simvx.core.nodes_2d.trail

Trail2D – Ribbon trail that follows a moving node.

Module Contents

Classes

Trail2D

Ribbon trail that follows this node’s movement.

API

class simvx.core.nodes_2d.trail.Trail2D(**kwargs)

Bases: simvx.core.nodes_2d.node2d.Node2D

Ribbon trail that follows this node’s movement.

Records positions over time and renders a fading ribbon. Attach as child of a moving node for sword swipes, missile trails, movement effects, etc.

The node manages the point buffer and self-renders via on_draw, emitting one tapered, colour-graded line segment per pair of trail points. trail_points exposes the per-point centreline (position, width, colour); trail_geometry expands the same points into a triangle-strip ribbon for custom rendering or editor tooling.

Initialization

dynamic

True

length

‘Property(…)’

width

‘Property(…)’

width_curve

‘Property(…)’

colour

‘Colour(…)’

colour_end

‘Colour(…)’

lifetime

‘Property(…)’

emit

‘Property(…)’

gizmo_colour

‘Colour(…)’

on_update(dt: float)

Record position, age points, and cull expired ones.

on_draw(renderer)

Draw the ribbon as tapered, colour-graded line segments.

trail_points are a history of world positions (recorded from world_position in :meth:on_update), so each is mapped into this node’s space and the renderer’s transform puts it back where it was recorded, however the node has moved since.

clear()

Remove all trail points immediately.

property trail_points: list[dict]

Trail point data for rendering.

Each dict has: position (Vec2), normalized_age (0=new, 1=expired), width (float), colour (tuple).

property trail_geometry: list[dict]

Vertices for a triangle strip suitable for rendering.

Each vertex dict has: position (Vec2), colour (tuple). For each trail point, two vertices are generated offset perpendicular to the trail direction by +/- half the interpolated width.

get_gizmo_lines() → list[tuple[simvx.core.math.types.Vec2, simvx.core.math.types.Vec2]]

Return the trail centerline as connected line segments for editor gizmos.

position

‘_SpatialVecProperty(…)’

rotation

‘Property(…)’

scale

‘_SpatialVecProperty(…)’

top_level

‘Property(…)’

z_index

‘Property(…)’

z_as_relative

‘Property(…)’

render_layer

‘Property(…)’

set_render_layer(index: int, enabled: bool = True) → None

is_on_render_layer(index: int) → bool

property absolute_z_index: int

property rotation_degrees: float

property world_position: simvx.core.math.types.Vec2

property world_rotation: float

property world_scale: simvx.core.math.types.Vec2

property world_transform: tuple[simvx.core.math.types.Vec2, simvx.core.math.types.Vec2, float]

property forward: simvx.core.math.types.Vec2

property right: simvx.core.math.types.Vec2

translate(offset: tuple[float, float] | numpy.ndarray)

rotate(radians: float)

rotate_deg(degrees: float)

look_at(target: tuple[float, float] | numpy.ndarray)

to_global(point) → simvx.core.math.types.Vec2

to_local(point) → simvx.core.math.types.Vec2

transform_points(points: list[simvx.core.math.types.Vec2]) → list[simvx.core.math.types.Vec2]

wrap_screen(margin: float = 20)

post_processed

‘Property(…)’

property transform_render_dirty: bool

strict_errors: ClassVar[bool]

True

dev_checks: ClassVar[bool]

None

dev_warnings: ClassVar[bool]

None

freeze_check_interval: ClassVar[float]

1.0

visible

‘Property(…)’

update_mode

‘Property(…)’

focus_mode

‘Property(…)’

drag_threshold

‘Property(…)’

focus_entered

‘Signal(…)’

focus_exited

‘Signal(…)’

__properties__: ClassVar[dict[str, simvx.core.descriptors.Property]]

None

classmethod __init_subclass__(**kwargs)

property name: str

property visible_in_tree: bool

property input_player: simvx.core.input.players.InputPlayer

property input_context: simvx.core.input.contexts.InputContext | None

reset_error() → None

add_child(node: simvx.core.node.T) → simvx.core.node.T

remove_child(node: simvx.core.node.Node) → None

reparent(new_parent: simvx.core.node.Node)

node_at(path, default=_NO_DEFAULT)

find(target, *, direct: bool = False)

find_all(target, *, direct: bool = False)

expect(target, *, direct: bool = False)

ancestor(target)

walk(*, include_self: bool = True) → collections.abc.Iterator[simvx.core.node.Node]

property path: str

property is_scene_root: bool

add_to_group(group: str)

remove_from_group(group: str)

is_in_group(group: str) → bool

on_ready() → None

on_enter_tree() → None

on_exit_tree() → None

on_fixed_update(dt: float) → None

on_draw_3d(gizmos) → None

on_picked(event: simvx.core.input.events.PickEvent) → bool | None

on_gui_input(event: simvx.core.input.events.GuiInputEvent) → bool | None

start_coroutine(gen: simvx.core.descriptors.Coroutine) → simvx.core.descriptors.CoroutineHandle

stop_coroutine(gen_or_handle)

property focused: bool

property focus_rect: tuple[float, float, float, float] | None

drag_threshold_for(pointer_type: simvx.core.input.enums.PointerType | str) → float

grab_focus() → None

release_focus() → None

capture_pointer(pointer_id: int | None = None) → None

release_pointer(pointer_id: int | None = None) → None

queue_redraw() → None

property render_dirty: bool

clear_children()

destroy()

property destroying: bool

property destroyed: bool

call_deferred(method: collections.abc.Callable[..., Any], *args: Any) → None

property app

property tree: simvx.core.scene_tree.SceneTree

property viewport_size: simvx.core.math.types.Vec2

property viewport_insets: tuple[float, float, float, float]

property physics

property physics_2d

__getitem__(key: str)

classmethod get_properties() → dict[str, simvx.core.descriptors.Property]

__repr__()