1ALLEGRO_LOCKED_REGION(3)   Library Functions Manual   ALLEGRO_LOCKED_REGION(3)
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NAME

6       ALLEGRO_LOCKED_REGION
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SYNOPSIS

9              #include <allegro5/allegro.h>
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11              typedef struct ALLEGRO_LOCKED_REGION ALLEGRO_LOCKED_REGION;
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DESCRIPTION

14       Users  who  wish to manually edit or read from a bitmap are required to
15       lock it first.   The  ALLEGRO_LOCKED_REGION  structure  represents  the
16       locked  region  of  the  bitmap.   This call will work with any bitmap,
17       including memory bitmaps.
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19              typedef struct ALLEGRO_LOCKED_REGION {
20                  void *data;
21                  int format;
22                  int pitch;
23                  int pixel_size;
24              } ALLEGRO_LOCKED_REGION;
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26       · data points to the leftmost pixel of the first row  (row  0)  of  the
27         locked region.
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29       · format indicates the pixel format of the data.
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31       · pitch  gives  the  size  in  bytes of a single row (also known as the
32         stride).  The pitch may be greater  than  width * pixel_size  due  to
33         padding; this is not uncommon.  It is also not uncommon for the pitch
34         to be negative (the bitmap may be upside down).
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36       · pixel_size is the number of bytes used to represent a single pixel.
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SEE ALSO

39       al_lock_bitmap(3), al_lock_bitmap_region(3), al_unlock_bitmap(3), ALLE‐
40       GRO_PIXEL_FORMAT(3)
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44Allegro reference manual                              ALLEGRO_LOCKED_REGION(3)
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