simvx.core.nodes_2d.background_bands

BackgroundBands: horizontal colour bands relative to the camera.

Renders a stack of full-width horizontal stripes that fill the visible viewport. Useful for sky / sea / cave-tier backdrops where you want a few solid bands (or gradient bands) without authoring a backdrop texture.

Two scroll modes:

  • world_space=True (default): bands are anchored at fixed world-Y values: the camera can scroll past them, so a “horizon” stays put.

  • world_space=False: bands lock to the screen: the sky always stays at the top of the viewport, irrespective of camera Y. Equivalent to parenting a Node2D under a CanvasLayer.

A band entry is (top_y, colour, [bottom_colour]):

  • top_y: Y in the chosen space (world or screen) for the top of this band. Bands are sorted ascending; each band extends down to the next band’s top_y (or the viewport bottom for the last band).

  • colour: solid RGBA fill, or top colour for a vertical gradient.

  • bottom_colour: optional; if given, the band is a vertical gradient from colour (top) to bottom_colour (bottom).

Module Contents

Classes

BackgroundBands

Horizontal colour bands that follow the camera.

Data

Band

API

simvx.core.nodes_2d.background_bands.Band

None

class simvx.core.nodes_2d.background_bands.BackgroundBands(bands: collections.abc.Sequence[simvx.core.nodes_2d.background_bands.Band] | None = None, world_space: bool = True, **kwargs)[source]

Bases: simvx.core.nodes_2d.node2d.Node2D

Horizontal colour bands that follow the camera.

Example: sky / sea horizon at world-Y = 0::

bg = root.add_child(BackgroundBands())
bg.bands = [
    (-1e9, (0.4, 0.7, 1.0, 1.0), (0.7, 0.85, 1.0, 1.0)),  # sky
    (0.0,  (0.1, 0.3, 0.6, 1.0), (0.05, 0.15, 0.4, 1.0)),  # sea
]

Initialization

world_space

‘Property(…)’

property bands: list[simvx.core.nodes_2d.background_bands.Band][source]
add_band(top_y: float, colour: tuple[float, ...], bottom_colour: tuple[float, ...] | None = None) → None[source]

Append a band entry. Bands are sorted by top_y at draw time.

clear_bands() → None[source]
on_draw(renderer) → None[source]

Emit the band rects covering the visible viewport.

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

dynamic: bool

False

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_update(dt: float) → 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__()