4coder/platform_win32/win32_4ed.cpp

/*
 * Mr. 4th Dimention - Allen Webster
 *
 * 12.12.2014
 *
 * Win32 layer for 4coder
 *
 */

// TOP

#define IS_PLAT_LAYER
#include "4ed_os_comp_cracking.h"

//
// Program setup
//

#define UNICODE

#define FPS 60
#define frame_useconds (1000000 / FPS)

#include "4ed_defines.h"
#include "4coder_API/version.h"

#define WINDOW_NAME L"4coder: " L_VERSION

#include <string.h>
#include "4coder_lib/4coder_utf8.h"

#if defined(FRED_SUPER)
# include "4coder_API/keycodes.h"
# include "4coder_API/style.h"

# define FSTRING_IMPLEMENTATION
# define FSTRING_C
# include "4coder_lib/4coder_string.h"
# include "4coder_lib/4coder_mem.h"

# include "4coder_API/types.h"
# include "4ed_os_custom_api.h"

#else
# include "4coder_default_bindings.cpp"
#endif

#include "4ed_math.h"

#include "4ed_system.h"
#include "4ed_log.h"
#include "4ed_rendering.h"
#include "4ed.h"

#include <Windows.h>
#include <GL/gl.h>
#include "win32_gl.h"

#define GL_TEXTURE_MAX_LEVEL 0x813D

//////////////////////////////

#include "win32_utf8.h"

#include "4ed_file_track.h"
#include "4ed_font_interface_to_os.h"
#include "4ed_system_shared.h"

#include "4ed_shared_thread_constants.h"
#include "win32_threading_wrapper.h"

//
// Win32_Vars structs
//

#define WM_4coder_ANIMATE (WM_USER + 0)

struct Control_Keys{
    b8 l_ctrl;
    b8 r_ctrl;
    b8 l_alt;
    b8 r_alt;
};
global Control_Keys null_control_keys = {0};

struct Win32_Input_Chunk_Transient{
    Key_Input_Data key_data;
    b8 mouse_l_press, mouse_l_release;
    b8 mouse_r_press, mouse_r_release;
    b8 out_of_window;
    i8 mouse_wheel;
    b8 trying_to_kill;
};
global Win32_Input_Chunk_Transient null_input_chunk_transient = {0};

struct Win32_Input_Chunk_Persistent{
    i32 mouse_x, mouse_y;
    b8 mouse_l, mouse_r;
    
    Control_Keys controls;
    b8 control_keys[MDFR_INDEX_COUNT];
};

struct Win32_Input_Chunk{
    Win32_Input_Chunk_Transient trans;
    Win32_Input_Chunk_Persistent pers;
};

struct Win32_Coroutine{
    Coroutine coroutine;
    Win32_Coroutine *next;
    i32 done;
};

struct Win32_Vars{
    App_Functions app;
    Custom_API custom_api;
    HMODULE app_code;
    HMODULE custom;
    
    Win32_Coroutine coroutine_data[18];
    Win32_Coroutine *coroutine_free;
    
    Win32_Input_Chunk input_chunk;
    b32 lctrl_lalt_is_altgr;
    b32 got_useful_event;
    
    b32 full_screen;
    b32 do_toggle;
    WINDOWPLACEMENT GlobalWindowPosition;
    b32 send_exit_signal;
    
    HCURSOR cursor_ibeam;
    HCURSOR cursor_arrow;
    HCURSOR cursor_leftright;
    HCURSOR cursor_updown;
    
    u8 *clip_buffer;
    u32 clip_max;
    String clipboard_contents;
    b32 next_clipboard_is_self;
    DWORD clipboard_sequence;
    
    HWND window_handle;
    Render_Target target;
    i32 dpi_x, dpi_y;
    
    f64 count_per_usecond;
    b32 first;
    i32 running_cli;
    
    u32 log_position;
    
};

////////////////////////////////

global Win32_Vars win32vars;
global System_Functions sysfunc;
global Application_Memory memory_vars;
global Plat_Settings plat_settings;

////////////////////////////////

#define SLASH '\\'

internal HANDLE
handle_type(Plat_Handle h){
    HANDLE result;
    memcpy(&result, &h, sizeof(result));
    return(result);
}

internal Plat_Handle
handle_type(HANDLE h){
    Plat_Handle result = {0};
    memcpy(&result, &h, sizeof(h));
    return(result);
}

////////////////////////////////

#include "win32_4ed_functions.cpp"
#include "4ed_shared_file_handling.cpp"

////////////////////////////////

internal void
system_schedule_step(){
    PostMessage(win32vars.window_handle, WM_4coder_ANIMATE, 0, 0);
}

////////////////////////////////

//
// Threads
//

#include "4ed_work_queues.cpp"

//
// Coroutines
//

internal Win32_Coroutine*
Win32AllocCoroutine(){
    Win32_Coroutine *result = win32vars.coroutine_free;
    Assert(result != 0);
    win32vars.coroutine_free = result->next;
    return(result);
}

internal void
Win32FreeCoroutine(Win32_Coroutine *data){
    data->next = win32vars.coroutine_free;
    win32vars.coroutine_free = data;
}

internal void CALL_CONVENTION
Win32CoroutineMain(void *arg_){
    Win32_Coroutine *c = (Win32_Coroutine*)arg_;
    c->coroutine.func(&c->coroutine);
    c->done = 1;
    Win32FreeCoroutine(c);
    SwitchToFiber(c->coroutine.yield_handle);
}

internal
Sys_Create_Coroutine_Sig(system_create_coroutine){
    Win32_Coroutine *c;
    Coroutine *coroutine;
    void *fiber;
    
    c = Win32AllocCoroutine();
    c->done = 0;
    
    coroutine = &c->coroutine;
    
    fiber = CreateFiber(0, Win32CoroutineMain, coroutine);
    
    coroutine->plat_handle = handle_type(fiber);
    coroutine->func = func;
    
    return(coroutine);
}

internal
Sys_Launch_Coroutine_Sig(system_launch_coroutine){
    Win32_Coroutine *c = (Win32_Coroutine*)coroutine;
    void *fiber;
    
    fiber = handle_type(coroutine->plat_handle);
    coroutine->yield_handle = GetCurrentFiber();
    coroutine->in = in;
    coroutine->out = out;
    
    SwitchToFiber(fiber);
    
    if (c->done){
        DeleteFiber(fiber);
        Win32FreeCoroutine(c);
        coroutine = 0;
    }
    
    return(coroutine);
}

Sys_Resume_Coroutine_Sig(system_resume_coroutine){
    Win32_Coroutine *c = (Win32_Coroutine*)coroutine;
    void *fiber;
    
    Assert(c->done == 0);
    
    coroutine->yield_handle = GetCurrentFiber();
    coroutine->in = in;
    coroutine->out = out;
    
    fiber = handle_type(coroutine->plat_handle);
    
    SwitchToFiber(fiber);
    
    if (c->done){
        DeleteFiber(fiber);
        Win32FreeCoroutine(c);
        coroutine = 0;
    }
    
    return(coroutine);
}

Sys_Yield_Coroutine_Sig(system_yield_coroutine){
    SwitchToFiber(coroutine->yield_handle);
}


//
// Files
//

/*
NOTE(casey): This follows Raymond Chen's prescription
for fullscreen toggling, see:
http://blogs.msdn.com/b/oldnewthing/archive/2010/04/12/9994016.aspx
*/

internal void
Win32ToggleFullscreen(void){
    HWND Window = win32vars.window_handle;
    LONG_PTR Style = GetWindowLongPtr(Window, GWL_STYLE);
    if (Style & WS_OVERLAPPEDWINDOW){
        MONITORINFO MonitorInfo = {sizeof(MONITORINFO)};
        if(GetWindowPlacement(Window, &win32vars.GlobalWindowPosition) && GetMonitorInfo(MonitorFromWindow(Window, MONITOR_DEFAULTTOPRIMARY), &MonitorInfo))
        {
            SetWindowLongPtr(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);
            win32vars.full_screen = true;
        }
    }
    else{
        SetWindowLongPtr(Window, GWL_STYLE, Style | WS_OVERLAPPEDWINDOW);
        SetWindowPlacement(Window, &win32vars.GlobalWindowPosition);
        SetWindowPos(Window, 0, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_NOOWNERZORDER | SWP_FRAMECHANGED);
        win32vars.full_screen = false;
    }
}


//
// Clipboard
//

internal
Sys_Post_Clipboard_Sig(system_post_clipboard){
    if (OpenClipboard(win32vars.window_handle)){
        EmptyClipboard();
        HANDLE memory_handle;
        memory_handle = GlobalAlloc(GMEM_MOVEABLE, str.size+1);
        if (memory_handle){
            char *dest = (char*)GlobalLock(memory_handle);
            copy_fast_unsafe_cs(dest, str);
            GlobalUnlock(memory_handle);
            SetClipboardData(CF_TEXT, memory_handle);
            win32vars.next_clipboard_is_self = 1;
        }
        CloseClipboard();
    }
}

internal b32
win32_read_clipboard_contents(){
    b32 result = false;
    
    if (IsClipboardFormatAvailable(CF_UNICODETEXT)){
        result = true;
        if (OpenClipboard(win32vars.window_handle)){
            HANDLE clip_data = GetClipboardData(CF_UNICODETEXT);
            if (clip_data != 0){
                Partition *scratch = &shared_vars.scratch;
                Temp_Memory temp = begin_temp_memory(scratch);
                
                u16 *clip_16 = (u16*)GlobalLock(clip_data);
                
                if (clip_16 != 0){
                    u32 clip_16_len = 0;
                    for(;clip_16[clip_16_len];++clip_16_len);
                    
                    // TODO(allen): Extend the buffer if it is too small.
                    b32 error = false;
                    u32 clip_8_len = (u32)utf16_to_utf8_minimal_checking(win32vars.clip_buffer, win32vars.clip_max-1, clip_16, clip_16_len, &error);
                    
                    if (clip_8_len < win32vars.clip_max && !error){
                        win32vars.clip_buffer[clip_8_len] = 0;
                        
                        win32vars.clipboard_contents = make_string_cap(win32vars.clip_buffer, clip_8_len, win32vars.clip_max);
                    }
                    
                    GlobalUnlock(clip_data);
                }
                
                if (win32vars.clipboard_contents.str){
                    win32vars.clipboard_contents.size = str_size((char*)win32vars.clipboard_contents.str);
                }
                
                end_temp_memory(temp);
            }
            CloseClipboard();
        }
    }
    
    return(result);
}


//
// Command Line Exectuion
//

internal
Sys_CLI_Call_Sig(system_cli_call){
    char cmd[] = "c:\\windows\\system32\\cmd.exe";
    char *env_variables = 0;
    char command_line[2048];
    
    String s = make_fixed_width_string(command_line);
    copy_ss(&s, make_lit_string("/C "));
    append_partial_sc(&s, script_name);
    b32 success = terminate_with_null(&s);
    
    if (success){
        success = 0;
        
        SECURITY_ATTRIBUTES sec_attributes = {};
        HANDLE out_read;
        HANDLE out_write;
        
        sec_attributes.nLength = sizeof(SECURITY_ATTRIBUTES);
        sec_attributes.bInheritHandle = TRUE;
        
        if (CreatePipe(&out_read, &out_write, &sec_attributes, 0)){
            if (SetHandleInformation(out_read, HANDLE_FLAG_INHERIT, 0)){
                STARTUPINFO startup = {};
                startup.cb = sizeof(STARTUPINFO);
                startup.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
                startup.hStdError = out_write;
                startup.hStdOutput = out_write;
                startup.wShowWindow = SW_HIDE;
                
                PROCESS_INFORMATION info = {};
                
                Assert(sizeof(Plat_Handle) >= sizeof(HANDLE));
                if (CreateProcess_utf8((u8*)cmd, (u8*)command_line, 0, 0, TRUE, 0, env_variables, (u8*)path, &startup, &info)){
                    success = 1;
                    CloseHandle(info.hThread);
                    *(HANDLE*)&cli_out->proc = info.hProcess;
                    *(HANDLE*)&cli_out->out_read = out_read;
                    *(HANDLE*)&cli_out->out_write = out_write;
                    
                    ++win32vars.running_cli;
                }
                else{
                    CloseHandle(out_read);
                    CloseHandle(out_write);
                    *(HANDLE*)&cli_out->proc = INVALID_HANDLE_VALUE;
                    *(HANDLE*)&cli_out->out_read = INVALID_HANDLE_VALUE;
                    *(HANDLE*)&cli_out->out_write = INVALID_HANDLE_VALUE;
                }
            }
            else{
                // TODO(allen): failed SetHandleInformation
                CloseHandle(out_read);
                CloseHandle(out_write);
                *(HANDLE*)&cli_out->proc = INVALID_HANDLE_VALUE;
                *(HANDLE*)&cli_out->out_read = INVALID_HANDLE_VALUE;
                *(HANDLE*)&cli_out->out_write = INVALID_HANDLE_VALUE;
            }
        }
        else{
            // TODO(allen): failed CreatePipe
        }
    }
    
    return success;
}

struct CLI_Loop_Control{
    u32 remaining_amount;
};

internal
Sys_CLI_Begin_Update_Sig(system_cli_begin_update){
    Assert(sizeof(cli->scratch_space) >= sizeof(CLI_Loop_Control));
    CLI_Loop_Control *loop = (CLI_Loop_Control*)cli->scratch_space;
    loop->remaining_amount = 0;
}

internal
Sys_CLI_Update_Step_Sig(system_cli_update_step){
    HANDLE handle = *(HANDLE*)&cli->out_read;
    CLI_Loop_Control *loop = (CLI_Loop_Control*)cli->scratch_space;
    b32 has_more = 0;
    DWORD remaining = loop->remaining_amount;
    u32 pos = 0;
    DWORD read_amount = 0;
    
    for (;;){
        if (remaining == 0){
            if (!PeekNamedPipe(handle, 0, 0, 0, &remaining, 0)) break;
            if (remaining == 0) break;
        }
        
        if (remaining + pos < max){
            has_more = 1;
            ReadFile(handle, dest + pos, remaining, &read_amount, 0);
            TentativeAssert(remaining == read_amount);
            pos += remaining;
            remaining = 0;
        }
        else{
            has_more = 1;
            ReadFile(handle, dest + pos, max - pos, &read_amount, 0);
            TentativeAssert(max - pos == read_amount);
            loop->remaining_amount = remaining - (max - pos);
            pos = max;
            break;
        }
    }
    *amount = pos;
    
    return(has_more);
}

internal
Sys_CLI_End_Update_Sig(system_cli_end_update){
    b32 close_me = 0;
    HANDLE proc = *(HANDLE*)&cli->proc;
    DWORD result = 0;
    
    if (WaitForSingleObject(proc, 0) == WAIT_OBJECT_0){
        if (GetExitCodeProcess(proc, &result) == 0){
            cli->exit = -1;
        }
        else{
            cli->exit = (i32)result;
        }
        
        close_me = 1;
        CloseHandle(*(HANDLE*)&cli->proc);
        CloseHandle(*(HANDLE*)&cli->out_read);
        CloseHandle(*(HANDLE*)&cli->out_write);
        
        --win32vars.running_cli;
    }
    return(close_me);
}

//
// Appearence Settings
//

// TODO(allen): add a "shown but auto-hides on timer" setting here.
internal
Sys_Show_Mouse_Cursor_Sig(system_show_mouse_cursor){
    switch (show){
        case MouseCursorShow_Never:
        ShowCursor(false);
        break;
        
        case MouseCursorShow_Always:
        ShowCursor(true);
        break;
        
        // TODO(allen): MouseCursor_HideWhenStill
    }
}

internal
Sys_Toggle_Fullscreen_Sig(system_toggle_fullscreen){
    /* NOTE(allen): Don't actually change window size now!
    Tell the platform layer to do the toggle (or to cancel the toggle)
    later when the app.step function isn't running. If the size changes
    mid step, it messes up the rendering rules and stuff. */
    
    b32 success = false;
    
    // NOTE(allen): On windows we must be in stream mode to go fullscreen.
    if (plat_settings.stream_mode){
        win32vars.do_toggle = !win32vars.do_toggle;
        success = true;
    }
    
    return(success);
}

internal
Sys_Is_Fullscreen_Sig(system_is_fullscreen){
    /* NOTE(allen): This is a fancy way to say 'full_screen XOR do_toggle'
    This way this function can always report the state the fullscreen
    will have when the next frame runs, given the number of toggles
    that have occurred this frame and the original value. */
    bool32 result = (win32vars.full_screen + win32vars.do_toggle) & 1;
    return(result);
}

internal
Sys_Send_Exit_Signal_Sig(system_send_exit_signal){
    win32vars.send_exit_signal = 1;
}

//
// Linkage to Custom and Application
//

internal b32
Win32LoadAppCode(){
    b32 result = false;
    App_Get_Functions *get_funcs = 0;
    
    win32vars.app_code = LoadLibraryA("4ed_app.dll");
    if (win32vars.app_code){
        get_funcs = (App_Get_Functions*)GetProcAddress(win32vars.app_code, "app_get_functions");
    }
    
    if (get_funcs){
        result = true;
        win32vars.app = get_funcs();
    }
    
    return(result);
}

#include "4ed_font_data.h"
#include "4ed_system_shared.cpp"

internal void
Win32LoadRenderCode(){
    win32vars.target.push_clip = draw_push_clip;
    win32vars.target.pop_clip = draw_pop_clip;
    win32vars.target.push_piece = draw_push_piece;
}

//
// Helpers
//

global Key_Code keycode_lookup_table[255];

internal void
Win32KeycodeInit(){
    keycode_lookup_table[VK_BACK] = key_back;
    keycode_lookup_table[VK_DELETE] = key_del;
    keycode_lookup_table[VK_UP] = key_up;
    keycode_lookup_table[VK_DOWN] = key_down;
    keycode_lookup_table[VK_LEFT] = key_left;
    keycode_lookup_table[VK_RIGHT] = key_right;
    keycode_lookup_table[VK_INSERT] = key_insert;
    keycode_lookup_table[VK_HOME] = key_home;
    keycode_lookup_table[VK_END] = key_end;
    keycode_lookup_table[VK_PRIOR] = key_page_up;
    keycode_lookup_table[VK_NEXT] = key_page_down;
    keycode_lookup_table[VK_ESCAPE] = key_esc;
    
    keycode_lookup_table[VK_F1] = key_f1;
    keycode_lookup_table[VK_F2] = key_f2;
    keycode_lookup_table[VK_F3] = key_f3;
    keycode_lookup_table[VK_F4] = key_f4;
    keycode_lookup_table[VK_F5] = key_f5;
    keycode_lookup_table[VK_F6] = key_f6;
    keycode_lookup_table[VK_F7] = key_f7;
    keycode_lookup_table[VK_F8] = key_f8;
    keycode_lookup_table[VK_F9] = key_f9;
    
    keycode_lookup_table[VK_F10] = key_f10;
    keycode_lookup_table[VK_F11] = key_f11;
    keycode_lookup_table[VK_F12] = key_f12;
    keycode_lookup_table[VK_F13] = key_f13;
    keycode_lookup_table[VK_F14] = key_f14;
    keycode_lookup_table[VK_F15] = key_f15;
    keycode_lookup_table[VK_F16] = key_f16;
}

internal void
Win32RedrawScreen(HDC hdc){
    launch_rendering(&sysfunc, &win32vars.target);
    glFlush();
    SwapBuffers(hdc);
}

internal void
Win32Resize(i32 width, i32 height){
    if (width > 0 && height > 0){
        glViewport(0, 0, width, height);
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(0, width, height, 0, -1, 1);
        glScissor(0, 0, width, height);
        
        win32vars.target.width = width;
        win32vars.target.height = height;
    }
}

internal void*
win32_load_gl_always(char *name, HMODULE module){
    void *p = (void *)wglGetProcAddress(name), *r = 0;
    if(p == 0 ||
       (p == (void*)0x1) || (p == (void*)0x2) || (p == (void*)0x3) ||
       (p == (void*)-1) ){
        r = (void *)GetProcAddress(module, name);
    }
    else{
        r = p;
    }
    return(r);
}

internal void CALL_CONVENTION
OpenGLDebugCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const char *message, const void *userParam){
    OutputDebugStringA(message);
    OutputDebugStringA("\n");
}

internal void
Win32InitGL(){
    // GL context initialization
    {
        PIXELFORMATDESCRIPTOR format;
        format.nSize = sizeof(format);
        format.nVersion = 1;
        format.dwFlags = PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW;
        format.iPixelType = PFD_TYPE_RGBA;
        format.cColorBits = 32;
        format.cRedBits = 0;
        format.cRedShift = 0;
        format.cGreenBits = 0;
        format.cGreenShift = 0;
        format.cBlueBits = 0;
        format.cBlueShift = 0;
        format.cAlphaBits = 0;
        format.cAlphaShift = 0;
        format.cAccumBits = 0;
        format.cAccumRedBits = 0;
        format.cAccumGreenBits = 0;
        format.cAccumBlueBits = 0;
        format.cAccumAlphaBits = 0;
        format.cDepthBits = 24;
        format.cStencilBits = 8;
        format.cAuxBuffers = 0;
        format.iLayerType = PFD_MAIN_PLANE;
        format.bReserved = 0;
        format.dwLayerMask = 0;
        format.dwVisibleMask = 0;
        format.dwDamageMask = 0;
        
        HDC dc = GetDC(win32vars.window_handle);
        Assert(dc);
        int format_id = ChoosePixelFormat(dc, &format);
        Assert(format_id != 0);
        BOOL success = SetPixelFormat(dc, format_id, &format);
        Assert(success == TRUE); AllowLocal(success);
        
        HGLRC glcontext = wglCreateContext(dc);
        wglMakeCurrent(dc, glcontext);
        
        HMODULE module = LoadLibraryA("opengl32.dll");
        AllowLocal(module);
        
        wglCreateContextAttribsARB_Function *wglCreateContextAttribsARB = 0;
        wglCreateContextAttribsARB = (wglCreateContextAttribsARB_Function*)
            win32_load_gl_always("wglCreateContextAttribsARB", module);
        
        wglChoosePixelFormatARB_Function *wglChoosePixelFormatARB = 0;
        wglChoosePixelFormatARB = (wglChoosePixelFormatARB_Function*)
            win32_load_gl_always("wglChoosePixelFormatARB", module);
        
        if (wglCreateContextAttribsARB != 0 && wglChoosePixelFormatARB != 0){
            const int choosePixel_attribList[] =
            {
                WGL_DRAW_TO_WINDOW_ARB, TRUE,
                WGL_SUPPORT_OPENGL_ARB, TRUE,
                //WGL_DOUBLE_BUFFER_ARB, GL_TRUE,
                WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB,
                WGL_COLOR_BITS_ARB, 32,
                WGL_DEPTH_BITS_ARB, 24,
                WGL_STENCIL_BITS_ARB, 8,
                0,
            };
            
            i32 extended_format_id = 0;
            u32 num_formats = 0;
            BOOL result =  wglChoosePixelFormatARB(dc, choosePixel_attribList, 0, 1, &extended_format_id, &num_formats);
            
            if (result != 0 && num_formats > 0){
                const int createContext_attribList[] = {
                    WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
                    WGL_CONTEXT_MINOR_VERSION_ARB, 2,
                    WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB,
                    0
                };
                
                if (extended_format_id == format_id){
                    HGLRC extended_context = wglCreateContextAttribsARB(dc, 0, createContext_attribList);
                    if (extended_context){
                        wglMakeCurrent(dc, extended_context);
                        wglDeleteContext(glcontext);
                        glcontext = extended_context;
                    }
                }
            }
        }
        
#if (defined(BUILD_X64) && 1) || (defined(BUILD_X86) && 0)
#if defined(FRED_INTERNAL)
        // NOTE(casey): This slows down GL but puts error messages to
        // the debug console immediately whenever you do something wrong
        glDebugMessageCallback_type *glDebugMessageCallback = 
            (glDebugMessageCallback_type *)win32_load_gl_always("glDebugMessageCallback", module);
        glDebugMessageControl_type *glDebugMessageControl = 
            (glDebugMessageControl_type *)win32_load_gl_always("glDebugMessageControl", module);
        if(glDebugMessageCallback != 0 && glDebugMessageControl != 0)
        {
            glDebugMessageCallback(OpenGLDebugCallback, 0);
            glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, 0, GL_TRUE);
            glEnable(GL_DEBUG_OUTPUT);
            glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
        }
#endif
#endif
        
        ReleaseDC(win32vars.window_handle, dc);
    }
    
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_SCISSOR_TEST);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

internal void
Win32SetCursorFromUpdate(Application_Mouse_Cursor cursor){
    switch (cursor){
        case APP_MOUSE_CURSOR_ARROW:
        SetCursor(win32vars.cursor_arrow); break;
        
        case APP_MOUSE_CURSOR_IBEAM:
        SetCursor(win32vars.cursor_ibeam); break;
        
        case APP_MOUSE_CURSOR_LEFTRIGHT:
        SetCursor(win32vars.cursor_leftright); break;
        
        case APP_MOUSE_CURSOR_UPDOWN:
        SetCursor(win32vars.cursor_updown); break;
    }
}

internal u64
Win32HighResolutionTime(){
    u64 result = 0;
    LARGE_INTEGER t;
    if (QueryPerformanceCounter(&t)){
        result = (u64) (t.QuadPart / win32vars.count_per_usecond);
    }
    return(result);
}

internal LRESULT
Win32Callback(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam){
    LRESULT result = 0;
    
    switch (uMsg){
        case WM_MENUCHAR:break;
        
        case WM_SYSKEYDOWN:
        case WM_SYSKEYUP:
        case WM_KEYDOWN:
        case WM_KEYUP:
        {
            switch (wParam){
                case VK_CONTROL:case VK_LCONTROL:case VK_RCONTROL:
                case VK_MENU:case VK_LMENU:case VK_RMENU:
                case VK_SHIFT:case VK_LSHIFT:case VK_RSHIFT:
                {
                    Control_Keys *controls = &win32vars.input_chunk.pers.controls;
                    b8 *control_keys = win32vars.input_chunk.pers.control_keys;
                    
                    b8 down = ((lParam & Bit_31)?(0):(1));
                    b8 is_right = ((lParam & Bit_24)?(1):(0));
                    
                    if (wParam != 255){
                        switch (wParam){
                            case VK_SHIFT:
                            {
                                control_keys[MDFR_SHIFT_INDEX] = down;
                            }break;
                            
                            case VK_CONTROL:
                            {
                                if (is_right) controls->r_ctrl = down;
                                else controls->l_ctrl = down;
                            }break;
                            
                            case VK_MENU:
                            {
                                if (is_right) controls->r_alt = down;
                                else controls->l_alt = down;
                            }break;
                        }
                        
                        b8 ctrl = (controls->r_ctrl || (controls->l_ctrl && !controls->r_alt));
                        b8 alt = (controls->l_alt || (controls->r_alt && !controls->l_ctrl));
                        
                        if (win32vars.lctrl_lalt_is_altgr){
                            if (controls->l_alt && controls->l_ctrl){
                                ctrl = 0;
                                alt = 0;
                            }
                        }
                        
                        control_keys[MDFR_CONTROL_INDEX] = ctrl;
                        control_keys[MDFR_ALT_INDEX] = alt;
                    }
                }break;
                
                default:
                {
                    b8 current_state = ((lParam & Bit_31)?(0):(1));
                    
                    if (current_state){
                        Key_Code key = keycode_lookup_table[(u8)wParam];
                        
                        if (key != 0){
                            i32 *count = &win32vars.input_chunk.trans.key_data.count;
                            Key_Event_Data *data = win32vars.input_chunk.trans.key_data.keys;
                            b8 *control_keys = win32vars.input_chunk.pers.control_keys;
                            i32 control_keys_size = sizeof(win32vars.input_chunk.pers.control_keys);
                            
                            Assert(*count < KEY_INPUT_BUFFER_SIZE);
                            data[*count].character = 0;
                            data[*count].character_no_caps_lock = 0;
                            data[*count].keycode = key;
                            memcpy(data[*count].modifiers, control_keys, control_keys_size);
                            ++(*count);
                            
                            win32vars.got_useful_event = true;
                        }
                    }
                }break;
            }/* switch */
        }break;
        
        case WM_CHAR: case WM_SYSCHAR: case WM_UNICHAR:
        {
            u16 character = (u16)wParam;
            
            if (character == '\r'){
                character = '\n';
            }
            else if (character == '\t'){
                character = '\t';
            }
            else if (character < 32 || character == 127){
                break;
            }
            
            u16 character_no_caps_lock = character;
            
            i32 *count = &win32vars.input_chunk.trans.key_data.count;
            Key_Event_Data *data = win32vars.input_chunk.trans.key_data.keys;
            b8 *control_keys = win32vars.input_chunk.pers.control_keys;
            i32 control_keys_size = sizeof(win32vars.input_chunk.pers.control_keys);
            
            BYTE state[256];
            GetKeyboardState(state);
            if (state[VK_CAPITAL]){
                if (character_no_caps_lock >= 'a' && character_no_caps_lock <= 'z'){
                    character_no_caps_lock -= (u8)('a' - 'A');
                }
                else if (character_no_caps_lock >= 'A' && character_no_caps_lock <= 'Z'){
                    character_no_caps_lock += (u8)('a' - 'A');
                }
            }
            
            Assert(*count < KEY_INPUT_BUFFER_SIZE);
            data[*count].character = character;
            data[*count].character_no_caps_lock = character_no_caps_lock;
            data[*count].keycode = character_no_caps_lock;
            memcpy(data[*count].modifiers, control_keys, control_keys_size);
            ++(*count);
            
            win32vars.got_useful_event = true;
        }break;
        
        case WM_MOUSEMOVE:
        {
            i32 new_x = LOWORD(lParam);
            i32 new_y = HIWORD(lParam);
            
            if (new_x != win32vars.input_chunk.pers.mouse_x || new_y != win32vars.input_chunk.pers.mouse_y){
                win32vars.input_chunk.pers.mouse_x = new_x;
                win32vars.input_chunk.pers.mouse_y = new_y;
                
                win32vars.got_useful_event = true;
            }
        }break;
        
        case WM_MOUSEWHEEL:
        {
            win32vars.got_useful_event = true;
            i32 rotation = GET_WHEEL_DELTA_WPARAM(wParam);
            if (rotation > 0){
                win32vars.input_chunk.trans.mouse_wheel = 1;
            }
            else{
                win32vars.input_chunk.trans.mouse_wheel = -1;
            }
        }break;
        
        case WM_LBUTTONDOWN:
        {
            win32vars.got_useful_event = true;
            win32vars.input_chunk.trans.mouse_l_press = 1;
            win32vars.input_chunk.pers.mouse_l = 1;
        }break;
        
        case WM_RBUTTONDOWN:
        {
            win32vars.got_useful_event = true;
            win32vars.input_chunk.trans.mouse_r_press = 1;
            win32vars.input_chunk.pers.mouse_r = 1;
        }break;
        
        case WM_LBUTTONUP:
        {
            win32vars.got_useful_event = true;
            win32vars.input_chunk.trans.mouse_l_release = 1;
            win32vars.input_chunk.pers.mouse_l = 0;
        }break;
        
        case WM_RBUTTONUP:
        {
            win32vars.got_useful_event = true;
            win32vars.input_chunk.trans.mouse_r_release = 1;
            win32vars.input_chunk.pers.mouse_r = 0;
        }break;
        
        case WM_KILLFOCUS:
        case WM_SETFOCUS:
        {
            win32vars.got_useful_event = true;
            win32vars.input_chunk.pers.mouse_l = 0;
            win32vars.input_chunk.pers.mouse_r = 0;
            
            for (i32 i = 0; i < MDFR_INDEX_COUNT; ++i){
                win32vars.input_chunk.pers.control_keys[i] = 0;
            }
            win32vars.input_chunk.pers.controls = null_control_keys;
        }break;
        
        case WM_SIZE:
        {
            win32vars.got_useful_event = true;
            i32 new_width = LOWORD(lParam);
            i32 new_height = HIWORD(lParam);
            
            Win32Resize(new_width, new_height);
        }break;
        
        case WM_DISPLAYCHANGE:
        {
            win32vars.got_useful_event = true;
            
            LONG_PTR style = GetWindowLongPtr(hwnd, GWL_STYLE);
            if (!(style & WS_OVERLAPPEDWINDOW)){
                MONITORINFO monitor_info = {sizeof(MONITORINFO)};
                if(GetMonitorInfo(MonitorFromWindow(hwnd, MONITOR_DEFAULTTOPRIMARY), &monitor_info))
                {
                    SetWindowPos(hwnd, HWND_TOP,
                                 monitor_info.rcMonitor.left, monitor_info.rcMonitor.top,
                                 monitor_info.rcMonitor.right - monitor_info.rcMonitor.left,
                                 monitor_info.rcMonitor.bottom - monitor_info.rcMonitor.top,
                                 SWP_NOOWNERZORDER | SWP_FRAMECHANGED);
                }
            }
        }break;
        
        case WM_PAINT:
        {
            win32vars.got_useful_event = true;
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);
            Win32RedrawScreen(hdc);
            EndPaint(hwnd, &ps);
        }break;
        
        case WM_CLOSE:
        case WM_DESTROY:
        {
            win32vars.got_useful_event = true;
            win32vars.input_chunk.trans.trying_to_kill = 1;
        }break;
        
        case WM_4coder_ANIMATE:
        {
            win32vars.got_useful_event = true;
        }break;
        
        case WM_CANCELMODE:
        {
            result = DefWindowProc(hwnd, uMsg, wParam, lParam);
        }break;
        
        default:
        {
            result = DefWindowProc(hwnd, uMsg, wParam, lParam);
        }break;
    }
    
    return(result);
}

#include "4ed_link_system_functions.cpp"

int CALL_CONVENTION
WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow){
    i32 argc = __argc;
    char **argv = __argv;
    
    memset(&win32vars, 0, sizeof(win32vars));
    
    win32vars.GlobalWindowPosition.length = sizeof(win32vars.GlobalWindowPosition);
    
    system_init_threaded_work_system();
    
    //
    // Coroutines
    //
    
    ConvertThreadToFiber(0);
    win32vars.coroutine_free = win32vars.coroutine_data;
    for (i32 i = 0; i+1 < ArrayCount(win32vars.coroutine_data); ++i){
        win32vars.coroutine_data[i].next = &win32vars.coroutine_data[i + 1];
    }
    
    //
    // Memory Initialization
    //
    
    LPVOID base;
#if defined(FRED_INTERNAL)
#if defined(BUILD_X64)
    base = (LPVOID)TB(1);
#elif defined(BUILD_X86)
    base = (LPVOID)MB(96);
#endif
#else
    base = (LPVOID)0;
#endif
    
    memory_vars.vars_memory_size = MB(2);
    memory_vars.vars_memory = VirtualAlloc(base, memory_vars.vars_memory_size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
    
#if defined(FRED_INTERNAL)
#if defined(BUILD_X64)
    base = (LPVOID)TB(2);
#elif defined(BUILD_X86)
    base = (LPVOID)MB(98);
#endif
#else
    base = (LPVOID)0;
#endif
    memory_vars.target_memory_size = MB(512);
    memory_vars.target_memory = VirtualAlloc(base, memory_vars.target_memory_size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
    
    memory_vars.user_memory_size = MB(2);
    memory_vars.user_memory = system_memory_allocate(memory_vars.user_memory_size);
    
    memory_vars.debug_memory_size = MB(512);
    memory_vars.debug_memory = system_memory_allocate(memory_vars.debug_memory_size);
    
    win32vars.target.max = MB(1);
    win32vars.target.push_buffer = (char*)system_memory_allocate(win32vars.target.max);
    
    if (memory_vars.vars_memory == 0 || memory_vars.target_memory == 0 || memory_vars.user_memory == 0 || win32vars.target.push_buffer == 0){
        exit(1);
    }
    
    //
    // System and Application Layer Linkage
    //
    
    if (!Win32LoadAppCode()){
        exit(1);
    }
    
    
    link_system_code(&sysfunc);
    Win32LoadRenderCode();
    
    //
    // Shared Systems Init
    //
    
    init_shared_vars();
    
    //
    // Read Command Line
    //
    
    LOG("Reading command line\n");
    DWORD required = (GetCurrentDirectory(0, 0)*4) + 1;
    u8 *current_directory_mem = (u8*)system_memory_allocate(required);
    DWORD written = GetCurrentDirectory_utf8(required, current_directory_mem);
    
    String current_directory = make_string_cap(current_directory_mem, written, required);
    terminate_with_null(&current_directory);
    replace_char(&current_directory, '\\', '/');
    
    Command_Line_Parameters clparams;
    clparams.argv = argv;
    clparams.argc = argc;
    
    char **files = 0;
    i32 *file_count = 0;
    
    win32vars.app.read_command_line(&sysfunc, &memory_vars, current_directory, &plat_settings, &files, &file_count, clparams);
    
    sysshared_filter_real_files(files, file_count);
    LOG("Loaded system code, read command line.\n");
    
    //
    // Custom Layer Linkage
    //
    
#if defined(FRED_SUPER)
    char *custom_file_default = "custom_4coder.dll";
    char *custom_file = 0;
    if (plat_settings.custom_dll){
        custom_file = plat_settings.custom_dll;
    }
    else{
        custom_file = custom_file_default;
    }
    
    LOGF("Trying to load custom DLL: %s\n", custom_file);
    win32vars.custom = LoadLibraryA(custom_file);
    if (!win32vars.custom && custom_file != custom_file_default){
        if (!plat_settings.custom_dll_is_strict){
            LOGF("Trying to load custom DLL: %s\n", custom_file_default);
            win32vars.custom = LoadLibraryA(custom_file_default);
        }
    }
    
    if (win32vars.custom){
        win32vars.custom_api.get_alpha_4coder_version = (_Get_Version_Function*)GetProcAddress(win32vars.custom, "get_alpha_4coder_version");
        
        if (win32vars.custom_api.get_alpha_4coder_version == 0 || win32vars.custom_api.get_alpha_4coder_version(MAJOR, MINOR, PATCH) == 0){
            MessageBox_utf8(0, (u8*)"Error: The application and custom version numbers don't match.\n", (u8*)"Error",0);
            exit(1);
        }
        
        win32vars.custom_api.get_bindings = (Get_Binding_Data_Function*)GetProcAddress(win32vars.custom, "get_bindings");
    }
    
    if (win32vars.custom_api.get_bindings == 0){
        MessageBox_utf8(0, (u8*)"Error: The custom dll is missing.\n", (u8*)"Error", 0);
        exit(1);
    }
    
#else
    win32vars.custom_api.get_bindings = (Get_Binding_Data_Function*)get_bindings;
#endif
    
    //
    // Window and GL Initialization
    //
    
    WNDCLASS window_class = {0};
    window_class.style = CS_HREDRAW|CS_VREDRAW;
    window_class.lpfnWndProc = (WNDPROC)(Win32Callback);
    window_class.hInstance = hInstance;
    window_class.lpszClassName = L"4coder-win32-wndclass";
    window_class.hIcon = LoadIcon(hInstance, L"main");
    
    if (!RegisterClass(&window_class)){
        exit(1);
    }
    
    RECT window_rect = {0};
    if (plat_settings.set_window_size){
        window_rect.right = plat_settings.window_w;
        window_rect.bottom = plat_settings.window_h;
    }
    else{
        window_rect.right = 800;
        window_rect.bottom = 600;
    }
    
    if (!AdjustWindowRect(&window_rect, WS_OVERLAPPEDWINDOW, false)){
        LOG("Could not get adjusted window.\n");
    }
    
    i32 window_x = CW_USEDEFAULT;
    i32 window_y = CW_USEDEFAULT;
    
    if (plat_settings.set_window_pos){
        window_x = plat_settings.window_x;
        window_y = plat_settings.window_y;
        LOGF("Setting window position (%d, %d)\n", window_x, window_y);
    }
    
    i32 window_style = WS_OVERLAPPEDWINDOW;
    if (!plat_settings.fullscreen_window && plat_settings.maximize_window){
        window_style |= WS_MAXIMIZE;
    }
    
    LOG("Creating window... ");
    win32vars.window_handle = CreateWindow(window_class.lpszClassName, WINDOW_NAME, window_style, window_x, window_y, window_rect.right - window_rect.left, window_rect.bottom - window_rect.top, 0, 0, hInstance, 0);
    
    if (win32vars.window_handle == 0){
        LOG("Failed\n");
        exit(1);
    }
    else{
        LOG("Success\n");
    }
    
    {
        HDC hdc = GetDC(win32vars.window_handle);
        
        // TODO(allen): not Windows XP compatible, how do I handle that?
        SetProcessDPIAware();
        win32vars.dpi_x = GetDeviceCaps(hdc, LOGPIXELSX);
        win32vars.dpi_y = GetDeviceCaps(hdc, LOGPIXELSY);
        
        GetClientRect(win32vars.window_handle, &window_rect);
        ReleaseDC(win32vars.window_handle, hdc);
    }
    
    Win32InitGL();
    Win32Resize(window_rect.right - window_rect.left, window_rect.bottom - window_rect.top);
    
    //
    // Font System Init
    //
    
    LOG("Initializing fonts\n");
    system_font_init(&sysfunc.font, 0, 0, plat_settings.font_size, plat_settings.use_hinting);
    
    //
    // Misc System Initializations
    //
    
    LOG("Initializing clipboard\n");
    win32vars.clip_max = KB(16);
    win32vars.clip_buffer = (u8*)system_memory_allocate(win32vars.clip_max);
    
    win32vars.clipboard_sequence = GetClipboardSequenceNumber();
    if (win32vars.clipboard_sequence == 0){
        system_post_clipboard(make_lit_string(""));
        
        win32vars.clipboard_sequence = GetClipboardSequenceNumber();
        win32vars.next_clipboard_is_self = 0;
        
        if (win32vars.clipboard_sequence == 0){
            OutputDebugStringA("Failure while initializing clipboard\n");
        }
    }
    else{
        win32_read_clipboard_contents();
    }
    
    Win32KeycodeInit();
    
    win32vars.cursor_ibeam = LoadCursor(NULL, IDC_IBEAM);
    win32vars.cursor_arrow = LoadCursor(NULL, IDC_ARROW);
    win32vars.cursor_leftright = LoadCursor(NULL, IDC_SIZEWE);
    win32vars.cursor_updown = LoadCursor(NULL, IDC_SIZENS);
    
    LARGE_INTEGER f;
    if (QueryPerformanceFrequency(&f)){
        win32vars.count_per_usecond = (f32)f.QuadPart / 1000000.f;
        LOGF("Got performance frequency %f\n", win32vars.count_per_usecond);
    }
    else{
        // NOTE(allen): Just guess.
        win32vars.count_per_usecond = 1.f;
        LOG("Did not get performance frequency, just guessing with 1.\n");
    }
    Assert(win32vars.count_per_usecond > 0.f);
    
    //
    // Main Loop
    //
    
    LOG("Initializing application variables\n");
    win32vars.app.init(&sysfunc, &win32vars.target, &memory_vars, win32vars.clipboard_contents, current_directory, win32vars.custom_api);
    
    system_memory_free(current_directory.str, 0);
    
    b32 keep_playing = true;
    win32vars.first = true;
    timeBeginPeriod(1);
    
    if (plat_settings.fullscreen_window){
        Win32ToggleFullscreen();
    }
    
    SetForegroundWindow(win32vars.window_handle);
    SetActiveWindow(win32vars.window_handle);
    ShowWindow(win32vars.window_handle, SW_SHOW);
    
    LOG("Beginning main loop\n");
    u64 timer_start = Win32HighResolutionTime();
    system_acquire_lock(FRAME_LOCK);
    MSG msg;
    for (;keep_playing;){
        // TODO(allen): Find a good way to wait on a pipe
        // without interfering with the reading process
        //  Looks like we can ReadFile with a size of zero
        // in an IOCP for this effect.
        
        // NOTE(allen): When we're in stream mode we don't have
        // double buffering so we need to move ahead and call
        // the first step right away so it will render into the
        // window. With double buffering this is not an issue
        // for reasons I cannot at all comprehend.
        if (!(win32vars.first && plat_settings.stream_mode)){
            system_release_lock(FRAME_LOCK);
            
            if (win32vars.running_cli == 0){
                win32vars.got_useful_event = false;
            }
            
            b32 get_more_messages = true;
            do{
                if (win32vars.got_useful_event == 0){
                    get_more_messages = GetMessage(&msg, 0, 0, 0);
                }
                else{
                    get_more_messages = PeekMessage(&msg, 0, 0, 0, 1);
                }
                
                if (get_more_messages){
                    if (msg.message == WM_QUIT){
                        keep_playing = 0;
                    }else{
                        b32 treat_normally = true;
                        if (msg.message == WM_KEYDOWN || msg.message == WM_SYSKEYDOWN){
                            switch (msg.wParam){
                                case VK_CONTROL:case VK_LCONTROL:case VK_RCONTROL:
                                case VK_MENU:case VK_LMENU:case VK_RMENU:
                                case VK_SHIFT:case VK_LSHIFT:case VK_RSHIFT:break;
                                
                                default: treat_normally = false; break;
                            }
                        }
                        
                        if (treat_normally){
                            TranslateMessage(&msg);
                            DispatchMessage(&msg);
                        }
                        else{
                            Control_Keys *controls = &win32vars.input_chunk.pers.controls;
                            
                            b8 ctrl = (controls->r_ctrl || (controls->l_ctrl && !controls->r_alt));
                            b8 alt = (controls->l_alt || (controls->r_alt && !controls->l_ctrl));
                            
                            if (win32vars.lctrl_lalt_is_altgr){
                                if (controls->l_alt && controls->l_ctrl){
                                    ctrl = 0;
                                    alt = 0;
                                }
                            }
                            
                            BYTE ctrl_state = 0, alt_state = 0;
                            BYTE state[256];
                            if (ctrl || alt){
                                GetKeyboardState(state);
                                if (ctrl){
                                    ctrl_state = state[VK_CONTROL];
                                    state[VK_CONTROL] = 0;
                                }
                                if (alt){
                                    alt_state = state[VK_MENU];
                                    state[VK_MENU] = 0;
                                }
                                SetKeyboardState(state);
                                
                                TranslateMessage(&msg);
                                DispatchMessage(&msg);
                                
                                if (ctrl){
                                    state[VK_CONTROL] = ctrl_state;
                                }
                                if (alt){
                                    state[VK_MENU] = alt_state;
                                }
                                SetKeyboardState(state);
                            }
                            else{
                                TranslateMessage(&msg);
                                DispatchMessage(&msg);
                            }
                        }
                    }
                }
            }while(get_more_messages);
            
            system_acquire_lock(FRAME_LOCK);
        }
        
        POINT mouse_point;
        if (GetCursorPos(&mouse_point) &&
            ScreenToClient(win32vars.window_handle, &mouse_point)){
            
            i32_Rect screen;
            screen.x0 = 0;
            screen.y0 = 0;
            screen.x1 = win32vars.target.width;
            screen.y1 = win32vars.target.height;
            
            i32 mx = mouse_point.x;
            i32 my = mouse_point.y;
            
            b32 is_hit = false;
            if (mx >= screen.x0 && mx < screen.x1 && my >= screen.y0 && my < screen.y1){
                is_hit = true;
            }
            
            if (!is_hit){
                win32vars.input_chunk.trans.out_of_window = 1;
            }
            
            win32vars.input_chunk.pers.mouse_x = mouse_point.x;
            win32vars.input_chunk.pers.mouse_y = mouse_point.y;
        }
        else{
            win32vars.input_chunk.trans.out_of_window = 1;
        }
        
        Win32_Input_Chunk input_chunk = win32vars.input_chunk;
        win32vars.input_chunk.trans = null_input_chunk_transient;
        
        input_chunk.pers.control_keys[MDFR_CAPS_INDEX] = GetKeyState(VK_CAPITAL) & 0x1;
        
        win32vars.clipboard_contents = null_string;
        if (win32vars.clipboard_sequence != 0){
            DWORD new_number = GetClipboardSequenceNumber();
            if (new_number != win32vars.clipboard_sequence){
                win32vars.clipboard_sequence = new_number;
                if (win32vars.next_clipboard_is_self){
                    win32vars.next_clipboard_is_self = 0;
                }
                else{
                    win32_read_clipboard_contents();
                }
            }
        }
        
        Application_Step_Input input = {0};
        
        input.first_step = win32vars.first;
        
        // NOTE(allen): The expected dt given the frame limit in seconds.
        input.dt = frame_useconds / 1000000.f;
        
        input.keys = input_chunk.trans.key_data;
        
        input.mouse.out_of_window = input_chunk.trans.out_of_window;
        
        input.mouse.l = input_chunk.pers.mouse_l;
        input.mouse.press_l = input_chunk.trans.mouse_l_press;
        input.mouse.release_l = input_chunk.trans.mouse_l_release;
        
        input.mouse.r = input_chunk.pers.mouse_r;
        input.mouse.press_r = input_chunk.trans.mouse_r_press;
        input.mouse.release_r = input_chunk.trans.mouse_r_release;
        
        input.mouse.wheel = input_chunk.trans.mouse_wheel;
        input.mouse.x = input_chunk.pers.mouse_x;
        input.mouse.y = input_chunk.pers.mouse_y;
        
        input.clipboard = win32vars.clipboard_contents;
        
        
        Application_Step_Result result = {(Application_Mouse_Cursor)0};
        result.mouse_cursor_type = APP_MOUSE_CURSOR_DEFAULT;
        result.lctrl_lalt_is_altgr = win32vars.lctrl_lalt_is_altgr;
        result.trying_to_kill = input_chunk.trans.trying_to_kill;
        result.perform_kill = 0;
        
        if (win32vars.send_exit_signal){
            result.trying_to_kill = 1;
            win32vars.send_exit_signal = 0;
        }
        
        win32vars.app.step(&sysfunc, &win32vars.target, &memory_vars, &input, &result, clparams);
        
        if (result.perform_kill){
            keep_playing = 0;
        }
        
        if (win32vars.do_toggle){
            Win32ToggleFullscreen();
            win32vars.do_toggle = 0;
        }
        
        Win32SetCursorFromUpdate(result.mouse_cursor_type);
        win32vars.lctrl_lalt_is_altgr = result.lctrl_lalt_is_altgr;
        
        HDC hdc = GetDC(win32vars.window_handle);
        Win32RedrawScreen(hdc);
        ReleaseDC(win32vars.window_handle, hdc);
        
        win32vars.first = 0;
        
        if (result.animating){
            system_schedule_step();
        }
        
        flush_thread_group(BACKGROUND_THREADS);
        
        u64 timer_end = Win32HighResolutionTime();
        u64 end_target = timer_start + frame_useconds;
        
        system_release_lock(FRAME_LOCK);
        while (timer_end < end_target){
            DWORD samount = (DWORD)((end_target - timer_end) / 1000);
            if (samount > 0) Sleep(samount);
            timer_end = Win32HighResolutionTime();
        }
        system_acquire_lock(FRAME_LOCK);
        timer_start = Win32HighResolutionTime();
    }
    
    return(0);
}

#include "4ed_shared_fonts.cpp"
#include "win32_4ed_file_track.cpp"
#include "4ed_font_static_functions.cpp"
#include "win32_utf8.cpp"

#if 0
// NOTE(allen): In case I want to switch back to a console application at some point.
int main(int argc, char **argv){
    HINSTANCE hInstance = GetModuleHandle(0);
}
#endif

// BOTTOM