Raylib Backend With Wasm: A Zig And Dvui Guide

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Hey guys! So, I've been wrestling with a cool project, and I'm hoping to get some insights from you all. I'm building a tool for work, and I'm leveraging the power of raylib-zig for its Zig bindings. The goal? To have it running smoothly as both a native application and, crucially, in WebAssembly (Wasm). I've got things humming along nicely for native builds, and the Wasm version also works. The problem arises when I try to integrate dvui. While dvui works perfectly for native builds, I'm hitting a wall trying to compile it for Wasm. It's like my build system is throwing a wrench in the works, and I'm hoping someone out there has cracked the code. I'm pretty new to the Zig build system. Any help would be awesome.

The Challenge: Integrating dvui with Raylib in Wasm

So, here's the deal. I'm deep into this project, and the dream is to get dvui integrated with Raylib, all while keeping things running in Wasm. I can get my stuff working for native, but it is not working when compiling it for Wasm. For those who don't know, dvui is a UI library that would be super helpful, but getting it to play nice with Raylib and Wasm has been a struggle. I'm hoping the community can help me get this solved.

The Build.zig File: A Glimpse into the Build Process

I've put together a build.zig file that outlines how my project is set up. Let's take a closer look at my build.zig file to get a feel for how the project is structured and where the problem might be.

const std = @import("std");
const rlz = @import("raylib_zig");

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

    const raylib_dep = b.dependency("raylib_zig", .{
        .target = target,
        .optimize = optimize,
    });
    const raylib = raylib_dep.module("raylib");
    const raygui = raylib_dep.module("raygui");
    const raylib_artifact = raylib_dep.artifact("raylib");

    const dvui_dep = b.dependency("dvui", .{
        .target = target,
        .optimize = optimize,
    });
    const dvui = dvui_dep.module("dvui_raylib");
    const backend = dvui_dep.module("raylib");

    const nfd = b.dependency("nfd", .{
        .target = target,
    });
    const nfd_mod = nfd.module("nfd");

    const exe_mod = b.createModule(.{
        .root_source_file = b.path("src/main.zig"),
        .target = target,
        .optimize = optimize,
    });
    exe_mod.addImport("raylib", raylib);
    exe_mod.addImport("raygui", raygui);
    exe_mod.addImport("nfd", nfd_mod);
    exe_mod.addImport("dvui", dvui);
    exe_mod.addImport("backend", backend);
    exe_mod.linkLibrary(raylib_artifact);

    const run_step = b.step("run", "Run the app");

    //web exports are completely separate
    if (target.query.os_tag == .emscripten) {
        const emsdk = rlz.emsdk;
        const wasm = b.addLibrary(.{
            .name = "floorplan_editor",
            .root_module = exe_mod,
        });

        const install_dir: std.Build.InstallDir = .{ .custom = "web" };
        const emcc_flags = emsdk.emccDefaultFlags(b.allocator, .{ .optimize = optimize });
        var emcc_settings = emsdk.emccDefaultSettings(b.allocator, .{ .optimize = optimize });
        emcc_settings.put("INITIAL_HEAP", "33554432") catch {};

        const emcc_step = emsdk.emccStep(b, raylib_artifact, wasm, .{
            .optimize = optimize,
            .flags = emcc_flags,
            .settings = emcc_settings,
            .shell_file_path = b.path("src/template.html"),
            .install_dir = install_dir,
            //.embed_paths = &.{.{ .src_path = "resources/" }},
        });
        b.getInstallStep().dependOn(emcc_step);

        const html_filename = try std.fmt.allocPrint(b.allocator, "{s}.html", .{wasm.name});
        const emrun_step = emsdk.emrunStep(
            b,
            b.getInstallPath(install_dir, html_filename),
            &.{},
        );

        emrun_step.dependOn(emcc_step);
        run_step.dependOn(emrun_step);
    } else {
        const exe = b.addExecutable(.{
            .name = "floorplan_editor",
            .root_module = exe_mod,
        });
        b.installArtifact(exe);

        const run_cmd = b.addRunArtifact(exe);
        run_cmd.step.dependOn(b.getInstallStep());

        run_step.dependOn(&run_cmd.step);
    }
}

This build script sets up the dependencies, including raylib-zig, dvui, and nfd. It then defines the executable module and links the necessary libraries. The critical part is the conditional compilation for Emscripten (wasm). Here, it configures the Emscripten build process, sets the INITIAL_HEAP size, and creates steps for compilation and running the Wasm module. The issue is likely within the interaction between dvui, raylib-zig, and the Emscripten compilation process.

Potential Areas for Investigation

  1. Dependency Conflicts: Check if there are any version conflicts between raylib-zig, dvui, and any other dependencies. Zig's build system is pretty good, but sometimes things can get tricky. Make sure all dependencies are compatible with each other. Look for any errors or warnings during the build process that might indicate a conflict.
  2. Emscripten Configuration: The emcc_flags and emcc_settings might need adjustment for dvui. The INITIAL_HEAP setting is there, which is a good start, but you might need to tweak other settings. Look at the dvui documentation, if available, for specific Emscripten requirements. Also, check the Emscripten documentation for best practices.
  3. Linker Issues: The linker could be having trouble resolving symbols from dvui within the Wasm context. Double-check that all necessary libraries are being linked correctly during the Emscripten build. Make sure the linker is aware of where to find the necessary files for dvui. It could be a missing include or a problem with how the libraries are linked.
  4. Zig and Wasm Compatibility: There might be some compatibility issues between the version of Zig you're using and the way dvui is set up to work with Wasm. Ensure that your Zig compiler version is compatible with the version of raylib-zig and dvui you're using. Sometimes, updating or downgrading your Zig compiler can resolve these issues.
  5. Source Code: Make sure dvui is properly integrated with raylib-zig within your source code. Check the import statements, the way you're using dvui components, and how they interact with Raylib's functions. There might be some adjustments needed to make everything compatible with Wasm.

Troubleshooting Steps for Wasm Compilation Errors

Debugging Wasm compilation errors can be a bit tricky, but here are a few steps to help you pinpoint the issue:

  1. Detailed Error Messages: Pay close attention to the error messages. They often provide valuable clues about what's going wrong. Sometimes the errors are cryptic, but they usually point to a specific file, function, or line of code.
  2. Simplify and Isolate: Try to simplify the problem by creating a minimal example that reproduces the error. This helps to isolate the issue and reduces the number of variables to consider. Remove parts of the code to see if the error goes away. If it does, you can incrementally add them back until the error reappears.
  3. Logging and Debugging: Add logging statements to your code to track the execution flow and the values of variables. This can help you identify where the error is occurring. Use a debugger if possible. Zig's debugger can be very helpful for tracking down issues in your code.
  4. Incremental Builds: Make small changes and rebuild frequently. This helps you track down the exact point where the error is introduced. This helps to narrow down the possible causes and makes the debugging process more manageable.
  5. Check the Generated Code: After compilation, inspect the generated Wasm code (using tools like wasm-objdump) to see if the problematic functions are present and if there are any obvious issues.

Seeking Community Support

I'm turning to you all because I'm a bit stumped. Has anyone successfully integrated dvui with Raylib and compiled it for Wasm using Zig? Any specific advice, snippets of code, or pointers to resources would be amazing. I'm especially curious if anyone has dealt with similar issues in the Zig build system or has insights on configuring Emscripten for such a project.

Questions for the Community

  • Has anyone worked with dvui and Raylib in a Wasm environment using Zig? What were the key challenges and how did you solve them?
  • Are there any known compatibility issues between dvui, Raylib, and Emscripten that I should be aware of?
  • Are there any specific Emscripten flags or settings that are critical for making this combination work? Any tips or tricks for getting everything to play nicely together?
  • Could the issue be in the way I am importing the modules from raylib and dvui?

I am really hoping someone can help me get this project over the finish line. Thanks in advance for any assistance you can provide! Let's get this thing working in Wasm! Thanks for reading and I look forward to your suggestions.