In computer graphics, a drop shadow is a visual effect consisting of drawing that looks like the shadow of an object, giving the impression that the object is raised above the objects behind it. The drop shadow is often used for elements of a graphical user interface such as windows or menus, and for simple text. The text label for icons on desktops in many desktop environments has a drop shadow, as this effect effectively distinguishes the text from any colored background it may be in front of.
A simple way of drawing a drop shadow of a rectangular object is to draw a gray or black area underneath and offset from the object. In general, a drop shadow is a copy in black or gray of the object, drawn in a slightly different position. Realism may be increased by:
- Darkening the colors of the pixels where the shadow casts instead of making them gray. This can be done with alpha blending the shadow with the area it is cast on.
- Softening the edges of the shadow. This can be done by adding Gaussian blur to the shadow's alpha channel before blending.
Famous quotes containing the words drop and/or shadow:
“See, see where Christ’s blood streams in the firmament!
One drop would save my soul—half a drop! ah, my Christ!—
Ah, rend not my heart for naming of my Christ!—
Yet will I call on him!—O, spare me, Lucifer!—
Where is it now? ‘T is gone; and see where God
Stretcheth out his arm, and bends his ireful brows!—
Mountains and hills, come, come and fall on me,
And hide me from the heavy wrath of God!”
—Christopher Marlowe (1564–1593)
“A beautiful person among the Greeks, was thought to betray by this sign some secret favor of the immortal gods; and we can pardon pride, when a woman possesses such a figure that wherever she stands, or moves, or leaves a shadow on the wall, or sits for a portrait to the artist, she confers a favor on the world.”
—Ralph Waldo Emerson (1803–1882)