nearestPage method

Paging

# Scroll to the nearest page
nearestPage = (layerCount, pageSize, value, velocity) ->
		
	# Scroll position is negative... easier to think in terms of positive values
	value = - value
		
	lowerPageIndex = Math.max 0, Math.floor(value / pageSize)
	upperPageIndex = Math.min (layerCount - 1), (lowerPageIndex + 1)
		
	if velocity < -0.2
		return - upperPageIndex * pageSize
	else if velocity > 0.2
		return - lowerPageIndex * pageSize
		
	distanceToLowerPage = Math.abs(value - lowerPageIndex * pageSize)
	distanceToUpperPage = Math.abs(value - upperPageIndex * pageSize)
	
	if distanceToLowerPage < distanceToUpperPage
		return - lowerPageIndex * pageSize
	else
		return - upperPageIndex * pageSize