acdream/src/AcDream.Content/FlatCollisionAssetSerializer.cs
Erik 9cd42417a8 feat(content): bake and read flat collision assets
Append strict collision/topology payloads to the existing prepared package so later physics cutover can drop parsed DAT graphs without adding a second mapping or changing traversal behavior. The full 2,232,170-key catalog is deterministic across worker counts, exact-byte aliased, corruption-isolated, and cancellation-safe.
2026-07-25 15:22:08 +02:00

715 lines
24 KiB
C#

using System.Buffers;
using System.Buffers.Binary;
using System.Collections.Immutable;
using System.Numerics;
using AcDream.Core.Physics;
using DatReaderWriter.Enums;
namespace AcDream.Content;
/// <summary>
/// Strict little-endian package codec for immutable flat collision assets.
/// Every float is persisted through its exact IEEE-754 bit pattern. Readers
/// reject invalid counts, invalid enum/range/tree contracts, wrong payload
/// kinds, non-zero reserved bytes, truncation, and trailing bytes.
/// </summary>
public static class FlatCollisionAssetSerializer
{
private const uint Magic = 0x4C_43_43_41u; // "ACCL" little-endian
private const byte SchemaVersion = 1;
private const int MaximumRows = 16_777_216;
public static byte[] Serialize(
FlatGfxObjCollisionAsset asset,
CancellationToken cancellationToken = default)
{
ArgumentNullException.ThrowIfNull(asset);
var writer = new CollisionWriter();
writer.WriteHeader(CollisionPayloadKind.GfxObj);
WritePhysicsBsp(writer, asset.PhysicsBsp, cancellationToken);
writer.WriteOptionalSphere(asset.BoundingSphere);
writer.WriteBoolean(asset.VisualBounds.HasValue);
if (asset.VisualBounds is FlatGfxObjVisualBounds visual)
{
writer.WriteVector3(visual.Min);
writer.WriteVector3(visual.Max);
writer.WriteVector3(visual.Center);
writer.WriteSingle(visual.Radius);
writer.WriteVector3(visual.HalfExtents);
}
cancellationToken.ThrowIfCancellationRequested();
return writer.ToArray();
}
public static byte[] Serialize(
FlatSetupCollision asset,
CancellationToken cancellationToken = default)
{
ArgumentNullException.ThrowIfNull(asset);
var writer = new CollisionWriter();
writer.WriteHeader(CollisionPayloadKind.Setup);
writer.WriteCount(asset.Cylinders.Length, "Setup cylinder");
writer.WriteCount(asset.Spheres.Length, "Setup sphere");
writer.WriteSingle(asset.Height);
writer.WriteSingle(asset.Radius);
writer.WriteSingle(asset.StepUpHeight);
writer.WriteSingle(asset.StepDownHeight);
for (int i = 0; i < asset.Cylinders.Length; i++)
{
CheckCancellation(cancellationToken, i);
FlatCollisionCylinder cylinder = asset.Cylinders[i];
writer.WriteVector3(cylinder.Origin);
writer.WriteSingle(cylinder.Radius);
writer.WriteSingle(cylinder.Height);
}
for (int i = 0; i < asset.Spheres.Length; i++)
{
CheckCancellation(cancellationToken, i);
writer.WriteSphere(asset.Spheres[i]);
}
cancellationToken.ThrowIfCancellationRequested();
return writer.ToArray();
}
public static byte[] Serialize(
FlatCellStructureCollisionAsset asset,
CancellationToken cancellationToken = default)
{
ArgumentNullException.ThrowIfNull(asset);
var writer = new CollisionWriter();
writer.WriteHeader(CollisionPayloadKind.CellStructure);
WritePhysicsBsp(writer, asset.PhysicsBsp, cancellationToken);
WriteContainmentBsp(writer, asset.ContainmentBsp, cancellationToken);
WritePolygonTable(writer, asset.PortalPolygons, cancellationToken);
cancellationToken.ThrowIfCancellationRequested();
return writer.ToArray();
}
public static byte[] Serialize(
FlatEnvCellTopology asset,
CancellationToken cancellationToken = default)
{
ArgumentNullException.ThrowIfNull(asset);
var writer = new CollisionWriter();
writer.WriteHeader(CollisionPayloadKind.EnvCellTopology);
writer.WriteCount(asset.Portals.Length, "EnvCell portal");
writer.WriteCount(asset.VisibleCellIds.Length, "visible-cell");
writer.WriteBoolean(asset.SeenOutside);
for (int i = 0; i < asset.Portals.Length; i++)
{
CheckCancellation(cancellationToken, i);
FlatEnvCellPortal portal = asset.Portals[i];
writer.WriteUInt16(portal.OtherCellId);
writer.WriteUInt16(portal.PolygonId);
writer.WriteUInt16(portal.Flags);
writer.WriteInt32(portal.PolygonIndex);
}
for (int i = 0; i < asset.VisibleCellIds.Length; i++)
{
CheckCancellation(cancellationToken, i);
writer.WriteUInt32(asset.VisibleCellIds[i]);
}
cancellationToken.ThrowIfCancellationRequested();
return writer.ToArray();
}
public static FlatGfxObjCollisionAsset DeserializeGfxObj(
ReadOnlySpan<byte> bytes,
CancellationToken cancellationToken = default)
{
var reader = new CollisionReader(bytes, cancellationToken);
reader.ReadHeader(CollisionPayloadKind.GfxObj);
FlatPhysicsBsp physicsBsp = ReadPhysicsBsp(ref reader);
FlatCollisionSphere? boundingSphere = reader.ReadOptionalSphere();
FlatGfxObjVisualBounds? visualBounds = null;
if (reader.ReadBoolean())
{
visualBounds = new FlatGfxObjVisualBounds(
reader.ReadVector3(),
reader.ReadVector3(),
reader.ReadVector3(),
reader.ReadSingle(),
reader.ReadVector3());
}
reader.RequireEnd();
return new FlatGfxObjCollisionAsset(
physicsBsp,
boundingSphere,
visualBounds);
}
public static FlatSetupCollision DeserializeSetup(
ReadOnlySpan<byte> bytes,
CancellationToken cancellationToken = default)
{
var reader = new CollisionReader(bytes, cancellationToken);
reader.ReadHeader(CollisionPayloadKind.Setup);
int cylinderCount = reader.ReadCount(
"Setup cylinder",
bytesPerItem: 20);
int sphereCount = reader.ReadCount(
"Setup sphere",
bytesPerItem: 16);
reader.RequireRemaining(
checked(16L + (20L * cylinderCount) + (16L * sphereCount)),
"Setup collision rows");
float height = reader.ReadSingle();
float radius = reader.ReadSingle();
float stepUpHeight = reader.ReadSingle();
float stepDownHeight = reader.ReadSingle();
var cylinders =
ImmutableArray.CreateBuilder<FlatCollisionCylinder>(cylinderCount);
for (int i = 0; i < cylinderCount; i++)
{
reader.CheckCancellation(i);
cylinders.Add(new FlatCollisionCylinder(
reader.ReadVector3(),
reader.ReadSingle(),
reader.ReadSingle()));
}
var spheres =
ImmutableArray.CreateBuilder<FlatCollisionSphere>(sphereCount);
for (int i = 0; i < sphereCount; i++)
{
reader.CheckCancellation(i);
spheres.Add(reader.ReadSphere());
}
reader.RequireEnd();
return new FlatSetupCollision(
cylinders.MoveToImmutable(),
spheres.MoveToImmutable(),
height,
radius,
stepUpHeight,
stepDownHeight);
}
public static FlatCellStructureCollisionAsset DeserializeCellStructure(
ReadOnlySpan<byte> bytes,
CancellationToken cancellationToken = default)
{
var reader = new CollisionReader(bytes, cancellationToken);
reader.ReadHeader(CollisionPayloadKind.CellStructure);
FlatPhysicsBsp physicsBsp = ReadPhysicsBsp(ref reader);
FlatCellContainmentBsp containmentBsp = ReadContainmentBsp(ref reader);
FlatPolygonTable portalPolygons = ReadPolygonTable(ref reader);
reader.RequireEnd();
return new FlatCellStructureCollisionAsset(
physicsBsp,
containmentBsp,
portalPolygons);
}
public static FlatEnvCellTopology DeserializeEnvCellTopology(
ReadOnlySpan<byte> bytes,
CancellationToken cancellationToken = default)
{
var reader = new CollisionReader(bytes, cancellationToken);
reader.ReadHeader(CollisionPayloadKind.EnvCellTopology);
int portalCount = reader.ReadCount(
"EnvCell portal",
bytesPerItem: 10);
int visibleCount = reader.ReadCount(
"visible-cell",
bytesPerItem: 4);
reader.RequireRemaining(
checked(1L + (10L * portalCount) + (4L * visibleCount)),
"EnvCell topology rows");
bool seenOutside = reader.ReadBoolean();
var portals =
ImmutableArray.CreateBuilder<FlatEnvCellPortal>(portalCount);
for (int i = 0; i < portalCount; i++)
{
reader.CheckCancellation(i);
portals.Add(new FlatEnvCellPortal(
reader.ReadUInt16(),
reader.ReadUInt16(),
reader.ReadUInt16(),
reader.ReadInt32()));
}
var visible =
ImmutableArray.CreateBuilder<uint>(visibleCount);
for (int i = 0; i < visibleCount; i++)
{
reader.CheckCancellation(i);
visible.Add(reader.ReadUInt32());
}
reader.RequireEnd();
return new FlatEnvCellTopology(
portals.MoveToImmutable(),
visible.MoveToImmutable(),
seenOutside);
}
private static void WritePhysicsBsp(
CollisionWriter writer,
FlatPhysicsBsp bsp,
CancellationToken cancellationToken)
{
ArgumentNullException.ThrowIfNull(bsp);
writer.WriteInt32(bsp.RootIndex);
writer.WriteCount(bsp.Nodes.Length, "physics BSP node");
writer.WriteCount(
bsp.PolygonIndexStream.Length,
"physics BSP polygon-index");
for (int i = 0; i < bsp.Nodes.Length; i++)
{
CheckCancellation(cancellationToken, i);
FlatPhysicsBspNode node = bsp.Nodes[i];
writer.WriteUInt32((uint)node.Type);
writer.WritePlane(node.SplittingPlane);
writer.WriteInt32(node.PositiveChildIndex);
writer.WriteInt32(node.NegativeChildIndex);
writer.WriteInt32(node.LeafIndex);
writer.WriteInt32(node.Solid);
writer.WriteSphere(node.BoundingSphere);
writer.WriteRange(node.PolygonIndexRange);
}
for (int i = 0; i < bsp.PolygonIndexStream.Length; i++)
{
CheckCancellation(cancellationToken, i);
writer.WriteInt32(bsp.PolygonIndexStream[i]);
}
WritePolygonTable(writer, bsp.PolygonTable, cancellationToken);
}
private static FlatPhysicsBsp ReadPhysicsBsp(
ref CollisionReader reader)
{
int rootIndex = reader.ReadInt32();
int nodeCount = reader.ReadCount(
"physics BSP node",
bytesPerItem: 60);
int polygonIndexCount = reader.ReadCount(
"physics BSP polygon-index",
bytesPerItem: 4);
reader.RequireRemaining(
checked((60L * nodeCount) + (4L * polygonIndexCount) + 8L),
"physics BSP rows");
var nodes =
ImmutableArray.CreateBuilder<FlatPhysicsBspNode>(nodeCount);
for (int i = 0; i < nodeCount; i++)
{
reader.CheckCancellation(i);
nodes.Add(new FlatPhysicsBspNode(
(BSPNodeType)reader.ReadUInt32(),
reader.ReadPlane(),
reader.ReadInt32(),
reader.ReadInt32(),
reader.ReadInt32(),
reader.ReadInt32(),
reader.ReadSphere(),
reader.ReadRange()));
}
var polygonIndices =
ImmutableArray.CreateBuilder<int>(polygonIndexCount);
for (int i = 0; i < polygonIndexCount; i++)
{
reader.CheckCancellation(i);
polygonIndices.Add(reader.ReadInt32());
}
FlatPolygonTable polygons = ReadPolygonTable(ref reader);
return new FlatPhysicsBsp(
rootIndex,
nodes.MoveToImmutable(),
polygonIndices.MoveToImmutable(),
polygons);
}
private static void WriteContainmentBsp(
CollisionWriter writer,
FlatCellContainmentBsp bsp,
CancellationToken cancellationToken)
{
ArgumentNullException.ThrowIfNull(bsp);
writer.WriteInt32(bsp.RootIndex);
writer.WriteCount(bsp.Nodes.Length, "cell-containment BSP node");
for (int i = 0; i < bsp.Nodes.Length; i++)
{
CheckCancellation(cancellationToken, i);
FlatCellBspNode node = bsp.Nodes[i];
writer.WriteUInt32((uint)node.Type);
writer.WritePlane(node.SplittingPlane);
writer.WriteInt32(node.PositiveChildIndex);
writer.WriteInt32(node.NegativeChildIndex);
writer.WriteInt32(node.LeafIndex);
}
}
private static FlatCellContainmentBsp ReadContainmentBsp(
ref CollisionReader reader)
{
int rootIndex = reader.ReadInt32();
int nodeCount = reader.ReadCount(
"cell-containment BSP node",
bytesPerItem: 32);
var nodes =
ImmutableArray.CreateBuilder<FlatCellBspNode>(nodeCount);
for (int i = 0; i < nodeCount; i++)
{
reader.CheckCancellation(i);
nodes.Add(new FlatCellBspNode(
(BSPNodeType)reader.ReadUInt32(),
reader.ReadPlane(),
reader.ReadInt32(),
reader.ReadInt32(),
reader.ReadInt32()));
}
return new FlatCellContainmentBsp(
rootIndex,
nodes.MoveToImmutable());
}
private static void WritePolygonTable(
CollisionWriter writer,
FlatPolygonTable table,
CancellationToken cancellationToken)
{
ArgumentNullException.ThrowIfNull(table);
writer.WriteCount(table.Polygons.Length, "polygon");
writer.WriteCount(table.Vertices.Length, "polygon vertex");
for (int i = 0; i < table.Polygons.Length; i++)
{
CheckCancellation(cancellationToken, i);
FlatCollisionPolygon polygon = table.Polygons[i];
writer.WriteUInt16(polygon.Id);
writer.WriteUInt32((uint)polygon.SidesType);
writer.WriteInt32(polygon.NumPoints);
writer.WriteRange(polygon.VertexRange);
writer.WritePlane(polygon.Plane);
}
for (int i = 0; i < table.Vertices.Length; i++)
{
CheckCancellation(cancellationToken, i);
writer.WriteVector3(table.Vertices[i]);
}
}
private static FlatPolygonTable ReadPolygonTable(
ref CollisionReader reader)
{
int polygonCount = reader.ReadCount(
"polygon",
bytesPerItem: 34);
int vertexCount = reader.ReadCount(
"polygon vertex",
bytesPerItem: 12);
reader.RequireRemaining(
checked((34L * polygonCount) + (12L * vertexCount)),
"polygon-table rows");
var polygons =
ImmutableArray.CreateBuilder<FlatCollisionPolygon>(polygonCount);
for (int i = 0; i < polygonCount; i++)
{
reader.CheckCancellation(i);
polygons.Add(new FlatCollisionPolygon(
reader.ReadUInt16(),
reader.ReadPlaneAfterMetadata(out CullMode sides, out int count,
out FlatIndexRange range),
sides,
count,
range));
}
var vertices = ImmutableArray.CreateBuilder<Vector3>(vertexCount);
for (int i = 0; i < vertexCount; i++)
{
reader.CheckCancellation(i);
vertices.Add(reader.ReadVector3());
}
return new FlatPolygonTable(
polygons.MoveToImmutable(),
vertices.MoveToImmutable());
}
private static void CheckCancellation(
CancellationToken cancellationToken,
int index)
{
if ((index & 0xFF) == 0)
cancellationToken.ThrowIfCancellationRequested();
}
private enum CollisionPayloadKind : byte
{
GfxObj = 1,
Setup = 2,
CellStructure = 3,
EnvCellTopology = 4,
}
private sealed class CollisionWriter
{
private readonly ArrayBufferWriter<byte> _buffer = new(256);
public void WriteHeader(CollisionPayloadKind kind)
{
WriteUInt32(Magic);
WriteByte((byte)kind);
WriteByte(SchemaVersion);
WriteUInt16(0);
}
public void WriteCount(int value, string name)
{
if ((uint)value > MaximumRows)
{
throw new InvalidDataException(
$"{name} count {value} exceeds {MaximumRows}.");
}
WriteInt32(value);
}
public void WriteOptionalSphere(FlatCollisionSphere? sphere)
{
WriteBoolean(sphere.HasValue);
if (sphere.HasValue)
WriteSphere(sphere.Value);
}
public void WriteBoolean(bool value) => WriteByte(value ? (byte)1 : (byte)0);
public void WriteSphere(FlatCollisionSphere sphere)
{
WriteVector3(sphere.Origin);
WriteSingle(sphere.Radius);
}
public void WriteRange(FlatIndexRange range)
{
WriteInt32(range.Start);
WriteInt32(range.Count);
}
public void WritePlane(Plane plane)
{
WriteVector3(plane.Normal);
WriteSingle(plane.D);
}
public void WriteVector3(Vector3 vector)
{
WriteSingle(vector.X);
WriteSingle(vector.Y);
WriteSingle(vector.Z);
}
public void WriteSingle(float value) =>
WriteInt32(BitConverter.SingleToInt32Bits(value));
public void WriteByte(byte value)
{
Span<byte> span = _buffer.GetSpan(1);
span[0] = value;
_buffer.Advance(1);
}
public void WriteUInt16(ushort value)
{
Span<byte> span = _buffer.GetSpan(sizeof(ushort));
BinaryPrimitives.WriteUInt16LittleEndian(span, value);
_buffer.Advance(sizeof(ushort));
}
public void WriteInt32(int value)
{
Span<byte> span = _buffer.GetSpan(sizeof(int));
BinaryPrimitives.WriteInt32LittleEndian(span, value);
_buffer.Advance(sizeof(int));
}
public void WriteUInt32(uint value)
{
Span<byte> span = _buffer.GetSpan(sizeof(uint));
BinaryPrimitives.WriteUInt32LittleEndian(span, value);
_buffer.Advance(sizeof(uint));
}
public byte[] ToArray() => _buffer.WrittenSpan.ToArray();
}
private ref struct CollisionReader
{
private readonly ReadOnlySpan<byte> _bytes;
private readonly CancellationToken _cancellationToken;
private int _offset;
public CollisionReader(
ReadOnlySpan<byte> bytes,
CancellationToken cancellationToken)
{
_bytes = bytes;
_cancellationToken = cancellationToken;
_offset = 0;
_cancellationToken.ThrowIfCancellationRequested();
}
private int Remaining => _bytes.Length - _offset;
public void ReadHeader(CollisionPayloadKind expectedKind)
{
uint magic = ReadUInt32();
byte kind = ReadByte();
byte version = ReadByte();
ushort reserved = ReadUInt16();
if (magic != Magic)
{
throw new InvalidDataException(
$"collision payload magic 0x{magic:X8} does not match " +
$"0x{Magic:X8}.");
}
if (kind != (byte)expectedKind)
{
throw new InvalidDataException(
$"collision payload kind {kind} does not match " +
$"{(byte)expectedKind}.");
}
if (version != SchemaVersion)
{
throw new InvalidDataException(
$"collision payload schema {version} is unsupported.");
}
if (reserved != 0)
{
throw new InvalidDataException(
"collision payload reserved header bits are non-zero.");
}
}
public int ReadCount(string name, int bytesPerItem)
{
int count = ReadInt32();
if (count < 0 || count > MaximumRows)
{
throw new InvalidDataException(
$"{name} count {count} is outside [0,{MaximumRows}].");
}
if (bytesPerItem <= 0 || count > Remaining / bytesPerItem)
{
throw new InvalidDataException(
$"{name} count {count} exceeds the remaining payload.");
}
return count;
}
public FlatCollisionSphere? ReadOptionalSphere() =>
ReadBoolean() ? ReadSphere() : null;
public bool ReadBoolean()
{
byte value = ReadByte();
return value switch
{
0 => false,
1 => true,
_ => throw new InvalidDataException(
$"invalid collision boolean value {value}."),
};
}
public FlatCollisionSphere ReadSphere() =>
new(ReadVector3(), ReadSingle());
public FlatIndexRange ReadRange() =>
new(ReadInt32(), ReadInt32());
public Plane ReadPlane() =>
new(ReadVector3(), ReadSingle());
public Plane ReadPlaneAfterMetadata(
out CullMode sides,
out int numPoints,
out FlatIndexRange range)
{
sides = (CullMode)ReadUInt32();
numPoints = ReadInt32();
range = ReadRange();
return ReadPlane();
}
public Vector3 ReadVector3() =>
new(ReadSingle(), ReadSingle(), ReadSingle());
public float ReadSingle() =>
BitConverter.Int32BitsToSingle(ReadInt32());
public byte ReadByte()
{
Require(sizeof(byte));
return _bytes[_offset++];
}
public ushort ReadUInt16()
{
ReadOnlySpan<byte> span = Take(sizeof(ushort));
return BinaryPrimitives.ReadUInt16LittleEndian(span);
}
public int ReadInt32()
{
ReadOnlySpan<byte> span = Take(sizeof(int));
return BinaryPrimitives.ReadInt32LittleEndian(span);
}
public uint ReadUInt32()
{
ReadOnlySpan<byte> span = Take(sizeof(uint));
return BinaryPrimitives.ReadUInt32LittleEndian(span);
}
public void CheckCancellation(int index)
{
if ((index & 0xFF) == 0)
_cancellationToken.ThrowIfCancellationRequested();
}
public void RequireEnd()
{
_cancellationToken.ThrowIfCancellationRequested();
if (_offset != _bytes.Length)
{
throw new InvalidDataException(
$"collision payload contains {_bytes.Length - _offset} " +
"trailing byte(s).");
}
}
public void RequireRemaining(long required, string name)
{
if (required < 0 || required > Remaining)
{
throw new InvalidDataException(
$"{name} require {required} bytes but only {Remaining} remain.");
}
}
private ReadOnlySpan<byte> Take(int length)
{
Require(length);
ReadOnlySpan<byte> result = _bytes.Slice(_offset, length);
_offset += length;
return result;
}
private void Require(int length)
{
if (length < 0 || length > Remaining)
throw new EndOfStreamException("collision payload is truncated.");
}
}
}