小编mik*_*ike的帖子

- (float)angleFromCoordinate:(CLLocationCoordinate2D)first toCoordinate:(CLLocationCoordinate2D)second {

//first is origin

//second is point

float longitudinalDifference = second.longitude - first.longitude;
float latitudinalDifference = second.latitude - first.latitude;
float possibleAzimuth = (M_PI * .5f) - atan(latitudinalDifference / longitudinalDifference);

if (longitudinalDifference > 0)
{
    return possibleAzimuth;
}
else if (longitudinalDifference < 0)
{
   return possibleAzimuth + M_PI; 
} 
else if (latitudinalDifference < 0) 
{
       return M_PI; 
    }

    return 0.0f;
}

上面的代码(取自开源ARkit项目)计算从兴趣点到原点(用户位置)的角度.给定以弧度计算的方位角(航向),在AR app im建筑物中,我可以使用以下代码检测点是否在其视口内:

- (BOOL)viewportContainsCoordinate:(ARCoordinate *)coordinate {

double centerAzimuth = self.centerCoordinate.azimuth;
double leftAzimuth = centerAzimuth - VIEWPORT_WIDTH_RADIANS …