worldToScreen method
Implementation
DiagramPoint worldToScreen(DiagramPoint world) => DiagramPoint(
(world.x - center.x) * zoom + viewportSize.width / 2,
(world.y - center.y) * zoom + viewportSize.height / 2,
);
DiagramPoint worldToScreen(DiagramPoint world) => DiagramPoint(
(world.x - center.x) * zoom + viewportSize.width / 2,
(world.y - center.y) * zoom + viewportSize.height / 2,
);