vn/code/win32_main.cpp

#define NOMINMAX
#define WIN32_LEAN_AND_MEAN
#include "windows.h"
#include "timeapi.h"

#include "vn_platform.h"

#if W32_LINK_SINGLE
#include "vn.cpp"
#endif

#include "win32_main.h"
#include "win32_opengl.cpp"

global win32_state Global_Win32State;
global WINDOWPLACEMENT Global_WindowPosition = {sizeof(Global_WindowPosition)};;

static void Win32_PlatformError(char *Message, bool IsFatal)
{
	MessageBoxA(0, Message, "vn - Platform Error", MB_OK|(IsFatal?MB_ICONSTOP:MB_ICONEXCLAMATION));
	
	if(IsFatal)
	{
		ExitProcess((UINT)-1);
	}
}

static PLATFORM_SHOW_MESSAGE(Win32_ShowMessage)
{
	DWORD Flags = MB_OK;
	switch(Type)
	{
		case Platform_Message_Info:    { Flags |= MB_ICONINFORMATION; } break;
		case Platform_Message_Warning: { Flags |= MB_ICONWARNING;     } break;
		case Platform_Message_Error:   { Flags |= MB_ICONEXCLAMATION; } break;
		case Platform_Message_Fatal:   { Flags |= MB_ICONSTOP;        } break;
		
		InvalidDefaultCase;
	}
	
	// sixten(NOTE): Check for null-termination.
	Assert(Message.Data[Message.Count] == 0);
	
	MessageBoxA(0, (char *)Message.Data, "vn - A message from the developer", Flags);
	
	if(Type == Platform_Message_Fatal)
	{
		ExitProcess((UINT)-1);
	}
}

static u64 Win32_GetPageSize(void)
{
	SYSTEM_INFO Info;
	GetSystemInfo(&Info);
	return(Info.dwPageSize);
}

static PLATFORM_RESERVE(Win32_Reserve)
{
	u64 GigabyteAlignedSize = Size+Gigabytes(1)-1;
	GigabyteAlignedSize -= GigabyteAlignedSize%Gigabytes(1);
	void *Result = VirtualAlloc(0, GigabyteAlignedSize, MEM_RESERVE, PAGE_NOACCESS);
	return(Result);
}

static PLATFORM_RELEASE(Win32_Release)
{
	VirtualFree(Pointer, 0, MEM_RELEASE);
}

static PLATFORM_COMMIT(Win32_Commit)
{
	u64 PageAlignedSize = Size+Win32_GetPageSize()-1;
	PageAlignedSize -= PageAlignedSize%Win32_GetPageSize();
	VirtualAlloc(Pointer, PageAlignedSize, MEM_COMMIT, PAGE_READWRITE);
}

static PLATFORM_DECOMMIT(Win32_Decommit)
{
	VirtualFree(Pointer, Size, MEM_DECOMMIT);
}

static PLATFORM_ALLOCATE(Win32_Allocate)
{
	void *Result = VirtualAlloc(0, Size, MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE);
	return(Result);
}

static PLATFORM_DEALLOCATE(Win32_Deallocate)
{
	VirtualFree(Pointer, 0, MEM_DECOMMIT|MEM_RELEASE);
}

static PLATFORM_OPEN_FILE(Win32_OpenFile)
{
	DWORD DesiredAccess = 0;
	if(FileAccess & PlatformAccess_Read)
	{
		DesiredAccess |= GENERIC_READ;
	}
	if(FileAccess & PlatformAccess_Write)
	{
		DesiredAccess |= GENERIC_WRITE;
	}
	
	DWORD CreationAttributes = 0;
	if(FileAccess & PlatformAccess_Read)
	{
		CreationAttributes = OPEN_EXISTING;
	}
    if(FileAccess & PlatformAccess_Write)
    {
        CreationAttributes = CREATE_ALWAYS;
    }
    if(FileAccess & PlatformAccess_OpenAlways)
    {
        CreationAttributes = OPEN_ALWAYS;
    }
    
    temp Scratch = GetScratch(0, 0);
    
    string FullPath = PushFormat(Scratch.Arena, "%S\\%S", Global_Win32State.ContentsPath, Path);
    HANDLE File = CreateFileA((char *)FullPath.Data, DesiredAccess, 0, 0, CreationAttributes, 0, 0);
    
    ReleaseScratch(Scratch);
    
    platform_file_handle Result = {};
    Result.Platform = (u64)File;
    Result.IsValid = (File != INVALID_HANDLE_VALUE);
    
    return(Result);
}

static PLATFORM_CLOSE_FILE(Win32_CloseFile)
{
	HANDLE File = (HANDLE)Handle.Platform;
	if(File != INVALID_HANDLE_VALUE)
	{
		CloseHandle(File);
	}
}

static PLATFORM_READ_FILE(Win32_ReadFile)
{
	HANDLE File = (HANDLE)Handle.Platform;
	if(File != INVALID_HANDLE_VALUE)
	{
		DWORD BytesRead;
		ReadFile(File, Dest, Size, &BytesRead, 0);
	}
}

static PLATFORM_WRITE_FILE(Win32_WriteFile)
{
	HANDLE File = (HANDLE)Handle.Platform;
	if(File != INVALID_HANDLE_VALUE)
	{
		DWORD BytesWritten;
		WriteFile(File, Source, Size, &BytesWritten, 0);
		
		Assert(BytesWritten == Size);
	}
}

static PLATFORM_GET_FILE_SIZE(Win32_GetFileSize)
{
	u64 Result = 0;
	
	HANDLE File = (HANDLE)Handle.Platform;
	if(File != INVALID_HANDLE_VALUE)
	{
		LARGE_INTEGER FileSize;
		GetFileSizeEx(File, &FileSize);
		
		Result = FileSize.QuadPart;
	}
	
	return(Result);
}

static PLATFORM_SET_CURSOR(Win32_SetCursor)
{
	Global_Win32State.Cursor = Cursor;
}

static PLATFORM_BEGIN_FILE_ITER(Win32_BeginFileIter)
{
	win32_file_find_data *FileFindData = PushStruct(Arena, win32_file_find_data);
	temp Scratch = GetScratch(&Arena, 1);
	Path = PushFormat(Scratch.Arena, "%S/%S*", Global_Win32State.ContentsPath, Path);
	string16 Path16 = String16FromString8(Scratch.Arena, Path);
	FileFindData->Handle = FindFirstFileW((WCHAR *)Path16.Data, &FileFindData->FindData);
	ReleaseScratch(Scratch);
	platform_file_iter *Iter = (platform_file_iter *)FileFindData;
	return(Iter);
}

static PLATFORM_ADVANCE_FILE_ITER(Win32_AdvanceFileIter)
{
	b32 Result = false;
	win32_file_find_data *FileFindData = (win32_file_find_data *)Iter;
	WIN32_FIND_DATAW FindData = {};
	s64 InvalidCount = 0;
	for(;;)
	{
		if(FileFindData->FindFirstReturned)
		{
			Result = FindNextFileW(FileFindData->Handle, &FindData);
		}
		else
		{
			Result = (FileFindData->Handle != 0 && FileFindData->Handle != INVALID_HANDLE_VALUE);
			FindData = FileFindData->FindData;
			FileFindData->FindFirstReturned = true;
		}
		
		b32 NameIsInvalid = (FindData.cFileName[0] == '.' && (FindData.cFileName[1] == 0 || FindData.cFileName[1] == '.'));
		if(NameIsInvalid && InvalidCount < 10)
		{
			InvalidCount += 1;
			continue;
		}
		
		break;
	}
	
	if(Result != 0)
	{
		string16 Name16 = {};
		Name16.Data = (u16 *)FindData.cFileName;
		for(u16 Index = 0; Index < MAX_PATH; Index += 1)
		{
			if(FindData.cFileName[Index] == 0)
			{
				break;
			}
			Name16.Count += 1;
		}
		
		*OutInfo = {};
		OutInfo->Name = String8FromString16(Arena, Name16);
		OutInfo->IsDirectory = FindData.dwFileAttributes&FILE_ATTRIBUTE_DIRECTORY;
	}
	return(Result);
}

static PLATFORM_END_FILE_ITER(Win32_EndFileIter)
{
	win32_file_find_data *FileFindData = (win32_file_find_data *)Iter;
	FindClose(FileFindData->Handle);
}

inline u64 Win32_GetWallClock(void)
{
	LARGE_INTEGER Query;
	QueryPerformanceCounter(&Query);
	
	u64 Result = Query.QuadPart;
	return(Result);
}

inline r64 Win32_GetSecondsElapsed(u64 Start, u64 End)
{
	u64 Elapsed = End - Start;
	
	r64 Result = (r64)Elapsed/(r64)Global_Win32State.PerformanceFrequency;
	return(Result);
}

inline FILETIME Win32_GetLastWriteTime(char *Path)
{
	FILETIME Result = {};
	
	HANDLE File = CreateFileA(Path, GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, 0, 0);
	if(File)
	{
		FILETIME Creation, LastAccess, LastWrite;
		GetFileTime(File, &Creation, &LastAccess, &LastWrite);
		
		Result = LastWrite;
		
		CloseHandle(File);
	}
	
	return(Result);
}

#if !W32_LINK_SINGLE
static win32_loaded_code Win32_LoadCode(void)
{
	win32_loaded_code Code = {};
	
	win32_state *State = &Global_Win32State;
	
	if(CopyFile(State->DLLPath, State->TempDLLPath, FALSE))
	{
		Code.LastWriteTime = Win32_GetLastWriteTime(State->DLLPath);
		
		Code.DLL = LoadLibraryA(State->TempDLLPath);
		if(Code.DLL)
		{
			Code.UpdateAndRender = (vn_update_and_render *)GetProcAddress(Code.DLL, "VN_UpdateAndRender");
			if(Code.UpdateAndRender)
			{
				Code.IsValid = true;
			}
		}
	}
	
	return(Code);
}

static void Win32_UnloadCode(win32_loaded_code *Code)
{
	if(Code->DLL)
	{
		FreeLibrary(Code->DLL);
	}
	
	*Code = {};
}

static void Win32_UpdateCode(win32_loaded_code *Code)
{
	win32_state *State = &Global_Win32State;
	
	FILETIME LastWriteTime = Win32_GetLastWriteTime(State->DLLPath);
	if(CompareFileTime(&Code->LastWriteTime, &LastWriteTime) != 0)
	{
		Win32_UnloadCode(Code);
		*Code = Win32_LoadCode();
		
		// sixten(NOTE): Sometimes the program decides to crash upon reloads, so we just wait for those to be over...
		Sleep(500);
	}
}
#endif

static PLATFORM_TOGGLE_FULLSCREEN(Win32_ToggleFullscreen)
{
	HWND Window = Global_Win32State.Window;
	
	DWORD Style = GetWindowLong(Window, GWL_STYLE);
	if(Style & WS_OVERLAPPEDWINDOW)
	{
		MONITORINFO MonitorInfo = {sizeof(MonitorInfo)};
		if(GetWindowPlacement(Window, &Global_WindowPosition) &&
           GetMonitorInfo(MonitorFromWindow(Window, MONITOR_DEFAULTTOPRIMARY), &MonitorInfo))
		{
			// sixten(NOTE): This doesn't work when the window is maximized. One wordaround would be to set the 
			// window to "normal" size using ShowWindow(Window, SW_SHOWNORMAL) but it looks *very* scuffed.
			SetWindowLong(Window, GWL_STYLE, Style & ~WS_OVERLAPPEDWINDOW);
			SetWindowPos(Window, HWND_TOP,
                         MonitorInfo.rcMonitor.left, MonitorInfo.rcMonitor.top,
                         MonitorInfo.rcMonitor.right - MonitorInfo.rcMonitor.left,
                         MonitorInfo.rcMonitor.bottom - MonitorInfo.rcMonitor.top,
                         SWP_NOOWNERZORDER | SWP_FRAMECHANGED);
		}
	}
	else
	{
		SetWindowLong(Window, GWL_STYLE, Style | WS_OVERLAPPEDWINDOW);
		SetWindowPlacement(Window, &Global_WindowPosition);
		SetWindowPos(Window, 0, 0, 0, 0, 0,
                     SWP_NOMOVE|SWP_NOSIZE|SWP_NOZORDER|SWP_NOOWNERZORDER|SWP_FRAMECHANGED);
	}
}

static PLATFORM_SET_CLIPBOARD(Win32_SetClipboard)
{
	temp Scratch = GetScratch();
	if(OpenClipboard(0))
	{
		EmptyClipboard();
		
		string16 String16 = String16FromString8(Scratch.Arena, String);
		
		HANDLE CopyHandle = GlobalAlloc(GMEM_MOVEABLE, String16.Count*sizeof(u16)+1);
		if(CopyHandle)
		{
			u16 *CopyBuffer = (u16 *)GlobalLock(CopyHandle);
			Copy(CopyBuffer, String16.Data, String16.Count*sizeof(u16));
			CopyBuffer[String.Count] = 0;
			GlobalUnlock(CopyHandle);
			SetClipboardData(CF_UNICODETEXT, CopyHandle);
		}
		CloseClipboard();
	}
	ReleaseScratch(Scratch);
}

static PLATFORM_GET_CLIPBOARD(Win32_GetClipboard)
{
	string Result = {};
	if(IsClipboardFormatAvailable(CF_UNICODETEXT) && OpenClipboard(0))
	{
		HANDLE DataHandle = GetClipboardData(CF_UNICODETEXT);
		if(DataHandle)
		{
			u16 *Data = (u16 *)GlobalLock(DataHandle);
			if(Data)
			{
				s64 Count = StringLength16(Data);
				Result = String8FromString16(Arena, MakeString16(Data, Count));
				GlobalUnlock(DataHandle);
			}
		}
		CloseClipboard();
	}
	return(Result);
}

inline v2_r32 Win32_GetMouseP(HWND Window)
{
	POINT Point;
	GetCursorPos(&Point);
	ScreenToClient(Window, &Point);
	
	v2_r32 Result = V2R32(Point.x, Point.y);
	return(Result);
}

inline v2_r32 Win32_GetWindowDim(HWND Window)
{
	RECT ClientRect;
	GetClientRect(Window, &ClientRect);
	
	v2_r32 Result = V2R32(ClientRect.right - ClientRect.left, ClientRect.bottom - ClientRect.top);
	return(Result);
}

inline platform_modifiers Win32_GetModifiers(void)
{
	platform_modifiers Modifiers = 0;
	
	if(GetKeyState(VK_CONTROL) & 0x8000)
	{
		Modifiers |= PlatformModifier_Ctrl;
	}
	if(GetKeyState(VK_SHIFT) & 0x8000)
	{
		Modifiers |= PlatformModifier_Shift;
	}
	if(GetKeyState(VK_MENU) & 0x8000)
	{
		Modifiers |= PlatformModifier_Alt;
	}
	
	return(Modifiers);
}

static LRESULT Win32_WindowCallback(HWND Window, UINT Message, WPARAM WParam, LPARAM LParam)
{
	LRESULT Result = 0;
	
	win32_state *State = &Global_Win32State;
	
	temp Scratch = GetScratch(0, 0);
	
	platform_event *Event = 0;
	
	b32 ButtonIsUp = false;
	axis2 ScrollAxis = Axis2_Y;
	
	switch(Message)
	{
		case WM_CLOSE:
		{
			Event = PushStruct(State->EventArena, platform_event);
			Event->Type = PlatformEvent_WindowClose;
		} break;
		
		case WM_WINDOWPOSCHANGED:
		{
			// TODO(casey): For now, we are setting the window styles in here
			// because sometimes Windows can reposition our window out of fullscreen
			// without going through our ToggleFullscreen(), and we want to put our
			// title bar and border back when it does!
			
			WINDOWPOS *NewPos = (WINDOWPOS *)LParam;
			
			b32 BecomingFullscreen = false;
			MONITORINFO MonitorInfo = {sizeof(MonitorInfo)};
			if(GetMonitorInfo(MonitorFromWindow(Window, MONITOR_DEFAULTTOPRIMARY),
                              &MonitorInfo))
			{
				s32 MonWidth = (MonitorInfo.rcMonitor.right - MonitorInfo.rcMonitor.left);
				s32 MonHeight = (MonitorInfo.rcMonitor.bottom - MonitorInfo.rcMonitor.top);
				BecomingFullscreen = ((MonitorInfo.rcMonitor.left == NewPos->x) &&
                                      (MonitorInfo.rcMonitor.top == NewPos->y) &&
                                      (MonWidth == NewPos->cx) &&
                                      (MonHeight == NewPos->cy));
			}
			
			DWORD OldStyle = GetWindowLong(Window, GWL_STYLE);
			DWORD FullscreenStyle = OldStyle & ~WS_OVERLAPPEDWINDOW;
			DWORD WindowedStyle = OldStyle | WS_OVERLAPPEDWINDOW;
			DWORD NewStyle = (BecomingFullscreen) ? FullscreenStyle : WindowedStyle;
			
			if(NewStyle != OldStyle)
			{
				SetWindowLong(Window, GWL_STYLE, NewStyle);
			}
			
			Result = DefWindowProcA(Window, Message, WParam, LParam);
		} break;
		
		case WM_MOUSEHWHEEL:
		{
			ScrollAxis = Axis2_X;
		} fallthrough;
		case WM_MOUSEWHEEL:
		{
			Event = PushStruct(State->EventArena, platform_event);
			Event->Type = PlatformEvent_MouseScroll;
			Event->Scroll.E[ScrollAxis] = GET_WHEEL_DELTA_WPARAM(WParam) / 120.0;
		} break;
		
		case WM_LBUTTONUP:
		case WM_MBUTTONUP:
		case WM_RBUTTONUP:
		{
			ButtonIsUp = true;
		} fallthrough;
		
		case WM_LBUTTONDOWN:
		case WM_MBUTTONDOWN:
		case WM_RBUTTONDOWN:
		{
			platform_event_type Type = ButtonIsUp ? PlatformEvent_Release : PlatformEvent_Press;
			
			platform_key Key = Key_Invalid;
			switch(Message)
			{
				case WM_LBUTTONUP: case WM_LBUTTONDOWN: { Key = Key_MouseLeft; } break;
				case WM_MBUTTONUP: case WM_MBUTTONDOWN: { Key = Key_MouseMiddle; } break;
				case WM_RBUTTONUP: case WM_RBUTTONDOWN: { Key = Key_MouseRight; } break;
			}
			
			Event = PushStruct(State->EventArena, platform_event);
			Event->Type = Type;
			Event->Key = Key;
			Event->P = Win32_GetMouseP(Window);
		} break;
		
		case WM_SYSKEYUP:
		case WM_KEYUP:
		{
			ButtonIsUp = true;
		} fallthrough;
		case WM_SYSKEYDOWN:
		case WM_KEYDOWN:
		{
			platform_event_type Type = ButtonIsUp ? PlatformEvent_Release : PlatformEvent_Press;
			
			u32 VKCode = (u32)WParam;
			platform_key Key = Key_Invalid;
			
			if(VKCode >= 'A' && VKCode <= 'Z')
			{
				Key = (platform_key)(Key_A + (VKCode - 'A'));
			}
			else if(VKCode >= VK_F1 && VKCode <= VK_F12)
			{
				Key = (platform_key)(Key_F1 + (VKCode - VK_F1));
			}
			else if(VKCode == VK_LEFT) { Key = Key_Left; }
			else if(VKCode == VK_RIGHT) { Key = Key_Right; }
			else if(VKCode == VK_UP) { Key = Key_Up; }
			else if(VKCode == VK_DOWN) { Key = Key_Down; }
			else if(VKCode == VK_SPACE) { Key = Key_Space; }
			else if(VKCode == VK_RETURN) { Key = Key_Return; }
			else if(VKCode == VK_PRIOR) { Key = Key_PageUp; }
			else if(VKCode == VK_NEXT) { Key = Key_PageDown; }
			else if(VKCode == VK_HOME) { Key = Key_Home; }
			else if(VKCode == VK_END) { Key = Key_End; }
			else if(VKCode == VK_OEM_PLUS) { Key = Key_Plus; }
			else if(VKCode == VK_OEM_MINUS) { Key = Key_Minus; }
			else if(VKCode == VK_OEM_PERIOD) { Key = Key_Period; }
			else if(VKCode == VK_OEM_COMMA) { Key = Key_Comma; }
			else if(VKCode == VK_BACK) { Key = Key_Backspace; }
			else if(VKCode == VK_DELETE) { Key = Key_Delete; }
			else if(VKCode == VK_ESCAPE) { Key = Key_Escape; }
			
			if(Key != Key_Invalid)
			{
				Event = PushStruct(State->EventArena, platform_event);
				Event->Type = Type;
				Event->Key = Key;
			}
			
			if(!ButtonIsUp && (VKCode == VK_RETURN) && (LParam & (1 << 29)))
			{
				Win32_ToggleFullscreen();
			}
			else
			{
				Result = DefWindowProc(Window, Message, WParam, LParam);
			}
			
		} break;
		
		case WM_CHAR:
		{
			u32 Codepoint = (u32)WParam;
			if(Codepoint == '\r')
			{
				Codepoint = '\n';
			}
			
			if((Codepoint >= 32 && Codepoint != 127) || Codepoint == '\t' || Codepoint == '\n')
			{
				Event = PushStruct(State->EventArena, platform_event);
				Event->Type = PlatformEvent_Text;
				Event->Codepoint = Codepoint;
			}
		} break;
		
		case WM_SETCURSOR:
		{
			range2_r32 WindowRect = {};
			WindowRect.Max = Win32_GetWindowDim(Window);
			if(InRange(WindowRect, Win32_GetMouseP(Window)))
			{
				persist HCURSOR CursorTable[PlatformCursor_Count];
				persist b32 CursorTableLoaded = false;
				if(!CursorTableLoaded)
				{
					CursorTable[PlatformCursor_Arrow] = LoadCursor(0, IDC_ARROW);
					CursorTable[PlatformCursor_Cross] = LoadCursor(0, IDC_CROSS);
					CursorTable[PlatformCursor_Hand] = LoadCursor(0, IDC_HAND);
					CursorTable[PlatformCursor_Help] = LoadCursor(0, IDC_HELP);
					CursorTable[PlatformCursor_IBeam] = LoadCursor(0, IDC_IBEAM);
					CursorTable[PlatformCursor_SlashedCircle] = LoadCursor(0, IDC_NO);
					CursorTable[PlatformCursor_ArrowAll] = LoadCursor(0, IDC_SIZEALL);
					CursorTable[PlatformCursor_ArrowNESW] = LoadCursor(0, IDC_SIZENESW);
					CursorTable[PlatformCursor_ArrowVertical] = LoadCursor(0, IDC_SIZENS);
					CursorTable[PlatformCursor_ArrowNWSE] = LoadCursor(0, IDC_SIZENWSE);
					CursorTable[PlatformCursor_ArrowHorizontal] = LoadCursor(0, IDC_SIZEWE);
					CursorTable[PlatformCursor_Wait] = LoadCursor(0, IDC_WAIT);
					
					CursorTableLoaded = true;
				}
				
				SetCursor(CursorTable[Global_Win32State.Cursor]);
			}
			else
			{
				DefWindowProc(Window, Message, WParam, LParam);
			}
		} break;
		
		default:
		{
			Result = DefWindowProc(Window, Message, WParam, LParam);
		} break;
	}
	
	if(Event)
	{
		Event->Modifiers = Win32_GetModifiers();
		DLLInsertLast(State->EventList.First, State->EventList.Last, Event);
	}
	
	ReleaseScratch(Scratch);
	
	return(Result);
}

static void Win32_ProcessInput(vn_input *Input, HWND Window, r32 dtForFrame)
{
	win32_state *State = &Global_Win32State;
	
	ArenaClear(State->EventArena);
	
	MSG Message;
	while(PeekMessage(&Message, Window, 0, 0, PM_REMOVE))
	{
		TranslateMessage(&Message);
		DispatchMessageA(&Message);
	}
	
	Input->EventList = &State->EventList;
	
	v2_r32 NewMouseP = Win32_GetMouseP(Window);
	v2_r32 OldMouseP = Input->MouseP;
	
	Input->dMouseP = NewMouseP - OldMouseP;
	Input->MouseP  = NewMouseP;
	
	Input->dtForFrame = dtForFrame;
}

static void Win32_EnforceFrameRate(u64 FrameBegin, r32 TargetFrameRate)
{
	win32_state *State = &Global_Win32State;
	
	r64 TimeElapsed = Win32_GetSecondsElapsed(FrameBegin, Win32_GetWallClock());
	r64 Target = 1.0 / TargetFrameRate;
	
	r64 ToSleep = Target - TimeElapsed;
	if(ToSleep > 0)
	{
		u64 MSToSleep = (u64)Floor(ToSleep*1000);
		if(State->SleepIsGranular)
		{
			Sleep(MSToSleep);
		}
		
		while(ToSleep > 0)
		{
			TimeElapsed = Win32_GetSecondsElapsed(FrameBegin, Win32_GetWallClock());
			ToSleep = Target - TimeElapsed;
		}
	}
}

inline void Win32_GetRelevantPaths(win32_state *State)
{
	GetModuleFileName(0, State->EXEPath, ArrayCount(State->EXEPath));
	if(GetLastError() == ERROR_INSUFFICIENT_BUFFER)
	{
		Win32_PlatformError("Path to executable is too long. Try running the game from another directory", true);
	}
	
	string EXEPathString = MakeString(State->EXEPath);
	
	s64 OnePastLastSlash = LastIndexOf(EXEPathString, '\\') + 1;
	
	s64 BuildIndex = LastIndexOf(EXEPathString, StrLit("\\build\\")) + 1;
	if(BuildIndex == 0)
	{
		BuildIndex = LastIndexOf(EXEPathString, StrLit("//build//")) + 1;
	}
	
	if(BuildIndex == 0)
	{
		State->ContentsPath = MakeString(EXEPathString.Data, OnePastLastSlash);
	}
	else
	{
		State->ContentsPath = MakeString(EXEPathString.Data, BuildIndex);
	}
	
	string DLLName = StrLit("vn.dll");
	Copy(State->DLLPath, State->EXEPath, OnePastLastSlash);
	Copy(State->DLLPath+OnePastLastSlash, DLLName.Data, DLLName.Count);
	
	string TempDLLName = StrLit("temp_vn.dll");
	Copy(State->TempDLLPath, State->EXEPath, OnePastLastSlash);
	Copy(State->TempDLLPath+OnePastLastSlash, TempDLLName.Data, TempDLLName.Count);
}

int WinMain(HINSTANCE Instance, HINSTANCE PreviousInstance, LPSTR CommandLine, int ShowCommand)
{
	RegisterPlatformFunctions(Win32);
	
	thread_context ThreadContext = AllocateThreadContext();
	SetThreadContext(&ThreadContext);
	
	// sixten: Setup Win32 platform state.
	{
		win32_state *State = &Global_Win32State;
		Win32_GetRelevantPaths(State);
		
		LARGE_INTEGER FrequencyQuery;
		QueryPerformanceFrequency(&FrequencyQuery);
		State->PerformanceFrequency = FrequencyQuery.QuadPart;
		
		State->EventArena = ArenaAlloc(Gigabytes(1), false, "Win32 Event Arena");
		
		State->SleepIsGranular = (timeBeginPeriod(1) == TIMERR_NOERROR);
	}
	
	WNDCLASS WindowClass = {};
	WindowClass.lpszClassName = "vn-window-class";
	WindowClass.lpfnWndProc = Win32_WindowCallback;
	WindowClass.hCursor = LoadCursorA(0, IDC_ARROW);
	WindowClass.style = CS_OWNDC;
	
	if(RegisterClassA(&WindowClass))
	{
		HWND Window = CreateWindowEx(0,
                                     WindowClass.lpszClassName,
                                     "vn - January 2024 Build",
                                     WS_OVERLAPPEDWINDOW,
                                     CW_USEDEFAULT, CW_USEDEFAULT,
                                     CW_USEDEFAULT, CW_USEDEFAULT,
                                     0, 0, Instance, 0);
		if(Window)
		{
			Global_Win32State.Window = Window;
			
			vn_input Input = {};
			vn_render_commands RenderCommands = {};
			
			// sixten: Setup OpenGL
			HDC DeviceContext = GetDC(Window);
			Win32_CreateOpenGLContext(DeviceContext);
			opengl_context OpenGLContext = OpenGL_SetupContext(&RenderCommands, 64*1024);
			
			vn_memory Memory = {};
			Memory.PlatformAPI = Platform;
			
#if !W32_LINK_SINGLE
			win32_loaded_code LoadedCode = Win32_LoadCode();
#endif
			
			ShowWindow(Window, SW_SHOWNORMAL);
			
			u64 CurrentTime = Win32_GetWallClock();
			
			while(!Input.ExitRequested)
			{
				u64 NewTime = Win32_GetWallClock();
				r64 dtForFrame = Win32_GetSecondsElapsed(CurrentTime, NewTime);
				CurrentTime = NewTime;
				
				Win32_ProcessInput(&Input, Window, dtForFrame);
				
				Win32_SetCursor(PlatformCursor_Arrow);
				
				// sixten: Update and render frame.
				{
					v2_r32 RenderDim = Win32_GetWindowDim(Window);
					OpenGL_BeginFrame(&RenderCommands, RenderDim);
					
#if W32_LINK_SINGLE
					VN_UpdateAndRender(&ThreadContext, &Memory, &Input, &RenderCommands);
#else
					Win32_UpdateCode(&LoadedCode);
					if(LoadedCode.IsValid)
					{
						LoadedCode.UpdateAndRender(&ThreadContext, &Memory, &Input, &RenderCommands);
					}
#endif
					
					b32 UseVSync = (Input.RefreshRate == 0);
					wglSwapIntervalEXT(UseVSync);
					
					OpenGL_EndFrame(&OpenGLContext, &RenderCommands);
					wglSwapLayerBuffers(DeviceContext, WGL_SWAP_MAIN_PLANE);
				}
				
				b32 ShouldLimitFrameRate = (Input.RefreshRate > 0);
				if(ShouldLimitFrameRate)
				{
					Win32_EnforceFrameRate(CurrentTime, Input.RefreshRate);
				}
			}
		}
		else
		{
			Win32_PlatformError("Unable to create window.", true);
		}
	}
	else
	{
		Win32_PlatformError("Unable to register window class.", true);
	}
	
	return(0);
}

#if VN_ASAN_ENABLED
int main(int ArgumentCount, char **Arguments)
{
	return WinMain(GetModuleHandle(0), 0, 0, 0);
}
#endif