[petrkonecny2]

Description

Performance and smoothness fixes found while testing the carousel in the Ascension app on a device. One commit each.

perf: interpolate over the points near the slide only. interpolateInsideCarousel, behind useInterpolateInsideCarousel, built and searched one point per slide on every frame, for every slide using it. A long carousel got slower with every slide it had. Only the points around the slide, and around its clone with infinite scroll, change the result. Every other point sits on a flat stretch between two of those, so the helper now builds at most six points. The output is identical: a new test checks it against the previous all-slides version across 2 to 12 slides, three value sets including an offset, and both infinite modes.

fix: stop the row jumping when a drag starts or the carousel re-renders. Three problems in AnimatedPagedView:

• A jump at the start of every drag. The pan activated after 30pt of movement, but onUpdate subtracted translationX, which is measured from where the finger first touched down. The row jumped by about 30pt on activation. The starting point now includes the movement made before activation.
• Vertical scrolls could drag the carousel. minDistance counts movement in any direction, so scrolling a parent past the carousel could grab it, shift it sideways and snap it when the parent took the gesture back. The pan now uses activeOffsetX([-10, 10]) and failOffsetY([-10, 10]), so it only starts on horizontal movement and gives way to vertical scrolling.
• The gesture was rebuilt during drags. Gesture.Pan() was created on every render, and the carousel re-renders while it's dragged. It's now memoized, and the adapter's onScrollBeginDrag is stable so the memo holds.

perf: remove renderWindow. Added in #32, it unmounted slides far from the current one. On a device it made swiping worse:

• Slides mounted as they entered the window, during the snap animation, and building their views mid-animation made the swipe stutter.
• The page tracking behind it re-rendered the carousel on every page change, even with no window set.

Every slide stays mounted again. Removing it also removes isInRenderWindow and its tests, and the README row. This is a breaking change for anyone who passes renderWindow, but it only shipped in 0.1.15, today.

Testing: type:check, lint, test (38 passing) and Prettier. In the Ascension app, all three changes were patched in together. On a phone, swiping was choppy with renderWindow and smooth without it. On the iOS simulator, swipes still page and land centred. The drag-start jump fix follows from the code, but nobody has compared it side by side on a device.

Related Tickets/Issues

Follow-up to #32 and #34.

🤖 Generated with Claude Code

📦 Published PR as canary version: 0.1.18--canary.35.f944505.0

✨ Test out this PR locally via:

npm install @strv/react-native-hero-carousel@0.1.18--canary.35.f944505.0
# or 
yarn add @strv/react-native-hero-carousel@0.1.18--canary.35.f944505.0