rapid: A Nim repository from liquidev

A game engine written in Nim, optimized for making cool games fast. Made for convenience while coding and better performance than all-in-one solutions like Godot.

Note: As of June 2021, I'm not longer actively working on rapid. Please fork the repository if you want to keep the project alive.

Goals

Be easy to understand,
Have a rich set of flexible APIs,
Compile all C libraries statically to avoid dependency hell/linker errors,
Make game development a fun task for everyone.

Features

rapid/graphics
- Almost stateless graphics context API – the only state you ever have to worry about is the shape buffer
  - Supports text rendering using FreeType
  - Has a built-in polyline renderer for drawing wires, graphs, etc.
- Post-processing effects with HDR rendering support
- Built in texture packer
rapid/game
- Fixed timestep game loop
- Fixed-size and infinite-size tilemaps
rapid/ec
- Minimal entity-component decoupling pattern implementation
rapid/physics
- chipmunk – General-purpose physics engine, using Chipmunk2D
- simple – Simple and fast AABB-based physics engine
rapid/input
- Simplified input event distribution using procs like mouseButtonJustPressed + callback support
rapid/math
- Common math utilities for vector math, axis-aligned bounding boxes, interpolation, and type-safe units
rapid/ui – Fidget-style UI framework for games and applications

Coming soon

rapid/audio – Sound mixer with real-time effect support

Installing

Note that the new version of rapid (2020) is still under development, so you will have to install a specific commit from the master branch. The current release version is not supported anymore.

To install rapid, use the following command:

$ nimble install "rapid@#3e831cb"  # change the commit hash to the latest commit

In your .nimble file:

requires "rapid#3e831cb"

Pinning to a specific commit rather than #head is recommended, because #head doesn't name a specific point in development. This means that two different packages may end up requiring #head, and the #head that's installed locally may not match the #head that's required by the package. Thanks nimble, you're the best.

Linux

On Linux, the development headers for the following libraries must be installed:

for rapid/graphics:
- GL
- X11
- Xrandr
- Xxf86vm
- Xi
- Xcursor
- Xinerama

Debian and Ubuntu

sudo apt install \
  libgl-dev libx11-dev libxrandr-dev libxxf86vm-dev libxi-dev libxcursor-dev \
  libxinerama-dev

Fedora

sudo dnf install \
  mesa-libGL-devel libX11-devel libXrandr-devel libXxf86vm-devel \
  libXinerama-devel libXi-devel libXcursor-devel

openSUSE

sudo zypper in \
  Mesa-libGL-devel libX11-devel libXrandr-devel libXxf86vm-devel \
  libXinerama-devel libXi-devel libXcursor-devel

Examples

For examples, look in the tests directory.

Tips

Draw in batches whenever possible. This reduces the amount of time the CPU has to spend sending draw calls to the GPU, making your game run better. In general, whenever you have some object that doesn't change often, prefer an aglet Mesh rather than rapid's Graphics.
Compile your game with --opt:speed. Nim's rather primitive stack trace system can slow programs down by quite a bit, so compiling with speed optimizations enabled can be quite important to maintain playable performance. Though if your game's so CPU-heavy that it becomes unplayable without --opt:speed, you're doing something wrong. Go fix your code.

liquidev/rapid