/// <summary>
/// Function to normalize the offsets in the element list.
/// </summary>
public void NormalizeOffsets()
{
int lastOffset = 0;
for (int i = 0; i < _elements.Length - 1; i++)
{
_elements[i] = new GorgonInputElement(_elements[i], lastOffset);
lastOffset += _elements[i].Size;
}
}
/// <summary>
/// Function to determine if an element already exists with the same context, index and slot.
/// </summary>
/// <param name="element"></param>
private void FindDuplicateElements(GorgonInputElement element)
{
if (_elements.Any(
elementItem =>
!string.IsNullOrWhiteSpace(elementItem.Context) &&
((element.Offset == elementItem.Offset) ||
(string.Equals(element.Context, elementItem.Context, StringComparison.OrdinalIgnoreCase))) &&
element.Index == elementItem.Index && element.Slot == elementItem.Slot))
{
throw new ArgumentException(
string.Format(Resources.GORGFX_LAYOUT_ELEMENT_IN_USE, element.Offset, element.Context), "element");
}
}
/// <summary>
/// Function to retrieve the input layout from a specific type.
/// </summary>
/// <param name="type">Type of retrieve layout info from.</param>
/// <remarks>Use this to create an input element layout from a type. Properties and fields in this type must be marked with the <see cref="GorgonLibrary.Graphics.InputElementAttribute">GorgonInputElementAttribute</see> in order for the element list to consider it and those fields or properties must be public.
/// <para>Fields/properties marked with the attribute must be either a (u)byte, (u)short, (u)int, (u)long, float or one of the Vector2/3/4D types.</para>
/// </remarks>
/// <exception cref="System.ArgumentNullException">Thrown when the <paramref name="type"/> parameter is NULL (Nothing in VB.Net).</exception>
/// <exception cref="GorgonLibrary.GorgonException">Thrown if a field/property type cannot be mapped to a <see cref="GorgonLibrary.Graphics.BufferFormat">GorgonBufferFormat</see>.</exception>
internal void InitializeFromType(Type type)
{
IList <MemberInfo> members = type.GetMembers();
int byteOffset = 0;
if (type == null)
{
throw new ArgumentNullException("type");
}
// Get only properties and fields, and sort by explicit ordering (then by offset).
var propertiesAndFields = (from member in members
let memberAttribute =
member.GetCustomAttributes(typeof(InputElementAttribute), true) as
IList <InputElementAttribute>
where
((member.MemberType == MemberTypes.Property) ||
(member.MemberType == MemberTypes.Field)) &&
((memberAttribute != null) && (memberAttribute.Count > 0))
orderby memberAttribute[0].ExplicitOrder, memberAttribute[0].Offset
select new
{
member.Name,
ReturnType =
(member is FieldInfo
? ((FieldInfo)member).FieldType
: ((PropertyInfo)member).PropertyType),
Attribute = memberAttribute[0]
}).ToArray();
_elements = new GorgonInputElement[propertiesAndFields.Length];
for (int i = 0; i < _elements.Length; i++)
{
var item = propertiesAndFields[i];
BufferFormat format = item.Attribute.Format;
string contextName = item.Attribute.Context;
// Try to determine the format from the type.
if (format == BufferFormat.Unknown)
{
if (!_typeMapping.ContainsKey(item.ReturnType))
{
throw new GorgonException(GorgonResult.CannotCreate,
string.Format(Resources.GORGFX_LAYOUT_INVALID_ELEMENT_TYPE,
item.ReturnType.FullName));
}
format = _typeMapping[item.ReturnType];
}
// Determine the context name from the field name.
if (string.IsNullOrEmpty(contextName))
{
contextName = item.Name;
}
var element = new GorgonInputElement(contextName, format,
(item.Attribute.AutoOffset ? byteOffset : item.Attribute.Offset),
item.Attribute.Index, item.Attribute.Slot, item.Attribute.Instanced,
item.Attribute.InstanceCount);
FindDuplicateElements(element);
_elements[i] = element;
byteOffset += element.Size;
}
UpdateVertexSize();
}
