sokol-zig: A C repository from chakany

Auto-generated Zig bindings for the sokol headers.

For Zig version 0.13.0 and 0.14.0-dev

In case of breaking changes in Zig, the bindings might fall behind. Please don't hesitate to ping me via a Github issue, or even better, provide a PR :)

Support for stable Zig versions is in branches (e.g. zig-0.12.0), those versions are 'frozen in time' though.

Related projects:

Building the samples

Supported platforms are: Windows, macOS, Linux (with X11) and web

On Linux install the following packages: libglu1-mesa-dev, mesa-common-dev, xorg-dev, libasound-dev (or generally: the dev packages required for X11, GL and ALSA development)

To build the platform-native samples:

# just build:
zig build
# build and run samples:
zig build run-clear
zig build run-triangle
zig build run-quad
zig build run-bufferoffsets
zig build run-cube
zig build run-noninterleaved
zig build run-texcube
zig build run-offscreen
zig build run-instancing
zig build run-mrt
zig build run-saudio
zig build run-sgl
zig build run-sgl-context
zig build run-sgl-points
zig build run-debugtext
zig build run-debugtext-print
zig build run-debugtext-userfont
zig build run-shapes

(also run zig build -l to get a list of build targets)

By default, the backend 3D API will be selected based on the target platform:

macOS: Metal
Windows: D3D11
Linux: GL

To force the GL backend on macOS or Windows, build with -Dgl=true:

> zig build -Dgl=true run-clear

The clear sample prints the selected backend to the terminal:

sokol-zig ➤ zig build -Dgl=true run-clear
Backend: .sokol.gfx.Backend.GLCORE33

For the web-samples, run:

zig build -Dtarget=wasm32-emscripten
# or to build and run one of the samples
zig build run-clear -Dtarget=wasm32-emscripten
...

When building with target wasm32-emscripten for the first time, the build script will install and activate the Emscripten SDK into the Zig package cache for the latest SDK version. There is currently no build system functionality to update or delete the Emscripten SDK after this first install. The current workaround is to delete the global Zig cache (run zig env to see where the Zig cache resides).

Improving the Emscripten SDK integration with the Zig build system is planned for the future.

How to integrate sokol-zig into your project

Add a build.zig.zon file to your project which has at least a .sokol dependency:

.{
    .name = "my_project",
    .version = "0.1.0",
    .paths = .{
        "src",
        "build.zig",
        "build.zig.zon",
    },
    .dependencies = .{
        .sokol = .{
            .url = "git+https://github.com/floooh/sokol-zig.git#[commit-hash]",
            .hash = "[content-hash]",
        },
    },
}

For the [commit-sha] just pick the latest from here: https://github.com/floooh/sokol-zig/commits/master

To find out the [content-hash], just omit the .hash line, and run zig build, this will then output the expected hash on the terminal. Copy-paste this into the build.zig.zon file.

For a native-only project, a build.zig file looks entirely vanilla:

const std = @import("std");
const Build = std.Build;
const OptimizeMode = std.builtin.OptimizeMode;

pub fn build(b: *Build) !void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});
    const dep_sokol = b.dependency("sokol", .{
        .target = target,
        .optimize = optimize,
    });
   const hello = b.addExecutable(.{
        .name = "hello",
        .target = target,
        .optimize = optimize,
        .root_source_file = b.path("src/hello.zig"),
    });
    hello.root_module.addImport("sokol", dep_sokol.module("sokol"));
    b.installArtifact(hello);
    const run = b.addRunArtifact(hello);
    b.step("run", "Run hello").dependOn(&run.step);
}

If you also want to run on the web via -Dtarget=wasm32-emscripten, the web platform build must look special, because Emscripten must be used for linking, and to run the build result in a browser, a special run step must be created.

Such a 'hybrid' build script might look like this (copied straight from pacman.zig):

const std = @import("std");
const Build = std.Build;
const OptimizeMode = std.builtin.OptimizeMode;
const sokol = @import("sokol");

pub fn build(b: *Build) !void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});
    const dep_sokol = b.dependency("sokol", .{
        .target = target,
        .optimize = optimize,
    });

    // special case handling for native vs web build
    if (target.result.isWasm()) {
        try buildWeb(b, target, optimize, dep_sokol);
    } else {
        try buildNative(b, target, optimize, dep_sokol);
    }
}

// this is the regular build for all native platforms, nothing surprising here
fn buildNative(b: *Build, target: Build.ResolvedTarget, optimize: OptimizeMode, dep_sokol: *Build.Dependency) !void {
    const pacman = b.addExecutable(.{
        .name = "pacman",
        .target = target,
        .optimize = optimize,
        .root_source_file = b.path("src/pacman.zig"),
    });
    pacman.root_module.addImport("sokol", dep_sokol.module("sokol"));
    b.installArtifact(pacman);
    const run = b.addRunArtifact(pacman);
    b.step("run", "Run pacman").dependOn(&run.step);
}

// for web builds, the Zig code needs to be built into a library and linked with the Emscripten linker
fn buildWeb(b: *Build, target: Build.ResolvedTarget, optimize: OptimizeMode, dep_sokol: *Build.Dependency) !void {
    const pacman = b.addStaticLibrary(.{
        .name = "pacman",
        .target = target,
        .optimize = optimize,
        .root_source_file = b.path("src/pacman.zig"),
    });
    pacman.root_module.addImport("sokol", dep_sokol.module("sokol"));

    // create a build step which invokes the Emscripten linker
    const emsdk = dep_sokol.builder.dependency("emsdk", .{});
    const link_step = try sokol.emLinkStep(b, .{
        .lib_main = pacman,
        .target = target,
        .optimize = optimize,
        .emsdk = emsdk,
        .use_webgl2 = true,
        .use_emmalloc = true,
        .use_filesystem = false,
        .shell_file_path = dep_sokol.path("src/sokol/web/shell.html").getPath(b),
    });
    // ...and a special run step to start the web build output via 'emrun'
    const run = sokol.emRunStep(b, .{ .name = "pacman", .emsdk = emsdk });
    run.step.dependOn(&link_step.step);
    b.step("run", "Run pacman").dependOn(&run.step);
}

wasm32-emscripten caveats

This list might grow longer over time!

Zig allocators use the @returnAddress builtin, which isn't supported in the Emscripten runtime out of the box (you'll get a runtime error in the browser's Javascript console looking like this: Cannot use convertFrameToPC (needed by __builtin_return_address) without -sUSE_OFFSET_CONVERTER. To make it work, do as the error message says, to add the -sUSE_OFFSET_CONVERTER arg to the Emscripten linker step in your build.zig file:
```
    const link_step = try sokol.emLinkStep(b, .{
      // ...other settings here
      .extra_args = &.{"-sUSE_OFFSET_CONVERTER=1"},
  });
```
Also see the kc85.zig build.zig as example!
the Zig stdlib only has limited support for the wasm32-emscripten target, for instance using std.fs functions will most likely fail to compile (the sokol-zig bindings might add more sokol headers in the future to fill some of the gaps)

Dear ImGui support

The sokol-zig bindings come with sokol_imgui.h (exposed as the Zig package sokol.imgui), but integration into a project's build.zig requires some extra steps, mainly because I didn't want to add a cimgui dependency to the sokol-zig package (especially since cimgui uses git submodule which are not supported by the Zig package manager).

The main steps to create Dear ImGui apps with sokol-zig are:

'bring your own cimgui'

tell the sokol dependency that it needs to include sokol_imgui.h into the compiled C library:

const dep_sokol = b.dependency("sokol", .{
    .target = target,
    .optimize = optimize,
    .with_sokol_imgui = true,
});

inject the path to the cimgui directory into the sokol dependency so that C compilation works (this needs to find the cimgui.h header)
```
dep_sokol.artifact("sokol_clib").addIncludePath(cimgui_root);
```

Also see the following example project:

https://github.com/floooh/sokol-zig-imgui-sample/

chakany/sokol-zig

Building the samples

How to integrate sokol-zig into your project

wasm32-emscripten caveats

Dear ImGui support