Function batch 

pub fn batch(list: &DrawList, active_clip: Option<[f32; 4]>) -> PreparedFrame

Classify, cull, sort, and batch the commands in list.

Visibility culling

If active_clip is Some([x, y, w, h]), commands whose conservative bounding box does not intersect the clip rectangle are skipped and counted in PreparedFrame::culled_count. Commands that carry no bounds (e.g. PopClip) always pass culling. Clip-stack management commands (PushClip / PopClip) are excluded from batching entirely.

Ordering guarantee

The sort is stable, so the relative submission order of commands that share the same BatchKey is preserved.