Not always

Python Code

from dataclasses import replace

from svan2d.component import TextRenderer, TextState
from svan2d.converter.converter_type import ConverterType
from svan2d import layout
from svan2d.transition import easing
from svan2d.core.logger import configure_logging
from svan2d.velement import VElement
from svan2d.vscene import VScene
from svan2d.vscene.vscene_exporter import VSceneExporter
from svan2d.core.color import Color

configure_logging(level="INFO")

START_COLOR = Color("#FDBE02")
END_COLOR = Color("#AA0000")


def main():

    # Create the scene
    scene = VScene(width=256, height=256, background=Color("#000017"))

    # Create text states for each number with consistent styling
    states = [
        TextState(
            text=str(num),
            font_family="Courier New",
            font_size=20,
        )
        for num in range(1, 10)
    ]

    x_shifts = [-100, 100]

    all_states = [
        layout.line(states, cx=x_shift, spacing=20, rotation=90) for x_shift in x_shifts
    ]

    # Create a text renderer for all numbers
    renderer = TextRenderer()

    # overriding the default easing for the x field for each element
    elements = [
        VElement(
            renderer=renderer,
            keystates=[
                (0.3 if i % 2 else 0, state_a),
                (0.7 if i % 2 else 1, state_b),
            ],
            attribute_easing={"x": easing.linear},
            attribute_keystates={"fill_color": [START_COLOR, END_COLOR]},
        )
        for i, (state_a, state_b) in enumerate(zip(*all_states))
    ]

    # Add all elements to the scene
    scene.add_elements(elements)

    # Create the exporter
    exporter = VSceneExporter(
        scene=scene,
        converter=ConverterType.PLAYWRIGHT,
        output_dir="output/",
    )

    # Export to MP4 file
    exporter.to_mp4(
        filename="not_always",
        total_frames=90,
        framerate=30,
        png_width_px=1024,
    )


if __name__ == "__main__":
    main()

Remarks

• keystates don’t need to cover the entire timeline [0, 1]; the element simply doesn’t exist before the first and after the last defined time point.