Not always

Python Code

from svan2d import (
    Color,
    configure_logging,
    ConverterType,
    easing,
    layout,
    Point2D,
    TextRenderer,
    TextState,
    VElement,
    VScene,
    VSceneExporter,
)

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, center=Point2D(x_shift, 0), 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)
        .attributes(
            easing_dict={"pos": easing.linear},
            keystates={"fill_color": [START_COLOR, END_COLOR]},
        )
        .keystates(states, at=[0.3 if i % 2 else 0, 0.7 if i % 2 else 1])
        for i, states in enumerate(zip(*all_states))
    ]

    # Add all elements to the scene
    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.