reinstated code for adding canvas layer

README.markdown

@@ -219,6 +219,8 @@ If you include a PNG image named `canvas.png` in the map directory, it will be a
 
 Generating your own vegetation layer can be accomplished using the 'color range' selection tool in Photoshop, for example, or other similar selection tools. (Selecting on a single channel, such as green or magenta, may be helpful.) You can also create additional vegetation markings (e.g. for the distinctive, nasty heath that sometimes appears in ACT rogaines) using the aerial imagery.
 
+If you wish to create your canvas at a lower resolution, it is fine to resample (resize) the aerial image to smaller pixel count before selecting and colouring the vegetation. However, it is important that you *resample the image by changing its resolution* (usually shown in pixels/inch), rather than by changing the width and height.
+
 ## Plantations
 
 If you include the `plantation` layer, a representation of pine forest plantations will be added to your map in darker green. The accuracy of this layer is not guaranteed however.

nswtopo.rb

@@ -726,7 +726,7 @@ def download(label, options, map)
   end
 
   module RasterRenderer
-    def default_resolution(label, option, map)
+    def default_resolution(label, options, map)
       params["resolution"] || map.scale / 12500.0
     end
 
@@ -1423,6 +1423,12 @@ def embed_image(label, options, map, dimensions, resolution, temp_dir)
   class CanvasServer < Server
     include NoDownload
     include RasterRenderer
+
+    def default_resolution(label, options, map)
+      canvas_path = File.join Dir.pwd, "#{label}.png"
+      raise BadLayerError.new("#{label}.png not found") unless File.exists? canvas_path
+      map.scale * 0.01 / %x[convert "#{canvas_path}" -units PixelsPerCentimeter -format "%[resolution.x]" info:].to_f
+    end
   end
 
   class AnnotationServer < Server
@@ -1864,13 +1870,6 @@ def self.run
     vegetation_server = VegetationServer.new(config["vegetation"])
 
     layers = {
-      "reference-topo-1" => {
-        "server" => lpi_ortho,
-        "image" => "/OTDF_Imagery/NSWTopoS2v2.ecw",
-        "otdf" => true,
-        "ext" => "png",
-        "resolution" => 4.0,
-      },
       "reference-topo-2" => {
         "server" => sixmaps,
         "service" => "NSWTopo",
@@ -1879,6 +1878,13 @@ def self.run
         "resolution" => 2.0,
         "background" => "white",
       },
+      "reference-topo-1" => {
+        "server" => lpi_ortho,
+        "image" => "/OTDF_Imagery/NSWTopoS2v2.ecw",
+        "otdf" => true,
+        "ext" => "png",
+        "resolution" => 4.0,
+      },
       "aerial-lpi-eastcoast" => {
         "server" => lpi_ortho,
         "image" => "/Imagery/lr94ortho1m.ecw",
@@ -1925,13 +1931,13 @@ def self.run
       #   "service" => "LPI_Imagery_Best",
       #   "ext" => "jpg",
       # },
+      "vegetation" => {
+        "server" => vegetation_server,
+      },
       "canvas" => {
         "server" => canvas_server,
         "ext" => "png",
       },
-      "vegetation" => {
-        "server" => vegetation_server,
-      },
       "plantation" => {
         "server" => atlas,
         "service" => "Economy_Forestry",
@@ -1966,18 +1972,18 @@ def self.run
           "labels" => %w[Labels],
         },
       },
+      "relief" => {
+        "server" => oneearth_relief,
+        "clips" => %w[topographic.HydroArea topographic.VSS_Oceans],
+        "ext" => "png",
+      },
       "holdings" => {
         "server" => sixmaps,
         "service" => "LHPA",
         "ext" => "svg",
         "layers" => %w[Holdings],
         "labels" => %w[Holdings],
       },
-      "relief" => {
-        "server" => oneearth_relief,
-        "clips" => %w[topographic.HydroArea topographic.VSS_Oceans],
-        "ext" => "png",
-      },
       "declination" => {
         "server" => declination_server,
       },
@@ -1986,23 +1992,27 @@ def self.run
       },
     }
 
-    includes = (%w[topographic] + config["include"]).map { |label_or_hash| [ *label_or_hash ].flatten }
-    layers.each do |label, options|
-      includes.each { |match, resolution| options.merge!("resolution" => resolution) if label[match] && resolution }
-    end
-    labels = layers.keys.select { |label| includes.any? { |match, _| label[match] } }
+    includes = %w[topographic]
+    includes << "canvas" if File.exists? "canvas.png"
 
     (config["overlays"] || {}).each do |filename_or_path, options|
       label = File.split(filename_or_path).last.partition(/\.\w+$/).first
       layers.merge! label => (options || {}).merge("server" => OverlayServer.new, "path" => filename_or_path)
-      labels << label
+      includes << label
     end
 
     if config["controls"]["file"]
       layers.merge! "controls" => { "server" => control_server}
-      labels << "controls"
+      includes << "controls"
     end
 
+    includes += config["include"]
+    includes.map! { |label_or_hash| [ *label_or_hash ].flatten }
+    layers.each do |label, options|
+      includes.each { |match, resolution| options.merge!("resolution" => resolution) if label[match] && resolution }
+    end
+    labels = layers.keys.select { |label| includes.any? { |match, _| label[match] } }
+
     puts "Map details:"
     puts "  name: #{map.name}"
     puts "  size: %imm x %imm" % map.extents.map { |extent| 1000 * extent / map.scale }
@@ -2108,7 +2118,6 @@ def self.run
   NSWTopo.run
 end
 
-# TODO: reinstate CanvasServer
 # TODO: put layer opacities in consistent location, use style="opacity:0.2" for use with inkscape
 # TODO: split shaded-relief into sun and shade layers for individual adjustment