Class: Twitterpunch::Sprite

Inherits:
Object
  • Object
show all
Includes:
Rubygame, Sprites::Sprite
Defined in:
lib/twitterpunch/sprite.rb

Instance Method Summary collapse

Constructor Details

#initialize(dimensions, image, text, pop = false) ⇒ Sprite

Returns a new instance of Sprite.



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# File 'lib/twitterpunch/sprite.rb', line 9

def initialize(dimensions, image, text, pop=false)
  # Invoking the base class constructor is important and yet easy to forget:
  super()

  @dimensions = dimensions
  @popped     = pop
  @text       = text
  @original   = Surface.load(image)

  if pop
    @image = @original
    @start = Time.now
    @stale = 10
  else
    @rate  = rand(35..150)
    @zoom  = rand(50..100) / 100.0
    @image = @original.zoom(@zoom)
  end

  max_width = dimensions[0] * 0.75
  if @image.width > max_width
    factor = max_width/@image.width
    @original = @original.zoom(factor)
    @image    = @image.zoom(factor)
  end

  if pop
    @left = (dimensions[0] - @image.width)  / 2
    @top  = (dimensions[1] - @image.height) / 2
  else
    @left = (dimensions[0] - @image.width ) * rand
    @top  = 0 - @image.height
  end

  @rect = @image.make_rect

  render_text
end

Instance Method Details

#damped_sin(input, cycles = 4, scale = 1) ⇒ Object 



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# File 'lib/twitterpunch/sprite.rb', line 108

def damped_sin(input, cycles = 4, scale = 1)
  Math.sin(input * cycles * Math::PI) * (1 - input) * scale
end

#draw(on_surface) ⇒ Object 



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# File 'lib/twitterpunch/sprite.rb', line 96

def draw(on_surface)
  @image.blit(on_surface, @rect)
end

#popped? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/twitterpunch/sprite.rb', line 112

def popped?
  return @popped
end

#render_text ⇒ Object 



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# File 'lib/twitterpunch/sprite.rb', line 48

def render_text
  if @text
    text = $font.render_utf8(@text, true, Color[:black], Color[:gray])

    # for some reason, windows doesn't deal with this properly
    text.alpha = 150 unless RUBY_PLATFORM =~ /mingw|cygwin/

    # Determine the dimensions in pixels of the area used to render the text.  The
    # "topleft" of the returned rectangle is at [ 0, 0]
    rt = text.make_rect

    # Re-use the "topleft" of the rectangle to indicate where the text should
    # appear on screen ( lower left corner )
    #rt.topleft = [ 12, @image.height - rt.height - 8]
    rt.topleft = [ 0, @image.height - rt.height]

    # Copy the pixels of the rendered text to the image
    text.blit(@image, rt)
  end
end

#update(seconds_passed) ⇒ Object

Animate this object. “seconds_passed” contains the number of real-world seconds that have passed since the last time this object was updated and is therefore useful for working out how far the object should move (which should be independent of the frame rate)



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# File 'lib/twitterpunch/sprite.rb', line 73

def update(seconds_passed)
  if @popped
    elapsed = (Time.now - @start).to_f

    if elapsed < 1
      scale = 1 + damped_sin(elapsed, 4, 0.05)

      @image = @original.zoom(scale)
      @top  *= scale
      @left *= scale

      # We changed image size, so rebuild the rect and draw new text
      @rect = @image.make_rect
      render_text
    elsif elapsed > @stale
      @image.alpha -= 5
    end
  else
    @top += seconds_passed * @rate
  end
  @rect.topleft = [ @left, @top ]
end

#visible ⇒ Object 



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# File 'lib/twitterpunch/sprite.rb', line 100

def visible
  if @popped
    @image.alpha > 0
  else
    @top < @dimensions[1]
  end
end