Question

I’m trying to draw a bmp image file from a 2 dimensional Boolean array. The objective is the following i need to draw a small square for each value and the color depends on the boolean if true it paints in a given color and if false it paints white.
the idea is to create a maze based on the matrix

Most solutions i find over the web are with 1 dimensional byte array using MemoryStream but i doesn’t paint a full square with a size of my choosing.

My main problem is how to draw on a bmp or an image using c#

thanks in advance for any advice

Answer 1

Here’s a solution that uses a 2 dimension array and saves the resulting bitmap. You’ll have to either read in the maze from a text file or hand enter it as I have done. You can adjust the size of the tiles with the squareWidth, squareHeight variables. Using a one-dimensional array would also work, but may not be as intuitive if you’re just learning about these things.

bool[,] maze = new bool[2,2];
maze[0, 0] = true;
maze[0, 1] = false;
maze[1, 0] = false;
maze[1, 1] = true;
const int squareWidth = 25;
const int squareHeight = 25;
using (Bitmap bmp = new Bitmap((maze.GetUpperBound(0) + 1) * squareWidth, (maze.GetUpperBound(1) + 1) * squareHeight))
{
    using (Graphics gfx = Graphics.FromImage(bmp))
    {
        gfx.Clear(Color.Black);
        for (int y = 0; y <= maze.GetUpperBound(1); y++)
        {
            for (int x = 0; x <= maze.GetUpperBound(0); x++)
            {
                if (maze[x, y])
                    gfx.FillRectangle(Brushes.White, new Rectangle(x * squareWidth, y * squareHeight, squareWidth, squareHeight));
                else
                    gfx.FillRectangle(Brushes.Black, new Rectangle(x * squareWidth, y * squareHeight, squareWidth, squareHeight));
            }
        }
    }
    bmp.Save(@"c:\maze.bmp");
}