Access byte arrays as arrays of vertex attributes.
Use create_attribute to create an attribute accessor given a simple format string. Alternatively, the classes may be constructed directly.
An attribute format string specifies the format of a vertex attribute. Format strings are accepted by the create_attribute function as well as most methods in the pyglet.graphics module.
Format strings have the following (BNF) syntax:
attribute ::= ( name | index 'g' 'n'? | texture 't' ) count type
name describes the vertex attribute, and is one of the following constants for the predefined attributes:
You can alternatively create a generic indexed vertex attribute by specifying its index in decimal followed by the constant g. For example, 0g specifies the generic vertex attribute with index 0. If the optional constant n is present after the g, the attribute is normalised to the range [0, 1] or [-1, 1] within the range of the data type.
Texture coordinates for multiple texture units can be specified with the texture number before the constant ‘t’. For example, 1t gives the texture coordinate attribute for texture unit 1.
count gives the number of data components in the attribute. For example, a 3D vertex position has a count of 3. Some attributes constrain the possible counts that can be used; for example, a normal vector must have a count of 3.
type gives the data type of each component of the attribute. The following types can be used:
Some attributes constrain the possible data types; for example, normal vectors must use one of the signed data types. The use of some data types, while not illegal, may have severe performance concerns. For example, the use of GLdouble is discouraged, and colours should be specified with GLubyte.
Whitespace is prohibited within the format string.
Some examples follow:
AbstractAttribute | Abstract accessor for an attribute in a mapped buffer. |
ColorAttribute | Color vertex attribute. |
EdgeFlagAttribute | Edge flag attribute. |
FogCoordAttribute | Fog coordinate attribute. |
GenericAttribute | Generic vertex attribute, used by shader programs. |
MultiTexCoordAttribute | Texture coordinate attribute. |
NormalAttribute | Normal vector attribute. |
SecondaryColorAttribute | Secondary color attribute. |
TexCoordAttribute | Texture coordinate attribute. |
VertexAttribute | Vertex coordinate attribute. |
create_attribute(format) | Create a vertex attribute description from a format string. |
interleave_attributes(attributes) | Interleave attribute offsets. |
serialize_attributes(count, attributes) | Serialize attribute offsets. |
str(object=’‘) -> string
Return a nice string representation of the object. If the argument is a string, the return value is the same object.
Defined