Double Jump

Enablement

Double Jump is disabled by default. To enable it, add the server group(s) that should have access to double jump in your config.yml:

double-jump-enable-groups:
  - tower

The feature is only active for players on server groups listed in double-jump-enable-groups. Attempts to trigger a double jump on a group not in this list are silently ignored.

Configuration

Double Jump is configured in plugins/AstralClasses/double-jump.yml:

Key	Type	Description
`horizontal-velocity-multiplier`	Vector (x, y, z)	Velocity multiplier applied when a directional key (forward, backward, left, right) is held during the jump. Each axis defaults to `0.0` if omitted.
`vertical-velocity-multiplier`	Vector (x, y, z)	Velocity multiplier applied when no directional key is held (straight-up jump). Each axis defaults to `0.0` if omitted.
`cooldown`	Duration	Time in milliseconds between consecutive air jumps. Applies to the second and subsequent jumps in an airborne sequence; the first jump (when grounded) has no cooldown.

Example configuration

# Velocity multiplier for horizontal movements
# Left/right (x) and forward/backward (z)
horizontal-velocity-multiplier:
  x: 0.9
  y: 0.10
  z: 0.9

# Velocity multiplier for vertical movement (y)
vertical-velocity-multiplier:
  x: 1.0
  y: 0.9
  z: 1.0

cooldown: 500

Behavior

The double jump mechanic tracks a per-player jump state:

Initial jump (grounded). When the player presses SPACE while touching the ground, the jump state is reset and records one jump. No velocity is applied by the skill; the player's normal Minecraft jump applies.
Second jump (airborne). When the player presses SPACE while airborne, JumpState.canDoubleJump(now, cooldown, 1) gates the trigger: it requires the tracked jump count to be below the hardcoded maximum of 1 and (no air jump recorded yet this cycle, or at least cooldown milliseconds elapsed since the last one). Otherwise, the jump is blocked and no velocity is applied.

Directional velocity. The velocity applied depends on the player's held movement keys at the moment of jump:
- No directional input: A base upward vector (0, 1, 0) is multiplied by vertical-velocity-multiplier.
- Directional input held: The player's facing direction is used to compute forward/backward components, and the right vector (perpendicular to facing) is used for left/right components. The combined direction vector is multiplied by horizontal-velocity-multiplier.
Jump state reset. When the player moves between blocks and touches the ground (detected via PlayerMoveEvent), the jump state is reset, allowing a new jump cycle to begin.

Effects

When a double jump triggers:

A CLOUD particle burst spawns at the player's feet (10 particles, offset 0.5 horizontal / 0.2 vertical).
The entity.breeze.jump sound plays at the player's location (volume 0.7, pitch 1.0).

Wiring

Double Jump is triggered through the plugin's input system:

InputPacketListener decodes raw client packets and detects SPACE key presses via PLAYER_INPUT packets.
Input events are deduplicated through InputBuffer so a held space key doesn't retrigger the jump on every packet — only the rising edge (false → true) triggers.
SkillService.tryTriggerSpace is called with InputType.SPACE and a SimpleInput wrapper of the client's input state.
Inside tryTriggerSpace, the method checks MainConfiguration.isDoubleJumpEnabledForGroup. If the player is on a group with double jump enabled, it calls DoubleJump.trigger(player, simpleInput, placeholderContainer) to apply the jump.

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