圆心在原点，半径为R的第一个4分圆的Bresenham画圆算法程序，将该算法程序推广到任一四分圆，从而形成一般的Bresenham画圆算法。并利用Bresenham画圆算法画出一个圆心在点(xc,yc), 半径为R, 圆周颜色为color的圆-Center in the basics of radius R for the first four hours round the Bresenham algorithm Circle procedures, procedures for the pr