Reproject and transform crop mask to geojson and then correctly zoom into the preview map if the map has been cropped :emoji: refs #94

Author: timwaters

app/assets/javascripts/warped.js

@@ -66,7 +66,16 @@ function warpedinit() {
 
     clipmap_bounds_merc = warped_bounds.transform(warpedmap.displayProjection, warpedmap.projection);
 
-    warpedmap.zoomToExtent(clipmap_bounds_merc);
+    if (mask_geojson) {
+      var vector = new OpenLayers.Layer.Vector("GeoJSON", {
+        projection: "EPSG:4326"
+      });
+      var gformat = new OpenLayers.Format.GeoJSON();
+      vector.addFeatures(gformat.read(mask_geojson));
+      warpedmap.zoomToExtent(vector.getDataExtent());
+    } else {
+      warpedmap.zoomToExtent(clipmap_bounds_merc);
+    }
 
     //set up slider
     jQuery("#slider").slider({

app/models/map.rb

@@ -612,6 +612,8 @@ def mask!
     else
       return "no masking file matching specified format found."
     end
+
+    self.mask_geojson = convert_mask_to_geojson
 
     masked_src_filename = self.masked_src_filename
     if File.exists?(masked_src_filename)
@@ -668,6 +670,8 @@ def warp!(resample_option, transform_option, use_mask="false")
     if use_mask == "true" && self.mask_status == :masked
       src_filename = self.masked_src_filename
       mask_options = " -srcnodata '17 17 17' "
+
+      self.mask_geojson = convert_mask_to_geojson  if self.mask_geojson.blank?
     else
       src_filename = self.unwarped_filename
     end
@@ -966,6 +970,32 @@ def clear_cache
     Rails.cache.delete_matched ".*/maps/wms/#{self.id}.png\?status=warped.*"
     Rails.cache.delete_matched "*/maps/tile/#{self.id}/*"
   end
+
+  #takes in the clipping mask file, transforms it to geo and converts to geojson, returning the geojson
+  def convert_mask_to_geojson
+    if self.gcps.hard.size < 3
+      return nil;
+    else
+      gcp_array = self.gcps.hard
+      gcp_string = ""
+      gcp_array.each do |gcp|
+        gcp_string = gcp_string + gcp.gdal_string
+      end
+
+      command = "ogr2ogr -f 'geojson' -s_srs 'epsg:4326' -t_srs 'epsg:3857' #{gcp_string} /dev/stdout  #{self.masking_file_gml}"
+      logger.info command
+      o_out, o_err = Open3.capture3( command )
+
+      if !o_err.blank? 
+        logger.error "Error ogr2ogr script" + o_err
+        logger.error "output = "+o_out
+        return nil;
+      end
+
+
+      return o_out
+    end
+  end
 
 
 end

app/views/maps/warped.html.erb

@@ -21,14 +21,15 @@
     <script type="text/javascript">
       var map_id = '<%=h @map.id -%>';
       var title = '<%=u @map.title -%>';
-      var warped_image_width = <%= @map.width %>
-      var warped_image_height = <%= @map.height %>
+      var warped_image_width = <%= @map.width %>;
+      var warped_image_height = <%= @map.height %>;
       var warpedwms_url = '<%= url_for :controller => 'maps', :action => 'wms', :id => @map  -%>';
       var warped_bounds = new OpenLayers.Bounds(<%=@map.bounds-%>);
       var layer_baseurl = '<%=url_for :controller => 'layers', :action => 'wms' %>';
       var layers_array = [<%=@other_layers.join(",")-%>];
       var warpedtiles_url = '<%= tile_map_base_url %>/';
       var use_tiles = <%= !user_signed_in? %>;
+      var mask_geojson = <%= @map.mask_status != :masked || @map.mask_geojson.blank? ? false : @map.mask_geojson.html_safe %>;
     </script>
 
 

db/migrate/20190228170210_add_mask_geojson_to_map.rb

@@ -0,0 +1,5 @@
+class AddMaskGeojsonToMap < ActiveRecord::Migration
+  def change
+    add_column :maps, :mask_geojson, :text
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20190221161545) do
+ActiveRecord::Schema.define(version: 20190228170210) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -207,6 +207,7 @@
     t.datetime "gcp_touched_at"
     t.integer  "issue_year"
     t.boolean  "protect",                                                                                  default: false
+    t.text     "mask_geojson"
   end
 
   add_index "maps", ["bbox_geom"], name: "index_maps_on_bbox_geom", using: :gist

test/models/map_test.rb

@@ -41,6 +41,16 @@ class MapTest < ActiveSupport::TestCase
     end
   end
 
+  test "converts mask to geojson" do
+    test_gml = File.join(Rails.root, "/test/fixtures/data/test.gml")
+    Map.any_instance.stubs(:masking_file_gml).returns(test_gml)
+    @map.mask!
+
+    assert_not_nil @map.mask_geojson
+    json = JSON.parse(@map.mask_geojson)
+    assert "FeatureCollection", json["type"]
+  end
+
   private 
 
   def delete_created_images(map)