.\" Automatically generated by Pandoc 3.5
.\"
.TH "al_lock_vertex_buffer" "3" "" "Allegro reference manual"
.SH NAME
al_lock_vertex_buffer \- Allegro 5 API
.SH SYNOPSIS
.IP
.EX
#include \f[B]<allegro5/allegro_primitives.h>\f[R]

void* al_lock_vertex_buffer(ALLEGRO_VERTEX_BUFFER* buffer, int offset,
   int length, int flags)
.EE
.SH DESCRIPTION
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.
.PP
\f[I]Parameters:\f[R]
.IP \[bu] 2
buffer \- Vertex buffer to lock
.IP \[bu] 2
offset \- Vertex index of the start of the locked range
.IP \[bu] 2
length \- How many vertices to lock
.IP \[bu] 2
flags \- ALLEGRO_LOCK_READONLY, ALLEGRO_LOCK_WRITEONLY or
ALLEGRO_LOCK_READWRITE
.SH SINCE
5.1.3
.SH SEE ALSO
ALLEGRO_VERTEX_BUFFER(3), al_unlock_vertex_buffer(3)