man hline (3): Draws a horizontal line onto the bitmap. Allegro game programming library.

hline(3) Draws a horizontal line onto the bitmap. Allegro game programming library.

SYNOPSIS

#include <allegro.h>

void hline(BITMAP *bmp, int x1, int y, int x2, int color);

Draws a horizontal line onto the bitmap, from point (x1, y) to (x2, y).

Note: hline() is implemented as an alias to another function. See ALLEGRO_NO_VHLINE_ALIAS in the `Differences between platforms' section for details.