classic-ui

Call UIManager::spawn_button with a size, color, and ButtonOptions containing a click_action closure. It creates a container, optional text or sprite child, registers a collider, sets consumes_click, and wires a HandlerKind::Click callback dispatched by physics.perform_calls().

Each child stores a self_anchor on the parent and a child_anchor on itself. set_child_position computes parent position plus parent anchor offset minus child anchor offset, so MidCenter to MidCenter centers the child within the parent.

UI rendering uses UiNode.size for the model matrix, not Transform.scale, which factories initialize to Vec3::ONE. For SDF text you must call measure_all_ui_labels() after spawning so the true text dimensions update UiNode.size.

No. The hover boolean is stored but never read since hover highlighting is always active, and click_feedback's countdown has no trigger that sets click_frames above zero, making it dead code.

UIManager::sync_colliders runs at the top of each frame before physics.perform_calls(), calling physics.sync_collider_rect with each element's current Transform.position and UiNode.size so colliders match the refreshed layout.

Partially. Setting clip_children propagates a clip_rect to children and position_children_of applies scroll_y, but only the SDF text render arm applies GL scissoring; UiRect and UiSprite children are not visually clipped.