Expo Confetti

Expo Confetti is a celebration overlay for React Native that runs real physics instead of a canned animation. Each piece solves the closed form of linear drag — v' = g − k·v — evaluated fresh every frame rather than integrated step by step, so pieces reach terminal velocity almost immediately (about 563 px/s at the shipped g = 900, k = 1.6) and fall the way paper actually falls rather than accelerating like a dropped rock. A sine term adds sideways flutter, and independent X, Y and Z rotation supplies the foil-flip glint. Every piece reads the same Reanimated shared value and derives its own position from it, so a 180-piece burst is one running animation rather than 180 — and because the trajectory is a worklet, none of it touches the JS thread. Colour, shape and launch style are independent axes: pass many colours for a classic multi-colour shower or exactly one for a branded single-colour effect, pick from seven shapes (strip, rect, square, circle, triangle, star and heart) drawn as plain views and react-native-svg paths rather than bitmaps, and fire the run as rain, a radial burst, twin corner cannons or a fountain. Mount it once at the root of a screen and drive it by ref: it renders nothing until play() is called and cleans itself up when the run ends.

• Seven particle shapes — strip, rect, square, circle, triangle, star, heart
• Four launch modes — rain, burst, cannons, fountain
• Five built-in palettes, or any array of hex colours
• Single-colour bursts from a one-entry array
• Closed-form linear drag — terminal velocity, not free fall
• One shared clock drives every piece, not one animation each
• SVG shapes rather than bitmaps — crisp at any size
• play() / stop() ref API, plus autoplay and onComplete
• Pieces past the bottom edge stop drawing
• Runs entirely on the UI thread (Reanimated 4 worklets)
• MIT licensed — full source on GitHub