Implement split Speed Booster items

[blkerby]

We would like to implement a new randomizer option that splits "Speed Booster" into two new items which will be mostly complementary with each other:

• Blue Booster: This allows gaining and retaining blue speed in the same way as in Speed Booster, and using it to break blocks or affect Samus' jump height. The key feature it lacks is the ability to shinespark.
• Spark Booster: This allows gaining blue speed and using it to shinecharge/shinespark. The blue speed can only be used while running, being lost if Samus jumps or runs off a ledge.

The work which needs to be done to support this is roughly as follows:

• Implement the core effects (e.g. physics changes) of the items
• Create graphics for the new items.
• Implement secondary effects of the items: look for all the places in the game that depend on Speed Booster, and determine how it should behave with the new items. Examples: lava trap in Speed Booster Hall, loss of blue when unpausing with Speed Booster unequipped.
• Implement the item PLMs.
• Update the equipment screen: replace the "Speed Booster" text with "Blue Booster"/"Spark Booster" when applicable, set the correct bits in equipped items, etc.
• Implement the collection time tracking and display in the credits.
• Add "Split Speed Booster" setting in the randomizer UI, under "Other options". Also incorporate the new items into the "Item progression" settings.
• Account for the items in the logic. This will need some changes on the sm-json-data side to model strats that use blue speed while jumping or falling (any cases not already covered under existing tech like "canSpeedball", "canBlueSpaceJump")

[blkerby]

Some additional details about the intended behavior of the items:

Blue Booster

• This includes the ability to retain blue speed in all the usual ways, including speed balls, blue Space Jump, blue Spring Ball bounces, and temporary blue chains.
• The difference with Speed Booster will be indicated visually by an absence of speed echoes: i.e., when reaching a dash counter of 4, Samus turns blue but does not gain echoes. This appearance of blue without echoes continues through other movements including speed balls, temp blue chains, etc.
• If Samus crouches with a dash counter of 4, then instead of gaining a shinecharge, she gains a "fake shinecharge". This has a different palette in which Samus flashes blue instead of white. It doesn't allow Samus to shinespark. The main purpose is to give the player feedback to remind them that they are using Blue Booster, so that they don't get confused and just think that they are missing their shortcharges. It also serves a purpose to force the player to still wait out the 180 frames before chaining temporary blue: if Samus jumps in a way that would normally activate a shinespark, then any temporary blue will be lost (dash counter reset to 0).

Spark Booster

• The difference with Speed Booster will be indicated visually by Samus not turning blue: i.e., when reaching a dash counter of 4, Samus gains speed echoes but does not turn blue.
• In spite of the visual absence of blue, Samus may still destroy enemies and break bomb and Speed blocks while running with a dash counter of 4. Likewise, shinesparks also have their normal effect on enemies and blocks.
• With Spark Booster, Samus may gain a flash suit in any of the usual ways (spikesuit, etc.).
• With Spark Booster, Samus may gain a blue suit by interrupting a shinespark (e.g with an R-mode forced standup or Crystal Flash). However, the blue suit will be lost when unpausing unless Samus has Blue Booster or Speed Booster equipped.

Speedless abilities

With the "Split Speed Booster" option, regardless of whether Samus has either "Blue Booster" or "Spark Booster", Samus can always still do everything that could be done without any speed item in the vanilla game. This includes

• the ability to gain a flash suit using an elevator Crystal Flash or R-mode interrupted Crystal Flash,
• the ability to use a flash suit to shinespark,
• the ability to convert a flash suit to a blue suit (e.g. using a Crystal Spark),
• the ability to shinecharge using a blue suit and use it to shinespark.

When Samus has a blue suit, it will always have the visual appearance that it has in the vanilla game, i.e., with Samus both being blue and having speed echoes following her, regardless of whether "Blue Booster" or "Spark Booster" are collected/equipped. And when using a blue suit to shinecharge, it will always have the appearance of a real shinecharge (flashing white), not a fake shinecharge.

[blkerby]

One other thing: when the "Split Speed Booster" setting is enabled, the plan is for the "Speed Booster" item to be overridden from being in the item pool; it should show as gray in the "Item progression" settings, similar to how "Wall jump boots" is gray when "Collectible wall jump" is disabled. And conversely, when "Split Speed Booster" is disabled, the "Blue Booster" and "Spark Booster" items should show as gray in "Item progression".

The split speed ASM patch is written in a generic way that could support "Speed Booster" also being in the pool: we don't want to allow that, but it makes things easier in case we could possibly change our minds in the future. Because "Speed Booster" won't also be in the pool along with the two new items, we only need to reserve one more row in the credits, rather than two.

[nn357]

How are you imagining the speedbooster trap is going to work with the new items? If it only triggers if both are collected? or it doesnt trigger at all?

it could make spikesuit logic easier if specific logic is going to be written for the split items or is the plan just to keep it vanilla?

[kjbranch]

How are you imagining the speedbooster trap is going to work with the new items?

I think it would make sense to be either item, as either would let you outrun it, which seems to be the main factor.

[nn357]

so no change to vanilla? it triggers if you have any speed-x item