Creating and using 32 bit RGBA sprites.
This program demonstrates how to use the 32 bit RGBA
translucency functions to store an alpha channel along with
a bitmap graphic. Two images are loaded from disk. One will
be used for the background and the other as a sprite. The
example generates an alpha channel for the sprite image,
composing the 32 bit RGBA bitmap during runtime, and draws
it at the position of the mouse cursor.