Primitive.p2t2

Provides a convenient way to describe a primitive, such as a single triangle strip or a triangle fan, that will internally allocate the necessary AttributeBuffer storage, describe the position and texture coordinate attributes with Attribute<!-- -->s and upload your data.

For example to draw a convex polygon with texture mapping you can do:

CoglVertexP2T2 triangle[] =
{
  { 0,   300,  0.0, 1.0},
  { 150, 0,    0.5, 0.0},
  { 300, 300,  1.0, 1.0}
};
prim = cogl_primitive_new_p2t2 (COGL_VERTICES_MODE_TRIANGLE_FAN,
                                3, triangle);
cogl_primitive_draw (prim);

The value passed as data.length is initially used to determine how much can be read from data but it will also be used to update the Primitive <structfield>n_vertices</structfield> property as if set_n_vertices were called. This property defines the number of vertices to read when drawing.

<note>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). You should pass the cogl_texture_no_slicing flag to all textures that might be used while drawing with this API. 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)</note>

Parameters:

context	A Context
mode	A VerticesMode defining how to draw the vertices
data	(type Cogl.VertexP2T2): An array of VertexP2T2 vertices
n_vertices	The number of vertices to read from data and also the number of vertices to read when later drawing.

Returns:

A newly allocated Primitive with a reference of 1. This can be freed using cogl_object_unref.