engine: complete portable glyph text backend

2026-07-30 19:47:21 -04:00
parent ef19ab79e0
commit d9f24c69ef
12 changed files with 619 additions and 840 deletions
--- a/godot/PortableTextRenderingPolicy.cs
+++ b/godot/PortableTextRenderingPolicy.cs
@@ -0,0 +1,104 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
+
+public sealed class PortableTextRenderingPolicy
+{
+    public const string ResourcePath = "res://config/himegari-text-rendering.json";
+
+    public string Id { get; set; } = "";
+    public int FontCacheCapacity { get; set; } = 8;
+    public int GlyphMaskCacheCapacity { get; set; } = 2048;
+    public PortableFontRasterPolicy Raster { get; set; } = new();
+    public string[] DefaultSubstitutes { get; set; } = [];
+    public PortableFontFamilyPolicy[] Families { get; set; } = [];
+
+    public static PortableTextRenderingPolicy Load()
+    {
+        string json = Godot.FileAccess.GetFileAsString(ResourcePath);
+        if (string.IsNullOrWhiteSpace(json))
+            throw new InvalidOperationException(
+                $"Portable text policy '{ResourcePath}' is missing or empty.");
+        var options = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
+        PortableTextRenderingPolicy policy =
+            JsonSerializer.Deserialize<PortableTextRenderingPolicy>(json, options)
+            ?? throw new InvalidOperationException(
+                $"Portable text policy '{ResourcePath}' decoded to null.");
+        policy.Validate();
+        return policy;
+    }
+
+    public string[] ResolveFamilies(string requestedFace)
+    {
+        string requested = requestedFace?.Trim() ?? "";
+        PortableFontFamilyPolicy? mapped = Families.FirstOrDefault(
+            family => family.Requested.Any(
+                alias => alias.Equals(requested, StringComparison.OrdinalIgnoreCase)));
+        IEnumerable<string> candidates = mapped?.Substitutes ?? DefaultSubstitutes;
+        // The authored face remains the last candidate. This preserves a useful match on systems
+        // that happen to provide it without making that Windows font a portable dependency.
+        return candidates
+            .Append(requested)
+            .Where(name => !string.IsNullOrWhiteSpace(name))
+            .Distinct(StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+    }
+
+    private void Validate()
+    {
+        if (string.IsNullOrWhiteSpace(Id))
+            throw new InvalidOperationException("Portable text policy requires a non-empty id.");
+        if (FontCacheCapacity <= 0)
+            throw new InvalidOperationException("Portable text fontCacheCapacity must be positive.");
+        if (GlyphMaskCacheCapacity <= 0)
+            throw new InvalidOperationException(
+                "Portable text glyphMaskCacheCapacity must be positive.");
+        if (DefaultSubstitutes.Length == 0)
+            throw new InvalidOperationException(
+                "Portable text policy requires at least one default substitute.");
+        Raster.Validate();
+        foreach (PortableFontFamilyPolicy family in Families)
+        {
+            if (family.Requested.Length == 0 || family.Substitutes.Length == 0)
+                throw new InvalidOperationException(
+                    "Every portable font family mapping requires requested aliases and substitutes.");
+        }
+    }
+}
+
+public sealed class PortableFontFamilyPolicy
+{
+    public string[] Requested { get; set; } = [];
+    public string[] Substitutes { get; set; } = [];
+}
+
+public sealed class PortableFontRasterPolicy
+{
+    public string Antialiasing { get; set; } = "gray";
+    public string Hinting { get; set; } = "normal";
+    public string SubpixelPositioning { get; set; } = "disabled";
+    public bool AllowSystemFallback { get; set; } = true;
+    public bool MultichannelSignedDistanceField { get; set; }
+    public int RegularWeight { get; set; } = 400;
+    public int BoldWeight { get; set; } = 700;
+    public int BoldThreshold { get; set; } = 700;
+
+    public void Validate()
+    {
+        if (Antialiasing is not ("none" or "gray" or "lcd"))
+            throw new InvalidOperationException(
+                "Portable raster antialiasing must be none, gray, or lcd.");
+        if (Hinting is not ("none" or "light" or "normal"))
+            throw new InvalidOperationException(
+                "Portable raster hinting must be none, light, or normal.");
+        if (SubpixelPositioning is not ("disabled" or "auto" or "one-half" or "one-quarter"))
+            throw new InvalidOperationException(
+                "Portable raster subpixelPositioning has an unsupported value.");
+        if (RegularWeight is < 100 or > 999
+            || BoldWeight is < 100 or > 999
+            || BoldThreshold is < 0 or > 1000)
+            throw new InvalidOperationException(
+                "Portable raster weights are outside their valid ranges.");
+    }
+}