From 3ac6e8392d56e1d7d735733744352930fc26dbe3 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Wed, 18 Oct 2023 17:34:12 -0700
Subject: [PATCH] pkg/cimgui: add metal backend

---
 pkg/cimgui/build.zig     | 8 ++++++++
 pkg/cimgui/build.zig.zon | 2 ++
 pkg/cimgui/c.zig         | 6 ++++++
 3 files changed, 16 insertions(+)

diff --git a/pkg/cimgui/build.zig b/pkg/cimgui/build.zig
index 9a508a699..344eee8a2 100644
--- a/pkg/cimgui/build.zig
+++ b/pkg/cimgui/build.zig
@@ -47,6 +47,14 @@ pub fn build(b: *std.Build) !void {
         .flags = flags.items,
     });
 
+    if (target.isDarwin()) {
+        if (!target.isNative()) try @import("apple_sdk").addPaths(b, lib);
+        lib.addCSourceFile(.{
+            .file = imgui.path("backends/imgui_impl_metal.mm"),
+            .flags = flags.items,
+        });
+    }
+
     lib.installHeadersDirectoryOptions(.{
         .source_dir = .{ .path = "vendor" },
         .install_dir = .header,
diff --git a/pkg/cimgui/build.zig.zon b/pkg/cimgui/build.zig.zon
index e4acd91e2..d29374536 100644
--- a/pkg/cimgui/build.zig.zon
+++ b/pkg/cimgui/build.zig.zon
@@ -9,5 +9,7 @@
             .url = "https://github.com/ocornut/imgui/archive/1d8e48c161370c37628c4f37f3f87cb19fbcb723.tar.gz",
             .hash = "12205e93e208aada4c835acdc3e2c1fac95b3ad92b47abe6412ab043f9f13817ad9b",
         },
+
+        .apple_sdk = .{ .path = "../apple-sdk" },
     },
 }
diff --git a/pkg/cimgui/c.zig b/pkg/cimgui/c.zig
index 42b620d4b..16e529312 100644
--- a/pkg/cimgui/c.zig
+++ b/pkg/cimgui/c.zig
@@ -11,3 +11,9 @@ pub extern fn ImGui_ImplOpenGL3_Init(?[*:0]const u8) callconv(.C) void;
 pub extern fn ImGui_ImplOpenGL3_Shutdown() callconv(.C) void;
 pub extern fn ImGui_ImplOpenGL3_NewFrame() callconv(.C) void;
 pub extern fn ImGui_ImplOpenGL3_RenderDrawData(*c.ImDrawData) callconv(.C) void;
+
+// Metal
+pub extern fn ImGui_ImplMetal_Init(*anyopaque) callconv(.C) bool;
+pub extern fn ImGui_ImplMetal_Shutdown() callconv(.C) void;
+pub extern fn ImGui_ImplMetal_NewFrame(*anyopaque) callconv(.C) void;
+pub extern fn ImGui_ImplMetal_RenderDrawData(*c.ImDrawData, *anyopaque, *anyopaque) callconv(.C) void;