A simulation of the game of curling, for practising the right calls - execution (including sweeping) is outside the players' control, so be sure to consider all possible outcomes! Written in Rust with Slint; the browser version below is the same code compiled to WebAssembly.
You can play the browser version: set up the player names and their accuracy (average error of weight and angle), then press Start. Click on the sheet to place a marker and see the stone's most probable resting position (don't adjust the marker for sweeping - it's assumed to be "included" in the delivering player's accuracy). Right-click to quickly switch rotation. Weight is expressed as hog-to-hog time - check "automatic" to set the weight to reach the marker.
$ cargo run --release
Tested mostly on Linux, but should work on all platforms supported by Slint.
To keep the simulation fast for analysis (e.g. quickly generating "heatmaps" of possible outcomes), it is advanced not step-by-step but event-to-event: from a starting situation we compute when the next event happens - a collision, a stone leaving play, or a stone coming to rest - and after each event recompute the velocity and acceleration vectors.
The "curling" of a stone's trajectory is modelled as a constant* force applied perpendicular to its motion. Because this acceleration vector rotates over time, computing it exactly is too complex; instead it is updated once per time quantum. The quantum length is adaptive — it ends when the approximation drifts too far from the true vector, so it's longer at high velocities.
*Not quite how real curling stones behave — they tend to curl more as their rotation slows down. Something to improve in the future.