diagnostics;

// Size of the drawn canvas.
const int canvasWidth = 128;
const int canvasHeight = 128;

// First point.
const int x1 = 101;
const int y1 = 28;

// Second point.
const int x2 = 15;
const int y2 = 92;

// Initialize the canvas.
int[,] canvas = new int[canvasWidth, canvasHeight];
for (int y = 0; y < canvasHeight; y++)
{
    for (int x = 0; x < canvasWidth; x++)
    {
        canvas[x, y] = 0;
    }
}

Stopwatch sw = new();

// Run & time the first implementation.
sw.Start();
foreach ((int x, int y) in BresenhamLine1(x1, y1, x2, y2))
{
    canvas[x, y] += 1;
}
sw.Stop();
long firstAlgorithmTime = sw.ElapsedMilliseconds;
sw.Reset();

// Run & time the second implementation.
sw.Start();
foreach ((int x, int y) in BresenhamLine2(x1, y1, x2, y2))
{
    canvas[x, y] += 2;
}
sw.Stop();
long secondAlgorithmTime = sw.ElapsedMilliseconds;

// NOTE: The drawing could be way more efficient by drawing lines, not individual characters, but then we'd lose the coloring.
// NOTE: But who cares. This is just a test anyways :)
for (int y = 0; y < canvasHeight; y++)
{
    for (int x = 0; x < canvasWidth; x++)
    {
        Console.BackgroundColor = canvas[x, y] switch
        {
            // Pixel not drawn
            0 => ConsoleColor.Black,
            // Pixel drawn by first algorithm
            1 => ConsoleColor.Blue,
            // Pixel drawn by second algorithm
            2 => ConsoleColor.Red,
            // Pixel drawn by both algorithms
            3 => ConsoleColor.Green,
            _ => throw new ArgumentOutOfRangeException()
        };

        Console.Write(canvas[x, y]);
    }
    Console.WriteLine();
}

Console.WriteLine($"First algorithm finished in {firstAlgorithmTime} ms.");
Console.WriteLine($"Second algorithm finished in {secondAlgorithmTime} ms.");

Console.ReadKey();

// Slower, but more accurate Bresenham's Line Algorithm.
// Modified from: https://stackoverflow.com/a/11683720
static IEnumerable<(int x, int y)> BresenhamLine1(int x1, int y1, int x2, int y2)
{
    int w = x2 - x1;
    int h = y2 - y1;
    int dx1 = 0, dy1 = 0, dx2 = 0, dy2 = 0;
    dx1 = w switch
    {
        < 0 => -1,
        > 0 => 1,
        _ => dx1
    };
    dy1 = h switch
    {
        < 0 => -1,
        > 0 => 1,
        _ => dy1
    };
    dx2 = w switch
    {
        < 0 => -1,
        > 0 => 1,
        _ => dx2
    };

    int longest = Math.Abs(w);
    int shortest = Math.Abs(h);

    if (longest <= shortest)
    {
        longest = Math.Abs(h);
        shortest = Math.Abs(w);
        if (h < 0) dy2 = -1;
        else if (h > 0) dy2 = 1;
        dx2 = 0;
    }

    int numerator = longest >> 1;
    for (int i = 0; i <= longest; i++)
    {
        yield return (x1, y1);
        numerator += shortest;
        if (numerator >= longest)
        {
            numerator -= longest;
            x1 += dx1;
            y1 += dy1;
        }
        else
        {
            x1 += dx2;
            y1 += dy2;
        }
    }
}

// Faster, but less accurate Bresenham's Line Algorithm.
// Modified from: http://ericw.ca/notes/bresenhams-line-algorithm-in-csharp.html
static IEnumerable<(int x, int y)> BresenhamLine2(int x1, int y1, int x2, int y2)
{
    bool steep = Math.Abs(y2 - y1) > Math.Abs(x2 - x1);
    if (steep)
    {
        int t = x1;
        x1 = y1;
        y1 = t;
        t = x2;
        x2 = y2;
        y2 = t;
    }

    if (x1 > x2)
    {
        int t = x1;
        x1 = x2;
        x2 = t;
        t = y1;
        y1 = y2;
        y2 = t;
    }

    int dx = x2 - x1;
    int dy = Math.Abs(y2 - y1);
    int error = dx / 2;
    int yStep = y1 < y2 ? 1 : -1;
    int y = y1;
    for (int x = x1; x <= x2; x++)
    {
        yield return (steep ? y : x, steep ? x : y);
        error -= dy;
        if (error >= 0) continue;
        y += yStep;
        error += dx;
    }
}