DOKK / manpages / debian 10 / allegro5-doc / al_lock_vertex_buffer.3alleg5.en
al_lock_vertex_buffer(3alleg5) al_lock_vertex_buffer(3alleg5)

al_lock_vertex_buffer - Allegro 5 API

#include <allegro5/allegro_primitives.h>
void* al_lock_vertex_buffer(ALLEGRO_VERTEX_BUFFER* buffer, int offset,
   int length, int flags)
    

Locks a vertex buffer so you can access its data. Will return NULL if the parameters are invalid, if reading is requested from a write only buffer, or if the buffer is already locked.

Parameters:

buffer - Vertex buffer to lock
offset - Vertex index of the start of the locked range
length - How many vertices to lock
flags - ALLEGRO_LOCK_READONLY, ALLEGRO_LOCK_WRITEONLY or ALLEGRO_LOCK_READWRITE

5.1.3

ALLEGRO_VERTEX_BUFFER(3alleg5), al_unlock_vertex_buffer(3alleg5)

Allegro reference manual