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;

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

       • format indicates the pixel format of the data.

       • 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).

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

SEE ALSO

       al_lock_bitmap(3alleg5),     al_lock_bitmap_region(3alleg5),    al_unlock_bitmap(3alleg5),
       ALLEGRO_PIXEL_FORMAT(3alleg5)