Module: NSWTopo::Raster

Included in:
ArcGISRaster, Import, Relief, Vegetation
Defined in:
lib/nswtopo/layer/raster.rb

Instance Method Summary collapse

Instance Method Details

#create ⇒ Object 



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# File 'lib/nswtopo/layer/raster.rb', line 3

def create
  tif = Dir.mktmppath do |temp_dir|
    tif_path = temp_dir / "final.tif"
    tfw_path = temp_dir / "final.tfw"
    out_path = temp_dir / "output.tif"

    resolution, raster_path = get_raster(temp_dir)
    dimensions, ppi, resolution = @map.raster_dimensions_at resolution: resolution
    density = 0.01 * @map.scale / resolution
    tiff_tags = %W[-mo TIFFTAG_XRESOLUTION=#{density} -mo TIFFTAG_YRESOLUTION=#{density} -mo TIFFTAG_RESOLUTIONUNIT=3]

    @map.write_world_file tfw_path, resolution: resolution
    OS.convert "-size", dimensions.join(?x), "canvas:none", "-type", "TrueColorMatte", "-depth", 8, tif_path
    OS.gdalwarp "-t_srs", @map.projection, "-r", "bilinear", raster_path, tif_path
    OS.gdal_translate "-a_srs", @map.projection, *tiff_tags, tif_path, out_path
    @map.write filename, out_path.binread
  end
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/nswtopo/layer/raster.rb', line 26

def empty?
  false
end

#filename ⇒ Object 



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# File 'lib/nswtopo/layer/raster.rb', line 22

def filename
  "#{@name}.tif"
end

#render(group, defs) ⇒ Object 



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# File 'lib/nswtopo/layer/raster.rb', line 47

def render(group, defs)
  (width, height), resolution = size_resolution
  group.add_attributes "style" => "opacity:%s" % params.fetch("opacity", 1)
  transform = "scale(#{1000.0 * resolution / @map.scale})"
  png = Dir.mktmppath do |temp_dir|
    tif_path = temp_dir / "raster.tif"
    png_path = temp_dir / "raster.png"
    tif_path.binwrite @map.read(filename)
    OS.gdal_translate "-of", "PNG", "-co", "ZLEVEL=9", tif_path, png_path
    png_path.binread
  end
  href = "data:image/png;base64,#{Base64.encode64 png}"
  group.add_element "image", "transform" => transform, "width" => width, "height" => height, "image-rendering" => "optimizeQuality", "xlink:href" => href
  group.add_attribute "mask", "url(#raster-mask)" if defs.elements["mask[@id='raster-mask']"]
end

#size_resolution ⇒ Object 



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# File 'lib/nswtopo/layer/raster.rb', line 30

def size_resolution
  json = OS.gdalinfo "-json", "/vsistdin/" do |stdin|
    stdin.binmode
    stdin.write @map.read(filename)
  end
  size, geotransform = JSON.parse(json).values_at "size", "geoTransform"
  resolution = geotransform.values_at(1, 2).norm
  return size, resolution
end

#to_s ⇒ Object 



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# File 'lib/nswtopo/layer/raster.rb', line 40

def to_s
  size, resolution = size_resolution
  megapixels = size.inject(&:*) / 1024.0 / 1024.0
  ppi = 0.0254 * @map.scale / resolution
  "%s: %i×%i (%.1fMpx) @ %.1fm/px (%.0f ppi)" % [@name, *size, megapixels, resolution, ppi]
end