Proud Lines of Code: DragonRuby DVD Game

main.rb

def tick args
  defaults args                                                               # initialize the defaults for the game
  render args                                                                 # render the game
  input args                                                                  # check for user input
  calc args                                                                   # run simulation
end

def defaults args
  args.state.colors       = [:red, :orange, :green, :blue, :indigo, :violet]  # colors for random selection
  args.state.box.size     = 50                                                # size of the box
  args.state.box.speed    = 1                                                 # movement speed
  args.state.box.x      ||= args.grid.w.half - args.state.box.size.half       # start the box center x
  args.state.box.y      ||= args.grid.h.half - args.state.box.size.half       # start the box center y
  args.state.box.dx     ||= [1, -1].sample                                    # pick a random direction of movement for x
  args.state.box.dy     ||= [1, -1].sample                                    # pick a random direction of movement for y
  args.state.box.status ||= :moving                                           # state variable that is consulted before moving the box
  set_box_color args    if !args.state.box.color                              # set the color of the box to a random one
end

def render args
  args.outputs.sprites << [                                                   # render the box sprite
    args.state.box.x,
    args.state.box.y,
    args.state.box.size,
    args.state.box.size,
    "sprites/square-#{args.state.box.color}.png"
  ]
end

def input args
  return unless args.inputs.keyboard.key_down.space                           # exit this function if space isn't pressed
  if args.state.box.status == :moving                                         # toggle the box state
    args.state.box.status = :stopped
  else
    args.state.box.status = :moving
  end
end

def calc args
  return unless args.state.box.status == :moving                              # do not move the box if the box status isn't :moving
  args.state.box.x += args.state.box.dx * args.state.box.speed                # move the box in the x direction by the speed
  args.state.box.y += args.state.box.dy * args.state.box.speed                # move the box in the y direction by the speed

                                                                              # collision logic: determine if the box is outside the
                                                                              # bounds of the 1280x720 canvas if it is, then change
                                                                              # the direction of the box and color

  if (args.state.box.x + args.state.box.size) > args.grid.w                   # right side of the canvas check
    args.state.box.x  = args.grid.w - args.state.box.size
    args.state.box.dx = -1
    set_box_color args
  elsif args.state.box.x < 0                                                  # left side of the canvas check
    args.state.box.x  = 0
    args.state.box.dx = 1
    set_box_color args
  end
  if (args.state.box.y + args.state.box.size) > args.grid.h                   # top of the canvas check
    args.state.box.y  = args.grid.h - args.state.box.size
    args.state.box.dy = -1
    set_box_color args
  elsif args.state.box.y < 0                                                  # bottom of the canvas check
    args.state.box.y  = 0
    args.state.box.dy = 1
    set_box_color args
  end
end

def set_box_color args                                                        # helper method for setting the box's color
  args.state.box.color = (args.state.colors - [args.state.box.color]).sample  # to something other than it's current color
end

thanks a lot @amirrajan! Works like a charm. Just a quick note that its seems the HTML gremlins got you. There's some > and < in this source. 🪲

thanks a lot @amirrajan! Works like a charm. Just a quick note that its seems the HTML gremlins got you. There's some > and < in this source. 🐞

fixed!