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ALLEGRO_LOCKED_REGION(3)                              ALLEGRO_LOCKED_REGION(3)

NAME
       ALLEGRO_LOCKED_REGION - Allegro 5 API

SYNOPSIS

              #include <allegro5/allegro.h>

              typedef struct ALLEGRO_LOCKED_REGION ALLEGRO_LOCKED_REGION;

DESCRIPTION
       Users who wish to manually edit or read from a bitmap are required to
       lock it first.  The ALLEGRO_LOCKED_REGION structure represents the
       locked region of the bitmap.  This call will work with any bitmap,
       including memory bitmaps.

              typedef struct ALLEGRO_LOCKED_REGION {
                  void *data;
                  int format;
                  int pitch;
                  int pixel_size;
              } ALLEGRO_LOCKED_REGION;

       o data points to the leftmost pixel of the first row (row 0) of the
         locked region.

       o format indicates the pixel format of the data.

       o pitch gives the size in bytes of a single row (also known as the
         stride).  The pitch may be greater than width * pixel_size due to
         padding; this is not uncommon.  It is also not uncommon for the pitch
         to be negative (the bitmap may be upside down).

       o pixel_size is the number of bytes used to represent a single pixel.

SEE ALSO
       al_lock_bitmap(3), al_lock_bitmap_region(3), al_unlock_bitmap(3),
       ALLEGRO_PIXEL_FORMAT(3)

Allegro reference manual                              ALLEGRO_LOCKED_REGION(3)