zgui

zgui v0.9.6 - dear imgui (1.89.4) bindings

Easy to use, hand-crafted API with default arguments, named parameters and Zig style text formatting. For a test application please see here.

Features

• Most public dear imgui API exposed
• All memory allocations go through user provided Zig allocator
• DrawList API for vector graphics, text rendering and custom widgets
• Plot API for advanced data visualizations

Getting started

Copy zgui folder to a libs subdirectory of the root of your project.

To get glfw/wgpu rendering backend working also copy zgpu, zglfw and zpool folders (see zgpu for the details). Alternatively, you can provide your own rendering backend, see: backend_glfw_wgpu.zig for an example.

Then in your build.zig add:

const zgui = @import("libs/zgui/build.zig");

// Needed for glfw/wgpu rendering backend
const zglfw = @import("libs/zglfw/build.zig");
const zgpu = @import("libs/zgpu/build.zig");
const zpool = @import("libs/zpool/build.zig");

pub fn build(b: *std.Build) void {
    ...
    const optimize = b.standardOptimizeOption(.{});
    const target = b.standardTargetOptions(.{});

    const zgui_pkg = zgui.package(b, target, optimize, .{
        .options = .{ .backend = .glfw_wgpu },
    });

    zgui_pkg.link(exe);
    
    // Needed for glfw/wgpu rendering backend
    const zglfw_pkg = zglfw.package(b, target, optimize, .{});
    const zpool_pkg = zpool.package(b, target, optimize, .{});
    const zgpu_pkg = zgpu.package(b, target, optimize, .{
        .deps = .{ .zpool = zpool_pkg.zpool, .zglfw = zglfw_pkg.zglfw },
    });

    zglfw_pkg.link(exe);
    zgpu_pkg.link(exe);
}

Now in your code you may import and use zgui:

const zgui = @import("zgui");

zgui.init(allocator);

_ = zgui.io.addFontFromFile(content_dir ++ "Roboto-Medium.ttf", 16.0);

zgui.backend.init(
    window,
    demo.gctx.device,
    @enumToInt(swapchain_format),
);

// Main loop
while (...) {
    zgui.backend.newFrame(framebuffer_width, framebuffer_height);

    zgui.bulletText(
        "Average :  {d:.3} ms/frame ({d:.1} fps)",
        .{ demo.gctx.stats.average_cpu_time, demo.gctx.stats.fps },
    );
    zgui.bulletText("W, A, S, D :  move camera", .{});
    zgui.spacing();

    if (zgui.button("Setup Scene", .{})) {
        // Button pressed.
    }

    if (zgui.dragFloat("Drag 1", .{ .v = &value0 })) {
        // value0 has changed
    }

    if (zgui.dragFloat("Drag 2", .{ .v = &value0, .min = -1.0, .max = 1.0 })) {
        // value1 has changed
    }

    // Setup wgpu render pass here

    zgui.backend.draw(pass);
}

Building a shared library

If your project spans multiple zig modules that both use ImGui, such as an exe paired with a dll, you may want to build the zgui dependencies (zgui_pkg.zgui_c_cpp) as a shared library. This can be enabled with the shared build option. Then, in build.zig, use zgui_pkg.link to link zgui to all the modules that use ImGui.

When built this way, the ImGui context will be located in the shared library. However, the zgui zig code (which is compiled separately into each module) requires its own memory buffer which has to be initialized separately with initNoContext.

In your executable:

const zgui = @import("zgui");
zgui.init(allocator);
defer zgui.deinit();

In your shared library:

const zgui = @import("zgui");
zgui.initNoContext(allocator);
defer zgui.deinitNoContxt();

DrawList API

draw_list.addQuad(.{
    .p1 = .{ 170, 420 },
    .p2 = .{ 270, 420 },
    .p3 = .{ 220, 520 },
    .p4 = .{ 120, 520 },
    .col = 0xff_00_00_ff,
    .thickness = 3.0,
});
draw_list.addText(.{ 130, 130 }, 0xff_00_00_ff, "The number is: {}", .{7});
draw_list.addCircleFilled(.{ .p = .{ 200, 600 }, .r = 50, .col = 0xff_ff_ff_ff });
draw_list.addCircle(.{ .p = .{ 200, 600 }, .r = 30, .col = 0xff_00_00_ff, .thickness = 11 });
draw_list.addPolyline(
    &.{ .{ 100, 700 }, .{ 200, 600 }, .{ 300, 700 }, .{ 400, 600 } },
    .{ .col = 0xff_00_aa_11, .thickness = 7 },
);

Plot API

if (zgui.plot.beginPlot("Line Plot", .{ .h = -1.0 })) {
    zgui.plot.setupAxis(.x1, .{ .label = "xaxis" });
    zgui.plot.setupAxisLimits(.x1, .{ .min = 0, .max = 5 });
    zgui.plot.setupLegend(.{ .south = true, .west = true }, .{});
    zgui.plot.setupFinish();
    zgui.plot.plotLineValues("y data", i32, .{ .v = &.{ 0, 1, 0, 1, 0, 1 } });
    zgui.plot.plotLine("xy data", f32, .{
        .xv = &.{ 0.1, 0.2, 0.5, 2.5 },
        .yv = &.{ 0.1, 0.3, 0.5, 0.9 },
    });
    zgui.plot.endPlot();
}