UiStyle.cs

using System;
using System.Drawing;
using System.Drawing.Text;

namespace CoreTempGPU
{
    /// <summary>
    /// Shared UI fonts + green→yellow→red heat scale.
    /// Default: Segoe UI Semibold — proportional Windows UI face, readable at strip size
    /// without Aptos Narrow thinness or JetBrains Mono code-block look.
    /// </summary>
    internal static class UiStyle
    {
        private static string _family;
        private static FontStyle _style = FontStyle.Bold;
        private static readonly object _lock = new object();

        public static string FontFamilyName
        {
            get
            {
                EnsureResolved();
                return _family;
            }
        }

        /// <summary>Body text — Semibold/Bold proportional UI font.</summary>
        public static Font Regular(float emSize)
        {
            return Make(emSize);
        }

        /// <summary>Title / emphasis — same family, bold weight.</summary>
        public static Font Bold(float emSize)
        {
            return Make(emSize);
        }

        private static void EnsureResolved()
        {
            lock (_lock)
            {
                if (_family != null) return;
                Resolve();
            }
        }

        private static Font Make(float emSize)
        {
            EnsureResolved();
            try { return new Font(_family, emSize, _style, GraphicsUnit.Point); }
            catch
            {
                try { return new Font("Segoe UI", emSize, FontStyle.Bold, GraphicsUnit.Point); }
                catch { return new Font("Tahoma", emSize, FontStyle.Bold, GraphicsUnit.Point); }
            }
        }

        private static void Resolve()
        {
            // Prefer proportional UI fonts (not monospace). Semibold > Bold > Regular.
            // Skip Narrow/Thin/Light and JetBrains Mono (too “codey” on a dense strip).
            string[] preferred =
            {
                "Segoe UI Semibold",
                "Segoe UI",
                "Bahnschrift SemiBold",
                "Bahnschrift",
                "Calibri",
                "Tahoma"
            };

            using (var coll = new InstalledFontCollection())
            {
                foreach (string want in preferred)
                {
                    foreach (FontFamily f in coll.Families)
                    {
                        if (!string.Equals(f.Name, want, StringComparison.OrdinalIgnoreCase))
                            continue;
                        _family = f.Name;
                        // "Segoe UI Semibold" is already a semibold face — Regular style is correct.
                        // Plain "Segoe UI" / Calibri / Tahoma → Bold for weight.
                        if (f.Name.IndexOf("Semibold", StringComparison.OrdinalIgnoreCase) >= 0
                            || f.Name.IndexOf("SemiBold", StringComparison.OrdinalIgnoreCase) >= 0)
                            _style = FontStyle.Regular;
                        else
                            _style = FontStyle.Bold;
                        return;
                    }
                }
            }
            _family = "Segoe UI";
            _style = FontStyle.Bold;
        }

        /// <summary>Bright green (low) → yellow (mid) → red (high). t is 0..100.</summary>
        public static Color Heat(double t)
        {
            if (t < 0) t = 0;
            if (t > 100) t = 100;
            if (t <= 50.0)
                return Lerp(Color.FromArgb(40, 220, 40), Color.FromArgb(255, 230, 0), t / 50.0);
            return Lerp(Color.FromArgb(255, 230, 0), Color.FromArgb(240, 30, 30), (t - 50.0) / 50.0);
        }

        private static Color Lerp(Color a, Color b, double u)
        {
            if (u < 0) u = 0;
            if (u > 1) u = 1;
            return Color.FromArgb(
                (int)Math.Round(a.R + (b.R - a.R) * u),
                (int)Math.Round(a.G + (b.G - a.G) * u),
                (int)Math.Round(a.B + (b.B - a.B) * u));
        }
    }
}