implement 'avoid-adges' for markers placements (point placement)

(TODO: support all placement types)

include/mapnik/grid/grid_marker_helpers.hpp

@@ -80,10 +80,11 @@ struct raster_markers_rasterizer_dispatch_grid : mapnik::noncopyable
         marker_placement_enum placement_method = get<marker_placement_enum>(sym_, keys::markers_placement_type, feature_, vars_, MARKER_POINT_PLACEMENT);
         bool ignore_placement = get<bool>(sym_, keys::ignore_placement, feature_, vars_, false);
         bool allow_overlap = get<bool>(sym_, keys::allow_overlap, feature_, vars_, false);
+        bool avoid_edges = get<bool>(sym_, keys::avoid_edges, feature_, vars_, false);
         box2d<double> bbox(0,0, src_.width(), src_.height());
         double spacing = get<double>(sym_, keys::spacing, feature_, vars_, 100.0);
         double max_error = get<double>(sym_, keys::max_error, feature_, vars_, 0.2);
-        markers_placement_params params { bbox, marker_trans_, spacing * scale_factor_, max_error, allow_overlap };
+        markers_placement_params params { bbox, marker_trans_, spacing * scale_factor_, max_error, allow_overlap, avoid_edges };
         markers_placement_finder<T, label_collision_detector4> placement_finder(
             placement_method, path, detector_, params);
         double x, y, angle = .0;
@@ -190,11 +191,12 @@ struct vector_markers_rasterizer_dispatch_grid : mapnik::noncopyable
         bool ignore_placement = get<bool>(sym_, keys::ignore_placement, feature_, vars_, false);
         double opacity = get<double>(sym_,keys::opacity, feature_, vars_, 1.0);
         bool allow_overlap = get<bool>(sym_, keys::allow_overlap, feature_, vars_, false);
+        bool avoid_edges = get<bool>(sym_, keys::avoid_edges, feature_, vars_, false);
         coord2d center = bbox_.center();
         agg::trans_affine_translation recenter(-center.x, -center.y);
         double spacing = get<double>(sym_, keys::spacing, feature_, vars_, 100.0);
         double max_error = get<double>(sym_, keys::max_error, feature_, vars_, 0.2);
-        markers_placement_params params { bbox_, marker_trans_, spacing * scale_factor_, max_error, allow_overlap };
+        markers_placement_params params { bbox_, marker_trans_, spacing * scale_factor_, max_error, allow_overlap, avoid_edges };
         markers_placement_finder<T, Detector> placement_finder(
             placement_method, path, detector_, params);
         double x, y, angle = .0;

include/mapnik/marker_helpers.hpp

@@ -111,13 +111,14 @@ struct vector_markers_rasterizer_dispatch : mapnik::noncopyable
         marker_placement_enum placement_method = get<marker_placement_enum>(sym_, keys::markers_placement_type, feature_, vars_, MARKER_POINT_PLACEMENT);
         bool ignore_placement = get<bool>(sym_, keys::ignore_placement, feature_, vars_, false);
         bool allow_overlap = get<bool>(sym_, keys::allow_overlap, feature_, vars_, false);
+        bool avoid_edges = get<bool>(sym_, keys::avoid_edges, feature_, vars_, false);
         double opacity = get<double>(sym_,keys::opacity, feature_, vars_, 1.0);
         double spacing = get<double>(sym_, keys::spacing, feature_, vars_, 100.0);
         double max_error = get<double>(sym_, keys::max_error, feature_, vars_, 0.2);
         coord2d center = bbox_.center();
         agg::trans_affine_translation recenter(-center.x, -center.y);
         agg::trans_affine tr = recenter * marker_trans_;
-        markers_placement_params params { bbox_, tr, spacing * scale_factor_, max_error, allow_overlap };
+        markers_placement_params params { bbox_, tr, spacing * scale_factor_, max_error, allow_overlap, avoid_edges };
         markers_placement_finder<T, Detector> placement_finder(
             placement_method, path, detector_, params);
         double x, y, angle = .0;
@@ -195,12 +196,13 @@ struct raster_markers_rasterizer_dispatch : mapnik::noncopyable
     {
         marker_placement_enum placement_method = get<marker_placement_enum>(sym_, keys::markers_placement_type, feature_, vars_, MARKER_POINT_PLACEMENT);
         bool allow_overlap = get<bool>(sym_, keys::allow_overlap, feature_, vars_, false);
+        bool avoid_edges = get<bool>(sym_, keys::avoid_edges, feature_, vars_, false);
         box2d<double> bbox_(0,0, src_.width(),src_.height());
         double opacity = get<double>(sym_, keys::opacity, feature_, vars_, 1.0);
         bool ignore_placement = get<bool>(sym_, keys::ignore_placement, feature_, vars_, false);
         double spacing = get<double>(sym_, keys::spacing, feature_, vars_, 100.0);
         double max_error = get<double>(sym_, keys::max_error, feature_, vars_, 0.2);
-        markers_placement_params params { bbox_, marker_trans_, spacing * scale_factor_, max_error, allow_overlap };
+        markers_placement_params params { bbox_, marker_trans_, spacing * scale_factor_, max_error, allow_overlap, avoid_edges };
         markers_placement_finder<T, label_collision_detector4> placement_finder(
             placement_method, path, detector_, params);
         double x, y, angle = .0;

include/mapnik/markers_placements/point.hpp

@@ -37,6 +37,7 @@ struct markers_placement_params
     double spacing;
     double max_error;
     bool allow_overlap;
+    bool avoid_edges;
 };
 
 template <typename Locator, typename Detector>
@@ -87,6 +88,10 @@ public:
         angle = 0;
         box2d<double> box = perform_transform(angle, x, y);
 
+        if (params_.avoid_edges && !detector_.extent().contains(box))
+        {
+            return false;
+        }
         if (!params_.allow_overlap && !detector_.has_placement(box))
         {
             return false;

include/mapnik/symbolizer_keys.hpp

@@ -90,6 +90,7 @@ enum class keys : std::uint8_t
     justify_alignment,
     vertical_alignment,
     upright,
+    avoid_edges,
     MAX_SYMBOLIZER_KEY
 };
 

src/cairo/process_markers_symbolizer.cpp

@@ -81,13 +81,14 @@ struct markers_dispatch : mapnik::noncopyable
             sym_, keys::markers_placement_type, feature_, vars_, MARKER_POINT_PLACEMENT);
         bool ignore_placement = get<bool>(sym_, keys::ignore_placement, feature_, vars_, false);
         bool allow_overlap = get<bool>(sym_, keys::allow_overlap, feature_, vars_, false);
+        bool avoid_edges = get<bool>(sym_, keys::avoid_edges, feature_, vars_, false);
         double opacity = get<double>(sym_, keys::opacity, feature_, vars_, 1.0);
         double spacing = get<double>(sym_, keys::spacing, feature_, vars_, 100.0);
         double max_error = get<double>(sym_, keys::max_error, feature_, vars_, 0.2);
         coord2d center = bbox_.center();
         agg::trans_affine_translation recenter(-center.x, -center.y);
         agg::trans_affine tr = recenter * marker_trans_;
-        markers_placement_params params { bbox_, tr, spacing * scale_factor_, max_error, allow_overlap };
+        markers_placement_params params { bbox_, tr, spacing * scale_factor_, max_error, allow_overlap, avoid_edges };
         markers_placement_finder<T, label_collision_detector4> placement_finder(
             placement_method, path, detector_, params);
         double x, y, angle = .0;
@@ -148,9 +149,10 @@ struct raster_markers_dispatch : mapnik::noncopyable
         double spacing = get<double>(sym_, keys::spacing, feature_, vars_,  100.0);
         double max_error = get<double>(sym_, keys::max_error, feature_, vars_,  0.2);
         bool allow_overlap = get<bool>(sym_, keys::allow_overlap, feature_, vars_,  false);
+        bool avoid_edges = get<bool>(sym_, keys::avoid_edges, feature_, vars_, false);
         bool ignore_placement = get<bool>(sym_, keys::ignore_placement, feature_, vars_,  false);
         box2d<double> bbox_(0,0, src_.width(),src_.height());
-        markers_placement_params params { bbox_, marker_trans_, spacing * scale_factor_, max_error, allow_overlap };
+        markers_placement_params params { bbox_, marker_trans_, spacing * scale_factor_, max_error, allow_overlap, avoid_edges };
         markers_placement_finder<T, label_collision_detector4> placement_finder(
             placement_method, path, detector_, params);
         double x, y, angle = .0;

src/load_map.cpp

@@ -957,6 +957,8 @@ void map_parser::parse_markers_symbolizer(rule & rule, xml_node const& node)
         set_symbolizer_property<markers_symbolizer,double>(sym, keys::max_error, node);
         // allow-overlap
         set_symbolizer_property<markers_symbolizer,boolean_type>(sym, keys::allow_overlap, node);
+        // avoid-edges
+        set_symbolizer_property<markers_symbolizer,boolean_type>(sym, keys::avoid_edges, node);
         // ignore-placement
         set_symbolizer_property<markers_symbolizer,boolean_type>(sym, keys::ignore_placement, node);
         // width

src/symbolizer_keys.cpp

@@ -116,7 +116,8 @@ static const property_meta_type key_meta[const_max_key] =
                         property_types::target_vertical_alignment},
     property_meta_type{ "upright", enumeration_wrapper(UPRIGHT_AUTO), [](enumeration_wrapper e)
                         {return enumeration<text_upright_enum,text_upright_enum_MAX>(text_upright_enum(e.value)).as_string();},
-                        property_types::target_upright}
+                        property_types::target_upright},
+    property_meta_type{ "avoid-edges",false, nullptr, property_types::target_bool },
 
 };