module SpriteAnimation

Constants

VERSION

Public Instance Methods

animate_sprite(image_src, frame_count, params = {}) click to toggle source

Returns an image_tag inside a div, an populates the image with data so it can be animated via javascript Params:

image_src: a sprite sheet source, just as you would pass to image_tag
frame_count: a string representing the number of frames for the sheet
params: a hash containing two optional parameters for the animation

scale

a decimal number that will multiply the frame size. Default: 1
orientation

a symbol representing the orientation of your sheet.

Can be: :vertical or :horizontal. If not given, it will try to guess.

# File lib/sprite_animation/sprite_animation_helper.rb, line 15
def animate_sprite(image_src, frame_count, params = {})
  scale = params[:scale] || 1

  img_width, img_height = ImageSize.size(image_src).map { |d| d*scale }

  orientation = params[:orientation] ||
    guess_orientation(img_width, img_height)

  frame =
    send(orientation,*[img_width,img_height,frame_count])

  image = image_tag(image_url(image_src), class: "animated",
                    frameCount: frame_count, 
                    frameLength: frame[:length],
                    frameSide: frame[:margin],
                    style: frame[:style])

  content_tag(:div, image, 
              style: animated_div_style(frame[:width],frame[:height]))
end

Private Instance Methods

animated_div_style(frame_width, frame_height) click to toggle source

# File lib/sprite_animation/sprite_animation_helper.rb, line 38
def animated_div_style(frame_width, frame_height)
  "width: #{frame_width}px;
   height: #{frame_height}px;
   display: block;
   overflow: hidden"
end

guess_orientation(img_width, img_height) click to toggle source

# File lib/sprite_animation/sprite_animation_helper.rb, line 69
def guess_orientation(img_width, img_height)
  img_height > img_width ? :vertical : :horizontal
end

horizontal(img_width, img_height, frame_count) click to toggle source

# File lib/sprite_animation/sprite_animation_helper.rb, line 45
def horizontal(img_width, img_height, frame_count)
  frame_width = img_width / frame_count.to_i
  frame_height = img_height
  {
    width: frame_width,
    height: frame_height,
    margin: "left",
    length: frame_width,
    style: "height: " + img_height.to_s + "px"
  }
end

vertical(img_width, img_height, frame_count) click to toggle source

# File lib/sprite_animation/sprite_animation_helper.rb, line 57
def vertical(img_width, img_height, frame_count)
  frame_width = img_width
  frame_height = img_height / frame_count.to_i
  {
    width: frame_width,
    height: frame_height,
    margin: "top",
    length: frame_height,
    style: "width: " + img_width.to_s + "px"
  }
end