Graphics.GL.Low.VertexAttrib

Documentation

To feed vertices into the vertex shader, the layout of a vertex must be specified in the current VAO for the current shader program. Make a list of LayoutElements and use setVertexLayout on it as seen below.

setVertexLayout
  [ Attrib "position"  3 GLFloat   -- first 12 bytes maps to: in vec3 position;
  , Attrib "shininess" 1 GLFloat   -- next 4 bytes maps to:   in float shininess;
  , Attrib "texcoord"  2 GLFloat   -- next 8 bytes maps to:   in vec2 texcoord;
  , Unused 2                       -- next 2 bytes ignored
  , Attrib "seed"      1 GLShort ] -- next 2 bytes maps to:   in float seed; bytes are treated as 16-bit signed int

In this example four mappings are established between the current shader and the current VBO. The information is stored in the current VAO.

setVertexLayout :: [LayoutElement] -> IO ()

This configures the currently bound VAO. It calls glVertexAttribPointer and glEnableVertexAttribArray.

data LayoutElement

The name of a vertex input to a program combined with the component format and number of components for that attribute in the vertex data. Alternatively the size of an unused section of the data in bytes.

Constructors

Attrib String Int DataType

Name, component count and component format of a vertex attribute.

Unused Int

Size in bytes of an unused section of the vertex data.

Instances

Show LayoutElement

data DataType

The size and interpretation of a vertex attribute component.

Constructors

GLFloat

4-byte float

GLByte

signed byte

GLUnsignedByte

unsigned byte

GLShort

2-byte signed integer

GLUnsignedShort

2-byte unsigned integer

GLInt

4-byte signed integer

GLUnsignedInt

4-byte unsigned integer

Instances

Eq DataType

Show DataType

ToGL DataType