feat(render): implement Campaign AR and terrain fidelity

src/AcDream.App/Rendering/Packs/RenderPackTextureBindingResolver.cs

@@ -0,0 +1,54 @@
+using AcDream.Plugin.Abstractions.Rendering;
+
+namespace AcDream.App.Rendering.Packs;
+
+internal readonly record struct RenderPackTextureInput(
+    RenderSemanticInput? Semantic,
+    string? ResourceId)
+{
+    internal static RenderPackTextureInput FromSemantic(RenderSemanticInput value) =>
+        new(value, null);
+
+    internal static RenderPackTextureInput FromResource(string value) =>
+        new(null, value);
+}
+
+/// <summary>
+/// Binary API-v1 texture-slot rule. Ordinary sampled inputs occupy push
+/// TextureIndexA..D in declaration order: sampled semantic inputs first, then
+/// declared resource reads. Directional depth uses its dedicated binding-6
+/// texture slot and therefore does not consume A..D.
+/// </summary>
+internal static class RenderPackTextureBindingResolver
+{
+    internal static IReadOnlyList<RenderPackTextureInput> Resolve(
+        RenderPassDeclaration pass,
+        IReadOnlyDictionary<string, RenderResourceDeclaration> resources)
+    {
+        ArgumentNullException.ThrowIfNull(pass);
+        ArgumentNullException.ThrowIfNull(resources);
+        var result = new List<RenderPackTextureInput>(4);
+        foreach (RenderSemanticInput semantic in pass.SemanticInputs)
+        {
+            if (semantic is RenderSemanticInput.WorldColor
+                or RenderSemanticInput.SceneDepth
+                or RenderSemanticInput.SceneNormals)
+                result.Add(RenderPackTextureInput.FromSemantic(semantic));
+        }
+        foreach (string resourceId in pass.ResourceReads)
+        {
+            if (!resources.TryGetValue(resourceId, out RenderResourceDeclaration? resource))
+                throw new InvalidOperationException($"Unknown render-pack resource '{resourceId}'.");
+            if (resource.Format == RenderFormatClass.DirectionalDepth
+                && pass.SemanticInputs.Contains(RenderSemanticInput.DirectionalShadowMaps))
+                continue;
+            result.Add(RenderPackTextureInput.FromResource(resourceId));
+        }
+        if (result.Count > 4)
+        {
+            throw new InvalidOperationException(
+                $"Render-pack pass '{pass.Id}' exceeds the four API-v1 texture slots.");
+        }
+        return result;
+    }
+}