这个例子是从Allegro V3.12的例程包中移植过来的,原文件为examples\\ex4.c

原作者是Shawn Hargreaves.这个程序示范怎样操作调色板,它把一套同

心的圆画在屏幕上并且通过循环调色板产生奇妙的特效.-this example from the routines Allegro V3.12 package transplant, the original document examples \\ ex4.c Shawn Hargreaves is the original author. This procedure demonstrated how to operate a palette, with a set of concentric circular painting on the screen through the cycle and have a wonderful palette of effects.