Water Currents

#===============================================================================
# Terrain tags (initializes current terrain tags and adds water properties)
#===============================================================================
module PBTerrain
  CurrentNorth    = 17
  CurrentEast     = 18
  CurrentSouth    = 19
  CurrentWest     = 20
end

  def PBTerrain.isSurfable?(tag)
    return PBTerrain.isWater?(tag)
  end

  def PBTerrain.isWater?(tag)
    return tag==PBTerrain::Water ||
           tag==PBTerrain::StillWater ||
           tag==PBTerrain::DeepWater ||
           tag==PBTerrain::WaterfallCrest ||
           tag==PBTerrain::Waterfall ||
           tag==PBTerrain::CurrentNorth ||
           tag==PBTerrain::CurrentEast ||
           tag==PBTerrain::CurrentSouth ||
           tag==PBTerrain::CurrentWest

  end

  def PBTerrain.isPassableWater?(tag)
    return tag==PBTerrain::Water ||
           tag==PBTerrain::StillWater ||
           tag==PBTerrain::DeepWater ||
           tag==PBTerrain::WaterfallCrest ||
           tag==PBTerrain::CurrentNorth ||
           tag==PBTerrain::CurrentEast ||
           tag==PBTerrain::CurrentSouth ||
           tag==PBTerrain::CurrentWest
  end

  def PBTerrain.isJustWater?(tag)
    return tag==PBTerrain::Water ||
           tag==PBTerrain::StillWater ||
           tag==PBTerrain::DeepWater ||
           tag==PBTerrain::CurrentNorth ||
           tag==PBTerrain::CurrentEast ||
           tag==PBTerrain::CurrentSouth ||
           tag==PBTerrain::CurrentWest
         end

  def PBTerrain.isCurrent?(tag)
    return tag==PBTerrain::CurrentNorth ||
           tag==PBTerrain::CurrentEast ||
           tag==PBTerrain::CurrentSouth ||
           tag==PBTerrain::CurrentWest
         end

#===============================================================================
# Terrain tags (initializes current terrain tags and adds water properties)
#===============================================================================

class PokemonEncounters
  def isEncounterPossibleHere?
    if PBTerrain.isCurrent?(pbGetTerrainTag($game_player))
      return false
    elsif $PokemonGlobal && $PokemonGlobal.surfing
      return true
    elsif PBTerrain.isIce?(pbGetTerrainTag($game_player))
      return false
    elsif self.isCave?
      return true
    elsif self.isGrass?
      return PBTerrain.isGrass?($game_map.terrain_tag($game_player.x,$game_player.y))
    end
    return false
  end
end

#===============================================================================
# Current Movement
#===============================================================================
def Kernel.pbWaterCurrent(event=nil)
  event=$game_player if !event
  return if !event
  return if (pbGetTerrainTag(event)!=PBTerrain::CurrentSouth &&
  pbGetTerrainTag(event)!=PBTerrain::CurrentWest && pbGetTerrainTag(event)!=PBTerrain::CurrentEast &&
  pbGetTerrainTag(event)!=PBTerrain::CurrentNorth)
  $PokemonGlobal.sliding=true
  oldwalkanime=event.walk_anime
  event.straighten
  event.pattern=0
  event.walk_anime=false
  loop do
    case pbGetTerrainTag(event)
      when PBTerrain::CurrentSouth
        direction=2
      when PBTerrain::CurrentWest
        direction=4
      when PBTerrain::CurrentEast
        direction=6
      when PBTerrain::CurrentNorth
        direction=8
    end
    break if (pbGetTerrainTag(event)!=PBTerrain::CurrentSouth && pbGetTerrainTag(event)!=PBTerrain::CurrentWest &&
    pbGetTerrainTag(event)!=PBTerrain::CurrentEast && pbGetTerrainTag(event)!=PBTerrain::CurrentNorth)
    break if !event.passable?(event.x,event.y,direction)
    case pbGetTerrainTag(event)
      when PBTerrain::CurrentSouth
        event.move_down(false)
      when PBTerrain::CurrentWest
        event.move_left(false)
      when PBTerrain::CurrentEast
        event.move_right(false)
      when PBTerrain::CurrentNorth
        event.move_up(false)
    end
    while event.moving?
      Graphics.update
      Input.update
      pbUpdateSceneMap
    end
  end
  event.center(event.x,event.y) if event==$game_player
  event.straighten
  event.walk_anime=oldwalkanime
  $PokemonGlobal.sliding=false
end

Events.onStepTakenFieldMovement+=proc{|sender,e|
  event=e[0] # Get the event affected by field movement
  currentTag=pbGetTerrainTag(event)
  if pbGetTerrainTag(event,true)==PBTerrain::Grass  # Won't show if under bridge
    $scene.spriteset.addUserAnimation(GRASS_ANIMATION_ID,event.x,event.y,true)
  elsif event==$game_player && currentTag==PBTerrain::WaterfallCrest
     # Descend waterfall, but only if this event is the player
    Kernel.pbDescendWaterfall(event)
  elsif (currentTag==PBTerrain::CurrentSouth || currentTag==PBTerrain::CurrentWest ||
    currentTag==PBTerrain::CurrentEast || currentTag==PBTerrain::CurrentNorth) && !$PokemonGlobal.sliding
    Kernel.pbWaterCurrent(event)
  elsif currentTag==PBTerrain::Ice && !$PokemonGlobal.sliding
    Kernel.pbSlideOnIce(event)
  end
}