Use castle for vecmath (doesn't work fully yet)

build.zig

@@ -7,10 +7,12 @@ pub fn build(b: *std.Build) !void {
     const optimize = b.standardOptimizeOption(.{});
     const llvm = b.option(bool, "llvm", "Use LLVM and LLD") orelse false;
 
+    const vecmath_dep = b.dependency("vecmath", .{});
     const vulkan_dep = b.dependency("vulkan_zig", .{ .registry = b.path("vendor/vk.xml") });
     const zglfw_dep = b.dependency("zglfw", .{ .import_vulkan = true });
     const zstbi_dep = b.dependency("zstbi", .{});
 
+    const vecmath_mod = vecmath_dep.module("vecmath");
     const vulkan_mod = vulkan_dep.module("vulkan-zig");
     const zglfw_mod = zglfw_dep.module("root");
     const zstbi_mod = zstbi_dep.module("root");
@@ -25,6 +27,7 @@ pub fn build(b: *std.Build) !void {
         .optimize = optimize,
     });
 
+    exe_mod.addImport("vecmath", vecmath_mod);
     exe_mod.addImport("vulkan", vulkan_mod);
     exe_mod.addImport("zglfw", zglfw_mod);
     exe_mod.addImport("zstbi", zstbi_mod);