impeller-zig

Zig wrapper for Impeller’s standalone impeller.h API.

Standalone SDK artifacts are packaged in impeller-sdk.

Examples here.

Features

• Linux + Vulkan
• macOS + Metal
• Windows + Vulkan
• Zig wrappers for contexts, surfaces, paints, paths, textures, display lists, typography, and basic geometry
• Flat domain modules such as impeller.geometry, impeller.paint, impeller.path, and impeller.text

Install

zig fetch --save git+https://github.com/impeller-interop/impeller-zig#main

Add the dependency in build.zig:

// ...
const impeller_pkg = @import("impeller_zig");

const impeller_dep = b.dependency("impeller_zig", .{
    .target = target,
    .optimize = optimize,
});

const exe_mod = b.createModule(.{
    .root_source_file = b.path("src/main.zig"),
    .target = target,
    .optimize = optimize,
    .imports = &.{
        .{ .name = "impeller", .module = impeller_dep.module("impeller") },
    },
});
const exe = b.addExecutable(.{
    .name = "app",
    .root_module = exe_mod,
});

// Link libimpeller and copy it beside the executable.
impeller_pkg.linkRuntime(exe, impeller_dep);
b.getInstallStep().dependOn(impeller_pkg.installRuntime(.{
    .compile_step = exe,
    .dependency = impeller_dep,
}));
// ...

Then import it:

const impeller = @import("impeller");

The main API is Zig-first:

var paint = try impeller.Paint.init();
defer paint.deinit();

paint.setColor(impeller.srgb(1.0, 0.2, 0.1, 1.0));

Common types are re-exported at the root for concise call sites. The same API is also split into flat domain modules:

const geometry = impeller.geometry;
const paint = impeller.paint;

const bounds = geometry.rect(0.0, 0.0, 640.0, 480.0);
var fill = try paint.Paint.init();
defer fill.deinit();

Use the impeller.c namespace only when you need raw C functions that are not wrapped yet.

The runtime link step is explicit so projects that only import the package without using Impeller do not load libimpeller.

For custom runtime install layouts and rpath setup, see BUILD.md.

Minimal drawing

Core drawing code:

var builder = try impeller.DisplayListBuilder.init(null);
defer builder.deinit();

var paint = try impeller.Paint.init();
defer paint.deinit();

paint.setColor(impeller.srgb(1.0, 1.0, 1.0, 1.0));
builder.drawPaint(paint);

paint.setColor(impeller.srgb(0.2, 0.4, 1.0, 1.0));
builder.drawRect(impeller.rect(120.0, 100.0, 240.0, 160.0), paint);

var list = try builder.build();
defer list.deinit();

try surface.draw(list);
try surface.present();

Examples

Runnable examples now live in the separate impeller-zig-examples repository so this package stays a pure library dependency with no windowing requirement.

API notes

See API.md for the API guide.

Developer Tools

Fetch the current pinned header:

python3 tools/fetch_h.py --current

This updates tools/impeller.h, which is committed alongside build.zig.zon.

Fetch the latest stable header for comparison:

python3 tools/fetch_h.py

Use --sha <engine-sha> to fetch a specific Flutter engine header into tools/impeller_<sha8>.h.

Export the current SDK header surface:

python3 tools/export_h.py

Compare the current SDK header with another SDK:

python3 tools/diff_h.py --new tools/impeller_<sha8>.h

By default diff_h.py compares against tools/impeller.h. Use --old /path/to/old/impeller.h to compare against a specific header.

LICENSE

MIT