Actionscript Cookbook

4.1. Drawing a Line

Problem

You want to draw a line using ActionScript.

Solution

Use the lineStyle( ) method to specify the thickness, color, and transparency of the line. Then use the lineTo( ) method to draw a line from the current pen position to a destination point.

Discussion

Before you can draw anything using ActionScript, you need to tell Flash what kind of line style to use. The line style consists of the line’s thickness, color, and alpha value (opacity), and you can set these values using the lineStyle( ) method on the movie clip in which you wish to draw. The line’s thickness should be specified in pixels, but any value less than 1 draws lines with hairline thickness. Color values should be specified as numbers, as explained in the Introduction to ???. The alpha value should be anywhere from 0 (completely transparent) to 100 (completely opaque).

// Set a 1-pixel, blue, completely opaque line style.
myMovieClip_mc.lineStyle(1, 0x0000FF, 100);

The most basic type of drawing that you can do with ActionScript is drawing a straight line. Flash uses the current pen position as the starting point, so you need to provide only the coordinates of the destination point. Use the MovieClip.lineTo( ) method to create a line from the current pen position to the specified destination point:

// Draws a line from the current pen position to (100,100) within the coordinate
// system of myMovieClip_mc.
myMovieClip_mc.lineTo(100, 100);

When you use ActionScript methods to draw, all the ...