Red tint = positive div(F) (source, field spreading out). Blue tint = negative div(F) (sink, field converging). No tint = div ≈ 0.
Green arcs (counter-clockwise) = positive curl. Orange arcs (clockwise) = negative curl. Arc size scales with |curl|.
Click "∮ Line Int", then click up to 10 points on the canvas to form a path. Double-click to finish. Green segments = positive F·dr, red = negative. Check "Closed" to auto-close the loop.
←→↑↓ Pan the view. +− Zoom in/out. Space Place probe at center. Esc Clear probe.
Student mode hides numerical values (div, curl, |F|, line integral result, gradient descent readout). Click "Reveal" to show them. Instructor mode shows everything.