Module: Animation

Defined in:
lib/scite/animation.rb

Overview

Basic implementation of an animation. Could be used anywhere. Optimized to not do anything when it is too late to display a frame.

Class Method Summary collapse

Class Method Details

.perform(initial_values, target_values, frames: 40, duration: 400.0, &interpolation) ⇒ Object 



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# File 'lib/scite/animation.rb', line 10

def perform(initial_values, target_values, frames: 40, duration: 400.0, &interpolation)
  keys = initial_values.merge(target_values).keys
  values_diff = keys.map_hash {|k| [k, target_values[k].to_f - initial_values[k].to_f]}
  
  initial_time = Time.now.to_f
  duration_ms = duration.to_f / 1000
  frame_count = frames
  wait_count = frames - 1
  
  1.upto(frame_count) {|frame_i|
    if frame_i != frame_count
      now = Time.now.to_f
      this_must_be_run_at = initial_time + duration_ms/wait_count * (frame_i - 1)
      next_must_be_run_at = initial_time + duration_ms/wait_count * frame_i
      next if now > this_must_be_run_at + 0.001
    end
    
    frame_values = keys.map_hash {|k|
      time_part = frame_i.to_f / frame_count
      [k, initial_values[k] + values_diff[k] * swing_easing(time_part)]
    }
    #$log << frame_values
    yield frame_values
    
    if frame_i != frame_count
      now = Time.now.to_f
      if now < next_must_be_run_at
        sleep next_must_be_run_at - now
      end
    end
  }
end

.swing_easing(part) ⇒ Object 



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# File 'lib/scite/animation.rb', line 6

def swing_easing(part)
  0.5 - Math.cos(part * Math::PI)/2
end