public static void CheckStandardGeometryAttributes(IG3D g3d)
{
var vertexBuffer = g3d.VertexAttribute;
var indexBuffer = g3d.IndexAttribute;
CheckAttribute(vertexBuffer, Association.assoc_vertex, AttributeType.attr_vertex, DataType.dt_float32, 3);
CheckAttribute(indexBuffer, Association.assoc_corner, AttributeType.attr_index, DataType.dt_int32, 1);
}
public static BFast ToBFast(this IG3D g3D)
{
var buffers = new List <IBytes>();
buffers.Add(G3D.DefaultHeader.ToBytesAscii().Pin());
var descriptors = g3D.Descriptors().ToArray().Pin();
buffers.Add(descriptors);
foreach (var attr in g3D.Attributes)
{
buffers.Add(attr.Bytes);
}
return(new BFast(buffers));
}
public G3DAdapter(IG3D g3D)
{
//g3D.Validate();
G3D = g3D;
FaceSizes = g3D.FaceSizes();
PointsPerFace = g3D.HasFixedFaceSize() ? g3D.FirstFaceSize() : 0;
Vertices = g3D.VertexAttribute.ToVector3s();
Indices = g3D.CornerVertexIndices();
NumFaces = g3D.FaceCount();
FaceIndices = g3D.FaceIndices();
MaterialIds = g3D.MaterialIds();
}
public static IAttribute FindAttribute(this IG3D g3D, AttributeType attributeType, bool throwIfMissing = true)
{
var candidates = g3D.FindAttributes(attributeType).ToList();
if (candidates.Count > 1)
{
throw new Exception($"Multiple matching attributes of type {attributeType.AttributeTypeString()}");
}
if (candidates.Count == 0)
{
if (throwIfMissing)
{
throw new Exception($"No matching attributes of type {attributeType.AttributeTypeString()}");
}
return(null);
}
return(candidates[0]);
}
public static int FaceCount(this IG3D g3d)
=> g3d.HasFixedFaceSize()
? g3d.CornerVertexIndices().Count / g3d.FirstFaceSize()
: g3d.FaceSizeAttribute.ToInts().Count;
public static bool HasFixedFaceSize(this IG3D g3d) => g3d.FaceSizeAttribute == null || g3d.FaceSizeAttribute.Descriptor.Association == Association.assoc_object;
public static int FirstFaceSize(this IG3D g3d) => g3d.FaceSizeAttribute?.ToInts()[0] ?? 3;
public static IEnumerable <IAttribute> FindAttributes(this IG3D g3D, Func <AttributeDescriptor, bool> predicate) => g3D.Attributes.Where(a => predicate(a.Descriptor));
public static IEnumerable <IAttribute> VertexAttributes(this IG3D g3d) => g3d.Attributes(Association.assoc_vertex);
public static int VertexCount(this IG3D g3d) => g3d.VertexAttribute.Count;
public static void Validate(this IG3D g3d)
{
// Check that no attributes are null
var n = g3d.Attributes.Count(attr => attr == null);
if (n > 0)
{
throw new Exception("Attributes cannot be null");
}
// Assure that there are no duplicates
g3d.Attributes.ToDictionary();
// Validate the descriptors
foreach (var attr in g3d.Attributes)
{
attr.Descriptor.Validate();
}
// Compute the number of faces
var faceCount = g3d.FaceCount();
// Assure that there is a vertex attribute
if (g3d.VertexAttribute.Descriptor.Association != Association.assoc_vertex)
{
throw new Exception("Vertex buffer is not associated with vertex: " + g3d.VertexAttribute.Descriptor);
}
if (g3d.VertexAttribute.Descriptor.DataArity != 3)
{
throw new Exception("Vertices should have an arity of 3");
}
if (g3d.Attributes(AttributeType.attr_vertex).Count() > 1)
{
throw new Exception("There can only be one vertex data set");
}
// Compute the number of vertices
var vertexCount = g3d.VertexCount();
// Computes the number of corners
var cornerCount = g3d.CornerVertexIndices().Count;
// Compute the number of groups. Groups requires the precense of a GroupIndex attribute
var groupCount = g3d.GroupIndexAttributes().FirstOrDefault()?.Count ?? -1;
// Compute the number of instance. The first instance channel determines the number of instances
var instanceCount = g3d.Attributes(Association.assoc_instance).FirstOrDefault()?.Count ?? -1;
// Check the number of items in each attribute
foreach (var attr in g3d.Attributes)
{
switch (attr.Descriptor.Association)
{
case Association.assoc_vertex:
if (attr.Count != vertexCount)
{
throw new Exception($"Attribute {attr.Descriptor} has {attr.Count} items, expected {vertexCount}");
}
break;
case Association.assoc_face:
if (attr.Count != faceCount)
{
throw new Exception($"Attribute {attr.Descriptor} has {attr.Count} items, expected {faceCount}");
}
break;
case Association.assoc_corner:
if (attr.Count != cornerCount)
{
throw new Exception($"Attribute {attr.Descriptor} has {attr.Count} items, expected {cornerCount}");
}
break;
case Association.assoc_edge:
if (attr.Count != cornerCount)
{
throw new Exception($"Attribute {attr.Descriptor} has {attr.Count} items, expected {cornerCount}");
}
break;
case Association.assoc_object:
if (attr.Count != 1)
{
throw new Exception($"Attribute {attr.Descriptor} has {attr.Count} items, expected 1");
}
break;
case Association.assoc_group:
if (attr.Count != groupCount)
{
throw new Exception($"Attribute {attr.Descriptor} has {attr.Count} items, expected {groupCount}");
}
break;
case Association.assoc_instance:
if (attr.Count != instanceCount)
{
throw new Exception($"Attribute {attr.Descriptor} has {attr.Count} items, expected {instanceCount}");
}
break;
case Association.assoc_none:
break;
default:
throw new Exception($"Attribute {attr.Descriptor} has invalid association");
}
}
// The following rules are stricter than absolutely necessary, but respecting them
// will make coding geometry libraries easier to write on top of the thing.
g3d.Attributes(AttributeType.attr_binormal).ToList()
.ValidateDataType(DataType.dt_float32)
.ValidateArity(3)
.ValidateAssociation(Association.assoc_vertex);
g3d.Attributes(AttributeType.attr_tangent).ToList()
.ValidateDataType(DataType.dt_float32)
.ValidateArity(3)
.ValidateAssociation(Association.assoc_vertex);
g3d.Attributes(AttributeType.attr_normal).ToList()
.ValidateDataType(DataType.dt_float32)
.ValidateArity(3)
.ValidateAssociation(Association.assoc_face, Association.assoc_corner, Association.assoc_vertex);
g3d.Attributes(AttributeType.attr_color).ToList()
.ValidateArity(1, 3, 4)
.ValidateAssociation(Association.assoc_face, Association.assoc_corner, Association.assoc_vertex,
Association.assoc_object);
g3d.Attributes(AttributeType.attr_visibility).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int8, DataType.dt_int32, DataType.dt_float32);
g3d.Attributes(AttributeType.attr_faceindex).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_face)
.ValidateMaxOne();
g3d.Attributes(AttributeType.attr_facesize).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_face, Association.assoc_object)
.ValidateMaxOne();
g3d.Attributes(AttributeType.attr_index).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_corner)
.ValidateMaxOne();
g3d.Attributes(AttributeType.attr_uv).ToList()
.ValidateArity(2, 3)
.ValidateDataType(DataType.dt_float32)
.ValidateAssociation(Association.assoc_vertex, Association.assoc_corner);
g3d.Attributes(AttributeType.attr_invalid).ToList()
.ValidateNone();
g3d.Attributes(AttributeType.attr_index).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_corner)
.ValidateMaxOne();
g3d.Attributes(AttributeType.attr_mapchannel_data).ToList()
.ValidateArity(3)
.ValidateDataType(DataType.dt_float32)
.ValidateAssociation(Association.assoc_none);
g3d.Attributes(AttributeType.attr_mapchannel_index).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_corner);
g3d.Attributes(AttributeType.attr_materialid).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_face);
g3d.Attributes(AttributeType.attr_pervertex).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_float32)
.ValidateAssociation(Association.assoc_vertex);
g3d.Attributes(AttributeType.attr_polygroup).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_face);
g3d.Attributes(AttributeType.attr_smoothing).ToList()
.ValidateArity(1)
.ValidateDataType(DataType.dt_int32)
.ValidateAssociation(Association.assoc_face);
g3d.Attributes(AttributeType.attr_instance_transform).ToList()
.ValidateArity(16)
.ValidateDataType(DataType.dt_float32)
.ValidateAssociation(Association.assoc_instance);
g3d.Attributes(AttributeType.attr_vertex).ToList()
.ValidateArity(3)
.ValidateDataType(DataType.dt_float32, DataType.dt_float64)
.ValidateAssociation(Association.assoc_vertex)
.ValidateExactlyOne();
}
public static IEnumerable <IAttribute> UVAttributes(this IG3D g3D) => g3D.Attributes(AttributeType.attr_uv);
public static IEnumerable <IAttribute> NormalAttributes(this IG3D g3D) => g3D.Attributes(AttributeType.attr_normal);
public static IEnumerable <IAttribute> ObjectAttributes(this IG3D g3d) => g3d.Attributes(Association.assoc_object);
public static IEnumerable <IAttribute> NoneAttributes(this IG3D g3d) => g3d.Attributes(Association.assoc_none);
public static IEnumerable <IAttribute> EdgeAttributes(this IG3D g3d) => g3d.Attributes(Association.assoc_edge);
public static IEnumerable <IAttribute> FaceAttributes(this IG3D g3d) => g3d.Attributes(Association.assoc_face);
public static IEnumerable <IAttribute> CornerAttributes(this IG3D g3d) => g3d.Attributes(Association.assoc_corner);
public static IArray <int> MaterialIds(this IG3D g3d) => g3d.MaterialIdAttribute?.ToInts() ?? (-1).Repeat(g3d.FaceCount());
public static IEnumerable <IAttribute> GroupIndexAttributes(this IG3D g3D) => g3D.Attributes(AttributeType.attr_group_index);
public static IArray <int> FaceIndices(this IG3D g3d)
=> g3d.FaceIndexAttribute?.ToInts()
?? (g3d.HasFixedFaceSize()
? g3d.CornerVertexIndices().Indices().Stride(g3d.FirstFaceSize())
: g3d.FaceSizes().Accumulate((x, y) => x + y));
public static IG3D AddAttributes(this IG3D g3d, params IAttribute[] attributes) => g3d.Attributes.Concat(attributes).ToG3D();
public static IArray <int> FaceSizes(this IG3D g3d)
=> g3d.HasFixedFaceSize()
? g3d.FaceCount().Select(i => g3d.FirstFaceSize())
: g3d.FaceSizeAttribute.ToInts();
public static IG3D ReplaceAttribute(this IG3D g3d, IAttribute attr)
=> g3d.AttributesExcept(attr.Descriptor).Concat(new[] { attr }).ToG3D();
public static IEnumerable <AttributeDescriptor> Descriptors(this IG3D g3D) => g3D.Attributes.Select(attr => attr.Descriptor);
public static IArray <int> CornerVertexIndices(this IG3D g3d)
=> g3d.IndexAttribute == null
? g3d.VertexCount().Range()
: g3d.IndexAttribute.ToInts();
public static IEnumerable <IAttribute> InstanceTransforms(this IG3D g3D) => g3D.Attributes(AttributeType.attr_instance_transform);
public static IEnumerable <IAttribute> Attributes(this IG3D g3d, Association assoc, AttributeType attrType) => g3d.Attributes.Where(attr => attr.Descriptor.Association == assoc && attr.Descriptor.AttributeType == attrType);
public static IGeometry ToIGeometry(this IG3D g) => new G3DAdapter(g);
public static IEnumerable <IAttribute> InstanceGroups(this IG3D g3D) => g3D.Attributes(AttributeType.attr_instance_group);
