Defines the vertex data layout. Each vertex can contain one or more data types, and each data type is described by a vertex element.
- uint16_t stream
- Stream number.
- uint16_t offset
- Offset from the beginning of the vertex data to the data associated with the particular data type.
- char type
- The data type, specified as a D3DDECLTYPE. One of several predefined types that define the data size. Some methods have an implied type.
- char method
- The method specifies the tessellator processing, which determines how the tessellator interprets (or operates on) the vertex data. For more information, see D3DDECLMETHOD.
- char usage
- Defines what the data will be used for; that is, the interoperability between vertex data layouts and vertex shaders.
- char usageIndex
- Modifies the usage data to allow the user to specify multiple usage types.
- int rwDecl
Defines what the data will be used for; that is, the interoperability between vertex data layouts and vertex shaders.
Each usage acts to bind a vertex declaration to a vertex shader. In some cases, they have a special interpretation. For example, an element that specifies D3DDECLUSAGE_NORMAL or D3DDECLUSAGE_POSITION is used by the N - patch tessellator to set up tessellation. See D3DDECLUSAGE for a list of the available semantics. D3DDECLUSAGE_TEXCOORD can be used for user - defined fields (which don't have an existing usage defined).