boxaAddBox

boxaAddBox is a function in the Leptonica image processing library that appends a bounding box to a Boxa, a dynamic array structure used to store multiple BOX records. It is commonly employed after region detection to collect bounding boxes for further analysis or processing.

The signature is typically BOXA boxaAddBox(BOXA boxa, BOX box, l_int32 copyflag); where:

- boxa is the target Boxa to which the box will be added.

- box is the BOX to add.

- copyflag specifies how the box is added, usually L_COPY to add a copy of the box, or L_NOCOPY to store the pointer directly.

Behavior and semantics:

- The function appends the provided box to the end of the Boxa, resizing the internal storage as needed.

- If copyflag is L_COPY, a duplicate of the box is created and stored; if L_NOCOPY, the original box pointer is stored.

- If either boxa or box is NULL, the function returns NULL to indicate an error.

Return value:

- On success, returns the (possibly reallocated) boxa pointer containing the new box.

- On failure, returns NULL and may set an error condition in the Leptonica error system.

Usage considerations:

- Copy semantics: using L_COPY ensures the Boxa owns its own copy of the box, avoiding side effects from later modifications to the original box.

- Memory management: when using L_COPY, the caller is responsible for freeing the original box if it was dynamically allocated; when using L_NOCOPY, the Boxa assumes responsibility for the stored pointer.

See also: boxaCreate, boxaGetBox, boxaGetCount, boxaReplaceBox, and other Boxa management routines.

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