Mega Man 3 - Weapon Select.lua

SCRIPT_TITLE	= "Mega Man 3 - Weapon Select"
SCRIPT_VERSION	= "1.0"

require "m_utils"
m_require("m_utils",0)

--[[

Just a quick script to allow Mega Man to cycle through his weapons with the select button without having to pause.
It works, but it's pretty buggy.
Mega Man does not change weapon sprites with this method, so the weapons look like garbage.
His colors do not change from the weapon you start with.
You can cycle through weapons you haven't unlocked yet.
Otherwise it's a lot of fun.  Really!

TODO: Fix weapon sprites, Mega Man's colors, "fix" cycling to currently locked weapons.

-steev
-]]

weapon_names = {"Arm Cannon", "Gemini Laser", "Needle Cannon", "Hard Knuckle", "Magnet Missle", "Top Spin", "Search 

Snake", "Rush Coil", "Spark Shock", "Rush Marine", "Shadow Blade", "Rush Jet"}
primary_colors = {17, 21, 17, 25, 0, 37, 20, 24, 38, 22, 22, 22}
secondary_colors = {44, 40, 48, 48, 48, 52, 52, 55, 48, 48, 48, 48}

function update_weapons(prev_select)
  j = joypad.read(1).select
  if j and prev_select == false then
    next_weapon = current_weapon + 1
    if next_weapon >= #weapon_names then next_weapon = 0 end

    -- weapon    
    memory.writebyte(0x00A0, next_weapon)

    if next_weapon < 6 then 
      memory.writebyte(0x00B4, 0) -- menu page
      memory.writebyte(0x00A1, next_weapon) -- position on the menu
    else
      memory.writebyte(0x00B4, 6)
      memory.writebyte(0x00A1, next_weapon - 6)
    end

  end
end

function display_weapon(current_weapon)
  gui.text(16,8, weapon_names[current_weapon+1])
  gui.text(16,16, current_weapon)
  gui.text(16,24, #weapon_names)
end

while(true) do
  current_weapon = memory.readbyte(0x00A0)
  display_weapon(current_weapon)

  update_weapons(prev_select)
  prev_select = joypad.read(1).select
	EMU.frameadvance()
end