[VX] On-map Bullet System

#==============================================================================
# On-map Bullet System
#==============================================================================
# Information:
#  This script enables you to spawn a bullet that can trigger using event's
#  self switch or switch (for hitting player).
#
# Usage:
#  - To create a bullet, use code:
#      @bullet = $scene.createbullet(name, source, speed, dir, atk[, target])
#    where
#      @bullet = last created bullet object
#      name = picture name for created bullet
#      source = Game_Character object from which the bullet is spawned
#                ($game_player or $game_map.events[@event_id])
#      speed = bullet speed
#      dir = 1: down
#            2: left
#            3: right
#            4: up
#            5: Southwest
#            6: Northwest
#            7: Northeast
#            8: Southeast
#            9: Toward target
#            10: Toward target (homing)
#            11: Angled direction (use @bullet.bullet_angle to determine angle)
#      atk = bullet attack value
#      target = Game_Character object to which the bullet move
#                (if use dir = 9 or 10)
#
#  - Accessible bullet properties:
#      @bullet.speed
#      @bullet.bullet_dir
#      @bullet.bullet_angle (in degrees, CCW from east)
#      @bullet.source (read-only)
#      @bullet.atk
#      and all attributes inherited from Game_Picture
#
#  - Global variables:
#      $scene.bullet_hitting = bullet that just hit an object
#
#  - Script configurations at module BulletMod.
#
# Installation:
#  Just place above Main.
#
# Credits
#  Alissa Liu
#
#==============================================================================

#---------------------------------------------------------------------------
# ** BulletMod Module
#---------------------------------------------------------------------------
module BulletMod
  FromPicID = 31              # Min Picture ID
  ToPicID = 61                # Max Picture ID
  PlayerHit = 16              # Player Hit Switch
  TriggerSS = "D"            # Target's Self Switch triggered when touching
                              # the bullet
end

#==============================================================================
# ** Game_Character
#------------------------------------------------------------------------------
#  This class deals with characters. It's used as a superclass of the
# Game_Player and Game_Event classes.
#==============================================================================

class Game_Character
  #--------------------------------------------------------------------------
  # * Determine Character Collision
  #    x : x-coordinate
  #    y : y-coordinate
  #    Detects normal character collision, including the player and vehicles.
  #--------------------------------------------------------------------------
  def collide_with_characters2?(x, y)
    if self != $game_player && x==$game_player.x && y==$game_player.y
      return $game_player
    end
    for event in $game_map.events_xy(x, y)          # Matches event position
      unless event.through                          # Passage OFF?
        if event!=self
          return event if event.priority_type == 1    # Target is normal char
        end
      end
    end
    return nil
  end
end

#==============================================================================
# ** Bullet
#------------------------------------------------------------------------------
# 
#==============================================================================
class Bullet < Game_Picture
  attr_accessor :speed
  attr_accessor :bullet_dir
  attr_accessor :bullet_angle
  attr_reader  :source
  attr_accessor :atk
  alias bulletinit initialize unless method_defined?('bulletinit')
  alias bulletshow show unless method_defined?('bulletshow')
  alias bulletupdate update unless method_defined?('bulletupdate')
  #--------------------------------------------------------------------------
  # * Object Initialization
  #    number : picture index
  #--------------------------------------------------------------------------
  def initialize(number)
    bulletinit(number)
    @bullet_dir = -1
    @bullet_angle = 0
    @speed = 0
  end
  #--------------------------------------------------------------------------
  # * Show Picture
  #--------------------------------------------------------------------------
  def show(name, source, speed, dir, target=nil)
    bulletshow(name,1,source.screen_x,source.screen_y-16,100,100,255,0)
    @real_x = source.real_x.to_f
    @real_y = source.real_y.to_f
    @real_xo = @real_x
    @real_yo = @real_y
    @speed = speed
    @bullet_dir = dir
    @source = source
    @target = target
    if source==target
      erase
    else
      if dir==9
        @dx = speed/Math::sqrt((target.real_x-source.real_x)*(target.real_x-source.real_x)+
          (target.real_y-source.real_y)*(target.real_y-source.real_y))*(target.real_x-source.real_x)
        @dy = speed/Math::sqrt((target.real_x-source.real_x)*(target.real_x-source.real_x)+
          (target.real_y-source.real_y)*(target.real_y-source.real_y))*(target.real_y-source.real_y)
      end
    end
  end
  #--------------------------------------------------------------------------
  # * Frame Update
  #--------------------------------------------------------------------------
  def update
    if @name != ""
      x_last = @real_x
      y_last = @real_y
      case @bullet_dir
      when 1
        @real_y += @speed  # Down
      when 2
        @real_x -= @speed  # Left
      when 3
        @real_x += @speed  # Right
      when 4
        @real_y -= @speed  # Up
      when 5
        # Southwest
        @real_y += @speed*0.707
        @real_x -= @speed*0.707
      when 6
        # Northwest
        @real_y -= @speed*0.707
        @real_x -= @speed*0.707
      when 7
        # Northeast
        @real_y -= @speed*0.707
        @real_x += @speed*0.707
      when 8
        # Southeast
        @real_y += @speed*0.707
        @real_x += @speed*0.707
      when 9
        # Towards target
        @real_x += @dx
        @real_y += @dy
      when 10
        # Homing
        @dx = speed/Math::sqrt((@target.real_x-@real_x)*(@target.real_x-@real_x)+
          (@target.real_y-@real_y)*(@target.real_y-@real_y))*(@target.real_x-@real_x)
        @dy = speed/Math::sqrt((@target.real_x-@real_x)*(@target.real_x-@real_x)+
          (@target.real_y-@real_y)*(@target.real_y-@real_y))*(@target.real_y-@real_y)
        @real_x += @dx
        @real_y += @dy
      when 11
        # Angled direction
        @dx = @speed*Math::cos(@bullet_angle*Math::PI/180)
        @dy = -@speed*Math::sin(@bullet_angle*Math::PI/180)
        @real_x += @dx
        @real_y += @dy
      end
      @x = (($game_map.adjust_x(@real_x) + 8007) / 8 - 1000 + 16).round
      @y = (($game_map.adjust_y(@real_y) + 8007) / 8 - 1000 + 16).round
      if ((x_last/256).round!=(@real_xo/256).round || (y_last/256).round!=(@real_yo/256).round)
        if !$game_map.passable?($game_map.round_x(@real_x/256).round,$game_map.round_y(@real_y/256).round) &&
          !$game_map.ship_passable?($game_map.round_x(@real_x/256).round,$game_map.round_y(@real_y/256).round)
          erase
        else
          coli = @source.collide_with_characters2?($game_map.round_x(@real_x/256).round,$game_map.round_y(@real_y/256).round)
          if (coli != nil)
            if coli == $game_player || coli.id<=0
              $game_switches[BulletMod::PlayerHit] = true
            else
              key = [$game_map.map_id,coli.id,BulletMod::TriggerSS]
              $game_self_switches[key] = true
            end
            $scene.bullet_source = @source
            $scene.bullet_hitting = self
            $scene.bullet_hitting_name = name
            erase
          end
        end
      end
      if @x<=0 || @x>=544 || @y<=0 || @y>=416
        erase
      end
      bulletupdate
    end
  end
end

#==============================================================================
# ** Scene_Map
#------------------------------------------------------------------------------
#  This class performs the map screen processing.
#==============================================================================
class Scene_Map < Scene_Base
  attr_accessor :bullet_source
  attr_accessor :bullet_hitting
  attr_accessor :bullet_hitting_name
  # Alias things
  alias bulletinit initialize unless method_defined?('bulletinit')
  alias bulletupdate update unless method_defined?('bulletupdate')
  alias bulletterminate terminate unless method_defined?('bulletterminate')
  #--------------------------------------------------------------------------
  # * Initialize
  #--------------------------------------------------------------------------
  def initialize
    $bullet_sprite = []
    for i in BulletMod::FromPicID..BulletMod::ToPicID
      $bullet_sprite[i-BulletMod::FromPicID] = Bullet.new(i)
    end
    bulletinit
  end
  #--------------------------------------------------------------------------
  # * createbullet
  #--------------------------------------------------------------------------
  def createbullet(name, source, speed, dir, atk, target=nil)
    ret_id = BulletMod::FromPicID
    while $bullet_sprite[ret_id-BulletMod::FromPicID].name != "" && ret_id<BulletMod::ToPicID
      ret_id += 1
    end
    if $bullet_sprite[ret_id-BulletMod::FromPicID].name == ""
      $bullet_sprite[ret_id-BulletMod::FromPicID].show(name, source, speed, dir, target)
      $bullet_sprite[ret_id-BulletMod::FromPicID].atk = atk
      return $bullet_sprite[ret_id-BulletMod::FromPicID]
    end
  end
  #--------------------------------------------------------------------------
  # * Frame Update
  #--------------------------------------------------------------------------
  def update
    bulletupdate
    for bulletspr in $bullet_sprite
      if bulletspr.name != ""
        if $game_player.transfer?
          bulletspr.erase
        else
          bulletspr.update
        end
      end
    end
  end
  #--------------------------------------------------------------------------
  # * Termination Processing
  #--------------------------------------------------------------------------
  def terminate
    for bulletspr in $bullet_sprite
      bulletspr.erase
    end
    bulletterminate
  end
end

class Spriteset_Map
  alias bulletcreatepic create_pictures unless method_defined?('bulletcreatepic')
  #--------------------------------------------------------------------------
  # * Create Picture Sprite
  #--------------------------------------------------------------------------
  def create_pictures(*args);bulletcreatepic(*args)
    for bulletspr in $bullet_sprite
      @picture_sprites.push(Sprite_Picture.new(@viewport1,bulletspr))
    end
  end
end

class Sprite_Picture < Sprite
  alias bulletpic_upd update unless method_defined?('bulletpic_upd')
  #--------------------------------------------------------------------------
  # * Frame Update
  #--------------------------------------------------------------------------
  def update(*args);bulletpic_upd(*args)
    if @picture.number >= BulletMod::FromPicID && @picture.number <= BulletMod::ToPicID
      self.z = $game_player.screen_z+50+@picture.number-BulletMod::FromPicID
    end
  end
end