feat(core): add LandblockLoader with Stab+Building → WorldEntity mapping

tests/AcDream.Core.Tests/World/LandblockLoaderTests.cs

@@ -0,0 +1,119 @@
+using System.Numerics;
+using AcDream.Core.World;
+using DatReaderWriter.DBObjs;
+using DatReaderWriter.Types;
+
+namespace AcDream.Core.Tests.World;
+
+public class LandblockLoaderTests
+{
+    private static LandBlock BuildFlatLandBlock()
+    {
+        var block = new LandBlock
+        {
+            HasObjects = true,
+            Terrain = new TerrainInfo[81],
+            Height = new byte[81],
+        };
+        for (int i = 0; i < 81; i++)
+        {
+            block.Terrain[i] = (ushort)0;
+            block.Height[i] = 0;
+        }
+        return block;
+    }
+
+    [Fact]
+    public void BuildEntitiesFromInfo_StabsAndBuildings_AreMappedToEntities()
+    {
+        var info = new LandBlockInfo
+        {
+            Objects =
+            {
+                new Stab
+                {
+                    Id = 0x01000042u,  // GfxObj id
+                    Frame = new Frame
+                    {
+                        Origin = new Vector3(10, 20, 5),
+                        Orientation = Quaternion.Identity,
+                    },
+                },
+                new Stab
+                {
+                    Id = 0x02000099u,  // Setup id
+                    Frame = new Frame
+                    {
+                        Origin = new Vector3(30, 40, 10),
+                        Orientation = Quaternion.Identity,
+                    },
+                },
+            },
+            Buildings =
+            {
+                new BuildingInfo
+                {
+                    ModelId = 0x020000AAu,  // Setup for a building
+                    Frame = new Frame
+                    {
+                        Origin = new Vector3(50, 60, 0),
+                        Orientation = Quaternion.Identity,
+                    },
+                },
+            },
+        };
+
+        var entities = LandblockLoader.BuildEntitiesFromInfo(info);
+
+        Assert.Equal(3, entities.Count);
+        Assert.Contains(entities, e => e.SourceGfxObjOrSetupId == 0x01000042u && e.Position == new Vector3(10, 20, 5));
+        Assert.Contains(entities, e => e.SourceGfxObjOrSetupId == 0x02000099u && e.Position == new Vector3(30, 40, 10));
+        Assert.Contains(entities, e => e.SourceGfxObjOrSetupId == 0x020000AAu && e.Position == new Vector3(50, 60, 0));
+    }
+
+    [Fact]
+    public void BuildEntitiesFromInfo_AssignsMonotonicIds()
+    {
+        var info = new LandBlockInfo
+        {
+            Objects =
+            {
+                new Stab { Id = 0x01000001u, Frame = new Frame() },
+                new Stab { Id = 0x01000002u, Frame = new Frame() },
+                new Stab { Id = 0x01000003u, Frame = new Frame() },
+            },
+        };
+
+        var entities = LandblockLoader.BuildEntitiesFromInfo(info);
+
+        var ids = entities.Select(e => e.Id).OrderBy(i => i).ToArray();
+        Assert.Equal(3, ids.Distinct().Count());  // all unique
+    }
+
+    [Fact]
+    public void BuildEntitiesFromInfo_UnsupportedIdType_IsSkipped()
+    {
+        // 0x03xxxxxx is neither GfxObj (0x01) nor Setup (0x02).
+        var info = new LandBlockInfo
+        {
+            Objects =
+            {
+                new Stab { Id = 0x01000001u, Frame = new Frame() },
+                new Stab { Id = 0x03000002u, Frame = new Frame() },  // skipped
+                new Stab { Id = 0x02000003u, Frame = new Frame() },
+            },
+        };
+
+        var entities = LandblockLoader.BuildEntitiesFromInfo(info);
+
+        Assert.Equal(2, entities.Count);
+        Assert.DoesNotContain(entities, e => e.SourceGfxObjOrSetupId == 0x03000002u);
+    }
+
+    [Fact]
+    public void BuildEntitiesFromInfo_Empty_ReturnsEmpty()
+    {
+        var entities = LandblockLoader.BuildEntitiesFromInfo(new LandBlockInfo());
+        Assert.Empty(entities);
+    }
+}