--- /dev/null
+
+require "observer"
+require File.dirname(__FILE__) + '/base'
+
+##
+# A scene is a non-linear graph that assembles layers together to tell a story.
+# Layers are folders with appropriately named files (see below). You can group
+# layers and control them together or just set their values individually.
+#
+# Examples:
+#
+# * A city scene that changes with the time of day and the weather conditions.
+# * A traffic map that shows red lines on streets that are crowded and green on free-flowing ones.
+#
+# Usage:
+#
+# g = Gruff::Scene.new("500x100", "artwork/city_scene")
+# g.layers = %w(background haze sky clouds)
+# g.weather_group = %w(clouds)
+# g.time_group = %w(background sky)
+# g.weather = "cloudy"
+# g.time = Time.now
+# g.haze = true
+# g.write "hazy_daytime_city_scene.png"
+#
+#
+#
+# If there is a file named 'default.png', it will be selected (unless other values are provided to override it).
+#
+class Gruff::Scene < Gruff::Base
+
+ # An array listing the foldernames that will be rendered, from back to front.
+ #
+ # g.layers = %w(sky clouds buildings street people)
+ #
+ attr_reader :layers
+
+ def initialize(target_width, base_dir)
+ @base_dir = base_dir
+ @groups = {}
+ @layers = []
+ super target_width
+ end
+
+ def draw
+ # Join all the custom paths and filter out the empty ones
+ image_paths = @layers.map { |layer| layer.path }.select { |path| !path.empty? }
+ images = Magick::ImageList.new(*image_paths)
+ @base_image = images.flatten_images
+ end
+
+ def layers=(ordered_list)
+ ordered_list.each do |layer_name|
+ @layers << Gruff::Layer.new(@base_dir, layer_name)
+ end
+ end
+
+ # Group layers to input values
+ #
+ # g.weather_group = ["sky", "sea", "clouds"]
+ #
+ # Set input values
+ #
+ # g.weather = "cloudy"
+ #
+ def method_missing(method_name, *args)
+ case method_name.to_s
+ when /^(\w+)_group=$/
+ add_group $1, *args
+ return
+ when /^(\w+)=$/
+ set_input $1, args.first
+ return
+ end
+ super
+ end
+
+private
+
+ def add_group(input_name, layer_names)
+ @groups[input_name] = Gruff::Group.new(input_name, @layers.select { |layer| layer_names.include?(layer.name) })
+ end
+
+ def set_input(input_name, input_value)
+ if not @groups[input_name].nil?
+ @groups[input_name].send_updates(input_value)
+ else
+ if chosen_layer = @layers.detect { |layer| layer.name == input_name }
+ chosen_layer.update input_value
+ end
+ end
+ end
+
+end
+
+
+class Gruff::Group
+
+ include Observable
+ attr_reader :name
+
+ def initialize(folder_name, layers)
+ @name = folder_name
+ layers.each do |layer|
+ layer.observe self
+ end
+ end
+
+ def send_updates(value)
+ changed
+ notify_observers value
+ end
+
+end
+
+
+class Gruff::Layer
+
+ attr_reader :name
+
+ def initialize(base_dir, folder_name)
+ @base_dir = base_dir.to_s
+ @name = folder_name.to_s
+ @filenames = Dir.open(File.join(base_dir, folder_name)).entries.select { |file| file =~ /^[^.]+\.png$/ }
+ @selected_filename = select_default
+ end
+
+ # Register this layer so it receives updates from the group
+ def observe(obj)
+ obj.add_observer self
+ end
+
+ # Choose the appropriate filename for this layer, based on the input
+ def update(value)
+ @selected_filename = case value.to_s
+ when /^(true|false)$/
+ select_boolean value
+ when /^(\w|\s)+$/
+ select_string value
+ when /^-?(\d+\.)?\d+$/
+ select_numeric value
+ when /(\d\d):(\d\d):\d\d/
+ select_time "#{$1}#{$2}"
+ else
+ select_default
+ end
+ # Finally, try to use 'default' if we're still blank
+ @selected_filename ||= select_default
+ end
+
+ # Returns the full path to the selected image, or a blank string
+ def path
+ unless @selected_filename.nil? || @selected_filename.empty?
+ return File.join(@base_dir, @name, @selected_filename)
+ end
+ ''
+ end
+
+private
+
+ # Match "true.png" or "false.png"
+ def select_boolean(value)
+ file_exists_or_blank value.to_s
+ end
+
+ # Match -5 to _5.png
+ def select_numeric(value)
+ file_exists_or_blank value.to_s.gsub('-', '_')
+ end
+
+ def select_time(value)
+ times = @filenames.map { |filename| filename.gsub('.png', '') }
+ times.each_with_index do |time, index|
+ if (time > value) && (index > 0)
+ return "#{times[index - 1]}.png"
+ end
+ end
+ return "#{times.last}.png"
+ end
+
+ # Match "partly cloudy" to "partly_cloudy.png"
+ def select_string(value)
+ file_exists_or_blank value.to_s.gsub(' ', '_')
+ end
+
+ def select_default
+ @filenames.include?("default.png") ? "default.png" : ''
+ end
+
+ # Returns the string "#{filename}.png", if it exists.
+ #
+ # Failing that, it returns default.png, or '' if that doesn't exist.
+ def file_exists_or_blank(filename)
+ @filenames.include?("#{filename}.png") ? "#{filename}.png" : select_default
+ end
+
+end
projects / selectricity / blobdiff