php - 判断坐标是否在区域内(MKMapView，PHP求解)

Question

我正在使用 MKMapView 并将我的 php 程序发送到可见区域(中心纬度、中心经度、跨度纬度、跨度经度)。我需要使用 php 确定坐标是否在该区域内。我希望某处有一个标准公式，但我还没有找到。我会继续尝试想出一个公式，但它出奇地复杂(希望不像半正弦那么复杂，我不相信我自己能弄清楚)。

Answer 1

让我们试试这个逻辑

$topRightLongitude = $centerLongitude + $spanLongitude/2;
if($topRightLongitude > 180 and ($pointLongitude < 0))
    $topRightLongitude = $topRightLongitude - 360; // (180*2) - positive becomes negative

$bottomLeftLongitude = $centerLongitude - $spanLongitude/2;
if($bottomLeftLongitude< -180 and ($pointLongitude > 0))
    $bottomLeftLongitude= 360 + $bottomLeftLongitude; // now is negative and will become positive

$topRightLatitude = $centerLatitude + $spanLatitude/2;
if($topRightLatitude > 90 and ($pointLatitude < 0))
    $topRightLatitude = $topRightLatitude - 180; // (90*2) - positive becomes negative

$bottomLeftLatitude = $centerLatitude - $spanLatitude/2;
if($bottomLeftLatitude< -90 and ($pointLatitude > 0))
    $bottomLeftLatitude= 180 + $bottomLeftLongitude; // now is negative and will become positive

如果你有

$centerLongitude = 179;
$spanLongitude = 20;
$pointLongitude = -179;

结果

$topRightLongitude = -171;
$bottomLeftLongitude = 169;

所以你的意思是如果你这样测试:

if($pointLongitude < $topRightLongitude &&
    $pointLongitude > $bottomLeftLongitude &&
    $pointLatitude < $topRightLatitude &&
    $pointLatitude > $bottomLeftLatitude){
    echo 'in';
}else{
    echo 'out';
}