feat: replace max/min_zoom with resolution levels and resolution level checks

Author: shri-acha

galileo/examples/vector_tiles_labels.rs

@@ -43,6 +43,8 @@ pub(crate) fn run() {
     let labels_style = VectorTileStyle {
         rules: vec![StyleRule {
             layer_name: None,
+            max_resolution:None,
+            min_resolution: None,
             properties: Default::default(),
             symbol: VectorTileSymbol::Label(VectorTileLabelSymbol {
                 pattern: String::from("{name}"),

galileo/src/layer/vector_tile_layer/builder.rs

@@ -458,6 +458,8 @@ impl VectorTileLayerBuilder {
             rules: vec![
                 StyleRule {
                     layer_name: None,
+                    max_resolution: None,
+                    min_resolution: None,
                     properties: Default::default(),
                     symbol: VectorTileSymbol::Line(VectorTileLineSymbol {
                         width: 1.0,
@@ -466,6 +468,8 @@ impl VectorTileLayerBuilder {
                 },
                 StyleRule {
                     layer_name: None,
+                    max_resolution: None,
+                    min_resolution: None,
                     properties: Default::default(),
                     symbol: VectorTileSymbol::Polygon(VectorTilePolygonSymbol {
                         fill_color: Color::GRAY,

galileo/src/layer/vector_tile_layer/style.rs

@@ -23,7 +23,7 @@ pub struct VectorTileStyle {
 
 impl VectorTileStyle {
     /// Get a rule for the given feature.
-    pub fn get_style_rule(&self, layer_name: &str, feature: &MvtFeature) -> Option<&StyleRule> {
+    pub fn get_style_rule(&self, layer_name: &str,resolution_level: f64, feature: &MvtFeature) -> Option<&StyleRule> {
         self.rules.iter().find(|&rule| {
             let correct_geometry_type = match feature.geometry {
                 MvtGeometry::Point(_)
@@ -50,6 +50,12 @@ impl VectorTileStyle {
             if rule.layer_name.as_ref().is_some_and(|v| v != layer_name) {
                 return false;
             }
+            if rule.max_resolution.is_some_and(|v| v < resolution_level) {
+                return false;
+            }
+            if rule.min_resolution.is_some_and(|v| v > resolution_level) {
+                return false;
+            }
 
             let filter_check_passed = rule.properties.iter().all(|filter| {
                 let value = feature.properties.get(&filter.property_name);
@@ -102,6 +108,10 @@ fn compare_numeric(a: &galileo_mvt::MvtValue, b: &str, cmp: impl Fn(f64, f64) ->
 pub struct StyleRule {
     /// If set, a feature must belong to the set layer. If not set, layer is not checked.
     pub layer_name: Option<String>,
+    /// Determins the maximum resolution
+    pub max_resolution: Option<f64>,
+    /// Determins the minimum resolution 
+    pub min_resolution: Option<f64>,
     /// Specifies a set of attributes of a feature that must have the given values for this rule to be applied.
     #[serde(default)]
     pub properties: Vec<PropertyFilter>,
@@ -331,6 +341,8 @@ mod tests {
     fn serialize_with_bincode() {
         let rule = StyleRule {
             layer_name: None,
+            min_resolution:None,
+            max_resolution:None,
             properties: vec![],
             symbol: VectorTileSymbol::None,
         };

galileo/src/layer/vector_tile_layer/tile_provider/vt_processor.rs

@@ -59,7 +59,7 @@ impl VtProcessor {
 
         for layer in mvt_tile.layers.iter().rev() {
             for feature in &layer.features {
-                let Some(rule) = style.get_style_rule(&layer.name, feature) else {
+                let Some(rule) = style.get_style_rule(&layer.name, lod_resolution, feature) else {
                     continue;
                 };
 

galileo/src/tile_schema/schema.rs

@@ -52,9 +52,7 @@ impl TileSchema {
         } else {
             None
         }
-    }
-
-    /// Width of a single tile.
+    } /// Width of a single tile.
     pub fn tile_width(&self) -> u32 {
         self.tile_width
     }