Compile-time option for float ZOrder (#486)

Author: systemed

docs/CONFIGURATION.md

@@ -134,7 +134,7 @@ To do that, you use these methods:
 * `node:Attribute(key,value)` or `node:Attribute(key,value)`: add an attribute to the most recently written layer.
 * `node:AttributeNumeric(key,value)`, `node:AttributeBoolean(key,value)` (and `way:`...): for numeric/boolean columns.
 * `node:Id()` or `way:Id()`: get the OSM ID of the current object.
-* `node:ZOrder(number)` or `way:ZOrder(number)`: Set a numeric value (default 0, 1-byte unsigned integer) used to sort features within a layer. Use this feature to ensure a proper rendering order if the rendering engine itself does not support sorting. Sorting is not supported across layers merged with `write_to`. Features with different z-order are not merged if `combine_below` or `combine_polygons_below` is used.
+* `node:ZOrder(number)` or `way:ZOrder(number)`: Set a numeric value (default 0, 1-byte signed integer) used to sort features within a layer. Use this feature to ensure a proper rendering order if the rendering engine itself does not support sorting. Sorting is not supported across layers merged with `write_to`. Features with different z-order are not merged if `combine_below` or `combine_polygons_below` is used.
 * `node:MinZoom(zoom)` or `way:MinZoom(zoom)`: set the minimum zoom level (0-15) at which this object will be written. Note that the JSON layer configuration minimum still applies (so `:MinZoom(5)` will have no effect if your layer only starts at z6).
 * `way:Length()` and `way:Area()`: return the length (metres)/area (square metres) of the current object. Requires recent Boost.
 * `way:Centroid()`: return the lat/lon of the centre of the current object as a two-element Lua table (element 1 is lat, 2 is lon).

docs/INSTALL.md

@@ -63,3 +63,13 @@ The docker container can be run like this:
     docker run -v /Users/Local/Downloads/:/srv -i -t --rm tilemaker /srv/germany-latest.osm.pbf --output=/srv/germany.mbtiles
 
 Keep in mind to map the volume your .osm.pbf files are in to a path within your docker container, as seen in the example above. 
+
+### Compile-time options
+
+tilemaker has two compile-time options that increase memory usage but may be useful in certain circumstances. You can include them when building like this:
+
+    make "CONFIG=-DFLOAT_Z_ORDER"
+
+FLOAT_Z_ORDER allows you to use a full range of ZOrder values in your Lua script, rather than being restricted to single-byte integer (-127 to 127).
+
+FAT_TILE_INDEX allows you to generate vector tiles at zoom level 17 or greater. You almost certainly don't need to do this. Vector tiles are usually generated up to zoom 14 (sometimes 15), and then the browser/app client uses the vector data to scale up at subsequent zoom levels.

include/osm_lua_processing.h

@@ -161,6 +161,7 @@ class OsmLuaProcessing {
 	void AttributeBooleanWithMinZoom(const std::string &key, const bool val, const char minzoom);
 	void MinZoom(const double z);
 	void ZOrder(const double z);
+	void ZOrderWithScale(const double z, const double scale);
 
 	// Relation scan support
 	kaguya::optional<int> NextRelation();

include/output_object.h

@@ -15,6 +15,12 @@
 #include "osmformat.pb.h"
 #include "vector_tile.pb.h"
 
+#ifdef FLOAT_Z_ORDER
+typedef float ZOrder;
+#else
+typedef int8_t ZOrder;
+#endif
+
 enum OutputGeometryType : unsigned int { POINT_, LINESTRING_, MULTILINESTRING_, POLYGON_ };
 
 #define OSMID_TYPE_OFFSET	40
@@ -46,16 +52,18 @@ class OutputObject {
 public:
 	NodeID objectID 			: 42;					// id of way (linestring/polygon) or node (point)
 	uint_least8_t layer 		: 8;					// what layer is it in?
-	int8_t z_order				: 8;					// z_order: used for sorting features within layers
+	ZOrder z_order				;						// z_order: used for sorting features within layers
 	OutputGeometryType geomType : 2;					// point, linestring, polygon
 	unsigned minZoom 			: 4;
 
 	AttributeStoreRef attributes;
 
-	void setZOrder(const int z) {
+	void setZOrder(const ZOrder z) {
+#ifndef FLOAT_Z_ORDER
 		if (z <= -127 || z >= 127) {
 			throw std::runtime_error("z_order is limited to 1 byte signed integer.");
 		}
+#endif
 		z_order = z;
 	}
 

src/osm_lua_processing.cpp

@@ -55,7 +55,7 @@ OsmLuaProcessing::OsmLuaProcessing(
 		.addOverloadedFunctions("AttributeNumeric", &OsmLuaProcessing::AttributeNumeric, &OsmLuaProcessing::AttributeNumericWithMinZoom)
 		.addOverloadedFunctions("AttributeBoolean", &OsmLuaProcessing::AttributeBoolean, &OsmLuaProcessing::AttributeBooleanWithMinZoom)
 		.addFunction("MinZoom", &OsmLuaProcessing::MinZoom)
-		.addFunction("ZOrder", &OsmLuaProcessing::ZOrder)
+		.addOverloadedFunctions("ZOrder", &OsmLuaProcessing::ZOrder, &OsmLuaProcessing::ZOrderWithScale)
 		.addFunction("Accept", &OsmLuaProcessing::Accept)
 		.addFunction("NextRelation", &OsmLuaProcessing::NextRelation)
 		.addFunction("FindInRelation", &OsmLuaProcessing::FindInRelation)
@@ -501,7 +501,21 @@ void OsmLuaProcessing::MinZoom(const double z) {
 // Set z_order
 void OsmLuaProcessing::ZOrder(const double z) {
 	if (outputs.size()==0) { ProcessingError("Can't set z_order if no Layer set"); return; }
+#ifdef FLOAT_Z_ORDER
+	outputs.back().first->setZOrder(make_valid<float>(z));
+#else
 	outputs.back().first->setZOrder(make_valid<int>(z));
+#endif
+}
+
+// Set z_order (variant with scaling)
+void OsmLuaProcessing::ZOrderWithScale(const double z, const double scale) {
+	if (outputs.size()==0) { ProcessingError("Can't set z_order if no Layer set"); return; }
+#ifdef FLOAT_Z_ORDER
+	outputs.back().first->setZOrder(make_valid<float>(z));
+#else
+	outputs.back().first->setZOrder(make_valid<int>(z/scale*127));
+#endif
 }
 
 // Read scanned relations