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Curveball

Curve generator for Neverball levels

👉 Click to run the web tool 👈

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Curveball is a curve generator tool for Neverball level developers.

This repository contains the Curveball curve generator engine lib-curveball and the graphical tool curveball.

You can run curveball on your machine, or you can use it on the web.

You can use lib-curveball as a library in your own curve generating tools.

Curveball produces Quake3 map data you can copy and paste into a program like Trenchbroom.

Features

Curveball generates a wider variety of curves than what is possible with curve.c.

Curveball supports generating these curves:

• Curve Classic
• Curve Slope
• Rayto
• Extrusion

Curve Classic

Curve Classic contains the same functionality as curve.c when slope is disabled. It produces circular arcs.

Curve Slope

Curve Classic contains the same functionality as curve.c when slope is enabled, with a little more flexibility.

Rayto

An oddity in the set of curves Curveball produces, Rayto fills in the "negative space" left by a circular arc. The resulting shape is useful for avoiding T-intersections when constructing maps.

Extrusion

The Extrusion tool generates curves in a manner inspired by mechanical CAD sofware. The tool allows you to select one of the following 2D profiles:

• Circle
• Circle sector
• Rectangle
• Parallelogram
• Annulus
• Any arbitrary set of convex polygons

The tool will extrude these 2D profiles along one of the following paths in 3D space:

• Line
• Revolve
• Sinusoid
• Bezier
• Catenary
• Serpentine

You can control how the profile is oriented as it is extruded along the path.

Installation

First, see if Curveball on the Web meets your needs.

For a local installation, consider downloading one of the releases in Github. Alternatively, you may compile from source.

Compiling

First, install Rust.

Then, use Cargo to build the software.

For example, cargo run --bin curveball --release will compile and run curveball in release mode.

You may also use cargo install to install the software. See here for more information.

Using Curveball in your own script

You may want to write your own curve generating scripts and use Curveball to help. To do this:

1. Make a new package with cargo new

2. Add Curveball with cargo add lib-curveball

3. Use the examples to get started

You can use lib-curveball to:

• Generate brushes directly from points, or

• Define your own profile or path and calling extrude()

Compiling for distribution

Building for distribution requires you to be set up for cross-compilation and compiling for the web. Dependencies include:

• just - a more convenient Makefile
• Trunk - to create a website with WASM
• cross - for simple cross-compilation; requires Docker or Podman

You will also need to add targets for x86_64-unknown-linux-gnu and x86_64-pc-windows-gnu with rustup target add <TARGET>.

Distribution simply requires running the justfile:

just build-linux
just build-windows
just build-web

Project Structure

Curveball is written in Rust.

This repository is a Cargo workspace with the following crates:

• curveball - Binary crate; compiles to the GUI tool.
• lib-curveball - Library crate containing functions to generate the various curves.

Is it any good?

Yes.

License

Licensed under either of

• Apache License, Version 2.0
• MIT License

at your option.

Notice

Future versions may be released under a different license. Neverball is licensed under the terms of GPLv2, so if Curveball ever makes use of Neverball assets or code, it will need to be released under a GPL license, too.

A license change will result in a major version bump.