VertexAttributeSetValue Method (Single, Single, Single, Single)

public void SetValue(
	float value0,
	float value1,
	float value2,
	float value3
)

Public Sub SetValue ( 
	value0 As Single,
	value1 As Single,
	value2 As Single,
	value3 As Single
)

public:
void SetValue(
	float value0, 
	float value1, 
	float value2, 
	float value3
)

member SetValue : 
        value0 : float32 * 
        value1 : float32 * 
        value2 : float32 * 
        value3 : float32 -> unit 

Parameters

value0

Type: SystemSingle
The first component value to set.

value1

Type: SystemSingle
The second component value to set.

value2

Type: SystemSingle
The third component value to set.

value3

Type: SystemSingle
The fourth component value to set.

When less than 4 float-type values are passed, the remaining components will be set to 0, except for the 4th component, which will be set to 1.

A user-defined attribute variable declared in a vertex shader can be bound to a generic attribute index using the constructor VertexAttribute(Program, Int32, String). This allows an application to use descriptive variable names in a vertex shader. A subsequent change to the specified generic vertex attribute will be immediately reflected as a change to the corresponding attribute variable in the vertex shader.

The binding between a generic vertex attribute index and a user-defined attribute variable in a vertex shader is part of the state of a program object, but the current value of the generic vertex attribute is not. The value of each generic vertex attribute is part of current state and it is maintained even if a different program object is used.

An application may freely modify generic vertex attributes that are not bound to a named vertex shader attribute variable. These values are simply maintained as part of current state and will not be accessed by the vertex shader. If a generic vertex attribute bound to an attribute variable in a vertex shader is not updated while the vertex shader is executing, the vertex shader will repeatedly use the current value for the generic vertex attribute.

Note: it is possible for an application to bind more than one attribute name to the same generic vertex attribute index. This is referred to as aliasing, and it is allowed only if just one of the aliased attribute variables is active in the vertex shader, or if no path through the vertex shader consumes more than one of the attributes aliased to the same location. OpenGL implementations are not required to do error checking to detect aliasing, they are allowed to assume that aliasing will not occur, and they are allowed to employ optimizations that work only in the absence of aliasing.

OpenGL API: glVertexAttrib4

Reference