API Reference¶

Complete reference for BLine-Lib classes and methods.

For the full Javadoc, see the online documentation.

Path Class¶

The Path class represents a sequence of path elements with optional constraints.

Constructors¶

// Load from JSON file (adds .json automatically)
Path(String filename)

// Create programmatically
Path(PathElement... elements)

// Create with custom constraints
Path(PathConstraints constraints, PathElement... elements)

Static Methods¶

// Set global defaults for all paths
static void setDefaultGlobalConstraints(DefaultGlobalConstraints constraints)

Instance Methods¶

Method	Returns	Description
`getStartPose()`	`Pose2d`	Starting pose for odometry reset
`getInitialModuleDirection()`	`Rotation2d`	Direction modules should face at start
`flip()`	`void`	Mirror path for opposite alliance
`undoFlip()`	`void`	Revert alliance flip
`getPathElementsWithConstraints()`	`List<...>`	Elements with resolved constraints

Path.Waypoint¶

A point with both position and rotation.

Constructors¶

// From Translation2d and Rotation2d
Waypoint(Translation2d translation, Rotation2d rotation)

// From Pose2d
Waypoint(Pose2d pose)

JSON Format¶

{
    "type": "waypoint",
    "translation_target": {
        "x_meters": 1.0,
        "y_meters": 1.0,
        "intermediate_handoff_radius_meters": 0.2
    },
    "rotation_target": {
        "rotation_radians": 0,
        "profiled_rotation": true
    }
}

Path.TranslationTarget¶

A position-only target.

Constructors¶

// From Translation2d
TranslationTarget(Translation2d translation)

// From coordinates
TranslationTarget(double x, double y)

JSON Format¶

{
    "type": "translation",
    "x_meters": 2.5,
    "y_meters": 2.0,
    "intermediate_handoff_radius_meters": 0.2
}

Path.RotationTarget¶

A rotation-only target positioned along a segment.

Constructors¶

// With t_ratio for position along segment
RotationTarget(Rotation2d rotation, double tRatio)

JSON Format¶

{
    "type": "rotation",
    "rotation_radians": 1.57,
    "t_ratio": 0.5,
    "profiled_rotation": true
}

Path.DefaultGlobalConstraints¶

Global constraint defaults for all paths.

Constructor¶

DefaultGlobalConstraints(
    double maxVelocityMetersPerSec,
    double maxAccelerationMetersPerSec2,
    double maxVelocityDegPerSec,
    double maxAccelerationDegPerSec2,
    double endTranslationToleranceMeters,
    double endRotationToleranceDeg,
    double intermediateHandoffRadiusMeters
)

Parameters¶

Parameter	Type	Description
`maxVelocityMetersPerSec`	`double`	Max translational velocity (m/s)
`maxAccelerationMetersPerSec2`	`double`	Max translational acceleration (m/s²)
`maxVelocityDegPerSec`	`double`	Max rotational velocity (deg/s)
`maxAccelerationDegPerSec2`	`double`	Max rotational acceleration (deg/s²)
`endTranslationToleranceMeters`	`double`	Final position tolerance (m)
`endRotationToleranceDeg`	`double`	Final rotation tolerance (deg)
`intermediateHandoffRadiusMeters`	`double`	Default handoff radius (m)

Path.PathConstraints¶

Fluent builder for path-specific constraints.

Methods¶

All methods return this for chaining.

Method	Parameter	Description
`setMaxVelocityMetersPerSec`	`double`	Set max translation velocity
`setMaxAccelerationMetersPerSec2`	`double`	Set max translation acceleration
`setMaxVelocityDegPerSec`	`double`	Set max rotation velocity
`setMaxAccelerationDegPerSec2`	`double`	Set max rotation acceleration
`setEndTranslationToleranceMeters`	`double`	Set end position tolerance
`setEndRotationToleranceDeg`	`double`	Set end rotation tolerance

Ranged Constraints¶

For ranged constraints, pass RangedConstraint objects:

setMaxVelocityMetersPerSec(RangedConstraint... constraints)

Path.RangedConstraint¶

A constraint that applies to a range of ordinals.

Constructor¶

RangedConstraint(double value, int startOrdinal, int endOrdinal)

Parameters¶

Parameter	Type	Description
`value`	`double`	The constraint value
`startOrdinal`	`int`	First element index (inclusive)
`endOrdinal`	`int`	Last element index (inclusive)

FollowPath.Builder¶

Builder for creating path-following commands.

Constructor¶

Builder(
    SubsystemBase driveSubsystem,
    Supplier<Pose2d> poseSupplier,
    Supplier<ChassisSpeeds> speedsSupplier,
    Consumer<ChassisSpeeds> speedsConsumer,
    PIDController translationController,
    PIDController rotationController,
    PIDController crossTrackController
)

Methods¶

Method	Parameter	Description
`build`	`Path`	Create command for the specified path
`withPoseReset`	`Consumer<Pose2d>`	Reset pose at path start
`withDefaultShouldFlip`	—	Auto-flip based on alliance
`withShouldFlip`	`Supplier<Boolean>`	Custom flip logic

FollowPath Logging Hooks¶

Static logging hooks for streaming internal state during path execution.

Static Methods¶

Method	Parameter	Description
`setPoseLoggingConsumer`	`Consumer<Pair<String, Pose2d>>`	Pose logging hook
`setTranslationListLoggingConsumer`	`Consumer<Pair<String, Translation2d[]>>`	Translation array logging hook
`setDoubleLoggingConsumer`	`Consumer<Pair<String, Double>>`	Numeric logging hook
`setBooleanLoggingConsumer`	`Consumer<Pair<String, Boolean>>`	Boolean logging hook

config.json Format¶

Global configuration file (src/main/deploy/autos/config.json):

{
    "default_max_velocity_meters_per_sec": 4.5,
    "default_max_acceleration_meters_per_sec2": 12.0,
    "default_max_velocity_deg_per_sec": 540,
    "default_max_acceleration_deg_per_sec2": 860,
    "default_end_translation_tolerance_meters": 0.03,
    "default_end_rotation_tolerance_deg": 2.0,
    "default_intermediate_handoff_radius_meters": 0.2
}

Path JSON Format¶

Complete path file format (src/main/deploy/autos/paths/*.json):

{
    "path_elements": [
        // Array of path elements (waypoint, translation, rotation)
    ],
    "constraints": {
        "max_velocity_meters_per_sec": 4.5,
        // Or ranged:
        "max_velocity_meters_per_sec": [
            { "value": 4.5, "start_ordinal": 0, "end_ordinal": 1 }
        ],
        "max_acceleration_meters_per_sec2": 12.0,
        "max_velocity_deg_per_sec": 540,
        "max_acceleration_deg_per_sec2": 860,
        "end_translation_tolerance_meters": 0.03,
        "end_rotation_tolerance_deg": 2.0
    }
}