refactor(render): extract frame presentation diagnostics

tests/AcDream.App.Tests/Rendering/DebugVmRenderFactsPublisherTests.cs

@@ -0,0 +1,167 @@
+using System.Numerics;
+using System.Reflection;
+using AcDream.App.Rendering;
+using AcDream.Core.Physics;
+
+namespace AcDream.App.Tests.Rendering;
+
+public sealed class DebugVmRenderFactsPublisherTests
+{
+    [Fact]
+    public void Defaults_MatchThePriorGameWindowCache()
+    {
+        var publisher = new DebugVmRenderFactsPublisher();
+
+        Assert.Equal(DebugVmRenderFacts.Initial, publisher.DebugVmFacts);
+        Assert.Equal(float.PositiveInfinity, publisher.DebugVmFacts.NearestObjectDistance);
+        Assert.Equal("-", publisher.DebugVmFacts.NearestObjectLabel);
+        Assert.False(publisher.DebugVmFacts.Colliding);
+    }
+
+    [Fact]
+    public void InactiveConsumer_DoesNotEnumerateOrReplacePriorFacts()
+    {
+        var publisher = new DebugVmRenderFactsPublisher();
+        publisher.PublishDebugVmFacts(
+            true,
+            3,
+            8,
+            Vector3.Zero,
+            [Entry(1, new Vector3(5, 0, 100), radius: 1)]);
+        DebugVmRenderFacts prior = publisher.DebugVmFacts;
+        var shadows = new CountingEnumerable([Entry(2, Vector3.One, 1)]);
+
+        publisher.PublishDebugVmFacts(
+            false,
+            99,
+            100,
+            new Vector3(90, 90, 90),
+            shadows);
+
+        Assert.Equal(0, shadows.EnumerationCount);
+        Assert.Equal(prior, publisher.DebugVmFacts);
+    }
+
+    [Fact]
+    public void Publish_UsesHorizontalDistanceAndSubtractsBothRadii()
+    {
+        var publisher = new DebugVmRenderFactsPublisher();
+        var origin = new Vector3(10, 20, -500);
+
+        publisher.PublishDebugVmFacts(
+            true,
+            7,
+            11,
+            origin,
+            [
+                Entry(0xA, new Vector3(16, 28, 500), radius: 1.52f),
+                Entry(0xB, new Vector3(30, 20, -500), radius: 2f),
+            ]);
+
+        DebugVmRenderFacts facts = publisher.DebugVmFacts;
+        Assert.Equal(7, facts.VisibleLandblocks);
+        Assert.Equal(11, facts.TotalLandblocks);
+        Assert.Equal(8.0f, facts.NearestObjectDistance, precision: 5);
+        Assert.Equal("0x0000000A Cylinder", facts.NearestObjectLabel);
+        Assert.False(facts.Colliding);
+    }
+
+    [Fact]
+    public void Publish_ClampsOverlapToZeroAndUsesUnclampedDistanceForCollision()
+    {
+        var publisher = new DebugVmRenderFactsPublisher();
+
+        publisher.PublishDebugVmFacts(
+            true,
+            1,
+            2,
+            Vector3.Zero,
+            [Entry(0x1234, new Vector3(1, 0, 200), radius: 0.6f)]);
+
+        Assert.Equal(0f, publisher.DebugVmFacts.NearestObjectDistance);
+        Assert.True(publisher.DebugVmFacts.Colliding);
+        Assert.Equal("0x00001234 Cylinder", publisher.DebugVmFacts.NearestObjectLabel);
+    }
+
+    [Fact]
+    public void Publish_DistanceAboveContactThresholdIsClearAndTieKeepsFirstEntry()
+    {
+        var publisher = new DebugVmRenderFactsPublisher();
+        float centerDistance = 1f + DebugVmRenderFactsPublisher.PlayerCollisionRadius
+            + DebugVmRenderFactsPublisher.ContactThreshold + 0.001f;
+
+        publisher.PublishDebugVmFacts(
+            true,
+            0,
+            0,
+            Vector3.Zero,
+            [
+                Entry(0x11, new Vector3(centerDistance, 0, 0), 1f),
+                Entry(0x22, new Vector3(0, centerDistance, 0), 1f),
+            ]);
+
+        Assert.True(publisher.DebugVmFacts.NearestObjectDistance
+            > DebugVmRenderFactsPublisher.ContactThreshold);
+        Assert.False(publisher.DebugVmFacts.Colliding);
+        Assert.Equal("0x00000011 Cylinder", publisher.DebugVmFacts.NearestObjectLabel);
+    }
+
+    [Fact]
+    public void Publish_EmptySequenceRestoresTheEmptyNearestFacts()
+    {
+        var publisher = new DebugVmRenderFactsPublisher();
+        publisher.PublishDebugVmFacts(
+            true,
+            1,
+            1,
+            Vector3.Zero,
+            [Entry(1, Vector3.Zero, 1)]);
+
+        publisher.PublishDebugVmFacts(true, 4, 9, Vector3.Zero, []);
+
+        Assert.Equal(4, publisher.DebugVmFacts.VisibleLandblocks);
+        Assert.Equal(9, publisher.DebugVmFacts.TotalLandblocks);
+        Assert.Equal(float.PositiveInfinity, publisher.DebugVmFacts.NearestObjectDistance);
+        Assert.Equal("-", publisher.DebugVmFacts.NearestObjectLabel);
+        Assert.False(publisher.DebugVmFacts.Colliding);
+    }
+
+    [Fact]
+    public void Publisher_RetainsNoRuntimeOwnerDelegateOrBorrowedSequence()
+    {
+        FieldInfo[] fields = typeof(DebugVmRenderFactsPublisher).GetFields(
+            BindingFlags.Instance | BindingFlags.NonPublic);
+
+        Assert.Single(fields);
+        Assert.Equal(typeof(DebugVmRenderFacts), fields[0].FieldType);
+        Assert.DoesNotContain(fields, field => field.FieldType == typeof(GameWindow));
+        Assert.DoesNotContain(fields, field => typeof(Delegate).IsAssignableFrom(field.FieldType));
+        Assert.DoesNotContain(fields, field =>
+            typeof(IEnumerable<ShadowEntry>).IsAssignableFrom(field.FieldType));
+        Assert.True(typeof(IDebugVmRenderFactsSource).IsAssignableFrom(
+            typeof(DebugVmRenderFactsPublisher)));
+    }
+
+    private static ShadowEntry Entry(uint id, Vector3 position, float radius) => new(
+        EntityId: id,
+        GfxObjId: 0,
+        Position: position,
+        Rotation: Quaternion.Identity,
+        Radius: radius,
+        CollisionType: ShadowCollisionType.Cylinder);
+
+    private sealed class CountingEnumerable(IReadOnlyList<ShadowEntry> entries)
+        : IEnumerable<ShadowEntry>
+    {
+        public int EnumerationCount { get; private set; }
+
+        public IEnumerator<ShadowEntry> GetEnumerator()
+        {
+            EnumerationCount++;
+            return entries.GetEnumerator();
+        }
+
+        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() =>
+            GetEnumerator();
+    }
+}