From 84062873e162bc4a7c799fb67f72dbd055eb15ca Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Wed, 1 May 2024 01:23:05 +0200
Subject: Some work on WSI

---
 deimos/core/os_win32.cpp | 71 ++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 66 insertions(+), 5 deletions(-)

(limited to 'deimos/core/os_win32.cpp')

diff --git a/deimos/core/os_win32.cpp b/deimos/core/os_win32.cpp
index d848530..fe904cd 100644
--- a/deimos/core/os_win32.cpp
+++ b/deimos/core/os_win32.cpp
@@ -8,6 +8,17 @@
 namespace deimos
 {
 
+gsl::cwzstring Utf8ToUtf16Z(StringView src, Span<wchar_t> buffer)
+{
+    Expects(buffer.size() > 0 && buffer.size() > src.size());
+    
+    int res = ::MultiByteToWideChar(CP_UTF8, 0, src.data(), (int)src.size_bytes(), buffer.data(), (int)buffer.size() - 1);
+    if (res < 0) { return L"< MBTWC ERROR >"; }
+
+    buffer[res] = L'\0';
+    return buffer.data();
+}
+
 class Win32ConsoleApiImpl : public OsConsoleApi
 {
     HANDLE m_stdout;
@@ -73,18 +84,68 @@ public:
     }
 };
 
+class Win32WindowApiImpl : public OsWindowApi
+{
+    static constexpr wchar_t kClassName[] = L"Deimos window class";
+    
+    bool m_class_registered = false;
+
+    void RegisterClass()
+    {
+        Expects(!m_class_registered);
+
+        WNDCLASSW wnd_class{};
+        wnd_class.lpfnWndProc   = ::DefWindowProcW;
+        wnd_class.hInstance     = ::GetModuleHandleW(nullptr);
+        wnd_class.lpszClassName = kClassName;
+
+        ::RegisterClassW(&wnd_class);
+
+        m_class_registered = true;
+    }
+    
+public:
+    StatusOr<gsl::owner<OsWindowHandle*>> Create(gsl::czstring title, int32_t width, int32_t height) override
+    {
+        if (!m_class_registered)
+        {
+            RegisterClass();
+        }
+        Ensures(m_class_registered);
+
+        wchar_t title_w_buffer[128]{};
+        gsl::cwzstring title_w = Utf8ToUtf16Z(title, title_w_buffer);
+
+        HWND hwnd = ::CreateWindowExW(
+            0, kClassName, title_w, WS_OVERLAPPEDWINDOW,
+            CW_USEDEFAULT, CW_USEDEFAULT, width, height,
+            nullptr, nullptr, ::GetModuleHandle(nullptr), nullptr);
+
+        if (hwnd == nullptr)
+        {
+            return InternalError("Error while creating Win32 window");
+        }
+
+        ::ShowWindow(hwnd, SW_SHOW);
+
+        return nullptr;
+    }
+};
+
 class Win32OsApiImpl : public OsApi
 {
-    Win32ConsoleApiImpl m_console_api;
-    Win32DllApiImpl m_dll_api;
-    Win32VirtualMemoryApiImpl m_virtual_memory_api;
+    Win32ConsoleApiImpl        m_console_api;
+    Win32DllApiImpl            m_dll_api;
+    Win32VirtualMemoryApiImpl  m_virtual_memory_api;
+    Win32WindowApiImpl         m_window_api;
 
 public:
     Win32OsApiImpl()
     {
-        console = &m_console_api;
-        dll = &m_dll_api;
+        console        = &m_console_api;
+        dll            = &m_dll_api;
         virtual_memory = &m_virtual_memory_api;
+        window         = &m_window_api;
     }
 };
 
-- 
cgit