man is_linear_bitmap () - Tells if a bitmap is linear. Allegro game programming library.
NAME
is_linear_bitmap - Tells if a bitmap is linear. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
int is_linear_bitmap(BITMAP *bmp);
DESCRIPTION
Returns TRUE if bmp is a linear bitmap, i.e. a bitmap that can be accessed linearly within each scanline (for example a memory bitmap, the DOS VGA or SVGA screen, Windows bitmaps, etc). Linear bitmaps can be used with the _putpixel(), _getpixel(), bmp_write_line(), and bmp_read_line() functions.
Historically there were only linear and planar bitmaps for Allegro, so is_linear_bitmap() is actually an alias for !is_planar_bitmap().