Width of the rectangles border is given by the width parameter, if the width is 0.0 then the rectangle is filled.
The swf_definerect() defines a rectangle with an upper left hand coordinate given by the x, x1, and the y, y1. And a lower right hand coordinate given by the x coordinate, x2, and the y coordinate, y2. Width of the rectangles border is given by the width parameter, if the width is 0.0 then the rectangle is filled.