3 files changed, 120 insertions, 0 deletions

diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
new file mode 100644
index 0000000..7b2bdaf
--- /dev/null
+++ b/app/CMakeLists.txt
@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+add_library(app
+    include/dxwindow.h
+    src/dxwindow.c)
+
+target_include_directories(app PUBLIC
+    include)
+
+target_link_libraries(app PUBLIC
+    glfw)
diff --git a/app/include/dxwindow.h b/app/include/dxwindow.h
new file mode 100644
index 0000000..7e5a373
--- /dev/null
+++ b/app/include/dxwindow.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <WinDef.h> // HWND
+
+#include <stdbool.h>
+
+typedef struct Window Window;
+
+/// Initialise the window subsystem.
+///
+/// This function must be called at the start of your application before any
+/// Windows are created.
+bool window_global_init();
+
+/// 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 window_global_quit();
+
+/// Return the last Window error.
+const char* window_get_error();
+
+Window* window_init(int width, int height, const char* title);
+void window_destroy(Window**);
+HWND window_handle(Window*);
+void window_update(Window*);
+bool window_should_close(const Window*);
diff --git a/app/src/dxwindow.c b/app/src/dxwindow.c
new file mode 100644
index 0000000..3f775e7
--- /dev/null
+++ b/app/src/dxwindow.c
@@ -0,0 +1,81 @@
+#include <dxwindow.h>
+
+// 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 <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct Window {
+    GLFWwindow* glfw_window;
+} Window;
+
+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);
+}
+
+bool window_global_init() {
+    glfwSetErrorCallback(glfw_error_callback);
+    return glfwInit() == GLFW_TRUE;
+}
+
+void window_global_quit() {
+    glfwTerminate();
+}
+
+const char* window_get_error(Window* wnd) {
+    assert(wnd);
+    return glfw_error;
+}
+
+Window* window_init(int width, int height, const char* title) {
+    Window* wnd = calloc(1, sizeof(Window));
+    if (!wnd) {
+        return 0;
+    }
+    // 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 ((wnd->glfw_window = glfwCreateWindow(
+        width, height, title, /*monitor=*/NULL, /*share=*/NULL)) == 0) {
+        free(wnd);
+        return 0;
+    }
+    return wnd;
+}
+
+void window_destroy(Window** ppWindow) {
+    assert(ppWindow);
+    Window* wnd = *ppWindow;
+    if (wnd) {
+        glfwDestroyWindow(wnd->glfw_window);
+        free(wnd);
+        *ppWindow = 0;
+    }
+}
+
+HWND window_handle(Window* wnd) {
+    assert(wnd);
+    return glfwGetWin32Window(wnd->glfw_window);
+}
+
+void window_update(Window* wnd) {
+    assert(wnd);
+    glfwPollEvents();
+}
+
+bool window_should_close(const Window* wnd) {
+    assert(wnd);
+    return glfwWindowShouldClose(wnd->glfw_window) == GLFW_TRUE;
+}