Clip before dealing with multiplier or filters in overzoom

felt · Aug 15, 2024 · 42c4426 · 42c4426
1 parent d891ca7
commit 42c4426
Showing 1 changed file with 37 additions and 31 deletions.
diff --git a/clip.cpp b/clip.cpp
@@ -1188,37 +1188,6 @@ std::string overzoom(std::vector<source_tile> const &tiles, int nz, int nx, int
 			static const std::string retain_points_multiplier_sequence = "tippecanoe:retain_points_multiplier_sequence";
 
 			for (auto feature : layer.features) {
-				bool flush_multiplier_cluster = false;
-				if (demultiply) {
-					for (ssize_t i = feature.tags.size() - 2; i >= 0; i -= 2) {
-						if (layer.keys[feature.tags[i]] == retain_points_multiplier_first) {
-							mvt_value v = layer.values[feature.tags[i + 1]];
-							if (v.type == mvt_bool && v.numeric_value.bool_value) {
-								flush_multiplier_cluster = true;
-								feature.tags.erase(feature.tags.begin() + i, feature.tags.begin() + i + 2);
-							}
-						} else if (i < (ssize_t) feature.tags.size() && layer.keys[feature.tags[i]] == retain_points_multiplier_sequence) {
-							mvt_value v = layer.values[feature.tags[i + 1]];
-							feature.seq = mvt_value_to_long_long(v);
-							feature.tags.erase(feature.tags.begin() + i, feature.tags.begin() + i + 2);
-						}
-					}
-				} else {
-					flush_multiplier_cluster = true;
-				}
-
-				if (flush_multiplier_cluster) {
-					if (pending_tile_features.size() > 0) {
-						feature_out(pending_tile_features, *outlayer, keep, attribute_accum, tile_stringpool);
-						pending_tile_features.clear();
-					}
-				}
-
-				std::set<std::string> exclude_attributes;
-				if (filter != NULL && !evaluate(feature, layer, filter, exclude_attributes, nz, unidecode_data)) {
-					continue;
-				}
-
 				drawvec geom;
 				int t = feature.type;
 
@@ -1268,6 +1237,7 @@ std::string overzoom(std::vector<source_tile> const &tiles, int nz, int nx, int
 
 					long long b = outtilesize * buffer / 256;
 					if (xmax < -b || ymax < -b || xmin > outtilesize + b || ymin > outtilesize + b) {
+						// quick exclusion by bounding box
 						continue;
 					}
 
@@ -1281,6 +1251,42 @@ std::string overzoom(std::vector<source_tile> const &tiles, int nz, int nx, int
 					}
 				}
 
+				if (geom.size() == 0) {
+					// clipped away
+					continue;
+				}
+
+				bool flush_multiplier_cluster = false;
+				if (demultiply) {
+					for (ssize_t i = feature.tags.size() - 2; i >= 0; i -= 2) {
+						if (layer.keys[feature.tags[i]] == retain_points_multiplier_first) {
+							mvt_value v = layer.values[feature.tags[i + 1]];
+							if (v.type == mvt_bool && v.numeric_value.bool_value) {
+								flush_multiplier_cluster = true;
+								feature.tags.erase(feature.tags.begin() + i, feature.tags.begin() + i + 2);
+							}
+						} else if (i < (ssize_t) feature.tags.size() && layer.keys[feature.tags[i]] == retain_points_multiplier_sequence) {
+							mvt_value v = layer.values[feature.tags[i + 1]];
+							feature.seq = mvt_value_to_long_long(v);
+							feature.tags.erase(feature.tags.begin() + i, feature.tags.begin() + i + 2);
+						}
+					}
+				} else {
+					flush_multiplier_cluster = true;
+				}
+
+				if (flush_multiplier_cluster) {
+					if (pending_tile_features.size() > 0) {
+						feature_out(pending_tile_features, *outlayer, keep, attribute_accum, tile_stringpool);
+						pending_tile_features.clear();
+					}
+				}
+
+				std::set<std::string> exclude_attributes;
+				if (filter != NULL && !evaluate(feature, layer, filter, exclude_attributes, nz, unidecode_data)) {
+					continue;
+				}
+
 				bool still_need_simplification_after_reduction = false;
 				if (t == VT_POLYGON && tiny_polygon_size > 0) {
 					bool simplified_away_by_reduction = false;