initial commit

Author: xunker

eclipse_gosu.rb

@@ -0,0 +1,231 @@
+#!/usr/bin/env ruby
+#
+# Visualizer to show sun and moon positions, give a certain time and position on
+# the earth.
+#
+# Uses "gosu" so you will need to install the following libraries:
+#  * gosu (brew install gosu on macos)
+#  * sdl2 (brew install sdl2 on macos)
+#
+# Uses gems:
+#  * suncalc
+#  * gosu
+
+# The moon is the brighter of the two bodies. The sun is the dimmer of the two.
+#
+# The green line is the horizon and will move up and down depending on the time
+# of the year.
+#
+# Default starting position on the earth is Grand Teton National Park, which
+# will be in the path of totality for the 2017 Eclipse. Default time is the
+# projected time of totality for that location.
+#
+# You can move through time with the left and right arrows. By default, right
+# arrow will move you 1 hour ahead, left will move you one hour behind. You can
+# change the movement speed using the up and down arrows. Your current movement
+# speed is shown in the window title bar.
+#
+# The "r" key will set the time to be sunrise of the current day.
+#
+# The "s" key will set the time to be sunset of the current day.
+#
+# Escape will exit.
+#
+# You can change the position on earth by changing the value of `@coords`
+# defined inthe Eclipse#initialize method. Insert your prefered Lat/Long
+# coordinates in decimal format.
+#
+# You can also change the default start time by changing `@current_time`
+# defined in the Eclipse#initialize method. You can also uses the SunCalc gem
+# to set the time to be sunrise, sunset, mid-day, etc.
+
+
+require 'suncalc'
+require 'time'
+
+require 'gosu'
+# brew install gosu
+# brew install sdl2
+
+# https://gist.github.com/jlnr/661266
+class Circle
+  attr_reader :columns, :rows
+
+  def initialize radius, color = 255
+    @columns = @rows = radius * 2
+    lower_half = (0...radius).map do |y|
+      x = Math.sqrt(radius**2 - y**2).round
+      right_half = "#{color.chr * x}#{0.chr * (radius - x)}"
+      "#{right_half.reverse}#{right_half}"
+    end.join
+    @blob = lower_half.reverse + lower_half
+    @blob.gsub!(/./) { |alpha| "#{255.chr}#{255.chr}#{255.chr}#{alpha}"}
+  end
+
+  def to_blob
+    @blob
+  end
+end
+
+class Eclipse < Gosu::Window
+  MOVEMENTS_MODES = [
+    # name, times, change in seconds * times
+    ['1 Minute', 1, 60],
+    ['1 Hour', 60, 60],
+    ['1 Day', 24, 3600],
+    ['30 Days', 30, 86400],
+    ['365 Days', 365, 86400]
+  ]
+
+  def initialize
+    @width = 1024
+    @height = 746
+    super @width, @height
+    self.caption = "Eclipse"
+
+    @moon_d = 24
+    @moon = Gosu::Image.new(self, Circle.new(@moon_d, 255), false)
+    @sun_d = 25
+    @sun = Gosu::Image.new(self, Circle.new(@sun_d, 128), false)
+    @you_d = 10
+    @you = Gosu::Image.new(self, Circle.new(@you_d, 200), false)
+
+    # @coords = [40.768860, -111.893273] # Salt Lake City, Utah
+    @coords = [43.833333, -110.700833] # grand teton NP, 11:36am
+
+    @current_time = Time.parse('2017-08-21 10:36:00') # grand teton NP totality, in MST/MDT time
+    # @current_time = SunCalc.get_times(Time.now, @coords.first, @coords.last)[:solar_noon]
+    # @current_time = SunCalc.get_times(Time.now, @coords.first, @coords.last)[:sunrise]
+    # @current_time = SunCalc.get_times(Time.now, @coords.first, @coords.last)[:sunset]
+    # @current_time = SunCalc.get_times(Time.parse('June 21, 2018'), @coords.first, @coords.last)[:sunrise]
+
+    # Can use one of: [:solar_noon, :nadir, :sunrise, :sunset, :sunrise_end, :sunset_start, :dawn, :dusk, :nautical_dawn, :nautical_dusk, :night_end, :night, :golden_hour_end, :golden_hour]
+
+    @current_movement_mode = 1
+
+    update_coords
+    update_horizon_y
+    puts 'update_horizon_y'
+
+    @counter = 0
+  end
+
+  def button_down(id)
+    return if @moving
+    case id
+    when Gosu::Button::KbRight
+      @moving = true
+      puts "Forward in time #{MOVEMENTS_MODES[@current_movement_mode][0]}"
+      @counter = MOVEMENTS_MODES[@current_movement_mode][1]
+    when Gosu::Button::KbLeft
+      @moving = true
+      puts "Backward in time #{MOVEMENTS_MODES[@current_movement_mode][0]}"
+      @counter = -MOVEMENTS_MODES[@current_movement_mode][1]
+    when Gosu::Button::KbUp
+      @current_movement_mode += 1
+      @current_movement_mode = 0 if @current_movement_mode > MOVEMENTS_MODES.length-1
+    when Gosu::Button::KbDown
+      @current_movement_mode -= 1
+      @current_movement_mode = MOVEMENTS_MODES.length-1 if @current_movement_mode < 0
+    when Gosu::Button::KbR
+      @current_time = get_times[:sunrise]
+    when Gosu::Button::KbS
+      @current_time = get_times[:sunset]
+    when Gosu::Button::KbEscape
+      exit
+    end
+  end
+
+  def get_times
+    SunCalc.get_times(@current_time, @coords.first, @coords.last)
+  end
+
+  # Sets horizon Y coordiate to be same as suns Y position at sunrise
+  def update_horizon_y
+    sunrise_time = get_times[:sunrise]
+
+    sunrise_coords = SunCalc.get_position(sunrise_time, @coords.first, @coords.last)
+
+    @horizon_y =  map_range([-180, +180], [@height-@sun_d/2, @sun_d], sph2cart(sunrise_coords[:azimuth], sunrise_coords[:altitude])[:y]).to_i
+  end
+
+  def update_coords
+    @sun_coords =  SunCalc.get_position(@current_time, @coords.first, @coords.last)
+    @moon_coords = SunCalc.get_moon_position(@current_time, @coords.first, @coords.last)
+  end
+
+  def update
+     if @counter != 0
+      update_horizon_y
+      update_caption
+    end
+
+    if @counter < 0
+      @current_time -= MOVEMENTS_MODES[@current_movement_mode][2]
+      @counter += 1
+    elsif @counter > 0
+      @current_time += MOVEMENTS_MODES[@current_movement_mode][2]
+      @counter -= 1
+    elsif @counter == 0 && @moving
+      update_horizon_y
+      @moving = false
+    end
+
+    update_coords
+  end
+
+  def draw
+    # draw horizon
+    draw_line(0, @horizon_y, Gosu::Color::GREEN, @width, @horizon_y, Gosu::Color::GREEN)
+
+    # draw "you"
+    @you.draw(@width/2, @horizon_y-@you_d, 0)
+
+    # Draw sun sphere - the dimmer of the two
+    @sun.draw(
+      map_range([-180, +180], [@width-@sun_d/2, @sun_d], sph2cart(@sun_coords[:azimuth], @sun_coords[:altitude])[:x]).to_i-(@sun_d/2),
+      map_range([-180, +180], [@height-@sun_d/2, @sun_d], sph2cart(@sun_coords[:azimuth], @sun_coords[:altitude])[:y]).to_i-(@sun_d/2),
+      0
+    )
+
+    # Draw moon sphere - the brighter of the two
+    @moon.draw(
+      map_range([-180, +180], [@width-@moon_d/2, @moon_d], sph2cart(@moon_coords[:azimuth], @moon_coords[:altitude])[:x]).to_i-(@moon_d/2),
+      map_range([-180, +180], [@height-@moon_d/2, @moon_d], sph2cart(@moon_coords[:azimuth], @moon_coords[:altitude])[:y]).to_i-(@moon_d/2),
+      0
+    )
+
+    unless @moving
+      # To prevent needless rapid redrawing if the screen isn't changing
+      sleep(0.25)
+      update_caption
+    end
+  end
+
+  def update_caption
+    self.caption = "#{(@current_time)} - #{MOVEMENTS_MODES[@current_movement_mode][0]}"
+  end
+
+  # Maps a number from one numeric range to another. In this case we need to be
+  # able to map the coordinates of the sun/moon in to the coordinate range of
+  # the Gosu window.
+  def map_range(a, b, s)
+    af, al, bf, bl = a.first, a.last, b.first, b.last
+    bf + (s - af)*(bl - bf).quo(al - af)
+  end
+
+  # Convert Spherical coordinates (azimuth/elevation) in to cartesian (x/y) coordinates
+  # https://www.mathworks.com/help/matlab/ref/sph2cart.html?requestedDomain=www.mathworks.com#input_argument_d0e929631
+  def sph2cart(azimuth, elevation)
+    {
+      # x: 180 * Math.cos(elevation) * Math.cos(azimuth),
+      # y: 180 * Math.cos(elevation) * Math.sin(azimuth)
+      x: 180 * Math.cos(elevation) * Math.sin(azimuth),
+      y: 180 * Math.cos(elevation) * Math.cos(azimuth)
+
+    }
+  end
+
+end
+
+Eclipse.new.show