Bridge our use of ImDrawList::PathStroke for newer versions of dear imgui where the thickness and flags arguments are swapped without enabling obsolet

0 = default; 1 = distinct alternate (see each spinner); 2 = reversed timeline.

SpinnerAng is a function that draws a spinner widget with a given angle.

Same as the above compatibility function but for ImDrawList::AddPolyline

Bounce center: three centre-anchored bars (max 50% height) bounce between vertical slots.

Cascade grow: three bottom-anchored bars grow in sequence (60→80→100% cascade).

Conic alternate: two 40% conic-corner tiles; the second slides on a diagonal (alternate).

Conic walk: two conic-corner tiles step through a 2×2 corner path (1.5 s loop).

Corner hop: three bars hop diagonally from bottom-right anchor toward the top row.

Corner wave: three bottom bars step through a corner wave (16.67% keyframes).

Diagonal grow: three bars (aspect 0.75) hop between corners via background-position steps.

Double row: two rows of three bar segments slide horizontally (33/66/100% positions).

Fill cascade: stripe rows fill left→right in a staggered cascade (0.75 s linear).

Flip six: six bars shrink height (0.5 s alternate) while positions flip every 2 s.

Grid fade: 3×3 dot grid; cells fade out in a travelling wave (2 s).

Grid spread: 3×3 dot grid; cells pulse box-shadow spread in a wave (2 s).

Jump bars: three bars (60% max height) swap between top and bottom at 33/66%.

March rows down: four stripe rows drop in from the top, pause, then exit downward (1.5 s).

March rows in: four stripe rows enter from the left, pause, then exit right (1.5 s).

Morph diagonal: three diagonal bars morph 20×100% → 20×20% → 100×20%.

Morph plus: five bars morph 20×100% → 20×20% → 100×20% (alternate ping-pong).

Ping-pong rows: four rows alternate stripe alignment (0↔100%) with a long hold.

Rising bars: three bars slide upward from the bottom (staggered 1/6 phase each).

Row drop stagger: four rows drop down one-by-one (aspect 0.8, alternate ping-pong).

Scale alternate: three bars pulse height 50%↔20%↔100% in sequence (animation-direction: alternate).

Sequential height pulse: three bars (20% width); each shrinks to 10% height in turn (33/50/66%).

Six-bar pulse: six corner bars (3×2) pulse height 50%→30% at 80% of the cycle.

Six-bar stagger: corner bars shrink to 30% height one-by-one, then grow back in wave order.

Slide diagonal: three diagonal bars shrink to 20% height while outer positions swap.

Swap tri-bottom: three bars shrink to 40% height while bottom anchors cycle positions.

Swap tri-zigzag: three bars shrink while anchors zigzag between corner pairs.

Wave rows wide: four rows wave between centre, left, and right (aspect 1.4).

Wave rows skew: four rows skew diagonally (aspect 1.6) then snap back to centre.

Zigzag rows: four rows alternate stripe alignment left/right (0.75 s).