.\" Automatically generated by Pandoc 2.9.2.1
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.TH "al_lock_vertex_buffer" "3alleg5" "" "Allegro reference manual" ""
.hy
.SH NAME
.PP
al_lock_vertex_buffer - Allegro 5 API
.SH SYNOPSIS
.IP
.nf
\f[C]
#include <allegro5/allegro_primitives.h>

void* al_lock_vertex_buffer(ALLEGRO_VERTEX_BUFFER* buffer, int offset,
   int length, int flags)
\f[R]
.fi
.SH DESCRIPTION
.PP
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
.PP
5.1.3
.SH SEE ALSO
.PP
ALLEGRO_VERTEX_BUFFER(3alleg5), al_unlock_vertex_buffer(3alleg5)