initial commit - it's working

.gitignore

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+.idea/
+.zig-cache/
+zig-out/

build.zig

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+const std = @import("std");
+
+pub fn build(b: *std.Build) !void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const imgui_dep = b.dependency("imgui", .{});
+    const cimgui_dep = b.dependency("cimgui", .{});
+
+    const luajit = try b.findProgram(&.{"luajit"}, &.{});
+
+    const gen = b.addSystemCommand(&.{luajit});
+    gen.setCwd(cimgui_dep.path("generator/"));
+    gen.addFileArg(cimgui_dep.path("generator/generator.lua"));
+    gen.addArgs(&.{
+        "zig cc",
+        "comments internal noimstrv",
+        "glfw",
+        "vulkan",
+    });
+    _ = gen.captureStdOut(); // to quiet output
+
+    {
+        const relpath = try std.fs.path.relative(
+            b.allocator,
+            cimgui_dep.path("generator").getPath(b),
+            imgui_dep.path("").getPath(b),
+        );
+        defer b.allocator.free(relpath);
+        gen.setEnvironmentVariable(
+            "IMGUI_PATH",
+            relpath,
+        );
+    }
+
+    const copy = b.addWriteFiles();
+    copy.step.dependOn(&gen.step);
+    _ = copy.addCopyDirectory(imgui_dep.path(""), "imgui", .{
+        .include_extensions = &.{ ".h", ".cpp" },
+    });
+    _ = copy.addCopyFile(cimgui_dep.path("cimgui.h"), "cimgui.h");
+    _ = copy.addCopyFile(cimgui_dep.path("cimgui.cpp"), "cimgui.cpp");
+    _ = copy.addCopyFile(cimgui_dep.path("generator/output/cimgui_impl.h"), "cimgui_impl.h");
+
+    const cimgui = b.addSharedLibrary(.{
+        .name = "cimgui",
+        .target = target,
+        .optimize = optimize,
+    });
+    cimgui.step.dependOn(&copy.step);
+    cimgui.linkLibC();
+    cimgui.linkLibCpp();
+    cimgui.addIncludePath(copy.getDirectory());
+    cimgui.addIncludePath(copy.getDirectory().path(b, "imgui"));
+    cimgui.addCSourceFiles(.{
+        .root = copy.getDirectory(),
+        .files = &.{
+            "cimgui.cpp",
+            "imgui/imgui.cpp",
+            "imgui/imgui_tables.cpp",
+            "imgui/imgui_widgets.cpp",
+            "imgui/imgui_demo.cpp",
+            "imgui/imgui_draw.cpp",
+            "imgui/backends/imgui_impl_glfw.cpp",
+            "imgui/backends/imgui_impl_vulkan.cpp",
+        },
+        .flags = &.{
+            "-DIMGUI_IMPL_VULKAN_NO_PROTOTYPES",
+        },
+    });
+    cimgui.installHeader(copy.getDirectory().path(b, "cimgui.h"), "cimgui.h");
+    cimgui.installHeader(copy.getDirectory().path(b, "cimgui_impl.h"), "cimgui_impl.h");
+
+    cimgui.linkSystemLibrary2("glfw3", .{
+        .needed = true,
+        .preferred_link_mode = .static,
+        .use_pkg_config = .force,
+    });
+
+    b.installArtifact(cimgui);
+
+    const zimgui_mod = b.addModule("zimgui", .{
+        .target = target,
+        .optimize = optimize,
+        .root_source_file = b.path("src/root.zig"),
+    });
+    zimgui_mod.linkLibrary(cimgui);
+}

build.zig.zon

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+.{
+    .name = "zimgui",
+    .version = "0.0.0",
+    .dependencies = .{
+        .cimgui = .{
+            .url = "https://github.com/cimgui/cimgui/archive/refs/tags/1.90.8dock.tar.gz",
+            .hash = "12207ee69164f88f4b41ee5d44edf3835ec4dab0c0cd885799da67d56668f4a3d46b",
+        },
+        .imgui = .{
+            .url = "https://github.com/ocornut/imgui/archive/refs/tags/v1.90.8-docking.tar.gz",
+            .hash = "122065151b97161e25abb71c9df2fd9fba42aaca8c33d689a480b883d82411c8fabe",
+        },
+    },
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+    },
+}

demo/build.zig

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+const std = @import("std");
+
+pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    // const cimgui = b.dependency("zimgui", .{}).artifact("cimgui");
+    const zimgui = b.dependency("zimgui", .{});
+
+    const exe = b.addExecutable(.{
+        .name = "demo",
+        .root_source_file = b.path("src/main.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+    exe.root_module.addImport("zimgui", zimgui.module("zimgui"));
+    exe.linkSystemLibrary2("glfw3", .{});
+    b.installArtifact(exe);
+
+    const run_cmd = b.addRunArtifact(exe);
+    run_cmd.step.dependOn(b.getInstallStep());
+    if (b.args) |args| {
+        run_cmd.addArgs(args);
+    }
+
+    const run_step = b.step("run", "Run the app");
+    run_step.dependOn(&run_cmd.step);
+}

demo/build.zig.zon

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+.{
+    .name = "demo",
+    .version = "0.0.0",
+    .dependencies = .{
+        .zimgui = .{ .path=".." },
+    },
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+    },
+}

demo/src/main.zig

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+const std = @import("std");
+
+const im = @import("zimgui");
+
+const c = @cImport({
+    @cDefine("GLFW_INCLUDE_NONE", {});
+    @cInclude("GLFW/glfw3.h");
+});
+
+pub fn main() !void {
+    im.init();
+    defer im.deinit();
+
+    _ = c.glfwInit();
+    defer c.glfwTerminate();
+
+    const w = c.glfwCreateWindow(1280, 720, "hello", null, null);
+    defer c.glfwDestroyWindow(w);
+
+    while (c.glfwWindowShouldClose(w) != c.GLFW_TRUE) {
+        c.glfwPollEvents();
+    }
+}
+
+test "simple test" {
+    var list = std.ArrayList(i32).init(std.testing.allocator);
+    defer list.deinit(); // try commenting this out and see if zig detects the memory leak!
+    try list.append(42);
+    try std.testing.expectEqual(@as(i32, 42), list.pop());
+}

src/root.zig

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+const std = @import("std");
+
+const c = @cImport({
+    @cDefine("CIMGUI_DEFINE_ENUMS_AND_STRUCTS", {});
+    @cInclude("cimgui.h");
+    @cInclude("cimgui_impl.h");
+});
+
+pub fn init() void {
+    _ = c.igCreateContext(null);
+    std.debug.print("Context Created!\n", .{});
+}
+
+pub fn deinit() void {
+    _ = c.igDestroyContext(null);
+    std.debug.print("Context Destroyed!\n", .{});
+}

zig-cimgui-tasks.md

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+- Export `IMGUI_PATH` environment variable to downloaded package.
+- cd `generator` directory
+- `luajit generator.lua 'zig cc' 'comments internal noimstrv' glfw vulkan`
+- compile cimgui/cimgui.cpp, imgui/*.cpp, imgui/backends/*.cpp all together
+- install cimgui/cimgui.h, imgui/*.h, cimgui/generator/output/cimgui_impl.h
+
+Zig needs to access cimgui.h and cimgui_impl.h
+
+Set a custom loader. Instructions in imgui_impl_vulkan.h
+
+- cdefine `IMGUI_IMPL_VULKAN_NO_PROTOTYPES`
+- call `ImGui_ImplVulkan_LoadFunctions` before `ImGui_ImplVulkan_Init`
+
+not quite sure yet what the role of `ImGui_ImplVulkanH_Window.UseDynamicRendering` is
+