Dual Keystate

Python Code

from dataclasses import replace

from svan2d import (
    CircleState,
    Color,
    ConverterType,
    VElement,
    VScene,
    VSceneExporter,
    configure_logging,
)

configure_logging(level="INFO")

START_COLOR = Color("#AA0000")
END_COLOR = Color("#0AEF21")


def main():

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

    start_state = CircleState(radius=50, fill_color=START_COLOR)

    end_state = replace(start_state, fill_color=END_COLOR)

    element = (
        VElement()
        .keystate(start_state, at=0)
        .keystate([start_state, end_state], at=0.5)
        .keystate(end_state, at=1)
    )

    # Add all elements to the scene
    scene = scene.add_element(element)

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

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


if __name__ == "__main__":
    main()

Remarks

* The same result can be achieved by creating two VElements—one for the red circle and one for the green, but dual keystates were introduced to improve readability and conciseness.