fireflies

Author: monkstone

contributed/data/background.png

@@ -0,0 +1,165 @@
+# Luciernagas
+# After an original by Marcel Miranda aka reaktivo
+# https://github.com/reaktivo/rp-luciernagas
+# translated and updated by Martin Prout for JRubyArt
+# features use of Vec2D class and grid method
+load_library :control_panel
+
+attr_reader :panel, :hide, :image_mask, :spots
+ACCURACY = 4
+
+# Firefly holder
+Flyer = Struct.new(:pos, :to_pos, :rotation, :positions)
+
+def settings
+  size 1024, 480, P2D
+  smooth
+end
+
+def setup
+  sketch_title 'Luciernagas'
+  control_panel do |control|
+    control.title 'Firefly Controller'
+    control.look_feel 'Nimbus'
+    control.slider(:speed, 0..20, 5)
+    control.slider(:tail_length, 0..400, 30)
+    control.slider(:rotation_max, 0..30, 7)
+    control.slider(:target_radius, 5...100, 20)
+    control.slider(:spot_distance, 5..200, 80)
+    control.button :reset
+    @panel = control
+  end
+  @hide = false
+  @spotlight = create_spotlight
+  @background = load_image(data_path('background.png'))
+  @image_mask = load_image(data_path('mask.png'))
+  load_spots(image_mask, ACCURACY)
+  reset
+end
+
+def reset
+  @flyers = (0..100).map { create_flyer }
+end
+
+def draw
+  unless hide
+    @hide = true
+    panel.set_visible(hide)
+  end
+  image @background, 0, 0
+  draw_lights
+  draw_flyers
+end
+
+def draw_lights
+  lights = create_graphics width, height, P2D
+  lights.begin_draw
+  @flyers.each do |flyer|
+    lights.push_matrix
+    position = flyer.pos
+    lights.translate position.x, position.y
+    lights.image @spotlight, -@spotlight.width / 2, -@spotlight.height / 2
+    lights.pop_matrix
+  end
+  lights.end_draw
+  image_mask.mask lights
+  image image_mask, 0, 0
+end
+
+def draw_flyers
+  rotation_max = @rotation_max / 100 * TWO_PI
+  @flyers.each do |flyer|
+    # check if point reached
+    if flyer.pos.dist(flyer.to_pos) <  @target_radius
+      spot = find_spot_near flyer.pos, @spot_distance
+      flyer.to_pos = spot
+    end
+    # set new rotation
+    to_rotation = (flyer.to_pos - flyer.pos).heading
+    to_rotation = find_nearest_rotation(flyer.rotation, to_rotation)
+    # rotate to new direction
+    if flyer.rotation < to_rotation
+      flyer.rotation = flyer.rotation + rotation_max
+      flyer.rotation = to_rotation if flyer.rotation > to_rotation
+    else
+      flyer.rotation = flyer.rotation - rotation_max
+      flyer.rotation = to_rotation if flyer.rotation < to_rotation
+    end
+    # add tail position
+    flyer.positions << flyer.pos.dup
+    flyer.positions.shift while flyer.positions.size > @tail_length
+    # set flyer position
+    flyer.pos.x = flyer.pos.x + @speed * cos(flyer.rotation)
+    flyer.pos.y = flyer.pos.y + @speed * sin(flyer.rotation)
+    # draw flyer tail
+    draw_tail flyer
+    # draw flyer
+    no_stroke
+    fill 201, 242, 2
+    push_matrix
+    translate flyer.pos.x, flyer.pos.y
+    ellipse 0, 0, 5, 5
+    pop_matrix
+  end
+end
+
+def create_flyer
+  spot = rand_spot
+  to_spot = find_spot_near spot, @spot_distance
+  rotation = rand * TWO_PI
+  Flyer.new(spot, to_spot, rotation, [])
+end
+
+def draw_tail(flyer)
+  positions = flyer.positions
+  return unless positions && !positions.empty?
+  alpha_add = (255 / positions.size).to_i
+  positions.each_index do |i|
+    stroke(255, i * alpha_add)
+    if i < positions.size - 2
+      line(positions[i].x, positions[i].y, positions[i + 1].x, positions[i + 1].y)
+    end
+  end
+end
+
+def load_spots(spot_image, accuracy = ACCURACY)
+  @spots = []
+  spot_image.load_pixels
+  corner_color = spot_image.get 0, 0
+  grid(spot_image.width, spot_image.height, accuracy, accuracy) do |x, y|
+    color = spot_image.get(x, y)
+    spots << Vec2D.new(x, y) if color != corner_color
+  end
+end
+
+def rand_spot
+  spots.sample
+end
+
+def find_spot_near(pos, distance)
+  spot = Vec2D.new(Float::INFINITY, Float::INFINITY)
+  spot = rand_spot until spot.dist(pos) < distance
+  spot
+end
+
+def find_nearest_rotation(from, to)
+  dif = (to - from) % TWO_PI
+  if dif != dif % PI
+    dif = dif < 0 ? dif + TWO_PI : dif - TWO_PI
+  end
+  from + dif
+end
+
+def create_spotlight
+  size = 60
+  spotlight = create_graphics size, size, P2D
+  spotlight.begin_draw
+  spotlight.no_stroke
+  spotlight.fill 255, 60
+  # spotlight.fill 255, 40
+  half_size = size / 2
+  spotlight.ellipse half_size, half_size, half_size, half_size
+  spotlight.filter BLUR, 4
+  spotlight.end_draw
+  spotlight
+end