Fix handling of MultiPolygon objects

This commit is contained in:
2024-08-17 23:57:25 +10:00
parent 3718378545
commit 7436c808e3
2 changed files with 44 additions and 19 deletions

File diff suppressed because one or more lines are too long

View File

@@ -38,6 +38,24 @@ fetch("wards_withboundaries.json")
"north": undefined
}
function addToBounds(coordinate) {
if (bounds.west == undefined || coordinate[0] < bounds.west) {
bounds.west = coordinate[0];
}
if (bounds.south == undefined || coordinate[1] < bounds.south) {
bounds.south = coordinate[1];
}
if (bounds.east == undefined || coordinate[0] > bounds.east) {
bounds.east = coordinate[0];
}
if (bounds.north == undefined || coordinate[1] > bounds.north) {
bounds.north = coordinate[1];
}
}
var labelFeatures = [];
filteredWardData.forEach(wardData => {
@@ -51,23 +69,18 @@ fetch("wards_withboundaries.json")
]
};
featureCollection.features[0].geometry.coordinates[0].forEach(coordinate => {
if (bounds.west == undefined || coordinate[0] < bounds.west) {
bounds.west = coordinate[0];
}
if (bounds.south == undefined || coordinate[1] < bounds.south) {
bounds.south = coordinate[1];
}
if (bounds.east == undefined || coordinate[0] > bounds.east) {
bounds.east = coordinate[0];
}
if (bounds.north == undefined || coordinate[1] > bounds.north) {
bounds.north = coordinate[1];
}
});
if (featureCollection.features[0].geometry.type == "Polygon") {
featureCollection.features[0].geometry.coordinates[0].forEach(coordinate => {
addToBounds(coordinate);
});
}
if (featureCollection.features[0].geometry.type == "MultiPolygon") {
featureCollection.features[0].geometry.coordinates.forEach(polygon => {
polygon[0].forEach(coordinate => {
addToBounds(coordinate);
});
});
}
// Add data
map.addSource("data_"+wardData.electorateId, {
@@ -87,7 +100,19 @@ fetch("wards_withboundaries.json")
}
});
const centrePoint = polylabel(featureCollection.features[0].geometry.coordinates, 0.000001);
var centrePoint;
if (featureCollection.features[0].geometry.type == "Polygon") {
centrePoint = polylabel(featureCollection.features[0].geometry.coordinates, 0.000001);
}
if (featureCollection.features[0].geometry.type == "MultiPolygon") {
// TODO: Find the biggest polygon in the multipolygon and use that to find the centre point
// instead of just picking the second polygon.
//
// The 2024 set of boundaries only uses 2 MultiPolygon objects (Cathedral in Murrindindi Shire Council and Island in Bass Coast Shire Council)
// Luckily, the second polygon for both objects results in a good label placement.
centrePoint = polylabel(featureCollection.features[0].geometry.coordinates[1], 0.000001);
}
if (wardData.electorateName.includes(' ')) {
// Breaking long names into newlines looks better