glVertexAttrib

glVertexAttrib is a function in OpenGL that enables the configuration and use of vertex attributes. Vertex attributes are pieces of data, such as position, color, or texture coordinates, that are passed from the application to the vertex shader. The function specifies the index of the vertex attribute to be modified, the number of components it contains, its data type, whether it should be normalized, and the stride and offset for accessing the data within the vertex array.

The index parameter identifies which vertex attribute is being configured. This index corresponds to the attribute location specified in the vertex shader program. The size parameter determines how many components make up the attribute (e.g., 1 for a single value, 2 for a 2D vector, 3 for a 3D vector, or 4 for a 4D vector). The type parameter specifies the data type of each component, such as GL_FLOAT, GL_INT, or GL_UNSIGNED_BYTE.

The normalized parameter indicates whether fixed-point data values should be automatically normalized to the range [-1, 1] or [0, 1] when converted to floating-point. The stride parameter defines the byte offset between consecutive vertex attributes of the same type in the vertex buffer. The pointer parameter specifies the offset of the first component of the vertex attribute in the first vertex. glVertexAttribPointer is often used in conjunction with glVertexAttrib to define how vertex data is laid out in memory. These functions are fundamental for sending custom data to the GPU for rendering.