如何在 Flutter Qibla 中找到 Qibla 角度答案

【问题标题】：how to find Qibla angle in Flutter Qibla如何在 Flutter Qibla 中找到 Qibla 角度
【发布时间】：2021-07-01 04:09:04
【问题描述】：

#这是我当前获取角度的代码，但这是十进制值，我想从 1 度到 360 度获取角度#

最终qiblahDirection = 快照.data; var _angle = ((qiblahDirection.qiblah ?? 0) * (pi / 180) * -1

【问题讨论】：

标签： flutter flutter-layout flutter-dependencies flutter-animation flutter-test

【解决方案1】：

double calculateQiblaDirection(Coordinates coordinates) {
    // Equation from "Spherical Trigonometry For the use of colleges and schools" page 50
    final longitudeDelta =
        radians(makkah.longitude) - radians(coordinates.longitude);
    final latitudeRadians = radians(coordinates.latitude);
    final term1 = sin(longitudeDelta);
    final term2 = cos(latitudeRadians) * tan(radians(makkah.latitude));
    final term3 = sin(latitudeRadians) * cos(longitudeDelta);

    final angle = atan2(term1, term2 - term3);
    return DoubleUtil.unwindAngle(degrees(angle));
  }


class DoubleUtil {
  static double normalizeWithBound(double value, double max) {
    return value - (max * ((value / max).floorToDouble()));
  }

  static double unwindAngle(double value) {
    return normalizeWithBound(value, 360);
  }

  static double closestAngle(double angle) {
    if (angle >= -180 && angle <= 180) {
      return angle;
    }
    return angle - (360 * (angle / 360).roundToDouble());
  }
}

【讨论】：