VAO

class demosys.opengl.VAO(name, mode=4)

Represents a vertex array object. A name must be provided for debug puporses. The default draw mode is moderngl.TRIANGLES

Methods

VAO.buffer(buffer, buffer_format:str, attribute_names, per_instance=False)

Register a buffer/vbo for the VAO. This can be called multiple times. adding multiple buffers (interleaved or not)

Parameters:
  • buffer – The buffer object. Can be ndarray or Buffer
  • buffer_format – The format of the buffer (‘f’, ‘u’, ‘i’)
Returns:

The buffer object
VAO.index_buffer(buffer, index_element_size=4)

Set the index buffer for this VAO

Parameters:
  • buffer – Buffer object or ndarray
  • index_element_size – Byte size of each element. 1, 2 or 4
VAO.subroutines(shader, routines:tuple)

Set the active subroutines

VAO.release()

Destroy the vao object and its buffers

Draw Methods

VAO.draw(shader:ShaderProgram, mode=None, vertices=-1, first=0, instances=1)

Draw the VAO. Will use glDrawElements if an element buffer is present and glDrawArrays if no element array is present.

Parameters:
  • shader – The shader to draw with
  • mode – Override the draw mode (GL_TRIANGLES etc)
  • vertices – The number of vertices to transform
  • first – The index of the first vertex to start with
  • instances – The number of instances
VAO.transform(shader, buffer:Buffer, mode=None, vertices=-1, first=0, instances=1)

Transform vertices. Stores the output in a single buffer.

Parameters:
  • buffer – The buffer to store the output
  • mode – Draw mode (for example POINTS
  • vertices – The number of vertices to transform
  • first – The index of the first vertex to start with
  • instances – The number of instances
Returns: