Fix #10490: Allow ships to exit depots if another is not moving at the exit point...

[openttd-github.git] / src / video / win32_v.cpp

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file win32_v.cpp Implementation of the Windows (GDI) video driver. */

#include "../stdafx.h"
#include "../openttd.h"
#include "../error_func.h"
#include "../gfx_func.h"
#include "../os/windows/win32.h"
#include "../blitter/factory.hpp"
#include "../core/geometry_func.hpp"
#include "../core/math_func.hpp"
#include "../core/random_func.hpp"
#include "../texteff.hpp"
#include "../thread.h"
#include "../progress.h"
#include "../window_gui.h"
#include "../window_func.h"
#include "../framerate_type.h"
#include "../library_loader.h"
#include "win32_v.h"
#include <windows.h>
#include <imm.h>
#include <versionhelpers.h>

#include "../safeguards.h"

/* Missing define in MinGW headers. */
#ifndef MAPVK_VK_TO_CHAR
#define MAPVK_VK_TO_CHAR    (2)
#endif

#ifndef PM_QS_INPUT
#define PM_QS_INPUT 0x20000
#endif

#ifndef WM_DPICHANGED
#define WM_DPICHANGED 0x02E0
#endif

bool _window_maximize;
static Dimension _bck_resolution;
DWORD _imm_props;

static Palette _local_palette; ///< Current palette to use for drawing.

bool VideoDriver_Win32Base::ClaimMousePointer()
{
        MyShowCursor(false, true);
        return true;
}

struct Win32VkMapping {
        byte vk_from;
        byte vk_count;
        byte map_to;
};

#define AS(x, z) {x, 0, z}
#define AM(x, y, z, w) {x, y - x, z}

static const Win32VkMapping _vk_mapping[] = {
        /* Pageup stuff + up/down */
        AM(VK_PRIOR, VK_DOWN, WKC_PAGEUP, WKC_DOWN),
        /* Map letters & digits */
        AM('A', 'Z', 'A', 'Z'),
        AM('0', '9', '0', '9'),

        AS(VK_ESCAPE,   WKC_ESC),
        AS(VK_PAUSE,    WKC_PAUSE),
        AS(VK_BACK,     WKC_BACKSPACE),
        AM(VK_INSERT,   VK_DELETE, WKC_INSERT, WKC_DELETE),

        AS(VK_SPACE,    WKC_SPACE),
        AS(VK_RETURN,   WKC_RETURN),
        AS(VK_TAB,      WKC_TAB),

        /* Function keys */
        AM(VK_F1, VK_F12, WKC_F1, WKC_F12),

        /* Numeric part */
        AM(VK_NUMPAD0, VK_NUMPAD9, '0', '9'),
        AS(VK_DIVIDE,   WKC_NUM_DIV),
        AS(VK_MULTIPLY, WKC_NUM_MUL),
        AS(VK_SUBTRACT, WKC_NUM_MINUS),
        AS(VK_ADD,      WKC_NUM_PLUS),
        AS(VK_DECIMAL,  WKC_NUM_DECIMAL),

        /* Other non-letter keys */
        AS(0xBF,  WKC_SLASH),
        AS(0xBA,  WKC_SEMICOLON),
        AS(0xBB,  WKC_EQUALS),
        AS(0xDB,  WKC_L_BRACKET),
        AS(0xDC,  WKC_BACKSLASH),
        AS(0xDD,  WKC_R_BRACKET),

        AS(0xDE,  WKC_SINGLEQUOTE),
        AS(0xBC,  WKC_COMMA),
        AS(0xBD,  WKC_MINUS),
        AS(0xBE,  WKC_PERIOD)
};

static uint MapWindowsKey(uint sym)
{
        const Win32VkMapping *map;
        uint key = 0;

        for (map = _vk_mapping; map != endof(_vk_mapping); ++map) {
                if ((uint)(sym - map->vk_from) <= map->vk_count) {
                        key = sym - map->vk_from + map->map_to;
                        break;
                }
        }

        if (GetAsyncKeyState(VK_SHIFT)   < 0) key |= WKC_SHIFT;
        if (GetAsyncKeyState(VK_CONTROL) < 0) key |= WKC_CTRL;
        if (GetAsyncKeyState(VK_MENU)    < 0) key |= WKC_ALT;
        return key;
}

/** Colour depth to use for fullscreen display modes. */
uint8_t VideoDriver_Win32Base::GetFullscreenBpp()
{
        /* Check modes for the relevant fullscreen bpp */
        return _support8bpp != S8BPP_HARDWARE ? 32 : BlitterFactory::GetCurrentBlitter()->GetScreenDepth();
}

/**
 * Instantiate a new window.
 * @param full_screen Whether to make a full screen window or not.
 * @param resize Whether to change window size.
 * @return True if the window could be created.
 */
bool VideoDriver_Win32Base::MakeWindow(bool full_screen, bool resize)
{
        /* full_screen is whether the new window should be fullscreen,
         * _wnd.fullscreen is whether the current window is. */
        _fullscreen = full_screen;

        /* recreate window? */
        if ((full_screen != this->fullscreen) && this->main_wnd) {
                DestroyWindow(this->main_wnd);
                this->main_wnd = 0;
        }

        if (full_screen) {
                DEVMODE settings;

                memset(&settings, 0, sizeof(settings));
                settings.dmSize = sizeof(settings);
                settings.dmFields =
                        DM_BITSPERPEL |
                        DM_PELSWIDTH |
                        DM_PELSHEIGHT;
                settings.dmBitsPerPel = this->GetFullscreenBpp();
                settings.dmPelsWidth  = this->width_org;
                settings.dmPelsHeight = this->height_org;

                /* Check for 8 bpp support. */
                if (settings.dmBitsPerPel == 8 && ChangeDisplaySettings(&settings, CDS_FULLSCREEN | CDS_TEST) != DISP_CHANGE_SUCCESSFUL) {
                        settings.dmBitsPerPel = 32;
                }

                /* Test fullscreen with current resolution, if it fails use desktop resolution. */
                if (ChangeDisplaySettings(&settings, CDS_FULLSCREEN | CDS_TEST) != DISP_CHANGE_SUCCESSFUL) {
                        RECT r;
                        GetWindowRect(GetDesktopWindow(), &r);
                        /* Guard against recursion. If we already failed here once, just fall through to
                         * the next ChangeDisplaySettings call which will fail and error out appropriately. */
                        if ((int)settings.dmPelsWidth != r.right - r.left || (int)settings.dmPelsHeight != r.bottom - r.top) {
                                return this->ChangeResolution(r.right - r.left, r.bottom - r.top);
                        }
                }

                if (ChangeDisplaySettings(&settings, CDS_FULLSCREEN) != DISP_CHANGE_SUCCESSFUL) {
                        this->MakeWindow(false, resize);  // don't care about the result
                        return false;  // the request failed
                }
        } else if (this->fullscreen) {
                /* restore display? */
                ChangeDisplaySettings(nullptr, 0);
                /* restore the resolution */
                this->width = _bck_resolution.width;
                this->height = _bck_resolution.height;
        }

        {
                RECT r;
                DWORD style, showstyle;
                int w, h;

                showstyle = SW_SHOWNORMAL;
                this->fullscreen = full_screen;
                if (this->fullscreen) {
                        style = WS_POPUP;
                        SetRect(&r, 0, 0, this->width_org, this->height_org);
                } else {
                        style = WS_OVERLAPPEDWINDOW;
                        /* On window creation, check if we were in maximize mode before */
                        if (_window_maximize) showstyle = SW_SHOWMAXIMIZED;
                        SetRect(&r, 0, 0, this->width, this->height);
                }

                AdjustWindowRect(&r, style, FALSE);
                w = r.right - r.left;
                h = r.bottom - r.top;

                if (this->main_wnd != nullptr) {
                        if (!_window_maximize && resize) SetWindowPos(this->main_wnd, 0, 0, 0, w, h, SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOZORDER | SWP_NOMOVE);
                } else {
                        int x = 0;
                        int y = 0;

                        /* For windowed mode, center on the workspace of the primary display. */
                        if (!this->fullscreen) {
                                MONITORINFO mi;
                                mi.cbSize = sizeof(mi);
                                GetMonitorInfo(MonitorFromWindow(0, MONITOR_DEFAULTTOPRIMARY), &mi);

                                x = (mi.rcWork.right - mi.rcWork.left - w) / 2;
                                y = (mi.rcWork.bottom - mi.rcWork.top - h) / 2;
                        }

                        std::string caption = VideoDriver::GetCaption();
                        this->main_wnd = CreateWindow(L"OTTD", OTTD2FS(caption).c_str(), style, x, y, w, h, 0, 0, GetModuleHandle(nullptr), this);
                        if (this->main_wnd == nullptr) UserError("CreateWindow failed");
                        ShowWindow(this->main_wnd, showstyle);
                }
        }

        BlitterFactory::GetCurrentBlitter()->PostResize();

        GameSizeChanged();
        return true;
}

/** Forward key presses to the window system. */
static LRESULT HandleCharMsg(uint keycode, char32_t charcode)
{
        static char32_t prev_char = 0;

        /* Did we get a lead surrogate? If yes, store and exit. */
        if (Utf16IsLeadSurrogate(charcode)) {
                if (prev_char != 0) Debug(driver, 1, "Got two UTF-16 lead surrogates, dropping the first one");
                prev_char = charcode;
                return 0;
        }

        /* Stored lead surrogate and incoming trail surrogate? Combine and forward to input handling. */
        if (prev_char != 0) {
                if (Utf16IsTrailSurrogate(charcode)) {
                        charcode = Utf16DecodeSurrogate(prev_char, charcode);
                } else {
                        Debug(driver, 1, "Got an UTF-16 lead surrogate without a trail surrogate, dropping the lead surrogate");
                }
        }
        prev_char = 0;

        HandleKeypress(keycode, charcode);

        return 0;
}

/** Should we draw the composition string ourself, i.e is this a normal IME? */
static bool DrawIMECompositionString()
{
        return (_imm_props & IME_PROP_AT_CARET) && !(_imm_props & IME_PROP_SPECIAL_UI);
}

/** Set position of the composition window to the caret position. */
static void SetCompositionPos(HWND hwnd)
{
        HIMC hIMC = ImmGetContext(hwnd);
        if (hIMC != nullptr) {
                COMPOSITIONFORM cf;
                cf.dwStyle = CFS_POINT;

                if (EditBoxInGlobalFocus()) {
                        /* Get caret position. */
                        Point pt = _focused_window->GetCaretPosition();
                        cf.ptCurrentPos.x = _focused_window->left + pt.x;
                        cf.ptCurrentPos.y = _focused_window->top  + pt.y;
                } else {
                        cf.ptCurrentPos.x = 0;
                        cf.ptCurrentPos.y = 0;
                }
                ImmSetCompositionWindow(hIMC, &cf);
        }
        ImmReleaseContext(hwnd, hIMC);
}

/** Set the position of the candidate window. */
static void SetCandidatePos(HWND hwnd)
{
        HIMC hIMC = ImmGetContext(hwnd);
        if (hIMC != nullptr) {
                CANDIDATEFORM cf;
                cf.dwIndex = 0;
                cf.dwStyle = CFS_EXCLUDE;

                if (EditBoxInGlobalFocus()) {
                        Point pt = _focused_window->GetCaretPosition();
                        cf.ptCurrentPos.x = _focused_window->left + pt.x;
                        cf.ptCurrentPos.y = _focused_window->top  + pt.y;
                        if (_focused_window->window_class == WC_CONSOLE) {
                                cf.rcArea.left   = _focused_window->left;
                                cf.rcArea.top    = _focused_window->top;
                                cf.rcArea.right  = _focused_window->left + _focused_window->width;
                                cf.rcArea.bottom = _focused_window->top  + _focused_window->height;
                        } else {
                                cf.rcArea.left   = _focused_window->left + _focused_window->nested_focus->pos_x;
                                cf.rcArea.top    = _focused_window->top  + _focused_window->nested_focus->pos_y;
                                cf.rcArea.right  = cf.rcArea.left + _focused_window->nested_focus->current_x;
                                cf.rcArea.bottom = cf.rcArea.top  + _focused_window->nested_focus->current_y;
                        }
                } else {
                        cf.ptCurrentPos.x = 0;
                        cf.ptCurrentPos.y = 0;
                        SetRectEmpty(&cf.rcArea);
                }
                ImmSetCandidateWindow(hIMC, &cf);
        }
        ImmReleaseContext(hwnd, hIMC);
}

/** Handle WM_IME_COMPOSITION messages. */
static LRESULT HandleIMEComposition(HWND hwnd, WPARAM wParam, LPARAM lParam)
{
        HIMC hIMC = ImmGetContext(hwnd);

        if (hIMC != nullptr) {
                if (lParam & GCS_RESULTSTR) {
                        /* Read result string from the IME. */
                        LONG len = ImmGetCompositionString(hIMC, GCS_RESULTSTR, nullptr, 0); // Length is always in bytes, even in UNICODE build.
                        std::wstring str(len + 1, L'\0');
                        len = ImmGetCompositionString(hIMC, GCS_RESULTSTR, str.data(), len);
                        str[len / sizeof(wchar_t)] = L'\0';

                        /* Transmit text to windowing system. */
                        if (len > 0) {
                                HandleTextInput(nullptr, true); // Clear marked string.
                                HandleTextInput(FS2OTTD(str).c_str());
                        }
                        SetCompositionPos(hwnd);

                        /* Don't pass the result string on to the default window proc. */
                        lParam &= ~(GCS_RESULTSTR | GCS_RESULTCLAUSE | GCS_RESULTREADCLAUSE | GCS_RESULTREADSTR);
                }

                if ((lParam & GCS_COMPSTR) && DrawIMECompositionString()) {
                        /* Read composition string from the IME. */
                        LONG len = ImmGetCompositionString(hIMC, GCS_COMPSTR, nullptr, 0); // Length is always in bytes, even in UNICODE build.
                        std::wstring str(len + 1, L'\0');
                        len = ImmGetCompositionString(hIMC, GCS_COMPSTR, str.data(), len);
                        str[len / sizeof(wchar_t)] = L'\0';

                        if (len > 0) {
                                static char utf8_buf[1024];
                                convert_from_fs(str.c_str(), utf8_buf, lengthof(utf8_buf));

                                /* Convert caret position from bytes in the input string to a position in the UTF-8 encoded string. */
                                LONG caret_bytes = ImmGetCompositionString(hIMC, GCS_CURSORPOS, nullptr, 0);
                                const char *caret = utf8_buf;
                                for (const wchar_t *c = str.c_str(); *c != '\0' && *caret != '\0' && caret_bytes > 0; c++, caret_bytes--) {
                                        /* Skip DBCS lead bytes or leading surrogates. */
                                        if (Utf16IsLeadSurrogate(*c)) {
                                                c++;
                                                caret_bytes--;
                                        }
                                        Utf8Consume(&caret);
                                }

                                HandleTextInput(utf8_buf, true, caret);
                        } else {
                                HandleTextInput(nullptr, true);
                        }

                        lParam &= ~(GCS_COMPSTR | GCS_COMPATTR | GCS_COMPCLAUSE | GCS_CURSORPOS | GCS_DELTASTART);
                }
        }
        ImmReleaseContext(hwnd, hIMC);

        return lParam != 0 ? DefWindowProc(hwnd, WM_IME_COMPOSITION, wParam, lParam) : 0;
}

/** Clear the current composition string. */
static void CancelIMEComposition(HWND hwnd)
{
        HIMC hIMC = ImmGetContext(hwnd);
        if (hIMC != nullptr) ImmNotifyIME(hIMC, NI_COMPOSITIONSTR, CPS_CANCEL, 0);
        ImmReleaseContext(hwnd, hIMC);
        /* Clear any marked string from the current edit box. */
        HandleTextInput(nullptr, true);
}

LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
        static uint32_t keycode = 0;
        static bool console = false;

        VideoDriver_Win32Base *video_driver = (VideoDriver_Win32Base *)GetWindowLongPtr(hwnd, GWLP_USERDATA);

        switch (msg) {
                case WM_CREATE:
                        SetWindowLongPtr(hwnd, GWLP_USERDATA, (LONG_PTR)((LPCREATESTRUCT)lParam)->lpCreateParams);
                        _cursor.in_window = false; // Win32 has mouse tracking.
                        SetCompositionPos(hwnd);
                        _imm_props = ImmGetProperty(GetKeyboardLayout(0), IGP_PROPERTY);
                        break;

                case WM_PAINT: {
                        RECT r;
                        GetUpdateRect(hwnd, &r, FALSE);
                        video_driver->MakeDirty(r.left, r.top, r.right - r.left, r.bottom - r.top);

                        ValidateRect(hwnd, nullptr);
                        return 0;
                }

                case WM_PALETTECHANGED:
                        if ((HWND)wParam == hwnd) return 0;
                        [[fallthrough]];

                case WM_QUERYNEWPALETTE:
                        video_driver->PaletteChanged(hwnd);
                        return 0;

                case WM_CLOSE:
                        HandleExitGameRequest();
                        return 0;

                case WM_DESTROY:
                        if (_window_maximize) _cur_resolution = _bck_resolution;
                        return 0;

                case WM_LBUTTONDOWN:
                        SetCapture(hwnd);
                        _left_button_down = true;
                        HandleMouseEvents();
                        return 0;

                case WM_LBUTTONUP:
                        ReleaseCapture();
                        _left_button_down = false;
                        _left_button_clicked = false;
                        HandleMouseEvents();
                        return 0;

                case WM_RBUTTONDOWN:
                        SetCapture(hwnd);
                        _right_button_down = true;
                        _right_button_clicked = true;
                        HandleMouseEvents();
                        return 0;

                case WM_RBUTTONUP:
                        ReleaseCapture();
                        _right_button_down = false;
                        HandleMouseEvents();
                        return 0;

                case WM_MOUSELEAVE:
                        UndrawMouseCursor();
                        _cursor.in_window = false;

                        if (!_left_button_down && !_right_button_down) MyShowCursor(true);
                        return 0;

                case WM_MOUSEMOVE: {
                        int x = (int16_t)LOWORD(lParam);
                        int y = (int16_t)HIWORD(lParam);

                        /* If the mouse was not in the window and it has moved it means it has
                         * come into the window, so start drawing the mouse. Also start
                         * tracking the mouse for exiting the window */
                        if (!_cursor.in_window) {
                                _cursor.in_window = true;
                                TRACKMOUSEEVENT tme;
                                tme.cbSize = sizeof(tme);
                                tme.dwFlags = TME_LEAVE;
                                tme.hwndTrack = hwnd;

                                TrackMouseEvent(&tme);
                        }

                        if (_cursor.fix_at) {
                                /* Get all queued mouse events now in case we have to warp the cursor. In the
                                 * end, we only care about the current mouse position and not bygone events. */
                                MSG m;
                                while (PeekMessage(&m, hwnd, WM_MOUSEMOVE, WM_MOUSEMOVE, PM_REMOVE | PM_NOYIELD | PM_QS_INPUT)) {
                                        x = (int16_t)LOWORD(m.lParam);
                                        y = (int16_t)HIWORD(m.lParam);
                                }
                        }

                        if (_cursor.UpdateCursorPosition(x, y)) {
                                POINT pt;
                                pt.x = _cursor.pos.x;
                                pt.y = _cursor.pos.y;
                                ClientToScreen(hwnd, &pt);
                                SetCursorPos(pt.x, pt.y);
                        }
                        MyShowCursor(false);
                        HandleMouseEvents();
                        return 0;
                }

                case WM_INPUTLANGCHANGE:
                        _imm_props = ImmGetProperty(GetKeyboardLayout(0), IGP_PROPERTY);
                        break;

                case WM_IME_SETCONTEXT:
                        /* Don't show the composition window if we draw the string ourself. */
                        if (DrawIMECompositionString()) lParam &= ~ISC_SHOWUICOMPOSITIONWINDOW;
                        break;

                case WM_IME_STARTCOMPOSITION:
                        SetCompositionPos(hwnd);
                        if (DrawIMECompositionString()) return 0;
                        break;

                case WM_IME_COMPOSITION:
                        return HandleIMEComposition(hwnd, wParam, lParam);

                case WM_IME_ENDCOMPOSITION:
                        /* Clear any pending composition string. */
                        HandleTextInput(nullptr, true);
                        if (DrawIMECompositionString()) return 0;
                        break;

                case WM_IME_NOTIFY:
                        if (wParam == IMN_OPENCANDIDATE) SetCandidatePos(hwnd);
                        break;

                case WM_DEADCHAR:
                        console = GB(lParam, 16, 8) == 41;
                        return 0;

                case WM_CHAR: {
                        uint scancode = GB(lParam, 16, 8);
                        uint charcode = wParam;

                        /* If the console key is a dead-key, we need to press it twice to get a WM_CHAR message.
                         * But we then get two WM_CHAR messages, so ignore the first one */
                        if (console && scancode == 41) {
                                console = false;
                                return 0;
                        }

                        /* IMEs and other input methods sometimes send a WM_CHAR without a WM_KEYDOWN,
                         * clear the keycode so a previous WM_KEYDOWN doesn't become 'stuck'. */
                        uint cur_keycode = keycode;
                        keycode = 0;

                        return HandleCharMsg(cur_keycode, charcode);
                }

                case WM_KEYDOWN: {
                        /* No matter the keyboard layout, we will map the '~' to the console. */
                        uint scancode = GB(lParam, 16, 8);
                        keycode = scancode == 41 ? (uint)WKC_BACKQUOTE : MapWindowsKey(wParam);

                        uint charcode = MapVirtualKey(wParam, MAPVK_VK_TO_CHAR);

                        /* No character translation? */
                        if (charcode == 0) {
                                HandleKeypress(keycode, 0);
                                return 0;
                        }

                        /* If an edit box is in focus, wait for the corresponding WM_CHAR message. */
                        if (!EditBoxInGlobalFocus()) {
                                /* Is the console key a dead key? If yes, ignore the first key down event. */
                                if (HasBit(charcode, 31) && !console) {
                                        if (scancode == 41) {
                                                console = true;
                                                return 0;
                                        }
                                }
                                console = false;

                                /* IMEs and other input methods sometimes send a WM_CHAR without a WM_KEYDOWN,
                                 * clear the keycode so a previous WM_KEYDOWN doesn't become 'stuck'. */
                                uint cur_keycode = keycode;
                                keycode = 0;

                                return HandleCharMsg(cur_keycode, LOWORD(charcode));
                        }

                        return 0;
                }

                case WM_SYSKEYDOWN: // user presses F10 or Alt, both activating the title-menu
                        switch (wParam) {
                                case VK_RETURN:
                                case 'F': // Full Screen on ALT + ENTER/F
                                        ToggleFullScreen(!video_driver->fullscreen);
                                        return 0;

                                case VK_MENU: // Just ALT
                                        return 0; // do nothing

                                case VK_F10: // F10, ignore activation of menu
                                        HandleKeypress(MapWindowsKey(wParam), 0);
                                        return 0;

                                default: // ALT in combination with something else
                                        HandleKeypress(MapWindowsKey(wParam), 0);
                                        break;
                        }
                        break;

                case WM_SIZE:
                        if (wParam != SIZE_MINIMIZED) {
                                /* Set maximized flag when we maximize (obviously), but also when we
                                 * switched to fullscreen from a maximized state */
                                _window_maximize = (wParam == SIZE_MAXIMIZED || (_window_maximize && _fullscreen));
                                if (_window_maximize || _fullscreen) _bck_resolution = _cur_resolution;
                                video_driver->ClientSizeChanged(LOWORD(lParam), HIWORD(lParam));
                        }
                        return 0;

                case WM_SIZING: {
                        RECT *r = (RECT*)lParam;
                        RECT r2;
                        int w, h;

                        SetRect(&r2, 0, 0, 0, 0);
                        AdjustWindowRect(&r2, GetWindowLong(hwnd, GWL_STYLE), FALSE);

                        w = r->right - r->left - (r2.right - r2.left);
                        h = r->bottom - r->top - (r2.bottom - r2.top);
                        w = std::max(w, 64);
                        h = std::max(h, 64);
                        SetRect(&r2, 0, 0, w, h);

                        AdjustWindowRect(&r2, GetWindowLong(hwnd, GWL_STYLE), FALSE);
                        w = r2.right - r2.left;
                        h = r2.bottom - r2.top;

                        switch (wParam) {
                                case WMSZ_BOTTOM:
                                        r->bottom = r->top + h;
                                        break;

                                case WMSZ_BOTTOMLEFT:
                                        r->bottom = r->top + h;
                                        r->left = r->right - w;
                                        break;

                                case WMSZ_BOTTOMRIGHT:
                                        r->bottom = r->top + h;
                                        r->right = r->left + w;
                                        break;

                                case WMSZ_LEFT:
                                        r->left = r->right - w;
                                        break;

                                case WMSZ_RIGHT:
                                        r->right = r->left + w;
                                        break;

                                case WMSZ_TOP:
                                        r->top = r->bottom - h;
                                        break;

                                case WMSZ_TOPLEFT:
                                        r->top = r->bottom - h;
                                        r->left = r->right - w;
                                        break;

                                case WMSZ_TOPRIGHT:
                                        r->top = r->bottom - h;
                                        r->right = r->left + w;
                                        break;
                        }
                        return TRUE;
                }

                case WM_DPICHANGED: {
                        auto did_adjust = AdjustGUIZoom(true);

                        /* Resize the window to match the new DPI setting. */
                        RECT *prcNewWindow = (RECT *)lParam;
                        SetWindowPos(hwnd,
                                nullptr,
                                prcNewWindow->left,
                                prcNewWindow->top,
                                prcNewWindow->right - prcNewWindow->left,
                                prcNewWindow->bottom - prcNewWindow->top,
                                SWP_NOZORDER | SWP_NOACTIVATE);

                        if (did_adjust) ReInitAllWindows(true);

                        return 0;
                }

/* needed for wheel */
#if !defined(WM_MOUSEWHEEL)
# define WM_MOUSEWHEEL 0x020A
#endif  /* WM_MOUSEWHEEL */
#if !defined(GET_WHEEL_DELTA_WPARAM)
# define GET_WHEEL_DELTA_WPARAM(wparam) ((short)HIWORD(wparam))
#endif  /* GET_WHEEL_DELTA_WPARAM */

                case WM_MOUSEWHEEL: {
                        int delta = GET_WHEEL_DELTA_WPARAM(wParam);

                        if (delta < 0) {
                                _cursor.wheel++;
                        } else if (delta > 0) {
                                _cursor.wheel--;
                        }
                        HandleMouseEvents();
                        return 0;
                }

                case WM_SETFOCUS:
                        video_driver->has_focus = true;
                        SetCompositionPos(hwnd);
                        break;

                case WM_KILLFOCUS:
                        video_driver->has_focus = false;
                        break;

                case WM_ACTIVATE: {
                        /* Don't do anything if we are closing openttd */
                        if (_exit_game) break;

                        bool active = (LOWORD(wParam) != WA_INACTIVE);
                        bool minimized = (HIWORD(wParam) != 0);
                        if (video_driver->fullscreen) {
                                if (active && minimized) {
                                        /* Restore the game window */
                                        Dimension d = _bck_resolution; // Save current non-fullscreen window size as it will be overwritten by ShowWindow.
                                        ShowWindow(hwnd, SW_RESTORE);
                                        _bck_resolution = d;
                                        video_driver->MakeWindow(true);
                                } else if (!active && !minimized) {
                                        /* Minimise the window and restore desktop */
                                        ShowWindow(hwnd, SW_MINIMIZE);
                                        ChangeDisplaySettings(nullptr, 0);
                                }
                        }
                        break;
                }
        }

        return DefWindowProc(hwnd, msg, wParam, lParam);
}

static void RegisterWndClass()
{
        static bool registered = false;

        if (registered) return;

        HINSTANCE hinst = GetModuleHandle(nullptr);
        WNDCLASS wnd = {
                CS_OWNDC,
                WndProcGdi,
                0,
                0,
                hinst,
                LoadIcon(hinst, MAKEINTRESOURCE(100)),
                LoadCursor(nullptr, IDC_ARROW),
                0,
                0,
                L"OTTD"
        };

        registered = true;
        if (!RegisterClass(&wnd)) UserError("RegisterClass failed");
}

static const Dimension default_resolutions[] = {
        {  640,  480 },
        {  800,  600 },
        { 1024,  768 },
        { 1152,  864 },
        { 1280,  800 },
        { 1280,  960 },
        { 1280, 1024 },
        { 1400, 1050 },
        { 1600, 1200 },
        { 1680, 1050 },
        { 1920, 1200 }
};

static void FindResolutions(uint8_t bpp)
{
        _resolutions.clear();

        DEVMODE dm;
        for (uint i = 0; EnumDisplaySettings(nullptr, i, &dm) != 0; i++) {
                if (dm.dmBitsPerPel != bpp || dm.dmPelsWidth < 640 || dm.dmPelsHeight < 480) continue;
                if (std::find(_resolutions.begin(), _resolutions.end(), Dimension(dm.dmPelsWidth, dm.dmPelsHeight)) != _resolutions.end()) continue;
                _resolutions.emplace_back(dm.dmPelsWidth, dm.dmPelsHeight);
        }

        /* We have found no resolutions, show the default list */
        if (_resolutions.empty()) {
                _resolutions.assign(std::begin(default_resolutions), std::end(default_resolutions));
        }

        SortResolutions();
}

void VideoDriver_Win32Base::Initialize()
{
        this->UpdateAutoResolution();

        RegisterWndClass();
        FindResolutions(this->GetFullscreenBpp());

        /* fullscreen uses those */
        this->width  = this->width_org  = _cur_resolution.width;
        this->height = this->height_org = _cur_resolution.height;

        Debug(driver, 2, "Resolution for display: {}x{}", _cur_resolution.width, _cur_resolution.height);
}

void VideoDriver_Win32Base::Stop()
{
        DestroyWindow(this->main_wnd);

        if (this->fullscreen) ChangeDisplaySettings(nullptr, 0);
        MyShowCursor(true);
}
void VideoDriver_Win32Base::MakeDirty(int left, int top, int width, int height)
{
        Rect r = {left, top, left + width, top + height};
        this->dirty_rect = BoundingRect(this->dirty_rect, r);
}

void VideoDriver_Win32Base::CheckPaletteAnim()
{
        if (!CopyPalette(_local_palette)) return;
        this->MakeDirty(0, 0, _screen.width, _screen.height);
}

void VideoDriver_Win32Base::InputLoop()
{
        bool old_ctrl_pressed = _ctrl_pressed;

        _ctrl_pressed = this->has_focus && GetAsyncKeyState(VK_CONTROL) < 0;
        _shift_pressed = this->has_focus && GetAsyncKeyState(VK_SHIFT) < 0;

        /* Speedup when pressing tab, except when using ALT+TAB
         * to switch to another application. */
        this->fast_forward_key_pressed = this->has_focus && GetAsyncKeyState(VK_TAB) < 0 && GetAsyncKeyState(VK_MENU) >= 0;

        /* Determine which directional keys are down. */
        if (this->has_focus) {
                _dirkeys =
                        (GetAsyncKeyState(VK_LEFT) < 0 ? 1 : 0) +
                        (GetAsyncKeyState(VK_UP) < 0 ? 2 : 0) +
                        (GetAsyncKeyState(VK_RIGHT) < 0 ? 4 : 0) +
                        (GetAsyncKeyState(VK_DOWN) < 0 ? 8 : 0);
        } else {
                _dirkeys = 0;
        }

        if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();
}

bool VideoDriver_Win32Base::PollEvent()
{
        MSG mesg;

        if (!PeekMessage(&mesg, nullptr, 0, 0, PM_REMOVE)) return false;

        /* Convert key messages to char messages if we want text input. */
        if (EditBoxInGlobalFocus()) TranslateMessage(&mesg);
        DispatchMessage(&mesg);

        return true;
}

void VideoDriver_Win32Base::MainLoop()
{
        this->StartGameThread();

        for (;;) {
                if (_exit_game) break;

                this->Tick();
                this->SleepTillNextTick();
        }

        this->StopGameThread();
}

void VideoDriver_Win32Base::ClientSizeChanged(int w, int h, bool force)
{
        /* Allocate backing store of the new size. */
        if (this->AllocateBackingStore(w, h, force)) {
                CopyPalette(_local_palette, true);

                BlitterFactory::GetCurrentBlitter()->PostResize();

                GameSizeChanged();
        }
}

bool VideoDriver_Win32Base::ChangeResolution(int w, int h)
{
        if (_window_maximize) ShowWindow(this->main_wnd, SW_SHOWNORMAL);

        this->width = this->width_org = w;
        this->height = this->height_org = h;

        return this->MakeWindow(_fullscreen); // _wnd.fullscreen screws up ingame resolution switching
}

bool VideoDriver_Win32Base::ToggleFullscreen(bool full_screen)
{
        bool res = this->MakeWindow(full_screen);

        InvalidateWindowClassesData(WC_GAME_OPTIONS, 3);
        return res;
}

void VideoDriver_Win32Base::EditBoxLostFocus()
{
        CancelIMEComposition(this->main_wnd);
        SetCompositionPos(this->main_wnd);
        SetCandidatePos(this->main_wnd);
}

static BOOL CALLBACK MonitorEnumProc(HMONITOR hMonitor, HDC, LPRECT, LPARAM data)
{
        auto &list = *reinterpret_cast<std::vector<int>*>(data);

        MONITORINFOEX monitorInfo = {};
        monitorInfo.cbSize = sizeof(MONITORINFOEX);
        GetMonitorInfo(hMonitor, &monitorInfo);

        DEVMODE devMode = {};
        devMode.dmSize = sizeof(DEVMODE);
        devMode.dmDriverExtra = 0;
        EnumDisplaySettings(monitorInfo.szDevice, ENUM_CURRENT_SETTINGS, &devMode);

        if (devMode.dmDisplayFrequency != 0) list.push_back(devMode.dmDisplayFrequency);
        return true;
}

std::vector<int> VideoDriver_Win32Base::GetListOfMonitorRefreshRates()
{
        std::vector<int> rates = {};
        EnumDisplayMonitors(nullptr, nullptr, MonitorEnumProc, reinterpret_cast<LPARAM>(&rates));
        return rates;
}

Dimension VideoDriver_Win32Base::GetScreenSize() const
{
        return { static_cast<uint>(GetSystemMetrics(SM_CXSCREEN)), static_cast<uint>(GetSystemMetrics(SM_CYSCREEN)) };
}

float VideoDriver_Win32Base::GetDPIScale()
{
        typedef UINT (WINAPI *PFNGETDPIFORWINDOW)(HWND hwnd);
        typedef UINT (WINAPI *PFNGETDPIFORSYSTEM)(VOID);
        typedef HRESULT (WINAPI *PFNGETDPIFORMONITOR)(HMONITOR hMonitor, int dpiType, UINT *dpiX, UINT *dpiY);

        static PFNGETDPIFORWINDOW _GetDpiForWindow = nullptr;
        static PFNGETDPIFORSYSTEM _GetDpiForSystem = nullptr;
        static PFNGETDPIFORMONITOR _GetDpiForMonitor = nullptr;

        static bool init_done = false;
        if (!init_done) {
                init_done = true;
                static LibraryLoader _user32("user32.dll");
                static LibraryLoader _shcore("shcore.dll");
                _GetDpiForWindow = _user32.GetFunction("GetDpiForWindow");
                _GetDpiForSystem = _user32.GetFunction("GetDpiForSystem");
                _GetDpiForMonitor = _shcore.GetFunction("GetDpiForMonitor");
        }

        UINT cur_dpi = 0;

        if (cur_dpi == 0 && _GetDpiForWindow != nullptr && this->main_wnd != nullptr) {
                /* Per window DPI is supported since Windows 10 Ver 1607. */
                cur_dpi = _GetDpiForWindow(this->main_wnd);
        }
        if (cur_dpi == 0 && _GetDpiForMonitor != nullptr && this->main_wnd != nullptr) {
                /* Per monitor is supported since Windows 8.1. */
                UINT dpiX, dpiY;
                if (SUCCEEDED(_GetDpiForMonitor(MonitorFromWindow(this->main_wnd, MONITOR_DEFAULTTOPRIMARY), 0 /* MDT_EFFECTIVE_DPI */, &dpiX, &dpiY))) {
                        cur_dpi = dpiX; // X and Y are always identical.
                }
        }
        if (cur_dpi == 0 && _GetDpiForSystem != nullptr) {
                /* Fall back to system DPI. */
                cur_dpi = _GetDpiForSystem();
        }

        return cur_dpi > 0 ? cur_dpi / 96.0f : 1.0f; // Default Windows DPI value is 96.
}

bool VideoDriver_Win32Base::LockVideoBuffer()
{
        if (this->buffer_locked) return false;
        this->buffer_locked = true;

        _screen.dst_ptr = this->GetVideoPointer();
        assert(_screen.dst_ptr != nullptr);

        return true;
}

void VideoDriver_Win32Base::UnlockVideoBuffer()
{
        assert(_screen.dst_ptr != nullptr);
        if (_screen.dst_ptr != nullptr) {
                /* Hand video buffer back to the drawing backend. */
                this->ReleaseVideoPointer();
                _screen.dst_ptr = nullptr;
        }

        this->buffer_locked = false;
}


static FVideoDriver_Win32GDI iFVideoDriver_Win32GDI;

const char *VideoDriver_Win32GDI::Start(const StringList &param)
{
        if (BlitterFactory::GetCurrentBlitter()->GetScreenDepth() == 0) return "Only real blitters supported";

        this->Initialize();

        this->MakePalette();
        this->AllocateBackingStore(_cur_resolution.width, _cur_resolution.height);
        this->MakeWindow(_fullscreen);

        MarkWholeScreenDirty();

        this->is_game_threaded = !GetDriverParamBool(param, "no_threads") && !GetDriverParamBool(param, "no_thread");

        return nullptr;
}

void VideoDriver_Win32GDI::Stop()
{
        DeleteObject(this->gdi_palette);
        DeleteObject(this->dib_sect);

        this->VideoDriver_Win32Base::Stop();
}

bool VideoDriver_Win32GDI::AllocateBackingStore(int w, int h, bool force)
{
        uint bpp = BlitterFactory::GetCurrentBlitter()->GetScreenDepth();

        w = std::max(w, 64);
        h = std::max(h, 64);

        if (!force && w == _screen.width && h == _screen.height) return false;

        BITMAPINFO *bi = (BITMAPINFO *)new char[sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * 256]();
        bi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);

        bi->bmiHeader.biWidth = this->width = w;
        bi->bmiHeader.biHeight = -(this->height = h);

        bi->bmiHeader.biPlanes = 1;
        bi->bmiHeader.biBitCount = bpp;
        bi->bmiHeader.biCompression = BI_RGB;

        if (this->dib_sect) DeleteObject(this->dib_sect);

        HDC dc = GetDC(0);
        this->dib_sect = CreateDIBSection(dc, bi, DIB_RGB_COLORS, (VOID **)&this->buffer_bits, nullptr, 0);
        if (this->dib_sect == nullptr) {
                delete[] bi;
                UserError("CreateDIBSection failed");
        }
        ReleaseDC(0, dc);

        _screen.width = w;
        _screen.pitch = (bpp == 8) ? Align(w, 4) : w;
        _screen.height = h;
        _screen.dst_ptr = this->GetVideoPointer();

        delete[] bi;
        return true;
}

bool VideoDriver_Win32GDI::AfterBlitterChange()
{
        assert(BlitterFactory::GetCurrentBlitter()->GetScreenDepth() != 0);
        return this->AllocateBackingStore(_screen.width, _screen.height, true) && this->MakeWindow(_fullscreen, false);
}

void VideoDriver_Win32GDI::MakePalette()
{
        CopyPalette(_local_palette, true);

        LOGPALETTE *pal = (LOGPALETTE *)new char[sizeof(LOGPALETTE) + (256 - 1) * sizeof(PALETTEENTRY)]();

        pal->palVersion = 0x300;
        pal->palNumEntries = 256;

        for (uint i = 0; i != 256; i++) {
                pal->palPalEntry[i].peRed   = _local_palette.palette[i].r;
                pal->palPalEntry[i].peGreen = _local_palette.palette[i].g;
                pal->palPalEntry[i].peBlue  = _local_palette.palette[i].b;
                pal->palPalEntry[i].peFlags = 0;

        }
        this->gdi_palette = CreatePalette(pal);
        delete[] pal;
        if (this->gdi_palette == nullptr) UserError("CreatePalette failed!\n");
}

void VideoDriver_Win32GDI::UpdatePalette(HDC dc, uint start, uint count)
{
        RGBQUAD rgb[256];

        for (uint i = 0; i != count; i++) {
                rgb[i].rgbRed   = _local_palette.palette[start + i].r;
                rgb[i].rgbGreen = _local_palette.palette[start + i].g;
                rgb[i].rgbBlue  = _local_palette.palette[start + i].b;
                rgb[i].rgbReserved = 0;
        }

        SetDIBColorTable(dc, start, count, rgb);
}

void VideoDriver_Win32GDI::PaletteChanged(HWND hWnd)
{
        HDC hDC = GetWindowDC(hWnd);
        HPALETTE hOldPalette = SelectPalette(hDC, this->gdi_palette, FALSE);
        UINT nChanged = RealizePalette(hDC);

        SelectPalette(hDC, hOldPalette, TRUE);
        ReleaseDC(hWnd, hDC);
        if (nChanged != 0) this->MakeDirty(0, 0, _screen.width, _screen.height);
}

void VideoDriver_Win32GDI::Paint()
{
        PerformanceMeasurer framerate(PFE_VIDEO);

        if (IsEmptyRect(this->dirty_rect)) return;

        HDC dc = GetDC(this->main_wnd);
        HDC dc2 = CreateCompatibleDC(dc);

        HBITMAP old_bmp = (HBITMAP)SelectObject(dc2, this->dib_sect);
        HPALETTE old_palette = SelectPalette(dc, this->gdi_palette, FALSE);

        if (_local_palette.count_dirty != 0) {
                Blitter *blitter = BlitterFactory::GetCurrentBlitter();

                switch (blitter->UsePaletteAnimation()) {
                        case Blitter::PALETTE_ANIMATION_VIDEO_BACKEND:
                                this->UpdatePalette(dc2, _local_palette.first_dirty, _local_palette.count_dirty);
                                break;

                        case Blitter::PALETTE_ANIMATION_BLITTER: {
                                blitter->PaletteAnimate(_local_palette);
                                break;
                        }

                        case Blitter::PALETTE_ANIMATION_NONE:
                                break;

                        default:
                                NOT_REACHED();
                }
                _local_palette.count_dirty = 0;
        }

        BitBlt(dc, 0, 0, this->width, this->height, dc2, 0, 0, SRCCOPY);
        SelectPalette(dc, old_palette, TRUE);
        SelectObject(dc2, old_bmp);
        DeleteDC(dc2);

        ReleaseDC(this->main_wnd, dc);

        this->dirty_rect = {};
}

#ifdef _DEBUG
/* Keep this function here..
 * It allows you to redraw the screen from within the MSVC debugger */
/* static */ int VideoDriver_Win32GDI::RedrawScreenDebug()
{
        static int _fooctr;

        VideoDriver_Win32GDI *drv = static_cast<VideoDriver_Win32GDI *>(VideoDriver::GetInstance());

        _screen.dst_ptr = drv->GetVideoPointer();
        UpdateWindows();

        drv->Paint();
        GdiFlush();

        return _fooctr++;
}
#endif

#ifdef WITH_OPENGL

#include <GL/gl.h>
#include "../3rdparty/opengl/glext.h"
#include "../3rdparty/opengl/wglext.h"
#include "opengl.h"

#ifndef PFD_SUPPORT_COMPOSITION
#       define PFD_SUPPORT_COMPOSITION 0x00008000
#endif

static PFNWGLCREATECONTEXTATTRIBSARBPROC _wglCreateContextAttribsARB = nullptr;
static PFNWGLSWAPINTERVALEXTPROC _wglSwapIntervalEXT = nullptr;
static bool _hasWGLARBCreateContextProfile = false; ///< Is WGL_ARB_create_context_profile supported?

/** Platform-specific callback to get an OpenGL function pointer. */
static OGLProc GetOGLProcAddressCallback(const char *proc)
{
        OGLProc ret = reinterpret_cast<OGLProc>(wglGetProcAddress(proc));
        if (ret == nullptr) {
                /* Non-extension GL function? Try normal loading. */
                ret = reinterpret_cast<OGLProc>(GetProcAddress(GetModuleHandle(L"opengl32"), proc));
        }
        return ret;
}

/**
 * Set the pixel format of a window-
 * @param dc Device context to set the pixel format of.
 * @return nullptr on success, error message otherwise.
 */
static const char *SelectPixelFormat(HDC dc)
{
        PIXELFORMATDESCRIPTOR pfd = {
                sizeof(PIXELFORMATDESCRIPTOR), // Size of this struct.
                1,                             // Version of this struct.
                PFD_DRAW_TO_WINDOW |           // Require window support.
                PFD_SUPPORT_OPENGL |           // Require OpenGL support.
                PFD_DOUBLEBUFFER   |           // Use double buffering.
                PFD_DEPTH_DONTCARE,
                PFD_TYPE_RGBA,                 // Request RGBA format.
                24,                            // 24 bpp (excluding alpha).
                0, 0, 0, 0, 0, 0, 0, 0,        // Colour bits and shift ignored.
                0, 0, 0, 0, 0,                 // No accumulation buffer.
                0, 0,                          // No depth/stencil buffer.
                0,                             // No aux buffers.
                PFD_MAIN_PLANE,                // Main layer.
                0, 0, 0, 0                     // Ignored/reserved.
        };

        pfd.dwFlags |= PFD_SUPPORT_COMPOSITION; // Make OpenTTD compatible with Aero.

        /* Choose a suitable pixel format. */
        int format = ChoosePixelFormat(dc, &pfd);
        if (format == 0) return "No suitable pixel format found";
        if (!SetPixelFormat(dc, format, &pfd)) return "Can't set pixel format";

        return nullptr;
}

/** Bind all WGL extension functions we need. */
static void LoadWGLExtensions()
{
        /* Querying the supported WGL extensions and loading the matching
         * functions requires a valid context, even for the extensions
         * regarding context creation. To get around this, we create
         * a dummy window with a dummy context. The extension functions
         * remain valid even after this context is destroyed. */
        HWND wnd = CreateWindow(_T("STATIC"), _T("dummy"), WS_OVERLAPPEDWINDOW, 0, 0, 0, 0, nullptr, nullptr, GetModuleHandle(nullptr), nullptr);
        HDC dc = GetDC(wnd);

        /* Set pixel format of the window. */
        if (SelectPixelFormat(dc) == nullptr) {
                /* Create rendering context. */
                HGLRC rc = wglCreateContext(dc);
                if (rc != nullptr) {
                        wglMakeCurrent(dc, rc);

#ifdef __MINGW32__
                        /* GCC doesn't understand the expected usage of wglGetProcAddress(). */
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-function-type"
#endif /* __MINGW32__ */

                        /* Get list of WGL extensions. */
                        PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB = (PFNWGLGETEXTENSIONSSTRINGARBPROC)wglGetProcAddress("wglGetExtensionsStringARB");
                        if (wglGetExtensionsStringARB != nullptr) {
                                const char *wgl_exts = wglGetExtensionsStringARB(dc);
                                /* Bind supported functions. */
                                if (FindStringInExtensionList(wgl_exts, "WGL_ARB_create_context") != nullptr) {
                                        _wglCreateContextAttribsARB = (PFNWGLCREATECONTEXTATTRIBSARBPROC)wglGetProcAddress("wglCreateContextAttribsARB");
                                }
                                _hasWGLARBCreateContextProfile = FindStringInExtensionList(wgl_exts, "WGL_ARB_create_context_profile") != nullptr;
                                if (FindStringInExtensionList(wgl_exts, "WGL_EXT_swap_control") != nullptr) {
                                        _wglSwapIntervalEXT = (PFNWGLSWAPINTERVALEXTPROC)wglGetProcAddress("wglSwapIntervalEXT");
                                }
                        }

#ifdef __MINGW32__
#pragma GCC diagnostic pop
#endif
                        wglMakeCurrent(nullptr, nullptr);
                        wglDeleteContext(rc);
                }
        }

        ReleaseDC(wnd, dc);
        DestroyWindow(wnd);
}

static FVideoDriver_Win32OpenGL iFVideoDriver_Win32OpenGL;

const char *VideoDriver_Win32OpenGL::Start(const StringList &param)
{
        if (BlitterFactory::GetCurrentBlitter()->GetScreenDepth() == 0) return "Only real blitters supported";

        Dimension old_res = _cur_resolution; // Save current screen resolution in case of errors, as MakeWindow invalidates it.

        LoadWGLExtensions();

        this->Initialize();
        this->MakeWindow(_fullscreen);

        /* Create and initialize OpenGL context. */
        const char *err = this->AllocateContext();
        if (err != nullptr) {
                this->Stop();
                _cur_resolution = old_res;
                return err;
        }

        this->driver_info = GetName();
        this->driver_info += " (";
        this->driver_info += OpenGLBackend::Get()->GetDriverName();
        this->driver_info += ")";

        this->ClientSizeChanged(this->width, this->height, true);
        /* We should have a valid screen buffer now. If not, something went wrong and we should abort. */
        if (_screen.dst_ptr == nullptr) {
                this->Stop();
                _cur_resolution = old_res;
                return "Can't get pointer to screen buffer";
        }
        /* Main loop expects to start with the buffer unmapped. */
        this->ReleaseVideoPointer();

        MarkWholeScreenDirty();

        this->is_game_threaded = !GetDriverParamBool(param, "no_threads") && !GetDriverParamBool(param, "no_thread");

        return nullptr;
}

void VideoDriver_Win32OpenGL::Stop()
{
        this->DestroyContext();
        this->VideoDriver_Win32Base::Stop();
}

void VideoDriver_Win32OpenGL::DestroyContext()
{
        OpenGLBackend::Destroy();

        wglMakeCurrent(nullptr, nullptr);
        if (this->gl_rc != nullptr) {
                wglDeleteContext(this->gl_rc);
                this->gl_rc = nullptr;
        }
        if (this->dc != nullptr) {
                ReleaseDC(this->main_wnd, this->dc);
                this->dc = nullptr;
        }
}

void VideoDriver_Win32OpenGL::ToggleVsync(bool vsync)
{
        if (_wglSwapIntervalEXT != nullptr) {
                _wglSwapIntervalEXT(vsync);
        } else if (vsync) {
                Debug(driver, 0, "OpenGL: Vsync requested, but not supported by driver");
        }
}

const char *VideoDriver_Win32OpenGL::AllocateContext()
{
        this->dc = GetDC(this->main_wnd);

        const char *err = SelectPixelFormat(this->dc);
        if (err != nullptr) return err;

        HGLRC rc = nullptr;

        /* Create OpenGL device context. Try to get an 3.2+ context if possible. */
        if (_wglCreateContextAttribsARB != nullptr) {
                /* Try for OpenGL 4.5 first. */
                int attribs[] = {
                        WGL_CONTEXT_MAJOR_VERSION_ARB, 4,
                        WGL_CONTEXT_MINOR_VERSION_ARB, 5,
                        WGL_CONTEXT_FLAGS_ARB, _debug_driver_level >= 8 ? WGL_CONTEXT_DEBUG_BIT_ARB : 0,
                        _hasWGLARBCreateContextProfile ? WGL_CONTEXT_PROFILE_MASK_ARB : 0, WGL_CONTEXT_CORE_PROFILE_BIT_ARB, // Terminate list if WGL_ARB_create_context_profile isn't supported.
                        0
                };
                rc = _wglCreateContextAttribsARB(this->dc, nullptr, attribs);

                if (rc == nullptr) {
                        /* Try again for a 3.2 context. */
                        attribs[1] = 3;
                        attribs[3] = 2;
                        rc = _wglCreateContextAttribsARB(this->dc, nullptr, attribs);
                }
        }

        if (rc == nullptr) {
                /* Old OpenGL or old driver, let's hope for the best. */
                rc = wglCreateContext(this->dc);
                if (rc == nullptr) return "Can't create OpenGL context";
        }
        if (!wglMakeCurrent(this->dc, rc)) return "Can't active GL context";

        this->ToggleVsync(_video_vsync);

        this->gl_rc = rc;
        return OpenGLBackend::Create(&GetOGLProcAddressCallback, this->GetScreenSize());
}

bool VideoDriver_Win32OpenGL::ToggleFullscreen(bool full_screen)
{
        if (_screen.dst_ptr != nullptr) this->ReleaseVideoPointer();
        this->DestroyContext();
        bool res = this->VideoDriver_Win32Base::ToggleFullscreen(full_screen);
        res &= this->AllocateContext() == nullptr;
        this->ClientSizeChanged(this->width, this->height, true);
        return res;
}

bool VideoDriver_Win32OpenGL::AfterBlitterChange()
{
        assert(BlitterFactory::GetCurrentBlitter()->GetScreenDepth() != 0);
        this->ClientSizeChanged(this->width, this->height, true);
        return true;
}

void VideoDriver_Win32OpenGL::PopulateSystemSprites()
{
        OpenGLBackend::Get()->PopulateCursorCache();
}

void VideoDriver_Win32OpenGL::ClearSystemSprites()
{
        OpenGLBackend::Get()->ClearCursorCache();
}

bool VideoDriver_Win32OpenGL::AllocateBackingStore(int w, int h, bool force)
{
        if (!force && w == _screen.width && h == _screen.height) return false;

        this->width = w = std::max(w, 64);
        this->height = h = std::max(h, 64);

        if (this->gl_rc == nullptr) return false;

        if (_screen.dst_ptr != nullptr) this->ReleaseVideoPointer();

        this->dirty_rect = {};
        bool res = OpenGLBackend::Get()->Resize(w, h, force);
        SwapBuffers(this->dc);
        _screen.dst_ptr = this->GetVideoPointer();

        return res;
}

void *VideoDriver_Win32OpenGL::GetVideoPointer()
{
        if (BlitterFactory::GetCurrentBlitter()->NeedsAnimationBuffer()) {
                this->anim_buffer = OpenGLBackend::Get()->GetAnimBuffer();
        }
        return OpenGLBackend::Get()->GetVideoBuffer();
}

void VideoDriver_Win32OpenGL::ReleaseVideoPointer()
{
        if (this->anim_buffer != nullptr) OpenGLBackend::Get()->ReleaseAnimBuffer(this->dirty_rect);
        OpenGLBackend::Get()->ReleaseVideoBuffer(this->dirty_rect);
        this->dirty_rect = {};
        _screen.dst_ptr = nullptr;
        this->anim_buffer = nullptr;
}

void VideoDriver_Win32OpenGL::Paint()
{
        PerformanceMeasurer framerate(PFE_VIDEO);

        if (_local_palette.count_dirty != 0) {
                Blitter *blitter = BlitterFactory::GetCurrentBlitter();

                /* Always push a changed palette to OpenGL. */
                OpenGLBackend::Get()->UpdatePalette(_local_palette.palette, _local_palette.first_dirty, _local_palette.count_dirty);
                if (blitter->UsePaletteAnimation() == Blitter::PALETTE_ANIMATION_BLITTER) {
                        blitter->PaletteAnimate(_local_palette);
                }

                _local_palette.count_dirty = 0;
        }

        OpenGLBackend::Get()->Paint();
        OpenGLBackend::Get()->DrawMouseCursor();

        SwapBuffers(this->dc);
}

#endif /* WITH_OPENGL */