Cogl.Primitive.new_p3
Description: Reference for Cogl.Primitive.new_p3

### Constructor

# Cogl Primitivenew_p3

#### Declaration [src]

    CoglPrimitive*
    cogl_primitive_new_p3 (
      CoglContext* context,
      CoglVerticesMode mode,
      int n_vertices,
      const CoglVertexP3* data
    )

#### Description [src]

Provides a convenient way to describe a primitive, such as a single triangle strip or a triangle fan, that will internally allocate the necessary `CoglAttributeBuffer` storage, describe the position attribute with a `CoglAttribute` and upload your data.

For example to draw a convex polygon you can do:

    CoglVertexP3 triangle[] =
    {
      { 0,   300, 0 },
      { 150, 0,   0 },
      { 300, 300, 0 }
    };
    prim = cogl_primitive_new_p3 (COGL_VERTICES_MODE_TRIANGLE_FAN,
                                  3, triangle);
    cogl_primitive_draw (prim);

The value passed as `n_vertices` is initially used to determine how much can be read from `data` but it will also be used to update the `CoglPrimitive` `n_vertices` property as if `cogl_primitive_set_n_vertices()` were called. This property defines the number of vertices to read when drawing.

The primitive API doesn’t support drawing with sliced textures (since switching between slices implies changing state and so that implies multiple primitives need to be submitted). If your hardware doesn’t support non-power of two textures (For example you are using GLES 1.1) then you will need to make sure your assets are resized to a power-of-two size (though they don’t have to be square).

#### Parameters

`context`

  Type: `CoglContext`

  A `CoglContext`.

  The data is owned by the caller of the function.

`mode`

  Type: `CoglVerticesMode`

  A `CoglVerticesMode` defining how to draw the vertices.

`n_vertices`

  Type: `int`

  The number of vertices to read from `data` and also the number of vertices to read when later drawing.

`data`

  Type: An array of `None`

  An array of `CoglVertexP3` vertices.

  The length of the array is specified in the `n_vertices` argument.
  The data is owned by the caller of the function.

#### Return value

Type: `CoglPrimitive`

A newly allocated `CoglPrimitive` with a reference of 1. This can be freed using g_object_unref().

The caller of the function takes ownership of the data, and is responsible for freeing it.