Submission #2392: gocha's DS Castlevania: Dawn of Sorrow in 08:20.12

• Emulator used: DeSmuME 0.9.4+ (with no lag reduction options; i.e. official timing)
  • The game sometimes lags more than the real console, because of the emulator's inaccurate timing emulation.
  • I recommend OpenGL. Both OpenGL and SoftRasterizer work well, but I think SoftRasterizer causes a minor display glitch.
• Aims for fastest time (to get the good ending)
• Abuses programming errors in the game / Uses zipping glitch
• Manipulates luck (for soul/item drops, boss moves, etc.)
• Takes damage to save time
• Genre: Action, Platform, RPG
• Colors a warp room

About the run

1. Prologue
2. Meet Yoko and Julius, obtain Magic Seal 1
3. Obtain Axe from Axe Armor
4. Defeat Flying Armor
5. Defeat Balore
6. Save game for later glitch use
7. Obtain Magic Seal 2
8. Defeat Dmitrii
9. Perform zipping to collect achieve things and suspend/restart the game
10. Go to Warp Room and warp to The Abyss. The castle will self-destruct in a few seconds

Tricks

Backdash

• Backdash-jump: (13784+13232+12680+12128+11576+11024+10472+9920+9368+8816+8264+7712)/12 = 10748
• Forward-backdash-blank: (6144 + 13784 + 11384)/3 = 10437.3333
• Backdash-crouching: (13784+13232+12680+12128+11576+11024+8624+0)/8 = 10381 (8 frame pattern = fastest one)
• Additional note: Replacing crouching to subweapon use seems to be slightly faster if it does not lag. It will greatly decrement your MP, though.

Motion cancels

• Backdash can cancel an attack motion. It is a well-known behavior.
• Landing can cancel an attack motion of some weapons. It is a well-known behavior, too.
• Axe Armor's ability can cancel a landing motion after damage.
• To cancel Black Panther's ability just before landing can cancel a landing motion.

Randomness

static int32_t x = 0; // $020c07e4
int32_t rand() {
    x = (x >> 8) * 0x3243f6ad + 0x1b0cb175;
    return x;
}

Crystal blocks

Go down floating footholds without losing speed (not used)

Activate a switch behind the wall (not used)

Infinite jump glitch (not used)

Zipping: General info

-- Address view for memory writing with zipping
-- Open the memory viewer to see what's actually going on.

if not emu then
  error("This script runs under DeSmuME.")
end

if not bit then
  require("bit")
end

function cvdosPosToMapFlag(x, y)
  x, y = x % 256, y % 256

  local xl, xh = x % 16, math.floor(x / 16) % 16
  local i = (y * 16) + (xh * 46 * 16) + xl
  local pos = 0x20F6E34 + math.floor(i / 8)
  local mask = math.pow(2, math.floor(i % 8))
  return pos, mask
end

gui.register(function()
  local x = memory.readbyte(0x0210F018)
  local y = memory.readbyte(0x0210F014)
  local i = (y * 16) + x
  local pos, mask = cvdosPosToMapFlag(x, y)
  agg.text(140, 5, string.format("%08X:%02x", pos, mask))
  agg.text(140, 24, string.format("[%04X-%04X]", cvdosPosToMapFlag(x - (x % 0x10), 0) % 0x10000, cvdosPosToMapFlag(bit.bor(x, 0x0f), 255) % 0x10000))
  agg.text(140, 43, string.format("[%04X-%04X]", cvdosPosToMapFlag(x - (x % 0x10) + 0x10, 0) % 0x10000, cvdosPosToMapFlag(bit.bor(x, 0x0f) + 0x10, 255) % 0x10000))
  agg.text(140, 62, string.format("(%03d/%X,%03d)", x, x % 16, y))
end)

Zipping: The Succubus glitch and its variations

1. Equip Cutall/Cinquedea/Alucard Sword and Succubus
2. Use its special attack then cancel the motion by Succubus immediately
3. Walk/Attack for about 2.5 seconds (do not stop, jump, backdash, and so on. It's important)
4. Use the special attack again against the wall
5. The special attack will be canceled in the wall if it succeed

Memory addresses

Stage by stage comments

Prologue

Lost Village - Up to Flying Armor

Lost Village & Wizardry Lab - From Flying Armor, up to Balore

Wizardry Lab & Garden of Madness - From Balore, up to the save room

Garden of Madness & The Dark Chapel - Up to the end of the Dmitrii battle

Outside of the world - The zipping part

1. Obtain Black Panther
2. Obtain Hippogryph (optional; I think it saves time rather than not use it, or more than obtaining Malphas instead)
3. Set $30 to $020F718A to skip Menace (as a result, the game considers the first conversation and the battle are already done)
4. Activate the warp to The Abyss

• Obtain Malphas
• Skip the "Warp Room" description of the first time

1. List up all possible useful locations (and dangerous locations as well)
2. Divide them into 4 groups (odd number address or even number address, in higher 4 bit or in lower 4 bit)
3. Count the minimum horizontal distance to get to each location, and group them by it (in the 16-bit alignment)
4. See what is near/far each other and consider about how to visit them

The finale

Comments

Special thanks

• Satoryu: for his non tool-assisted speedrun
• Groobo: for his semi tool-assisted speedrun
• People in the Dawn of Sorrow topic: You guys are always kind. Especially, I thank Atma for posting his first TAS attempt of the game. That motivated me a lot.
• #TASers: A Japanese IRC channel. They motivate me always! Especially, I thank pirohiko for inventing a new style of video editing! ヽ(＞ヮ＜)

Screenshots