man do_line () - Calculates all the points along a line. Allegro game programming library.
NAME
do_line - Calculates all the points along a line. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
void do_line(BITMAP *bmp, int x1, y1, x2, y2, int d, void (*proc)(BITMAP *bmp, int x, int y, int d));
DESCRIPTION
Calculates all the points along a line from point (x1, y1) to (x2, y2), calling the supplied function for each one. This will be passed a copy of the bmp parameter, the x and y position, and a copy of the d parameter, so it is suitable for use with putpixel(). Example:
void draw_dust_particle(BITMAP *bmp, int x, int y, int d)
{
...
}
do_line(screen, 0, 0, SCREEN_W-1, SCREEN_H-2,
dust_strength, draw_dust_particle);