synced samples

1 files changed, 887 insertions, 0 deletions

diff --git a/samples/99_genre_platformer/the_little_probe/app/main.rb b/samples/99_genre_platformer/the_little_probe/app/main.rb
new file mode 100644
index 0000000..1c90218
--- /dev/null
+++ b/samples/99_genre_platformer/the_little_probe/app/main.rb
@@ -0,0 +1,887 @@
+class FallingCircle
+  attr_gtk
+
+  def tick
+    fiddle
+    defaults
+    render
+    input
+    calc
+  end
+
+  def fiddle
+    state.gravity     = -0.02
+    circle.radius     = 15
+    circle.elasticity = 0.4
+    camera.follow_speed = 0.4 * 0.4
+  end
+
+  def render
+    render_stage_editor
+    render_debug
+    render_game
+  end
+
+  def defaults
+    if state.tick_count == 0
+      outputs.sounds << "sounds/bg.ogg"
+    end
+
+    state.storyline ||= [
+      { text: "<- -> to aim, hold space to charge",                            distance_gate: 0 },
+      { text: "the little probe - by @amirrajan, made with DragonRuby Game Toolkit", distance_gate: 0 },
+      { text: "mission control, this is sasha. landing on europa successful.", distance_gate: 0 },
+      { text: "operation \"find earth 2.0\", initiated at 8-29-2036 14:00.",   distance_gate: 0 },
+      { text: "jupiter's sure is beautiful...",   distance_gate: 4000 },
+      { text: "hmm, it seems there's some kind of anomoly in the sky",   distance_gate: 7000 },
+      { text: "dancing lights, i'll call them whisps.",   distance_gate: 8000 },
+      { text: "#todo... look i ran out of time -_-",   distance_gate: 9000 },
+      { text: "there's never enough time",   distance_gate: 9000 },
+      { text: "the game jam was fun though ^_^",   distance_gate: 10000 },
+    ]
+
+    load_level force: args.state.tick_count == 0
+    state.line_mode            ||= :terrain
+
+    state.sound_index          ||= 1
+    circle.potential_lift      ||= 0
+    circle.angle               ||= 90
+    circle.check_point_at      ||= -1000
+    circle.game_over_at        ||= -1000
+    circle.x                   ||= -485
+    circle.y                   ||= 12226
+    circle.check_point_x       ||= circle.x
+    circle.check_point_y       ||= circle.y
+    circle.dy                  ||= 0
+    circle.dx                  ||= 0
+    circle.previous_dy         ||= 0
+    circle.previous_dx         ||= 0
+    circle.angle               ||= 0
+    circle.after_images        ||= []
+    circle.terrains_to_monitor ||= {}
+    circle.impact_history      ||= []
+
+    camera.x                   ||= 0
+    camera.y                   ||= 0
+    camera.target_x            ||= 0
+    camera.target_y            ||= 0
+    state.snaps                ||= { }
+    state.snap_number            = 10
+
+    args.state.storyline_x ||= -1000
+    args.state.storyline_y ||= -1000
+  end
+
+  def render_game
+    outputs.background_color = [0, 0, 0]
+    outputs.sprites << [-circle.x + 1100,
+                        -circle.y - 100,
+                        2416 * 4,
+                        3574 * 4,
+                        'sprites/jupiter.png']
+    outputs.sprites << [-circle.x,
+                        -circle.y,
+                        2416 * 4,
+                        3574 * 4,
+                        'sprites/level.png']
+    outputs.sprites << state.whisp_queue
+    render_aiming_retical
+    render_circle
+    render_notification
+  end
+
+  def render_notification
+    toast_length = 500
+    if circle.game_over_at.elapsed_time < toast_length
+      label_text = "..."
+    elsif circle.check_point_at.elapsed_time > toast_length
+      args.state.current_storyline = nil
+      return
+    end
+    if circle.check_point_at &&
+       circle.check_point_at.elapsed_time == 1 &&
+       !args.state.current_storyline
+       if args.state.storyline.length > 0 && args.state.distance_traveled > args.state.storyline[0][:distance_gate]
+         args.state.current_storyline = args.state.storyline.shift[:text]
+         args.state.distance_traveled ||= 0
+         args.state.storyline_x = circle.x
+         args.state.storyline_y = circle.y
+       end
+      return unless args.state.current_storyline
+    end
+    label_text = args.state.current_storyline
+    return unless label_text
+    x = circle.x + camera.x
+    y = circle.y + camera.y - 40
+    w = 900
+    h = 30
+    outputs.primitives << [x - w.idiv(2), y - h, w, h, 255, 255, 255, 255].solid
+    outputs.primitives << [x - w.idiv(2), y - h, w, h, 0, 0, 0, 255].border
+    outputs.labels << [x, y - 4, label_text, 1, 1, 0, 0, 0, 255]
+  end
+
+  def render_aiming_retical
+    outputs.sprites << [state.camera.x + circle.x + circle.angle.vector_x(circle.potential_lift * 10) - 5,
+                        state.camera.y + circle.y + circle.angle.vector_y(circle.potential_lift * 10) - 5,
+                        10, 10, 'sprites/circle-orange.png']
+    outputs.sprites << [state.camera.x + circle.x + circle.angle.vector_x(circle.radius * 3) - 5,
+                        state.camera.y + circle.y + circle.angle.vector_y(circle.radius * 3) - 5,
+                        10, 10, 'sprites/circle-orange.png', 0, 128]
+    if rand > 0.9
+      outputs.sprites << [state.camera.x + circle.x + circle.angle.vector_x(circle.radius * 3) - 5,
+                          state.camera.y + circle.y + circle.angle.vector_y(circle.radius * 3) - 5,
+                          10, 10, 'sprites/circle-white.png', 0, 128]
+    end
+  end
+
+  def render_circle
+    outputs.sprites << circle.after_images.map do |ai|
+      ai.merge(x: ai.x + state.camera.x - circle.radius,
+               y: ai.y + state.camera.y - circle.radius,
+               w: circle.radius * 2,
+               h: circle.radius * 2,
+               path: 'sprites/circle-white.png')
+    end
+
+    outputs.sprites << [(circle.x - circle.radius) + state.camera.x,
+                        (circle.y - circle.radius) + state.camera.y,
+                        circle.radius * 2,
+                        circle.radius * 2,
+                        'sprites/probe.png']
+  end
+
+  def render_debug
+    return unless state.debug_mode
+
+    outputs.labels << [10, 30, state.line_mode, 0, 0, 0, 0, 0]
+    outputs.labels << [12, 32, state.line_mode, 0, 0, 255, 255, 255]
+
+    args.outputs.lines << trajectory(circle).line.to_hash.tap do |h|
+      h[:x] += state.camera.x
+      h[:y] += state.camera.y
+      h[:x2] += state.camera.x
+      h[:y2] += state.camera.y
+    end
+
+    outputs.primitives << state.terrain.find_all do |t|
+      circle.x.between?(t.x - 640, t.x2 + 640) || circle.y.between?(t.y - 360, t.y2 + 360)
+    end.map do |t|
+      [
+        t.line.associate(r: 0, g: 255, b: 0) do |h|
+          h.x  += state.camera.x
+          h.y  += state.camera.y
+          h.x2 += state.camera.x
+          h.y2 += state.camera.y
+          if circle.rect.intersect_rect? t[:rect]
+            h[:r] = 255
+            h[:g] = 0
+          end
+          h
+        end,
+        t[:rect].border.associate(r: 255, g: 0, b: 0) do |h|
+          h.x += state.camera.x
+          h.y += state.camera.y
+          h.b = 255 if line_near_rect? circle.rect, t
+          h
+        end
+      ]
+    end
+
+    outputs.primitives << state.lava.find_all do |t|
+      circle.x.between?(t.x - 640, t.x2 + 640) || circle.y.between?(t.y - 360, t.y2 + 360)
+    end.map do |t|
+      [
+        t.line.associate(r: 0, g: 0, b: 255) do |h|
+          h.x  += state.camera.x
+          h.y  += state.camera.y
+          h.x2 += state.camera.x
+          h.y2 += state.camera.y
+          if circle.rect.intersect_rect? t[:rect]
+            h[:r] = 255
+            h[:b] = 0
+          end
+          h
+        end,
+        t[:rect].border.associate(r: 255, g: 0, b: 0) do |h|
+          h.x += state.camera.x
+          h.y += state.camera.y
+          h.b = 255 if line_near_rect? circle.rect, t
+          h
+        end
+      ]
+    end
+
+    if state.god_mode
+      border = circle.rect.merge(x: circle.rect.x + state.camera.x,
+                                 y: circle.rect.y + state.camera.y,
+                                 g: 255)
+    else
+      border = circle.rect.merge(x: circle.rect.x + state.camera.x,
+                                 y: circle.rect.y + state.camera.y,
+                                 b: 255)
+    end
+
+    outputs.borders << border
+
+    overlapping ||= {}
+
+    circle.impact_history.each do |h|
+      label_mod = 300
+      x = (h[:body][:x].-(150).idiv(label_mod)) * label_mod + camera.x
+      y = (h[:body][:y].+(150).idiv(label_mod)) * label_mod + camera.y
+      10.times do
+        if overlapping[x] && overlapping[x][y]
+          y -= 52
+        else
+          break
+        end
+      end
+
+      overlapping[x] ||= {}
+      overlapping[x][y] ||= true
+      outputs.primitives << [x, y - 25, 300, 50, 0, 0, 0, 128].solid
+      outputs.labels << [x + 10, y + 24, "dy: %.2f" % h[:body][:new_dy], -2, 0, 255, 255, 255]
+      outputs.labels << [x + 10, y +  9, "dx: %.2f" % h[:body][:new_dx], -2, 0, 255, 255, 255]
+      outputs.labels << [x + 10, y -  5, " ?: #{h[:body][:new_reason]}", -2, 0, 255, 255, 255]
+
+      outputs.labels << [x + 100, y + 24, "angle: %.2f" % h[:impact][:angle], -2, 0, 255, 255, 255]
+      outputs.labels << [x + 100, y + 9, "m(l): %.2f" % h[:terrain][:slope], -2, 0, 255, 255, 255]
+      outputs.labels << [x + 100, y - 5, "m(c): %.2f" % h[:body][:slope], -2, 0, 255, 255, 255]
+
+      outputs.labels << [x + 200, y + 24, "ray: #{h[:impact][:ray]}", -2, 0, 255, 255, 255]
+      outputs.labels << [x + 200, y +  9, "nxt: #{h[:impact][:ray_next]}", -2, 0, 255, 255, 255]
+      outputs.labels << [x + 200, y -  5, "typ: #{h[:impact][:type]}", -2, 0, 255, 255, 255]
+    end
+
+    if circle.floor
+      outputs.labels << [circle.x + camera.x + 30, circle.y + camera.y + 100, "point: #{circle.floor_point.slice(:x, :y).values}", -2, 0]
+      outputs.labels << [circle.x + camera.x + 31, circle.y + camera.y + 101, "point: #{circle.floor_point.slice(:x, :y).values}", -2, 0, 255, 255, 255]
+      outputs.labels << [circle.x + camera.x + 30, circle.y + camera.y +  85, "circle: #{circle.hash.slice(:x, :y).values}", -2, 0]
+      outputs.labels << [circle.x + camera.x + 31, circle.y + camera.y +  86, "circle: #{circle.hash.slice(:x, :y).values}", -2, 0, 255, 255, 255]
+      outputs.labels << [circle.x + camera.x + 30, circle.y + camera.y +  70, "rel: #{circle.floor_relative_x} #{circle.floor_relative_y}", -2, 0]
+      outputs.labels << [circle.x + camera.x + 31, circle.y + camera.y +  71, "rel: #{circle.floor_relative_x} #{circle.floor_relative_y}", -2, 0, 255, 255, 255]
+    end
+  end
+
+  def render_stage_editor
+    return unless state.god_mode
+    return unless state.point_one
+    args.lines << [state.point_one, inputs.mouse.point, 0, 255, 255]
+  end
+
+  def trajectory body
+    [body.x + body.dx,
+     body.y + body.dy,
+     body.x + body.dx * 1000,
+     body.y + body.dy * 1000,
+     0, 255, 255]
+  end
+
+  def lengthen_line line, num
+    line = normalize_line(line)
+    slope = geometry.line_slope(line, replace_infinity: 10).abs
+    if slope < 2
+      [line.x - num, line.y, line.x2 + num, line.y2].line.to_hash
+    else
+      [line.x, line.y, line.x2, line.y2].line.to_hash
+    end
+  end
+
+  def normalize_line line
+    if line.x > line.x2
+      x  = line.x2
+      y  = line.y2
+      x2 = line.x
+      y2 = line.y
+    else
+      x  = line.x
+      y  = line.y
+      x2 = line.x2
+      y2 = line.y2
+    end
+    [x, y, x2, y2]
+  end
+
+  def rect_for_line line
+    if line.x > line.x2
+      x  = line.x2
+      y  = line.y2
+      x2 = line.x
+      y2 = line.y
+    else
+      x  = line.x
+      y  = line.y
+      x2 = line.x2
+      y2 = line.y2
+    end
+
+    w = x2 - x
+    h = y2 - y
+
+    if h < 0
+      y += h
+      h = h.abs
+    end
+
+    if w < circle.radius
+      x -= circle.radius
+      w = circle.radius * 2
+    end
+
+    if h < circle.radius
+      y -= circle.radius
+      h = circle.radius * 2
+    end
+
+    { x: x, y: y, w: w, h: h }
+  end
+
+  def snap_to_grid x, y, snaps
+    snap_number = 10
+    x = x.to_i
+    y = y.to_i
+
+    x_floor = x.idiv(snap_number) * snap_number
+    x_mod   = x % snap_number
+    x_ceil  = (x.idiv(snap_number) + 1) * snap_number
+
+    y_floor = y.idiv(snap_number) * snap_number
+    y_mod   = y % snap_number
+    y_ceil  = (y.idiv(snap_number) + 1) * snap_number
+
+    if snaps[x_floor]
+      x_result = x_floor
+    elsif snaps[x_ceil]
+      x_result = x_ceil
+    elsif x_mod < snap_number.idiv(2)
+      x_result = x_floor
+    else
+      x_result = x_ceil
+    end
+
+    snaps[x_result] ||= {}
+
+    if snaps[x_result][y_floor]
+      y_result = y_floor
+    elsif snaps[x_result][y_ceil]
+      y_result = y_ceil
+    elsif y_mod < snap_number.idiv(2)
+      y_result = y_floor
+    else
+      y_result = y_ceil
+    end
+
+    snaps[x_result][y_result] = true
+    return [x_result, y_result]
+
+  end
+
+  def snap_line line
+    x, y, x2, y2 = line
+  end
+
+  def string_to_line s
+    x, y, x2, y2 = s.split(',').map(&:to_f)
+
+    if x > x2
+      x2, x = x, x2
+      y2, y = y, y2
+    end
+
+    x, y = snap_to_grid x, y, state.snaps
+    x2, y2 = snap_to_grid x2, y2, state.snaps
+    [x, y, x2, y2].line.to_hash
+  end
+
+  def load_lines file
+    data = gtk.read_file(file) || ""
+    data.each_line
+        .reject { |l| l.strip.length == 0 }
+        .map { |l| string_to_line l }
+        .map { |h| h.merge(rect: rect_for_line(h))  }
+  end
+
+  def load_terrain
+    load_lines 'level.txt'
+  end
+
+  def load_lava
+    load_lines 'level_lava.txt'
+  end
+
+  def load_level force: false
+    if force
+      state.snaps = {}
+      state.terrain = load_terrain
+      state.lava = load_lava
+    else
+      state.terrain ||= load_terrain
+      state.lava ||= load_lava
+    end
+  end
+
+  def save_lines lines, file
+    s = lines.map do |l|
+      "#{l.x1},#{l.y1},#{l.x2},#{l.y2}"
+    end.join("\n")
+    gtk.write_file(file, s)
+  end
+
+  def save_level
+    save_lines(state.terrain, 'level.txt')
+    save_lines(state.lava, 'level_lava.txt')
+    load_level force: true
+  end
+
+  def line_near_rect? rect, terrain
+    geometry.intersect_rect?(rect, terrain[:rect])
+  end
+
+  def point_within_line? point, line
+    return false if !point
+    return false if !line
+    return true
+  end
+
+  def calc_impacts x, dx, y, dy, radius
+    results = { }
+    results[:x] = x
+    results[:y] = y
+    results[:dx] = x
+    results[:dy] = y
+    results[:point] = { x: x, y: y }
+    results[:rect] = { x: x - radius, y: y - radius, w: radius * 2, h: radius * 2 }
+    results[:trajectory] = trajectory(results)
+    results[:impacts] = terrain.find_all { |t| line_near_rect? results[:rect], t }.map do |t|
+      {
+        terrain: t,
+        point: geometry.line_intersect(results[:trajectory], t),
+        type: :terrain
+      }
+    end.reject { |t| !point_within_line? t[:point], t[:terrain] }
+
+    results[:impacts] += lava.find_all { |t| line_near_rect? results[:rect], t }.map do |t|
+      {
+        terrain: t,
+        point: geometry.line_intersect(results[:trajectory], t),
+        type: :lava
+      }
+    end.reject { |t| !point_within_line? t[:point], t[:terrain] }
+
+    results
+  end
+
+  def calc_potential_impacts
+    impact_results = calc_impacts circle.x, circle.dx, circle.y, circle.dy, circle.radius
+    circle.rect = impact_results[:rect]
+    circle.trajectory = impact_results[:trajectory]
+    circle.impacts = impact_results[:impacts]
+  end
+
+  def calc_terrains_to_monitor
+    circle.impact = nil
+    circle.impacts.each do |i|
+      circle.terrains_to_monitor[i[:terrain]] ||= {
+        ray_start: geometry.ray_test(circle, i[:terrain]),
+      }
+
+      circle.terrains_to_monitor[i[:terrain]][:ray_current] = geometry.ray_test(circle, i[:terrain])
+      if circle.terrains_to_monitor[i[:terrain]][:ray_start] != circle.terrains_to_monitor[i[:terrain]][:ray_current]
+        if circle.x.between?(i[:terrain].x, i[:terrain].x2) || circle.y.between?(i[:terrain].y, i[:terrain].y2)
+          circle.impact = i
+          circle.ray_current = circle.terrains_to_monitor[i[:terrain]][:ray_current]
+        end
+      end
+    end
+  end
+
+  def impact_result body, impact
+    infinity_alias = 1000
+    r = {
+      body: {},
+      terrain: {},
+      impact: {}
+    }
+
+    r[:body][:line] = body.trajectory.dup
+    r[:body][:slope] = geometry.line_slope(body.trajectory, replace_infinity: infinity_alias)
+    r[:body][:slope_sign] = r[:body][:slope].sign
+    r[:body][:x] = body.x
+    r[:body][:y] = body.y
+    r[:body][:dy] = body.dy
+    r[:body][:dx] = body.dx
+
+    r[:terrain][:line] = impact[:terrain].dup
+    r[:terrain][:slope] = geometry.line_slope(impact[:terrain], replace_infinity: infinity_alias)
+    r[:terrain][:slope_sign] = r[:terrain][:slope].sign
+
+    r[:impact][:angle] = geometry.angle_between_lines(body.trajectory, impact[:terrain], replace_infinity: infinity_alias)
+    r[:impact][:point] = { x: impact[:point].x, y: impact[:point].y }
+    r[:impact][:same_slope_sign] = r[:body][:slope_sign] == r[:terrain][:slope_sign]
+    r[:impact][:ray] = body.ray_current
+    r[:body][:new_on_floor] = body.on_floor
+    r[:body][:new_floor] = r[:terrain][:line]
+
+    if r[:impact][:angle].abs < 90 && r[:terrain][:slope].abs < 3
+      play_sound
+      r[:body][:new_dy] = r[:body][:dy] * circle.elasticity * -1
+      r[:body][:new_dx] = r[:body][:dx] * circle.elasticity
+      r[:impact][:type] = :horizontal
+      r[:body][:new_reason] = "-"
+    elsif r[:impact][:angle].abs < 90 && r[:terrain][:slope].abs > 3
+      play_sound
+      r[:body][:new_dy] = r[:body][:dy] * 1.1
+      r[:body][:new_dx] = r[:body][:dx] * -circle.elasticity
+      r[:impact][:type] = :vertical
+      r[:body][:new_reason] = "|"
+    else
+      play_sound
+      r[:body][:new_dx] = r[:body][:dx] * -circle.elasticity
+      r[:body][:new_dy] = r[:body][:dy] * -circle.elasticity
+      r[:impact][:type] = :slanted
+      r[:body][:new_reason] = "/"
+    end
+
+    r[:impact][:energy] = r[:body][:new_dx].abs + r[:body][:new_dy].abs
+
+    if r[:impact][:energy] <= 0.3 && r[:terrain][:slope].abs < 4
+      r[:body][:new_dx] = 0
+      r[:body][:new_dy] = 0
+      r[:impact][:energy] = 0
+      r[:body][:new_on_floor] = true
+      r[:body][:new_floor] = r[:terrain][:line]
+      r[:body][:new_reason] = "0"
+    end
+
+    r[:impact][:ray_next] = geometry.ray_test({ x: r[:body][:x] - (r[:body][:dx] * 1.1) + r[:body][:new_dx],
+                                                y: r[:body][:y] - (r[:body][:dy] * 1.1) + r[:body][:new_dy] + state.gravity },
+                                              r[:terrain][:line])
+
+    if r[:impact][:ray_next] == r[:impact][:ray]
+      r[:body][:new_dx] *= -1
+      r[:body][:new_dy] *= -1
+      r[:body][:new_reason] = "clip"
+    end
+
+    r
+  end
+
+  def game_over!
+    circle.x = circle.check_point_x
+    circle.y = circle.check_point_y
+    circle.dx = 0
+    circle.dy = 0
+    circle.game_over_at = state.tick_count
+  end
+
+  def not_game_over!
+    impact_history_entry = impact_result circle, circle.impact
+    circle.impact_history << impact_history_entry
+    circle.x -= circle.dx * 1.1
+    circle.y -= circle.dy * 1.1
+    circle.dx = impact_history_entry[:body][:new_dx]
+    circle.dy = impact_history_entry[:body][:new_dy]
+    circle.on_floor = impact_history_entry[:body][:new_on_floor]
+
+    if circle.on_floor
+      circle.check_point_at = state.tick_count
+      circle.check_point_x = circle.x
+      circle.check_point_y = circle.y
+    end
+
+    circle.previous_floor = circle.floor || {}
+    circle.floor = impact_history_entry[:body][:new_floor] || {}
+    circle.floor_point = impact_history_entry[:impact][:point]
+    if circle.floor.slice(:x, :y, :x2, :y2) != circle.previous_floor.slice(:x, :y, :x2, :y2)
+      new_relative_x = if circle.dx > 0
+                         :right
+                       elsif circle.dx < 0
+                         :left
+                       else
+                         nil
+                       end
+
+      new_relative_y = if circle.dy > 0
+                         :above
+                       elsif circle.dy < 0
+                         :below
+                       else
+                         nil
+                       end
+
+      circle.floor_relative_x = new_relative_x
+      circle.floor_relative_y = new_relative_y
+    end
+
+    circle.impact = nil
+    circle.terrains_to_monitor.clear
+  end
+
+  def calc_physics
+    if args.state.god_mode
+      calc_potential_impacts
+      calc_terrains_to_monitor
+      return
+    end
+
+    if circle.y < -700
+      game_over
+      return
+    end
+
+    return if state.game_over
+    return if circle.on_floor
+    circle.previous_dy = circle.dy
+    circle.previous_dx = circle.dx
+    circle.x  += circle.dx
+    circle.y  += circle.dy
+    args.state.distance_traveled ||= 0
+    args.state.distance_traveled += circle.dx.abs + circle.dy.abs
+    circle.dy += state.gravity
+    calc_potential_impacts
+    calc_terrains_to_monitor
+    return unless circle.impact
+    if circle.impact && circle.impact[:type] == :lava
+      game_over!
+    else
+      not_game_over!
+    end
+  end
+
+  def input_god_mode
+    state.debug_mode = !state.debug_mode if inputs.keyboard.key_down.forward_slash
+
+    # toggle god mode
+    if inputs.keyboard.key_down.g
+      state.god_mode = !state.god_mode
+      state.potential_lift = 0
+      circle.floor = nil
+      circle.floor_point = nil
+      circle.floor_relative_x = nil
+      circle.floor_relative_y = nil
+      circle.impact = nil
+      circle.terrains_to_monitor.clear
+      return
+    end
+
+    return unless state.god_mode
+
+    circle.x = circle.x.to_i
+    circle.y = circle.y.to_i
+
+    # move god circle
+    if inputs.keyboard.left || inputs.keyboard.a
+      circle.x -= 20
+    elsif inputs.keyboard.right || inputs.keyboard.d || inputs.keyboard.f
+      circle.x += 20
+    end
+
+    if inputs.keyboard.up || inputs.keyboard.w
+      circle.y += 20
+    elsif inputs.keyboard.down || inputs.keyboard.s
+      circle.y -= 20
+    end
+
+    # delete terrain
+    if inputs.keyboard.key_down.x
+      calc_terrains_to_monitor
+      state.terrain = state.terrain.reject do |t|
+        t[:rect].intersect_rect? circle.rect
+      end
+
+      state.lava = state.lava.reject do |t|
+        t[:rect].intersect_rect? circle.rect
+      end
+
+      calc_potential_impacts
+      save_level
+    end
+
+    # change terrain type
+    if inputs.keyboard.key_down.l
+      if state.line_mode == :terrain
+        state.line_mode = :lava
+      else
+        state.line_mode = :terrain
+      end
+    end
+
+    if inputs.mouse.click && !state.point_one
+      state.point_one = inputs.mouse.click.point
+    elsif inputs.mouse.click && state.point_one
+      l = [*state.point_one, *inputs.mouse.click.point]
+      l = [l.x  - state.camera.x,
+           l.y  - state.camera.y,
+           l.x2 - state.camera.x,
+           l.y2 - state.camera.y].line.to_hash
+      l[:rect] = rect_for_line l
+      if state.line_mode == :terrain
+        state.terrain << l
+      else
+        state.lava << l
+      end
+      save_level
+      next_x = inputs.mouse.click.point.x - 640
+      next_y = inputs.mouse.click.point.y - 360
+      circle.x += next_x
+      circle.y += next_y
+      state.point_one = nil
+    elsif inputs.keyboard.one
+      state.point_one = [circle.x + camera.x, circle.y+ camera.y]
+    end
+
+    # cancel chain lines
+    if inputs.keyboard.key_down.nine || inputs.keyboard.key_down.escape || inputs.keyboard.key_up.six || inputs.keyboard.key_up.one
+      state.point_one = nil
+    end
+  end
+
+  def play_sound
+    return if state.sound_debounce > 0
+    state.sound_debounce = 5
+    outputs.sounds << "sounds/03#{"%02d" % state.sound_index}.wav"
+    state.sound_index += 1
+    if state.sound_index > 21
+      state.sound_index = 1
+    end
+  end
+
+  def input_game
+    if inputs.keyboard.down || inputs.keyboard.space
+      circle.potential_lift += 0.03
+      circle.potential_lift = circle.potential_lift.lesser(10)
+    elsif inputs.keyboard.key_up.down || inputs.keyboard.key_up.space
+      play_sound
+      circle.dy += circle.angle.vector_y circle.potential_lift
+      circle.dx += circle.angle.vector_x circle.potential_lift
+
+      if circle.on_floor
+        if circle.floor_relative_y == :above
+          circle.y += circle.potential_lift.abs * 2
+        elsif circle.floor_relative_y == :below
+          circle.y -= circle.potential_lift.abs * 2
+        end
+      end
+
+      circle.on_floor = false
+      circle.potential_lift = 0
+      circle.terrains_to_monitor.clear
+      circle.impact_history.clear
+      circle.impact = nil
+      calc_physics
+    end
+
+    # aim probe
+    if inputs.keyboard.right || inputs.keyboard.a
+      circle.angle -= 2
+    elsif inputs.keyboard.left || inputs.keyboard.d
+      circle.angle += 2
+    end
+  end
+
+  def input
+    input_god_mode
+    input_game
+  end
+
+  def calc_camera
+    state.camera.target_x = 640 - circle.x
+    state.camera.target_y = 360 - circle.y
+    xdiff = state.camera.target_x - state.camera.x
+    ydiff = state.camera.target_y - state.camera.y
+    state.camera.x += xdiff * camera.follow_speed
+    state.camera.y += ydiff * camera.follow_speed
+  end
+
+  def calc
+    state.sound_debounce ||= 0
+    state.sound_debounce -= 1
+    state.sound_debounce = 0 if state.sound_debounce < 0
+    if state.god_mode
+      circle.dy *= 0.1
+      circle.dx *= 0.1
+    end
+    calc_camera
+    state.whisp_queue ||= []
+    if state.tick_count.mod_zero?(4)
+      state.whisp_queue << {
+        x: -300,
+        y: 1400 * rand,
+        speed: 2.randomize(:ratio) + 3,
+        w: 20,
+        h: 20, path: 'sprites/whisp.png',
+        a: 0,
+        created_at: state.tick_count,
+        angle: 0,
+        r: 100,
+        g: 128 + 128 * rand,
+        b: 128 + 128 * rand
+      }
+    end
+
+    state.whisp_queue.each do |w|
+      w.x += w[:speed] * 2
+      w.x -= circle.dx * 0.3
+      w.y -= w[:speed]
+      w.y -= circle.dy * 0.3
+      w.angle += w[:speed]
+      w.a = w[:created_at].ease(30) * 255
+    end
+
+    state.whisp_queue = state.whisp_queue.reject { |w| w[:x] > 1280 }
+
+    if state.tick_count.mod_zero?(2) && (circle.dx != 0 || circle.dy != 0)
+      circle.after_images << {
+        x: circle.x,
+        y: circle.y,
+        w: circle.radius,
+        h: circle.radius,
+        a: 255,
+        created_at: state.tick_count
+      }
+    end
+
+    circle.after_images.each do |ai|
+      ai.a = ai[:created_at].ease(10, :flip) * 255
+    end
+
+    circle.after_images = circle.after_images.reject { |ai| ai[:created_at].elapsed_time > 10 }
+    calc_physics
+  end
+
+  def circle
+    state.circle
+  end
+
+  def camera
+    state.camera
+  end
+
+  def terrain
+    state.terrain
+  end
+
+  def lava
+    state.lava
+  end
+end
+
+# $gtk.reset
+
+def tick args
+  args.outputs.background_color = [0, 0, 0]
+  if args.inputs.keyboard.r
+    args.gtk.reset
+    return
+  end
+  # uncomment the line below to slow down the game so you
+  # can see each tick as it passes
+  # args.gtk.slowmo! 30
+  $game ||= FallingCircle.new
+  $game.args = args
+  $game.tick
+end
+
+def reset
+  $game = nil
+end