std::vector<SymbolFeature> SymbolBucket::processFeatures(const GeometryTileLayer& layer,
const FilterExpression& filter,
GlyphStore &glyphStore) {
const bool has_text = !layout.text.field.empty() && !layout.text.font.empty();
const bool has_icon = !layout.icon.image.empty();
std::vector<SymbolFeature> features;
if (!has_text && !has_icon) {
return features;
}
// Determine and load glyph ranges
std::set<GlyphRange> ranges;
for (std::size_t i = 0; i < layer.featureCount(); i++) {
auto feature = layer.getFeature(i);
GeometryTileFeatureExtractor extractor(*feature);
if (!evaluate(filter, extractor))
continue;
SymbolFeature ft;
auto getValue = [&feature](const std::string& key) -> std::string {
auto value = feature->getValue(key);
return value ? toString(*value) : std::string();
};
if (has_text) {
std::string u8string = util::replaceTokens(layout.text.field, getValue);
if (layout.text.transform == TextTransformType::Uppercase) {
u8string = platform::uppercase(u8string);
} else if (layout.text.transform == TextTransformType::Lowercase) {
u8string = platform::lowercase(u8string);
}
ft.label = util::utf8_to_utf32::convert(u8string);
if (ft.label.size()) {
// Loop through all characters of this text and collect unique codepoints.
for (char32_t chr : ft.label) {
ranges.insert(getGlyphRange(chr));
}
}
}
if (has_icon) {
ft.sprite = util::replaceTokens(layout.icon.image, getValue);
}
if (ft.label.length() || ft.sprite.length()) {
auto &multiline = ft.geometry;
GeometryCollection geometryCollection = feature->getGeometries();
for (auto& line : geometryCollection) {
multiline.emplace_back();
for (auto& point : line) {
multiline.back().emplace_back(point.x, point.y);
}
}
features.push_back(std::move(ft));
}
}
if (layout.placement == PlacementType::Line) {
util::mergeLines(features);
}
if (glyphStore.requestGlyphRangesIfNeeded(layout.text.font, ranges)) {
needsGlyphs_ = true;
return {};
}
return features;
}
