VRIO/tools/VPlasma.Wire/PlasmaBitmap.cs

using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Drawing.Text;
using System.Text;
using VPlasma.Core.Device;
using VPlasma.Core.Protocol;

namespace VPlasma.Wire;

/// <summary>
/// Plasma bitmap authoring — ported from TeslaSuite's <c>PlasmaBitmaps</c>
/// (the console's Plasma Font Tool / Bitmap Decoder / Editor). Renders text in
/// a Windows font to a 1bpp panel bitmap, converts bitmaps to and from the
/// game's <c>bitmap=</c> hex encoding, and bridges either to an <c>ESC P</c>
/// wire stream the display (or vPLASMA / the replica) can show.
/// </summary>
internal static class PlasmaBitmap
{
    public const string DefaultFont = "Microsoft Sans Serif";

    /// <summary>
    /// Render <paramref name="text"/> centered in a <paramref name="width"/>×
    /// <paramref name="height"/> 1bpp image, auto-shrinking the font to fit —
    /// the Plasma Font Tool's behavior.
    /// </summary>
    public static Bitmap RenderText(int width, int height, string fontName, string text)
    {
        var bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
        using var g = Graphics.FromImage(bmp);
        g.SmoothingMode = SmoothingMode.None;
        g.InterpolationMode = InterpolationMode.NearestNeighbor;
        g.TextRenderingHint = TextRenderingHint.SingleBitPerPixelGridFit;
        g.Clear(Color.Black);

        var rect = new Rectangle(0, 0, width, height);
        using var fmt = new StringFormat { Alignment = StringAlignment.Center, LineAlignment = StringAlignment.Center };
        for (int size = 24; ; size = size <= 2 ? size / 2 : size - 2)
        {
            using var font = new Font(fontName, Math.Max(1, size));
            SizeF sz = g.MeasureString(text, font);
            if (size <= 1 || (sz.Width <= width && sz.Height <= height))
            {
                g.DrawString(text, font, Brushes.White, rect, fmt);
                return bmp;
            }
        }
    }

    /// <summary>Threshold an image to a <paramref name="w"/>×<paramref name="h"/> on/off grid.</summary>
    public static bool[,] ToGrid(Bitmap src, int w, int h, double threshold)
    {
        using var scaled = new Bitmap(w, h, PixelFormat.Format24bppRgb);
        using (var g = Graphics.FromImage(scaled))
        {
            g.InterpolationMode = src.Width == w && src.Height == h
                ? InterpolationMode.NearestNeighbor : InterpolationMode.HighQualityBicubic;
            g.DrawImage(src, 0, 0, w, h);
        }
        var grid = new bool[w, h];
        for (int y = 0; y < h; y++)
            for (int x = 0; x < w; x++)
                grid[x, y] = scaled.GetPixel(x, y).GetBrightness() >= threshold;
        return grid;
    }

    /// <summary>The game's <c>bitmap=</c> hex encoding (MSB-first, 8 px/byte).</summary>
    public static string ToHexEncoding(bool[,] grid)
    {
        int w = grid.GetLength(0), h = grid.GetLength(1);
        if (w % 8 != 0)
            throw new ArgumentException("width must be a multiple of 8");
        var sb = new StringBuilder();
        for (int y = 0; y < h; y++)
        {
            sb.Append("bitmap=");
            for (int j = 0; j < w / 8; j++)
            {
                byte b = 0;
                for (int k = 0; k < 8; k++)
                    if (grid[j * 8 + k, y]) b |= (byte)(0x80 >> k);
                sb.Append(b.ToString("X2"));
            }
            sb.Append('\n');
        }
        sb.Append($"x={w}\n");
        sb.Append($"y={h}\n");
        return sb.ToString();
    }

    /// <summary>Parse a <c>bitmap=</c>/<c>x=</c>/<c>y=</c> encoding back to a grid.</summary>
    public static bool[,] FromHexEncoding(string text)
    {
        var rows = new List<byte[]>();
        int declaredX = 0, declaredY = 0;
        foreach (string raw in text.Split('\n'))
        {
            string line = raw.Trim();
            if (line.StartsWith("bitmap=", StringComparison.OrdinalIgnoreCase))
            {
                string hex = line.Substring("bitmap=".Length).Trim();
                var bytes = new byte[hex.Length / 2];
                for (int i = 0; i < bytes.Length; i++)
                    bytes[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);
                rows.Add(bytes);
            }
            else if (line.StartsWith("x=", StringComparison.OrdinalIgnoreCase))
                int.TryParse(line.Substring(2), out declaredX);
            else if (line.StartsWith("y=", StringComparison.OrdinalIgnoreCase))
                int.TryParse(line.Substring(2), out declaredY);
        }
        if (rows.Count == 0)
            throw new ArgumentException("no 'bitmap=' rows found");
        int w = declaredX > 0 ? declaredX : rows[0].Length * 8;
        int h = declaredY > 0 ? declaredY : rows.Count;
        var grid = new bool[w, h];
        for (int y = 0; y < h && y < rows.Count; y++)
            for (int j = 0; j < rows[y].Length && j * 8 < w; j++)
                for (int k = 0; k < 8 && j * 8 + k < w; k++)
                    grid[j * 8 + k, y] = (rows[y][j] & (0x80 >> k)) != 0;
        return grid;
    }

    /// <summary>
    /// Pack a grid into an <c>ESC P</c> wire stream (clear + cursor-off + one
    /// full-width row per line), the way L4PLASMA streams a frame.
    /// </summary>
    public static byte[] ToEscP(bool[,] grid)
    {
        int w = grid.GetLength(0), h = grid.GetLength(1);
        int wbytes = (w + 7) / 8;
        var b = new List<byte>
        {
            PlasmaProtocol.Esc, PlasmaProtocol.CmdCursorMode, 0x00,  // hide cursor
            PlasmaProtocol.Esc, PlasmaProtocol.CmdClearScreen,
        };
        for (int y = 0; y < h; y++)
        {
            b.Add(PlasmaProtocol.Esc);
            b.Add(PlasmaProtocol.CmdGraphicsWrite);
            b.Add(0);            // screen
            b.Add((byte)y);      // y
            b.Add(0);            // x byte
            b.Add((byte)wbytes); // width in bytes
            b.Add(1);            // one row
            for (int j = 0; j < wbytes; j++)
            {
                byte v = 0;
                for (int k = 0; k < 8; k++)
                    if (j * 8 + k < w && grid[j * 8 + k, y]) v |= (byte)(0x80 >> k);
                b.Add(v);
            }
        }
        return b.ToArray();
    }

    /// <summary>Render a grid to a plasma-orange PNG (for previews / decoding).</summary>
    public static void SaveGridPng(bool[,] grid, string path, int scale)
    {
        int w = grid.GetLength(0), h = grid.GetLength(1);
        int pitch = scale, dot = Math.Max(1, scale - 2);
        using var bmp = new Bitmap(w * pitch, h * pitch, PixelFormat.Format24bppRgb);
        using var g = Graphics.FromImage(bmp);
        g.Clear(Color.FromArgb(26, 14, 6));
        using var unlit = new SolidBrush(Color.FromArgb(46, 24, 10));
        using var lit = new SolidBrush(Color.FromArgb(255, 106, 26));
        for (int y = 0; y < h; y++)
            for (int x = 0; x < w; x++)
                g.FillRectangle(grid[x, y] ? lit : unlit, x * pitch, y * pitch, dot, dot);
        bmp.Save(path, ImageFormat.Png);
    }

    /// <summary>Reduce a rendered vPLASMA frame (flag bytes) to an on/off grid.</summary>
    public static bool[,] FrameToGrid(byte[] frame)
    {
        var grid = new bool[VPlasmaDevice.Width, VPlasmaDevice.Height];
        for (int y = 0; y < VPlasmaDevice.Height; y++)
            for (int x = 0; x < VPlasmaDevice.Width; x++)
                grid[x, y] = (frame[y * VPlasmaDevice.Width + x] & VPlasmaDevice.PixelLit) != 0;
        return grid;
    }
}