public static int ExpectedElementCount(this IGeometryAttributes self, AttributeDescriptor desc)
{
switch (desc.Association)
{
case Association.assoc_all:
return(1);
case Association.assoc_none:
return(0);
case Association.assoc_vertex:
return(self.NumVertices);
case Association.assoc_face:
return(self.NumFaces);
case Association.assoc_corner:
return(self.NumCorners);
case Association.assoc_edge:
return(self.NumCorners);
case Association.assoc_subgeometry:
return(self.NumSubgeometries);
case Association.assoc_instance:
return(self.NumInstances);
}
return(-1);
}
/// <summary>
/// Applies a transformation function to position attributes and another to normal attributes. When deforming, we may want to
/// apply a similar deformation to the normals. For example a matrix can change the position, rotation, and scale of a geometry,
/// but the only changes should be to the direction of the normal, not the length.
/// </summary>
public static IGeometryAttributes Deform(this IGeometryAttributes g, Func <Vector3, Vector3> positionTransform, Func <Vector3, Vector3> normalTransform)
=> g.Attributes.Select(
a =>
(a.Descriptor.Semantic == "position" && a is GeometryAttribute <Vector3> p) ? p.Data.Select(positionTransform).ToAttribute(a.Descriptor) :
(a.Descriptor.Semantic == "normal" && a is GeometryAttribute <Vector3> n) ? n.Data.Select(normalTransform).ToAttribute(a.Descriptor) :
a)
.ToGeometryAttributes();
/// <summary>
/// Converts a quadrilateral mesh into a triangular mesh carrying over all attributes.
/// </summary>
public static IGeometryAttributes TriangulateQuadMesh(this IGeometryAttributes g)
{
if (g.NumCornersPerFace != 4)
{
throw new Exception("Not a quad mesh");
}
var cornerRemap = new int[g.NumFaces * 6];
var faceRemap = new int[g.NumFaces * 2];
var cur = 0;
for (var i = 0; i < g.NumFaces; ++i)
{
cornerRemap[cur++] = i * 4 + 0;
cornerRemap[cur++] = i * 4 + 1;
cornerRemap[cur++] = i * 4 + 2;
cornerRemap[cur++] = i * 4 + 0;
cornerRemap[cur++] = i * 4 + 2;
cornerRemap[cur++] = i * 4 + 3;
faceRemap[i * 2 + 0] = i;
faceRemap[i * 2 + 1] = i;
}
return(g.RemapFacesAndCorners(faceRemap.ToIArray(), cornerRemap.ToIArray(), 3));
}
/// <summary>
/// Applies vertex colors
/// </summary>
public static IGeometryAttributes Color(this IGeometryAttributes g, Vector4 color)
{
return(g.Attributes
.Where(a => a.Descriptor.Semantic != Semantic.Color)
.Concat(Enumerable.Repeat(g.NumVertices.Select(_ => color).ToAttribute(new AttributeDescriptor(Association.assoc_vertex, Semantic.Color, DataType.dt_float32, 4)), 1))
.ToGeometryAttributes());
}
public static byte[] WriteToBytes(this IGeometryAttributes self)
{
using (var memoryStream = new MemoryStream())
{
self.Write(memoryStream);
return(memoryStream.ToArray());
}
}
public G3dWriter(IGeometryAttributes g, G3dHeader?header = null)
{
Attributes = g;
Meta = (header ?? G3dHeader.Default).ToBytes().ToNamedBuffer("meta");
Names = new[] { Meta.Name }.Concat(g.Attributes.ToEnumerable().Select(attr => attr.Name)).ToArray();
Sizes = new[] { Meta.NumBytes() }.Concat(g.Attributes.ToEnumerable().Select(attr => attr.GetByteSize())).ToArray();
Header = BFast.BFast.CreateBFastHeader(Sizes, Names);
}
/// <summary> /// Low-level remap function. Maps faces and corners at the same time. /// In some cases, this is important (e.g. triangulating quads). /// Note: sub-geometries are lost. /// </summary> public static IGeometryAttributes RemapFacesAndCorners(this IGeometryAttributes g, IArray <int> faceRemap, IArray <int> cornerRemap, int numCornersPerFace = -1) => g.VertexAttributes() .Concat(g.NoneAttributes()) .Concat(g.FaceAttributes().Select(attr => attr.Remap(faceRemap))) .Concat(g.EdgeAttributes().Select(attr => attr.Remap(cornerRemap))) .Concat(g.CornerAttributes().Select(attr => attr.Remap(cornerRemap))) .Concat(g.WholeGeometryAttributes()) .SetFaceSizeAttribute(numCornersPerFace) .ToGeometryAttributes();
public static IGeometryAttributes FlipWindingOrder(this IGeometryAttributes g) => g.VertexAttributes() .Concat(g.NoneAttributes()) .Concat(g.FaceAttributes()) .Concat(g.EdgeAttributes().Select(attr => attr.Remap(g.IndexFlippedRemapping()))) .Concat(g.CornerAttributes().Select(attr => attr.Remap(g.IndexFlippedRemapping()))) .Concat(g.WholeGeometryAttributes()) .FlipNormalAttributes() .ToGeometryAttributes();
/// <summary>
/// Updates the vertex buffer (e.g. after identifying unwanted faces) and the index
/// buffer. Vertices are either re-ordered, removed, or deleted. Does not affect any other
/// </summary>
public static IGeometryAttributes RemapVertices(this IGeometryAttributes g, IArray <int> newVertices, IArray <int> newIndices)
=> (new[] { newIndices.ToIndexAttribute() }
.Concat(
g.VertexAttributes()
.Select(attr => attr.Remap(newVertices)))
.Concat(g.NoneAttributes())
.Concat(g.FaceAttributes())
.Concat(g.EdgeAttributes())
.Concat(g.CornerAttributes())
.Concat(g.WholeGeometryAttributes())
)
.ToGeometryAttributes();
/// <summary>
/// The vertRemap is a list of vertices in the new vertex buffer, and where they came from.
/// This could be a reordering of the original vertex buffer, it could even be a repetition.
/// It could also be some vertices were deleted, BUT if those vertices are still referenced
/// then this will throw an exception.
/// The values in the index buffer will change, but it will stay the same length.
/// </summary>
public static IGeometryAttributes RemapVertices(this IGeometryAttributes g, IArray <int> vertRemap)
{
var vertLookup = (-1).Repeat(g.NumVertices).ToArray();
for (var i = 0; i < vertRemap.Count; ++i)
{
var oldVert = vertRemap[i];
vertLookup[oldVert] = i;
}
var oldIndices = g.GetAttributeIndex()?.Data ?? g.NumVertices.Range();
var newIndices = oldIndices.Select(i => vertLookup[i]).Evaluate();
if (newIndices.Any(x => x == -1))
{
throw new Exception("At least one of the indices references a vertex that no longer exists");
}
return(g.RemapVertices(vertRemap, newIndices));
}
public static GeometryAttribute <int> GetAttributeIndex(this IGeometryAttributes self) => self.GetAttribute <int>(CommonAttributes.Index);
public static IArray <int> GetAttributeDataObjectFaceSize(this IGeometryAttributes self) => self.GetAttributeObjectFaceSize()?.Data;
public static GeometryAttribute <Vector4> GetAttributeVertexTangent(this IGeometryAttributes self) => self.GetAttribute <Vector4>(CommonAttributes.VertexTangent);
public static GeometryAttribute <Byte4> GetAttributeVertexColor8Bit(this IGeometryAttributes self) => self.GetAttribute <Byte4>(CommonAttributes.VertexColor8Bit);
public static IArray <Vector3> GetAttributeDataVertexNormal(this IGeometryAttributes self) => self.GetAttributeVertexNormal()?.Data;
public static IArray <Vector2> GetAttributeDataVertexUv(this IGeometryAttributes self) => self.GetAttributeVertexUv()?.Data;
public static IArray <Vector3> GetAttributeDataPosition(this IGeometryAttributes self) => self.GetAttributePosition()?.Data;
public static IArray <int> GetAttributeDataIndex(this IGeometryAttributes self) => self.GetAttributeIndex()?.Data;
public static GeometryAttribute <Vector3> GetAttributePosition(this IGeometryAttributes self) => self.GetAttribute <Vector3>(CommonAttributes.Position);
public static GeometryAttribute <Matrix4x4> GetAttributeInstanceTransforms(this IGeometryAttributes self) => self.GetAttribute <Matrix4x4>(CommonAttributes.InstanceTransforms);
public static GeometryAttribute <Vector2> GetAttributeVertexUv(this IGeometryAttributes self) => self.GetAttribute <Vector2>(CommonAttributes.VertexUv);
public static IArray <Matrix4x4> GetAttributeDataInstanceTransforms(this IGeometryAttributes self) => self.GetAttributeInstanceTransforms()?.Data;
public static GeometryAttribute <Vector3> GetAttributeVertexNormal(this IGeometryAttributes self) => self.GetAttribute <Vector3>(CommonAttributes.VertexNormal);
public static GeometryAttribute <int> GetAttributeInstanceGeometries(this IGeometryAttributes self) => self.GetAttribute <int>(CommonAttributes.InstanceGeometries);
public static GeometryAttribute <Vector4> GetAttributeVertexColor(this IGeometryAttributes self) => self.GetAttribute <Vector4>(CommonAttributes.VertexColor);
public static GeometryAttribute <Vector3> GetAttributeLineTangentOut(this IGeometryAttributes self) => self.GetAttribute <Vector3>(CommonAttributes.LineTangentOut);
public static IArray <Byte4> GetAttributeDataVertexColor8Bit(this IGeometryAttributes self) => self.GetAttributeVertexColor8Bit()?.Data;
public static IArray <Vector3> GetAttributeDataLineTangentOut(this IGeometryAttributes self) => self.GetAttributeLineTangentOut()?.Data;
public static IArray <Vector4> GetAttributeDataVertexTangent(this IGeometryAttributes self) => self.GetAttributeVertexTangent()?.Data;
public static GeometryAttribute <int> GetAttributeObjectFaceSize(this IGeometryAttributes self) => self.GetAttribute <int>(CommonAttributes.ObjectFaceSize);
