---
name: "do_line"
section: "3alleg"
platform: "linux"
package: "liballegro-doc"
version: "2:4.2.2-2.2"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/do_line"
---

# do\_line(3alleg)

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);
```

## SEE ALSO

[**do\_circle**(3alleg)](/do_circle/3alleg.md), [**do\_ellipse**(3alleg)](/do_ellipse/3alleg.md), [**do\_arc**(3alleg)](/do_arc/3alleg.md), [**line**(3alleg)](/line/3alleg.md)