4 files changed, 118 insertions, 135 deletions

diff --git a/dxwindow/CMakeLists.txt b/dxwindow/CMakeLists.txt
index baf99de..16c1709 100644
--- a/dxwindow/CMakeLists.txt
+++ b/dxwindow/CMakeLists.txt
@@ -1,10 +1,10 @@
-cmake_minimum_required(VERSION 3.20)
+cmake_minimum_required(VERSION 3.25)
 
-add_library(dxwindow
-    src/dxwindow.cc)
+add_library(dxwindow)
 
-target_include_directories(dxwindow PUBLIC
-    include/)
+target_sources(dxwindow PUBLIC
+    FILE_SET cxx_modules TYPE CXX_MODULES FILES
+    dxwindow.ixx)
 
 target_link_libraries(dxwindow PUBLIC
     glfw)
diff --git a/dxwindow/dxwindow.ixx b/dxwindow/dxwindow.ixx
new file mode 100644
index 0000000..6efcc18
--- /dev/null
+++ b/dxwindow/dxwindow.ixx
@@ -0,0 +1,113 @@
+module;
+
+// Include Windows.h before GLFW to avoid macro redefinition warnings.
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+
+#define GLFW_INCLUDE_NONE  // Do not include OpenGL headers.
+#include <GLFW/glfw3.h>
+
+#define GLFW_EXPOSE_NATIVE_WIN32
+#include <GLFW/glfw3native.h>
+
+#include <cassert>
+#include <cstdio>
+
+export module dxwindow;
+
+namespace dx {
+
+char glfw_error[1024] = {};
+
+void glfw_error_callback(int error, const char* description)
+{
+    sprintf_s(glfw_error, sizeof(glfw_error),
+        "GLFW error %d: %s", error, description);
+}
+
+export {
+
+class Window
+{
+public:
+    ~Window()
+    {
+        if (m_window != nullptr)
+        {
+            glfwDestroyWindow(m_window);
+        }
+    }
+
+    /// Creates the window.
+    bool Initialise(int width, int height, const char* title)
+    {
+        // GLFW by default creates an OpenGL context with the window.
+        // Use GLFW_NO_API to tell it not to do so.
+        glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
+
+        if ((m_window = glfwCreateWindow(
+            width, height, title, /*monitor=*/NULL, /*share=*/NULL)) == nullptr)
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    /// Returns the native window handle.
+    /// If the window has not been initialized, returns an invalid handle.
+    HWND GetWindowHandle()
+    {
+        if (!m_window)
+        {
+            return NULL;
+        }
+        return glfwGetWin32Window(m_window);
+    }
+
+    /// Updates the window by polling for user input.
+    void Update()
+    {
+        assert(m_window);
+        glfwPollEvents();
+    }
+
+    /// Returns true if the user tried to close the window, false otherwise.
+    bool ShouldClose() const
+    {
+        assert(m_window);
+        return glfwWindowShouldClose(m_window) == GLFW_TRUE;
+    }
+
+private:
+    GLFWwindow* m_window = nullptr;
+};
+
+/// Initialise the window subsystem.
+///
+/// This function must be called at the start of your application before any
+/// Windows are created.
+bool WindowInitialise()
+{
+    glfwSetErrorCallback(glfw_error_callback);
+    return glfwInit() == GLFW_TRUE;
+}
+
+/// Terminate the window subsystem.
+///
+/// This function should be called at the end of your application. Any existing
+/// Windows are destroyed and are invalid beyond this call.
+void WindowTerminate()
+{
+    glfwTerminate();
+}
+
+/// Returns the last Window error.
+const char* GetWindowError()
+{
+    return glfw_error;
+}
+
+} // export
+
+} // namespace dx
diff --git a/dxwindow/include/dxwindow.h b/dxwindow/include/dxwindow.h
deleted file mode 100644
index e8f551a..0000000
--- a/dxwindow/include/dxwindow.h
+++ /dev/null
@@ -1,50 +0,0 @@
-#pragma once
-
-// Include Windows.h before GLFW to avoid macro redefinition warnings.
-#define WIN32_LEAN_AND_MEAN
-#include <Windows.h>
-
-#define GLFW_INCLUDE_NONE  // Do not include OpenGL headers.
-#include <GLFW/glfw3.h>
-
-namespace dx
-{
-
-class Window
-{
-public:
-    ~Window();
-
-    /// Creates the window.
-    bool Initialise(int width, int height, const char* title);
-
-    /// Returns the native window handle.
-    /// If the window has not been initialized, returns an invalid handle.
-    HWND GetWindowHandle();
-
-    /// Updates the window by polling for user input.
-    void Update();
-
-    /// Returns true if the user tried to close the window, false otherwise.
-    bool ShouldClose() const;
-
-private:
-    GLFWwindow* m_window = nullptr;
-};
-
-/// Initialise the window subsystem.
-///
-/// This function must be called at the start of your application before any
-/// Windows are created.
-bool WindowInitialise();
-
-/// Terminate the window subsystem.
-///
-/// This function should be called at the end of your application. Any existing
-/// Windows are destroyed and are invalid beyond this call.
-void WindowTerminate();
-
-/// Returns the last Window error.
-const char* GetWindowError();
-
-}  // namespace dx
diff --git a/dxwindow/src/dxwindow.cc b/dxwindow/src/dxwindow.cc
deleted file mode 100644
index 8848a7e..0000000
--- a/dxwindow/src/dxwindow.cc
+++ /dev/null
@@ -1,80 +0,0 @@
-#include "dxwindow.h"
-
-#define GLFW_EXPOSE_NATIVE_WIN32
-#include <GLFW/glfw3native.h>
-
-#include <cassert>
-#include <cstdio>
-
-namespace dx
-{
-
-static char glfw_error[1024] = {};
-
-static void glfw_error_callback(int error, const char* description)
-{
-    sprintf_s(glfw_error, sizeof(glfw_error),
-        "GLFW error %d: %s", error, description);
-}
-
-Window::~Window()
-{
-    if (m_window != nullptr)
-    {
-        glfwDestroyWindow(m_window);
-    }
-}
-
-bool Window::Initialise(int width, int height, const char* title)
-{
-    // GLFW by default creates an OpenGL context with the window.
-    // Use GLFW_NO_API to tell it not to do so.
-    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
-
-    if ((m_window = glfwCreateWindow(
-        width, height, title, /*monitor=*/NULL, /*share=*/NULL)) == nullptr)
-    {
-        return false;
-    }
-
-    return true;
-}
-
-HWND Window::GetWindowHandle()
-{
-    if (!m_window)
-    {
-        return NULL;
-    }
-    return glfwGetWin32Window(m_window);
-}
-
-void Window::Update()
-{
-    assert(m_window);
-    glfwPollEvents();
-}
-
-bool Window::ShouldClose() const
-{
-    assert(m_window);
-    return glfwWindowShouldClose(m_window) == GLFW_TRUE;
-}
-
-bool WindowInitialise()
-{
-    glfwSetErrorCallback(glfw_error_callback);
-    return glfwInit() == GLFW_TRUE;
-}
-
-void WindowTerminate()
-{
-    glfwTerminate();
-}
-
-const char* GetWindowError()
-{
-    return glfw_error;
-}
-
-}  // namespace dx