export function getFrustumPlanes()

in modules/core/src/utils/math-utils.js [39:118]
66 lines of code
2 McCabe index (conditional complexity)

export function getFrustumPlanes({aspect, near, far, fovyRadians, position, direction, up, right}) {
  cameraDirection.copy(direction);

  // Account for any scaling of the z axis (e.g. in
  // mercator view matrix)
  const nearFarScale = 1 / cameraDirection.len();
  cameraDirection.normalize();

  cameraPosition.copy(position);

  cameraUp.copy(up);
  // Account for scaling of the xy axis
  const widthScale = 1 / cameraUp.len();
  cameraUp.normalize();
  cameraRight.copy(right).normalize();

  const nearHeight = 2 * Math.tan(fovyRadians / 2) * near * widthScale;
  const nearWidth = nearHeight * aspect;

  nearCenter
    .copy(cameraDirection)
    .scale(near * nearFarScale)
    .add(cameraPosition);
  farCenter
    .copy(cameraDirection)
    .scale(far * nearFarScale)
    .add(cameraPosition);

  let normal = cameraDirection.clone().negate();
  let distance = normal.dot(nearCenter);

  const planes = {
    near: {
      distance,
      normal
    },
    far: {
      distance: cameraDirection.dot(farCenter),
      normal: cameraDirection.clone()
    }
  };

  a.copy(cameraRight)
    .scale(nearWidth * 0.5)
    .add(nearCenter)
    .subtract(cameraPosition)
    .normalize();
  normal = new Vector3(a).cross(cameraUp);
  distance = cameraPosition.dot(normal);
  planes.right = {normal, distance};

  a.copy(cameraRight)
    .scale(-nearWidth * 0.5)
    .add(nearCenter)
    .subtract(cameraPosition)
    .normalize();
  normal = new Vector3(cameraUp).cross(a);
  distance = cameraPosition.dot(normal);
  planes.left = {normal, distance};

  a.copy(cameraUp)
    .scale(nearHeight * 0.5)
    .add(nearCenter)
    .subtract(cameraPosition)
    .normalize();
  normal = new Vector3(cameraRight).cross(a);
  distance = cameraPosition.dot(normal);
  planes.top = {normal, distance};

  a.copy(cameraUp)
    .scale(-nearHeight * 0.5)
    .add(nearCenter)
    .subtract(cameraPosition)
    .normalize();
  normal = new Vector3(a).cross(cameraRight);
  distance = cameraPosition.dot(normal);
  planes.bottom = {normal, distance};

  return planes;
}