/// <summary>
/// <para>Creates a vertex buffer that will map an array of float or vector primitives to a specified Vertex Usage and index</para>
/// </summary>
/// <param name="data"></param>
/// <param name="elementUsage"></param>
/// <param name="index"></param>
/// <returns></returns>
public static Vertices <VertexType> CreateSingleElementVertices(VertexType[] data, VertexElementUsage elementUsage, int index)
{
if (typeof(float) != typeof(VertexType) &&
typeof(Vector2) != typeof(VertexType) &&
typeof(Vector3) != typeof(VertexType) &&
typeof(Vector4) != typeof(VertexType) &&
typeof(Microsoft.Xna.Framework.Graphics.PackedVector.HalfVector2) != typeof(VertexType) &&
typeof(Microsoft.Xna.Framework.Graphics.PackedVector.HalfVector4) != typeof(VertexType))
{
throw new ArgumentException("Only float and vector types are supported for single element vertex buffers");
}
if (data == null)
{
throw new ArgumentNullException();
}
if (index >= 16 || index < 0)
{
throw new ArgumentException("index");
}
VertexElementFormat format = VertexDeclarationBuilder.DetermineFormat(typeof(VertexType));
VertexElement[] elements = new VertexElement[] { new VertexElement(0, 0, format, VertexElementMethod.Default, elementUsage, (byte)index) };
int stride = VertexElementAttribute.CalculateVertexStride(elements);
return(new Vertices <VertexType>(data, elements, stride));
}
/// <summary>
/// Computes the stride for a vertex format
/// </summary>
/// <param name="elements"></param>
/// <returns></returns>
public static int CalculateVertexStride(VertexElement[] elements)
{
int stride = 0;
for (int i = 0; i < elements.Length; i++)
{
stride = Math.Max(stride, elements[i].Offset + VertexElementAttribute.SizeOfFormatType(elements[i].VertexElementFormat));
}
return(stride);
}
/// <summary>
/// [NOT VALIDATED] Use with caution. No validation is performed by this method. Creates a vertex buffer from a raw data array, using a user specified <see cref="VertexElement"/> array.
/// </summary>
/// <param name="data"></param>
/// <param name="elements"></param>
/// <returns></returns>
/// <remarks>This method is only here to get around some limitations of the XNA content pipeline</remarks>
public static Vertices <VertexType> CreateRawDataVertices(VertexType[] data, VertexElement[] elements)
{
if (typeof(byte) != typeof(VertexType))
{
throw new ArgumentException("Only byte[] raw vertices are supported at this time");
}
if (data == null || elements == null)
{
throw new ArgumentNullException();
}
if (elements.Length == 0)
{
throw new ArgumentException();
}
int stride = VertexElementAttribute.CalculateVertexStride(elements);
return(new Vertices <VertexType>(data, elements, stride));
}
public VertexElement[] GetDeclaration(Type type)
{
lock (declarationMapping)
{
VertexElement[] mapping;
if (declarationMapping.TryGetValue(type, out mapping))
{
return(mapping);
}
if (type == typeof(Vector3)) //special case
{
mapping = new VertexElement[] { new VertexElement(0, 0, VertexElementFormat.Vector3, VertexElementMethod.Default, VertexElementUsage.Position, 0) }
}
;
if (type == typeof(Vector4))
{
mapping = new VertexElement[] { new VertexElement(0, 0, VertexElementFormat.Vector4, VertexElementMethod.Default, VertexElementUsage.Position, 0) }
}
;
if (mapping == null)
{
List <VertexElement> elements = new List <VertexElement>();
int offset = 0;
if (type.IsValueType == false)
{
throw new ArgumentException("Type " + type.Name + " is a not a ValueType (struct)");
}
foreach (FieldInfo f in type.GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance))
{
if (!f.ReflectedType.IsValueType)
{
throw new ArgumentException("Field " + type.Name + "." + f.Name + " is a not a ValueType (struct)");
}
int size = Marshal.SizeOf(f.FieldType);
bool attribSet = false;
foreach (object o in f.GetCustomAttributes(true))
{
if (o is VertexElementAttribute)
{
VertexElementAttribute att = (VertexElementAttribute)o;
VertexElementFormat format = att.VertexElementFormat;
if (format == VertexElementFormat.Unused)
{
format = DetermineFormat(f);
}
else
{
int formatSize;
if (!formatMappingSize.TryGetValue(format, out formatSize))
{
throw new ArgumentException(string.Format("Invlaid VertexElementFormat ({0}) specified in VertexElementAttribute for {1}.{2}", format, type.FullName, f.Name));
}
if (formatSize != Marshal.SizeOf(f.FieldType))
{
throw new ArgumentException(string.Format("VertexElementFormat size mismatch in {4}.{5}, {0} requires a size of {1}, specified type {2} has size {3}", format, formatSize, f.FieldType.FullName, Marshal.SizeOf(f.FieldType), type.FullName, f.Name));
}
}
elements.Add(new VertexElement(0, (short)offset, format, VertexElementMethod.Default, att.VertexElementUsage, (byte)att.UsageIndex));
attribSet = true;
break;
}
}
if (!attribSet)
{
VertexElementFormat format = DetermineFormat(f);
int index;
VertexElementUsage usage = DetermineUsage(elements, f, out index);
elements.Add(new VertexElement(0, (short)offset, format, VertexElementMethod.Default, usage, (byte)index));
}
offset += size;
}
mapping = elements.ToArray();
}
declarationMapping.Add(type, mapping);
return(mapping);
}
}
