获取五角星的顶点坐标

获取五角星的坐标

//获取十个点得坐标:从最上面顺时针

radius:半径

center:中心点坐标

CGFloat radius = 130;

CGFloat angle = 2 * M_PI / 5;

CGPoint center=CGPointMake(160, 240);

NSMutableArray *arrayM = [NSMutableArray arrayWithCapacity:10];

 for (NSInteger i = 0; i < 10; i++) {

 if (i%2 == 0) {

            // cosf()返回参数的余弦值

            CGFloat x = cosf(i/2 * angle - M_PI_2) * radius;

            // sinf()返回参数的正弦值

            CGFloat y = sinf(i/2 * angle - M_PI_2) * radius;

            CGPoint point = CGPointMake(x+ center.x, y+ center.y);

            [arrayM addObject:[NSValue valueWithCGPoint:point]];

        }else

        {

            CGFloat l = radius*(sinf(15/180.0*M_PI)/sinf(135/180.0*M_PI));

            CGFloat x = cosf(i/2 * angle + 1/6.0*M_PI - M_PI_2) * l;

            // sinf()返回参数的正弦值

            CGFloat y = sinf(i/2 * angle + 1/6.0*M_PI - M_PI_2) * l;

            CGPoint point = CGPointMake(x+ center.x, y+ center.y);

            [arrayM addObject:[NSValue valueWithCGPoint:point]];

        }

 }

获取五个点坐标画五角星(交叉获取)

//画图时直接用这五个点就可以画图(交叉连接)

CGFloat radius = 130;

CGFloat angle = 4 * M_PI / 5;

CGPoint center=CGPointMake(160, 240);

NSMutableArray *arrayM = [NSMutableArray arrayWithCapacity:5];

for (NSInteger i = 0; i < 5; i++) {

// cosf()返回参数的余弦值

CGFloat x = cosf(i/2 * angle - M_PI_2) * radius;

// sinf()返回参数的正弦值

CGFloat y = sinf(i/2 * angle - M_PI_2) * radius;

CGPoint point = CGPointMake(x+ center.x, y+ center.y);

[arrayM addObject:[NSValue valueWithCGPoint:point]];  

}

//将NSValue类型转换成CGPoint

CGPoint point = [value CGPointValue];