input/.gitignore log/.gitignore output/.gitignore @@ -4,3 +4,4 @@ log/* db/*.sqlite3 *.swp database.yml +doc/* .gitignore @@ -1,32 +1,62 @@ require 'lib/ruby-processing' -$co2_low_bound = 370 +# global variables for the benefit of Processing +# lower and upper bounds for recorded CO2 +$co2_low_bound = 370 $co2_high_bound = 450 +# Co2ColorCode implements the color scale used to render columns of +# CO2 in Google Earth. +# +# == Usage +# +# Co2ColorCode.colorify(co2_ppm) #=> appropriate color in hex format +# Co2ColorCode.make_color_bar #=> outputs an image of the color scale class Co2ColorCode + + # Returns the color associated with @value@ of CO2 + # + # Return format is #AABBGGRR in hexadecimal notation def self.colorify(value) v = value.to_f - if v == -9999.99 + if v == -9999.99 # -9999.99 is the fill value for the dataset return abgr(0,0,0,0) else - c = normalized_colorify(normalize(v, $co2_low_bound, $co2_high_bound)) + c = normalized_colorify( + normalize($co2_low_bound, $co2_high_bound, v) + ) + abgr(255 ,255*c[2], 255*c[1], 255*c[0]) end end + # Returns the color for the associated normalized value + # + # Return format is [red, green, blue] where all components are in range + # [0.0, 1.0] def self.normalized_colorify(norm_value) hsv((norm_value*300) +60, 0.75, 0.75) end + # Writes a PNG of the color scale to disk using Processing. This image can + # be used as a ScreenOverlay in Google Earth def self.make_color_bar Co2ColorCodeBar.new :title => "Color Bar", :height => 400, :width => 60 end - + # Convenience method to format integer color components into abgr hex format def self.abgr(a,b,g,r) "%02X%02X%02X%02X" % [a,b,g,r] end + # Converts a value expressed in HSV colormode to RGB + # + # @h@ is on range [0, 360] + # @s@ and @v@ are on range [0.0, 1.0] + # + # Returns [red, green, blue] where all components are on range [0.0, 1.0] + # Math stolen from + # http://en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_HSV_to_RGB def self.hsv(h, s, v) h_i = (h/60).floor.to_i % 6 f = (h/60) - (h/60).floor @@ -50,8 +80,8 @@ class Co2ColorCode end end - - def self.normalize(value, min, max) + # Constrains values on range [min, max] to between 0.0 and 1.0 + def self.normalize(min, max, value) if value > max return max elsif value < min @@ -61,34 +91,45 @@ class Co2ColorCode end end + # Linear Interpolation: transforms @value@ on range [0.0, 1.0] to equivalent + # value on range [min, max] def self.lerp(min, max, value) (max-min)*value + min end end +# Processing class to create color bar for Co2ColorCode class Co2ColorCodeBar < Processing::App def setup background(255) font = load_font("#{GTRON_ROOT}/lib/Electron-12.vlw") text_font(font) fill(0) - last_line_number = nil + + last_line_number = nil #ensures proper spacing of labels for i in (0...height) value = (1.0/height)*i - colors = Co2ColorCode.normalized_colorify(value).map{|v| (255*v).to_i } + + #transform colors on range [0.0, 1.0] to colors on range [0, 255] + colors = Co2ColorCode.normalized_colorify(value).map{|v| (255*v).to_i } + stroke(colors[0], colors[1], colors[2]) line(25,i,width,i) + # find co2 measurement associated with generated normalized value orig_val = Co2ColorCode.lerp($co2_low_bound, $co2_high_bound, value).to_i + # label significant points on the bar with values if (orig_val % 10 == 0) && orig_val != last_line_number last_line_number = orig_val text("#{orig_val}", 2, i+12) - #stroke(0) - #line(23,i,height,i) end end + save "#{GTRON_ROOT}/output/co2_color_bar.png" + + # close window and quit the method + # There might be a cleaner way exit end end lib/co2_color_code.rb @@ -13,18 +13,36 @@ include Math # the ones without that suffix return KML::Polygon class KmlShapes + # Creates an extruded circle centered on (@lat@, @lon@) at altitude @alt@ + # with a radius of @radius@ (in meters) + # + # Google Earth is extremely weird about making real cylinders (I would love + # a triangle strip primitive) so cylinders are faked by extruding towards + # the center of the earth. Luckily this meets the needs of the ASCENDS + # visualization def self.cylinder(lon, lat, alt, radius) cylinder = circle(lon, lat, alt, radius) cylinder.extrude = true cylinder end + # Creates a Google Earth polygon that is a circle centered on (@lat@, @lon@) + # at an altitude of @alt@ with a radius of @radius@ (in meters). def self.circle(lon, lat, alt, radius) bounds = circle_coords(lon, lat, alt, radius) - KML::Polygon.new(:outer_boundary_is => format_bounds(bounds + [bounds.first]), - :altitude_mode => 'absolute') + KML::Polygon.new( + :outer_boundary_is => format_bounds(bounds + [bounds.first]), + :altitude_mode => 'absolute' + ) end + # generates coordinates in the form [[lon, lat, alt],...] for a circle + # centered on (@lon@, @lat@) at altitude @alt@ with a radius of @radius@ + # (in meters) + # + # This code uses the haversine formula and was ported from a PHP + # Google Earth circle generator: + # http://dev.bt23.org/keyhole/circlegen/output.phps def self.circle_coords(lon, lat, alt, radius) lat = deg2rad(lat) lon = deg2rad(lon) @@ -45,14 +63,18 @@ class KmlShapes end private + + # converts degrees to radians def self.deg2rad(degree) degree.to_f*(PI/180.0) end + # converts radians to degrees def self.rad2deg(radian) radian.to_f*(180.0/PI) end + # returns LinearRing object with correct bounds def self.format_bounds(bounds) KML::LinearRing.new(:coordinates => bounds) end lib/kml_shapes.rb a6b76decde0ab2a790fe4a53f7e2316d4b713cd9 Ben Hughes ben@pixelmachine.org http://github.com/schleyfox/ascends_viz/commit/83d8a100b3b02037c6b3905385215f442d900c6a 83d8a100b3b02037c6b3905385215f442d900c6a 2008-06-24T14:48:40-07:00 2008-06-24T14:48:40-07:00 Commented my helper libraries * added dirs so it doesn't fail weirdly c1da0e3336a8c0ad93b36aa997b232bdf95a131d Ben Hughes ben@pixelmachine.org