public function getImageCornerLatLngs()
{
$corners = array();
$rotation = -$this->rotation;
$corners["ne"] = new LatLng($this->north, $this->east);
$corners["nw"] = new LatLng($this->north, $this->west);
$corners["sw"] = new LatLng($this->south, $this->west);
$corners["se"] = new LatLng($this->south, $this->east);
$projectionOrigin = new LatLng(($this->north + $this->south) / 2, ($this->east + $this->west) / 2);
$projectedMapCenter = $projectionOrigin->project($projectionOrigin);
$projectedCorners = array();
$projectedCorners["ne"] = $corners["ne"]->project($projectionOrigin);
$projectedCorners["nw"] = $corners["nw"]->project($projectionOrigin);
$projectedCorners["sw"] = $corners["sw"]->project($projectionOrigin);
$projectedCorners["se"] = $corners["se"]->project($projectionOrigin);
$projectedRotatedCorners = array();
$projectedRotatedCorners["ne"] = LinearAlgebraUtil::rotate($projectedCorners["ne"], $projectedMapCenter, $rotation);
$projectedRotatedCorners["nw"] = LinearAlgebraUtil::rotate($projectedCorners["nw"], $projectedMapCenter, $rotation);
$projectedRotatedCorners["sw"] = LinearAlgebraUtil::rotate($projectedCorners["sw"], $projectedMapCenter, $rotation);
$projectedRotatedCorners["se"] = LinearAlgebraUtil::rotate($projectedCorners["se"], $projectedMapCenter, $rotation);
$projectedRotatedCorners = array();
$projectedRotatedCorners["ne"] = LinearAlgebraUtil::rotate($projectedCorners["ne"], $projectedMapCenter, $rotation);
$projectedRotatedCorners["nw"] = LinearAlgebraUtil::rotate($projectedCorners["nw"], $projectedMapCenter, $rotation);
$projectedRotatedCorners["sw"] = LinearAlgebraUtil::rotate($projectedCorners["sw"], $projectedMapCenter, $rotation);
$projectedRotatedCorners["se"] = LinearAlgebraUtil::rotate($projectedCorners["se"], $projectedMapCenter, $rotation);
$rotatedCorners = array();
$rotatedCorners["nw"] = $projectedRotatedCorners["nw"]->deproject($projectionOrigin);
$rotatedCorners["ne"] = $projectedRotatedCorners["ne"]->deproject($projectionOrigin);
$rotatedCorners["sw"] = $projectedRotatedCorners["sw"]->deproject($projectionOrigin);
$rotatedCorners["se"] = $projectedRotatedCorners["se"]->deproject($projectionOrigin);
return $rotatedCorners;
}
private function getKmlLatLonBox($pixelImageCorners, $projectionOrigin, $inverseTransformationMatrix)
{
// translate corner pixels of map image to projected points
$projectedCorners = array();
$projectedCorners["nw"] = LinearAlgebraUtil::transformPoint($pixelImageCorners["nw"], $inverseTransformationMatrix);
$projectedCorners["ne"] = LinearAlgebraUtil::transformPoint($pixelImageCorners["ne"], $inverseTransformationMatrix);
$projectedCorners["sw"] = LinearAlgebraUtil::transformPoint($pixelImageCorners["sw"], $inverseTransformationMatrix);
$projectedCorners["se"] = LinearAlgebraUtil::transformPoint($pixelImageCorners["se"], $inverseTransformationMatrix);
// get rotation
$dx = $projectedCorners["nw"]->x - $projectedCorners["sw"]->x;
$dy = $projectedCorners["nw"]->y - $projectedCorners["sw"]->y;
$mapRotation = $dy == 0 ? 0 : -atan($dx / $dy);
// in radians
$corners = array();
$corners["nw"] = $projectedCorners["nw"]->deproject($projectionOrigin);
$corners["ne"] = $projectedCorners["ne"]->deproject($projectionOrigin);
$corners["sw"] = $projectedCorners["sw"]->deproject($projectionOrigin);
$corners["se"] = $projectedCorners["se"]->deproject($projectionOrigin);
$mapCenter = new LatLng($corners["nw"]->lat / 4 + $corners["ne"]->lat / 4 + $corners["sw"]->lat / 4 + $corners["se"]->lat / 4, $corners["nw"]->lng / 4 + $corners["ne"]->lng / 4 + $corners["sw"]->lng / 4 + $corners["se"]->lng / 4);
$projectedMapCenter = $mapCenter->project($projectionOrigin);
$projectedRotatedCorners = array();
$projectedRotatedCorners["nw"] = LinearAlgebraUtil::rotate($projectedCorners["nw"], $projectedMapCenter, $mapRotation);
$projectedRotatedCorners["ne"] = LinearAlgebraUtil::rotate($projectedCorners["ne"], $projectedMapCenter, $mapRotation);
$projectedRotatedCorners["sw"] = LinearAlgebraUtil::rotate($projectedCorners["sw"], $projectedMapCenter, $mapRotation);
$projectedRotatedCorners["se"] = LinearAlgebraUtil::rotate($projectedCorners["se"], $projectedMapCenter, $mapRotation);
$rotatedCorners = array();
$rotatedCorners["nw"] = $projectedRotatedCorners["nw"]->deproject($projectionOrigin);
$rotatedCorners["ne"] = $projectedRotatedCorners["ne"]->deproject($projectionOrigin);
$rotatedCorners["sw"] = $projectedRotatedCorners["sw"]->deproject($projectionOrigin);
$rotatedCorners["se"] = $projectedRotatedCorners["se"]->deproject($projectionOrigin);
// get latlng bounding box
$box = new KmlLatLonBox();
$box->north = max($rotatedCorners["nw"]->lat, $rotatedCorners["ne"]->lat, $rotatedCorners["sw"]->lat, $rotatedCorners["se"]->lat);
$box->south = min($rotatedCorners["nw"]->lat, $rotatedCorners["ne"]->lat, $rotatedCorners["sw"]->lat, $rotatedCorners["se"]->lat);
$box->east = max($rotatedCorners["nw"]->lng, $rotatedCorners["ne"]->lng, $rotatedCorners["sw"]->lng, $rotatedCorners["se"]->lng);
$box->west = min($rotatedCorners["nw"]->lng, $rotatedCorners["ne"]->lng, $rotatedCorners["sw"]->lng, $rotatedCorners["se"]->lng);
$box->rotation = $mapRotation;
// still in radians, will get converted to degrees later on
return $box;
}
