Crate pix_engine

Expand description

PixEngine

Summary

pix_engine is a cross-platform graphics & UI library for simple games, visualizations, digital art, and graphics applications written in Rust, supporting SDL2 (and soon Web-Assembly!) renderers.

The primary goal of this library is to be simple to setup and use for graphics or algorithm exploration and is not meant to be as fully-featured as other, larger graphics libraries.

It is intended to be more than just a toy library, however, and can be used to drive real applications. The Tetanes NES emulator, for example uses pix_engine for rendering, window and event handling.

Some examples of things you can create with pix-engine:

2D ray casting of scenes or objects.
2D games like Asteroids, Tetris, Pong, or platformers including sound effects, music and UI elements.
User interfaces for basic applications or configuration.
Algorithm visualizations for sorting, searching, or particle simulations.
Image viewing and editing.
Visual art.

Minimum Supported Rust Version (MSRV)

The current minimum Rust version is 1.59.0.

Screenshots

Asteroids Maze Generation & A* Search 2D Raycasting UI Widgets Fluid Simulation Matrix Rain

Getting Started

Installing Dependencies

First and foremost you’ll need Rust installed! Follow the latest directions at https://www.rust-lang.org/learn/get-started.

When building or running applications for a desktop target such as macOS, Linux, or Windows and not a Web-Assembly target, you must install SDL2 libraries. Note for windows: You may need to install Visual Studio C++ Build Tools.

There are several options for installing SDL2, but these are the most common:

Install via homebrew for macOS, a package management tool like apt for Linux or MSVC for Windows.

For more details and installation options see the rust-sdl2 documentation.

macOS, Linux, or Windows 10 Subsystem for Linux (homebrew)

brew install sdl2 sdl2_gfx sdl2_image sdl2_mixer sdl2_ttf

Linux (package manager)

Note: The minimum SDL2 version is 2.0.20. Some package managers may not have the latest versions available.

Ubuntu:

sudo apt-get install libsdl2-dev libsdl2-gfx-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev

Fedora:

sudo dnf install SDL2-devel SDL2_gfx-devel SDL2_image-devel SDL2_mixer-devel SDL2_ttf-devel

Arch:

sudo pacman -S sdl2 sdl2_gfx sdl2_image sdl2_mixer sdl2_ttf

Windows (MSVC)

Download the latest SDL2 MSVC development libraries from https://www.libsdl.org/download-2.0.php e.g. (SDL2-devel-2.0.20-VC.zip).
Download the latest SDL2_image, SDL2_mixer, and SDL2_ttf MSVC development libraries from https://www.libsdl.org/projects/. e.g. (SDL2_image-devel-2.0.5-VC.zip).
Unzip each .zip file into a folder.
Copy library files:
- from: lib\x64\
- to: C:\Users\{Username}\.rustup\toolchains\{current toolchain}\lib\rustlib\{current toolchain}\lib where {current toolchain} is likely stable-x86_64-pc-windows-msvc.
- Note: If you don’t use rustup, See rust-sdl2 for more info on Windows installation.
Copy all dll files:
- from: lib\x64\
- to: your cargo project next to Cargo.toml.

MSVC binaries for SDL2 are also present in this repository under the lib folder.

Creating Your Application

Creating a visual or interactive application using pix-engine requires implementing only a single method of the AppState trait for your application: AppState::on_update which gets executed as often as possible. Within that function you’ll have access to a mutable PixState object which provides several methods for modifying settings and drawing to the screen.

AppState provides additional methods that can be implemented to respond to user events and handle application startup and teardown.

Here’s an example application which simply draws a circle following the mouse and renders it white or black depending if the mouse is held down or not:

use pix_engine::prelude::*;

struct MyApp;

impl AppState for MyApp {
    // Set up application state and initial settings. `PixState` contains
    // engine specific state and utility methods for actions like getting mouse
    // coordinates, drawing shapes, etc. (Optional)
    fn on_start(&mut self, s: &mut PixState) -> PixResult<()> {
        // Set the background to GRAY and clear the screen.
        s.background(Color::GRAY);

        // Change the font family to NOTO and size to 16 instead of using the
        // defaults.
        s.font_family(Font::NOTO)?;
        s.font_size(16);

        // Returning `Err` instead of `Ok` would indicate initialization failed,
        // and that the application should terminate immediately.
        Ok(())
    }

    // Main update/render loop. Called as often as possible unless
    // `target_frame_rate` was set with a value. (Required)
    fn on_update(&mut self, s: &mut PixState) -> PixResult<()> {
        // Set fill color to black if mouse is pressed, otherwise wite.
        if s.mouse_pressed() {
            s.fill(color!(0));
        } else {
            s.fill(color!(255));
        }

        // Draw a circle with fill color at the mouse position with a radius of
        // 80.
        let m = s.mouse_pos();
        s.circle([m.x(), m.y(), 80])?;

        Ok(())
    }

    // Clean up any state or resources before exiting such as deleting temporary
    // files or saving game state. (Optional)
    fn on_stop(&mut self, s: &mut PixState) -> PixResult<()> {
        Ok(())
    }
}

fn main() -> PixResult<()> {
    let mut engine = PixEngine::builder()
      .with_dimensions(800, 600)
      .with_title("MyApp")
      .with_frame_rate()
      .resizable()
      .build()?;
    let mut app = MyApp;
    engine.run(&mut app)
}

Crate Features

Logging

This library uses the log crate. To leverage logging in your application, choose one of the supported logger implementations and initialize it in your main function.

Example using env_logger:

fn main() -> PixResult<()> {
    env_logger::init();

    let mut engine = PixEngine::builder()
      .with_dimensions(800, 600)
      .with_title("MyApp")
      .build()?;
    let mut app = MyApp;
    engine.run(&mut app)
}

Utility Features

serde - Adds serde Serialize/Deserialize implementations for all enums/structs.
backtrace - Enables the backtrace feature for anyhow, which allows printing backtraces based on environment variables outlined in std::backtrace. Useful for debugging.

Renderer Features

opengl - Forces sdl2 to use opengl as its renderer. This feature is disabled by default, allowing sdl2 to use whichever renderer it defaults to on the target system. For example, macOS defaults to metal.