imagesetbrush() sets the brush
image to be used by all line drawing functions (such as
imageline() and
imagepolygon()) when drawing with
the special colors IMG_COLOR_BRUSHED
or IMG_COLOR_STYLEDBRUSHED.
注: You need not take special action when you are finished with a brush, but if you destroy the brush image, you must not use the IMG_COLOR_BRUSHED or IMG_COLOR_STYLEDBRUSHED colors until you have set a new brush image!
注: This function was added in PHP 4.0.6