Feature: Variable GUI scale.

GUI scale is now variable from 100% to 500%, and no longer restricted to
powers-of-2.

src/fontcache/freetypefontcache.cpp

@@ -65,18 +65,19 @@ void FreeTypeFontCache::SetFontSize(FontSize fs, FT_Face face, int pixels)
 {
 	if (pixels == 0) {
 		/* Try to determine a good height based on the minimal height recommended by the font. */
-		int scaled_height = ScaleFontTrad(this->GetDefaultFontHeight(this->fs));
+		int scaled_height = ScaleGUITrad(this->GetDefaultFontHeight(this->fs));
 		pixels = scaled_height;
 
 		TT_Header *head = (TT_Header *)FT_Get_Sfnt_Table(this->face, ft_sfnt_head);
 		if (head != nullptr) {
 			/* Font height is minimum height plus the difference between the default
 			 * height for this font size and the small size. */
-			int diff = scaled_height - ScaleFontTrad(this->GetDefaultFontHeight(FS_SMALL));
+			int diff = scaled_height - ScaleGUITrad(this->GetDefaultFontHeight(FS_SMALL));
-			pixels = Clamp(std::min<uint>(head->Lowest_Rec_PPEM, MAX_FONT_MIN_REC_SIZE) + diff, scaled_height, MAX_FONT_SIZE);
+			/* Clamp() is not used as scaled_height could be greater than MAX_FONT_SIZE, which is not permitted in Clamp(). */
+			pixels = std::min(std::max(std::min<int>(head->Lowest_Rec_PPEM, MAX_FONT_MIN_REC_SIZE) + diff, scaled_height), MAX_FONT_SIZE);
 		}
 	} else {
-		pixels = ScaleFontTrad(pixels);
+		pixels = ScaleGUITrad(pixels);
 	}
 	this->used_size = pixels;
 

src/fontcache/spritefontcache.cpp

@@ -28,7 +28,8 @@ static const int ASCII_LETTERSTART = 32; ///< First printable ASCII letter.
 SpriteFontCache::SpriteFontCache(FontSize fs) : FontCache(fs), glyph_to_spriteid_map(nullptr)
 {
 	this->InitializeUnicodeGlyphMap();
-	this->height = ScaleFontTrad(this->GetDefaultFontHeight(this->fs));
+	this->height = ScaleGUITrad(this->GetDefaultFontHeight(this->fs));
+	this->ascender = (this->height - ScaleSpriteTrad(this->GetDefaultFontHeight(this->fs))) / 2;
 }
 
 /**
@@ -104,7 +105,8 @@ void SpriteFontCache::ClearGlyphToSpriteMap()
 void SpriteFontCache::ClearFontCache()
 {
 	Layouter::ResetFontCache(this->fs);
-	this->height = ScaleFontTrad(this->GetDefaultFontHeight(this->fs));
+	this->height = ScaleGUITrad(this->GetDefaultFontHeight(this->fs));
+	this->ascender = (this->height - ScaleSpriteTrad(this->GetDefaultFontHeight(this->fs))) / 2;
 }
 
 const Sprite *SpriteFontCache::GetGlyph(GlyphID key)

src/gfx.cpp

@@ -61,12 +61,9 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode,
 
 static ReusableBuffer<uint8> _cursor_backup;
 
-ZoomLevel _gui_zoom; ///< GUI Zoom level
+ZoomLevel _gui_zoom = ZOOM_LVL_OUT_4X;     ///< GUI Zoom level
-ZoomLevel _font_zoom; ///< Font Zoom level
+int _gui_scale      = MIN_INTERFACE_SCALE; ///< GUI scale, 100 is 100%.
-
+int _gui_scale_cfg;                        ///< GUI scale in config.
-int8 _gui_zoom_cfg;  ///< GUI zoom level in config.
-int8 _font_zoom_cfg; ///< Font zoom level in config.
-
 
 /**
  * The rect for repaint.
@@ -2028,48 +2025,52 @@ void SortResolutions()
 void UpdateGUIZoom()
 {
 	/* Determine real GUI zoom to use. */
-	if (_gui_zoom_cfg == ZOOM_LVL_CFG_AUTO) {
+	if (_gui_scale_cfg == -1) {
-		_gui_zoom = static_cast<ZoomLevel>(Clamp(VideoDriver::GetInstance()->GetSuggestedUIZoom(), _settings_client.gui.zoom_min, _settings_client.gui.zoom_max));
+		_gui_scale = VideoDriver::GetInstance()->GetSuggestedUIScale();
 	} else {
-		/* Ensure the gui_zoom is clamped between min/max. Change the
+		_gui_scale = Clamp(_gui_scale_cfg, MIN_INTERFACE_SCALE, MAX_INTERFACE_SCALE);
-		 * _gui_zoom_cfg if it isn't, as this is used to visually show the
-		 * selection in the Game Options. */
-		_gui_zoom_cfg = Clamp(_gui_zoom_cfg, _settings_client.gui.zoom_min, _settings_client.gui.zoom_max);
-		_gui_zoom = static_cast<ZoomLevel>(_gui_zoom_cfg);
 	}
 
-	/* Determine real font zoom to use. */
+	int8 new_zoom = ScaleGUITrad(1) <= 1 ? ZOOM_LVL_OUT_4X : ScaleGUITrad(1) >= 4 ? ZOOM_LVL_MIN : ZOOM_LVL_OUT_2X;
-	if (_font_zoom_cfg == ZOOM_LVL_CFG_AUTO) {
+	/* Ensure the gui_zoom is clamped between min/max. */
-		_font_zoom = static_cast<ZoomLevel>(VideoDriver::GetInstance()->GetSuggestedUIZoom());
+	new_zoom = Clamp(new_zoom, _settings_client.gui.zoom_min, _settings_client.gui.zoom_max);
-	} else {
+	_gui_zoom = static_cast<ZoomLevel>(new_zoom);
-		_font_zoom = static_cast<ZoomLevel>(_font_zoom_cfg);
-	}
 }
 
 /**
  * Resolve GUI zoom level and adjust GUI to new zoom, if auto-suggestion is requested.
+ * @param automatic Set if the change is occuring due to OS DPI scaling being changed.
  * @returns true when the zoom level has changed, caller must call ReInitAllWindows(true)
  * after resizing the application's window/buffer.
  */
-bool AdjustGUIZoom()
+bool AdjustGUIZoom(bool automatic)
 {
-	auto old_zoom = _gui_zoom;
+	ZoomLevel old_zoom = _gui_zoom;
+	int old_scale = _gui_scale;
 	UpdateGUIZoom();
-	if (old_zoom == _gui_zoom) return false;
+	if (old_scale == _gui_scale) return false;
-	GfxClearSpriteCache();
+
-	VideoDriver::GetInstance()->ClearSystemSprites();
+	/* Reload sprites if sprite zoom level has changed. */
+	if (old_zoom != _gui_zoom) {
+		GfxClearSpriteCache();
+		VideoDriver::GetInstance()->ClearSystemSprites();
+		UpdateCursorSize();
+	}
+
 	ClearFontCache();
-	GfxClearSpriteCache();
+	LoadStringWidthTable();
 	UpdateAllVirtCoords();
 
 	/* Adjust all window sizes to match the new zoom level, so that they don't appear
 	   to move around when the application is moved to a screen with different DPI. */
 	auto zoom_shift = old_zoom - _gui_zoom;
 	for (Window *w : Window::Iterate()) {
-		w->left = AdjustByZoom(w->left, zoom_shift);
+		if (automatic) {
-		w->top = AdjustByZoom(w->top, zoom_shift);
+			w->left   = (w->left   * _gui_scale) / old_scale;
-		w->width = AdjustByZoom(w->width, zoom_shift);
+			w->top    = (w->top    * _gui_scale) / old_scale;
-		w->height = AdjustByZoom(w->height, zoom_shift);
+			w->width  = (w->width  * _gui_scale) / old_scale;
+			w->height = (w->height * _gui_scale) / old_scale;
+		}
 		if (w->viewport != nullptr) {
 			w->viewport->zoom = Clamp(ZoomLevel(w->viewport->zoom - zoom_shift), _settings_client.gui.zoom_min, _settings_client.gui.zoom_max);
 		}

src/gfx_func.h

@@ -79,8 +79,7 @@ void ChangeGameSpeed(bool enable_fast_forward);
 void DrawMouseCursor();
 void ScreenSizeChanged();
 void GameSizeChanged();
-void UpdateGUIZoom();
+bool AdjustGUIZoom(bool automatic);
-bool AdjustGUIZoom();
 void UndrawMouseCursor();
 
 /** Size of the buffer used for drawing strings. */

src/gfx_layout.cpp

@@ -339,12 +339,12 @@ FallbackParagraphLayout::FallbackVisualRun::FallbackVisualRun(Font *font, const
 	/* Positions contains the location of the begin of each of the glyphs, and the end of the last one. */
 	this->positions = MallocT<float>(this->glyph_count * 2 + 2);
 	this->positions[0] = x;
-	this->positions[1] = 0;
+	this->positions[1] = font->fc->GetAscender();
 
 	for (int i = 0; i < this->glyph_count; i++) {
 		this->glyphs[i] = font->fc->MapCharToGlyph(chars[i]);
 		this->positions[2 * i + 2] = this->positions[2 * i] + font->fc->GetGlyphWidth(this->glyphs[i]);
-		this->positions[2 * i + 3] = 0;
+		this->positions[2 * i + 3] = font->fc->GetAscender();
 		this->glyph_to_char[i] = i;
 	}
 }

src/graph_gui.cpp

@@ -900,7 +900,7 @@ struct PaymentRatesGraphWindow : BaseGraphWindow {
 	void OnInit() override
 	{
 		/* Width of the legend blob. */
-		this->legend_width = (FONT_HEIGHT_SMALL - ScaleFontTrad(1)) * 8 / 5;
+		this->legend_width = (FONT_HEIGHT_SMALL - ScaleGUITrad(1)) * 8 / 5;
 	}
 
 	void UpdateExcludedData()

src/lang/english.txt

@@ -1008,24 +1008,19 @@ STR_GAME_OPTIONS_VIDEO_VSYNC_TOOLTIP                            :{BLACK}Check th
 
 STR_GAME_OPTIONS_VIDEO_DRIVER_INFO                              :{BLACK}Current driver: {RAW_STRING}
 
-STR_GAME_OPTIONS_GUI_ZOOM_FRAME                                 :{BLACK}Interface size
+STR_GAME_OPTIONS_GUI_SCALE_FRAME                                :{BLACK}Interface size
-STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_TOOLTIP                      :{BLACK}Select the interface element size to use
+STR_GAME_OPTIONS_GUI_SCALE_TOOLTIP                              :{BLACK}Drag slider to set interface size. Hold Ctrl for continuous adjustment
+STR_GAME_OPTIONS_GUI_SCALE_AUTO                                 :{BLACK}Auto-detect size
+STR_GAME_OPTIONS_GUI_SCALE_AUTO_TOOLTIP                         :{BLACK}Check this box to detect interface size automatically
 
 STR_GAME_OPTIONS_GUI_SCALE_BEVELS                               :{BLACK}Scale bevels
 STR_GAME_OPTIONS_GUI_SCALE_BEVELS_TOOLTIP                       :{BLACK}Check this box to scale bevels by interface size
 
-STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_AUTO                         :(auto-detect)
+STR_GAME_OPTIONS_GUI_SCALE_1X                                   :1x
-STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_NORMAL                       :Normal
+STR_GAME_OPTIONS_GUI_SCALE_2X                                   :2x
-STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_2X_ZOOM                      :Double size
+STR_GAME_OPTIONS_GUI_SCALE_3X                                   :3x
-STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_4X_ZOOM                      :Quad size
+STR_GAME_OPTIONS_GUI_SCALE_4X                                   :4x
-
+STR_GAME_OPTIONS_GUI_SCALE_5X                                   :5x
-STR_GAME_OPTIONS_FONT_ZOOM                                      :{BLACK}Font size
-STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_TOOLTIP                     :{BLACK}Select the interface font size to use
-
-STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_AUTO                        :(auto-detect)
-STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_NORMAL                      :Normal
-STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_2X_ZOOM                     :Double size
-STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_4X_ZOOM                     :Quad size
 
 STR_GAME_OPTIONS_GRAPHICS                                       :{BLACK}Graphics
 

src/news_gui.cpp

@@ -1159,7 +1159,7 @@ struct MessageHistoryWindow : Window {
 			/* Months are off-by-one, so it's actually 8. Not using
 			 * month 12 because the 1 is usually less wide. */
 			SetDParam(0, ConvertYMDToDate(ORIGINAL_MAX_YEAR, 7, 30));
-			this->date_width = GetStringBoundingBox(STR_SHORT_DATE).width + ScaleFontTrad(5);
+			this->date_width = GetStringBoundingBox(STR_SHORT_DATE).width + ScaleGUITrad(5);
 
 			size->height = 4 * resize->height + WidgetDimensions::scaled.framerect.Vertical(); // At least 4 lines are visible.
 			size->width = std::max(200u, size->width); // At least 200 pixels wide.

src/openttd.cpp

@@ -756,7 +756,9 @@ int openttd_main(int argc, char *argv[])
 
 	/* Initialize the zoom level of the screen to normal */
 	_screen.zoom = ZOOM_LVL_NORMAL;
-	UpdateGUIZoom();
+
+	/* The video driver is now selected, now initialise GUI zoom */
+	AdjustGUIZoom(false);
 
 	NetworkStartUp(); // initialize network-core
 

src/os/macosx/font_osx.cpp

@@ -173,7 +173,7 @@ void CoreTextFontCache::SetFontSize(int pixels)
 {
 	if (pixels == 0) {
 		/* Try to determine a good height based on the height recommended by the font. */
-		int scaled_height = ScaleFontTrad(this->GetDefaultFontHeight(this->fs));
+		int scaled_height = ScaleGUITrad(this->GetDefaultFontHeight(this->fs));
 		pixels = scaled_height;
 
 		CFAutoRelease<CTFontRef> font(CTFontCreateWithFontDescriptor(this->font_desc.get(), 0.0f, nullptr));
@@ -197,11 +197,12 @@ void CoreTextFontCache::SetFontSize(int pixels)
 
 			/* Font height is minimum height plus the difference between the default
 			 * height for this font size and the small size. */
-			int diff = scaled_height - ScaleFontTrad(this->GetDefaultFontHeight(FS_SMALL));
+			int diff = scaled_height - ScaleGUITrad(this->GetDefaultFontHeight(FS_SMALL));
-			pixels = Clamp(std::min<int>(min_size, MAX_FONT_MIN_REC_SIZE) + diff, scaled_height, MAX_FONT_SIZE);
+			/* Clamp() is not used as scaled_height could be greater than MAX_FONT_SIZE, which is not permitted in Clamp(). */
+			pixels = std::min(std::max(std::min<int>(min_size, MAX_FONT_MIN_REC_SIZE) + diff, scaled_height), MAX_FONT_SIZE);
 		}
 	} else {
-		pixels = ScaleFontTrad(pixels);
+		pixels = ScaleGUITrad(pixels);
 	}
 	this->used_size = pixels;
 

src/os/windows/font_win32.cpp

@@ -392,7 +392,7 @@ void Win32FontCache::SetFontSize(FontSize fs, int pixels)
 {
 	if (pixels == 0) {
 		/* Try to determine a good height based on the minimal height recommended by the font. */
-		int scaled_height = ScaleFontTrad(this->GetDefaultFontHeight(this->fs));
+		int scaled_height = ScaleGUITrad(this->GetDefaultFontHeight(this->fs));
 		pixels = scaled_height;
 
 		HFONT temp = CreateFontIndirect(&this->logfont);
@@ -405,14 +405,15 @@ void Win32FontCache::SetFontSize(FontSize fs, int pixels)
 
 			/* Font height is minimum height plus the difference between the default
 			 * height for this font size and the small size. */
-			int diff = scaled_height - ScaleFontTrad(this->GetDefaultFontHeight(FS_SMALL));
+			int diff = scaled_height - ScaleGUITrad(this->GetDefaultFontHeight(FS_SMALL));
-			pixels = Clamp(std::min(otm->otmusMinimumPPEM, MAX_FONT_MIN_REC_SIZE) + diff, scaled_height, MAX_FONT_SIZE);
+			/* Clamp() is not used as scaled_height could be greater than MAX_FONT_SIZE, which is not permitted in Clamp(). */
+			pixels = std::min(std::max(std::min<int>(otm->otmusMinimumPPEM, MAX_FONT_MIN_REC_SIZE) + diff, scaled_height), MAX_FONT_SIZE);
 
 			SelectObject(dc, old);
 			DeleteObject(temp);
 		}
 	} else {
-		pixels = ScaleFontTrad(pixels);
+		pixels = ScaleGUITrad(pixels);
 	}
 	this->used_size = pixels;
 

src/settings_gui.cpp

@@ -57,22 +57,6 @@ static const StringID _autosave_dropdown[] = {
 	INVALID_STRING_ID,
 };
 
-static const StringID _gui_zoom_dropdown[] = {
-	STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_AUTO,
-	STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_NORMAL,
-	STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_2X_ZOOM,
-	STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_4X_ZOOM,
-	INVALID_STRING_ID,
-};
-
-static const StringID _font_zoom_dropdown[] = {
-	STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_AUTO,
-	STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_NORMAL,
-	STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_2X_ZOOM,
-	STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_4X_ZOOM,
-	INVALID_STRING_ID,
-};
-
 static Dimension _circle_size; ///< Dimension of the circle +/- icon. This is here as not all users are within the class of the settings window.
 
 static const void *ResolveObject(const GameSettings *settings_ptr, const IntSettingDesc *sd);
@@ -158,14 +142,36 @@ static void AddCustomRefreshRates()
 	std::copy(monitorRates.begin(), monitorRates.end(), std::inserter(_refresh_rates, _refresh_rates.end()));
 }
 
+static const std::map<int, StringID> _scale_labels = {
+	{  100, STR_GAME_OPTIONS_GUI_SCALE_1X },
+	{  125, STR_NULL },
+	{  150, STR_NULL },
+	{  175, STR_NULL },
+	{  200, STR_GAME_OPTIONS_GUI_SCALE_2X },
+	{  225, STR_NULL },
+	{  250, STR_NULL },
+	{  275, STR_NULL },
+	{  300, STR_GAME_OPTIONS_GUI_SCALE_3X },
+	{  325, STR_NULL },
+	{  350, STR_NULL },
+	{  375, STR_NULL },
+	{  400, STR_GAME_OPTIONS_GUI_SCALE_4X },
+	{  425, STR_NULL },
+	{  450, STR_NULL },
+	{  475, STR_NULL },
+	{  500, STR_GAME_OPTIONS_GUI_SCALE_5X },
+};
+
 struct GameOptionsWindow : Window {
 	GameSettings *opt;
 	bool reload;
+	int gui_scale;
 
 	GameOptionsWindow(WindowDesc *desc) : Window(desc)
 	{
 		this->opt = &GetGameSettings();
 		this->reload = false;
+		this->gui_scale = _gui_scale;
 
 		AddCustomRefreshRates();
 
@@ -264,24 +270,6 @@ struct GameOptionsWindow : Window {
 				}
 				break;
 
-			case WID_GO_GUI_ZOOM_DROPDOWN: {
-				*selected_index = _gui_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _gui_zoom + 1 : 0;
-				const StringID *items = _gui_zoom_dropdown;
-				for (int i = 0; *items != INVALID_STRING_ID; items++, i++) {
-					list.emplace_back(new DropDownListStringItem(*items, i, i != 0 && _settings_client.gui.zoom_min > ZOOM_LVL_OUT_4X - i + 1));
-				}
-				break;
-			}
-
-			case WID_GO_FONT_ZOOM_DROPDOWN: {
-				*selected_index = _font_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _font_zoom + 1 : 0;
-				const StringID *items = _font_zoom_dropdown;
-				for (int i = 0; *items != INVALID_STRING_ID; items++, i++) {
-					list.emplace_back(new DropDownListStringItem(*items, i, false));
-				}
-				break;
-			}
-
 			case WID_GO_BASE_GRF_DROPDOWN:
 				list = BuildSetDropDownList<BaseGraphics>(selected_index, (_game_mode == GM_MENU));
 				break;
@@ -304,8 +292,6 @@ struct GameOptionsWindow : Window {
 			case WID_GO_CURRENCY_DROPDOWN:     SetDParam(0, _currency_specs[this->opt->locale.currency].name); break;
 			case WID_GO_AUTOSAVE_DROPDOWN:     SetDParam(0, _autosave_dropdown[_settings_client.gui.autosave]); break;
 			case WID_GO_LANG_DROPDOWN:         SetDParamStr(0, _current_language->own_name); break;
-			case WID_GO_GUI_ZOOM_DROPDOWN:     SetDParam(0, _gui_zoom_dropdown[_gui_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _gui_zoom_cfg + 1 : 0]); break;
-			case WID_GO_FONT_ZOOM_DROPDOWN:    SetDParam(0, _font_zoom_dropdown[_font_zoom_cfg != ZOOM_LVL_CFG_AUTO ? ZOOM_LVL_OUT_4X - _font_zoom_cfg + 1 : 0]); break;
 			case WID_GO_BASE_GRF_DROPDOWN:     SetDParamStr(0, BaseGraphics::GetUsedSet()->name); break;
 			case WID_GO_BASE_GRF_STATUS:       SetDParam(0, BaseGraphics::GetUsedSet()->GetNumInvalid()); break;
 			case WID_GO_BASE_SFX_DROPDOWN:     SetDParamStr(0, BaseSounds::GetUsedSet()->name); break;
@@ -346,6 +332,10 @@ struct GameOptionsWindow : Window {
 				DrawStringMultiLine(r.left, r.right, r.top, UINT16_MAX, STR_BLACK_RAW_STRING);
 				break;
 
+			case WID_GO_GUI_SCALE:
+				DrawSliderWidget(r, MIN_INTERFACE_SCALE, MAX_INTERFACE_SCALE, this->gui_scale, _scale_labels);
+				break;
+
 			case WID_GO_BASE_SFX_VOLUME:
 				DrawSliderWidget(r, 0, INT8_MAX, _settings_client.music.effect_vol, {});
 				break;
@@ -486,6 +476,30 @@ struct GameOptionsWindow : Window {
 				break;
 			}
 
+			case WID_GO_GUI_SCALE:
+				if (ClickSliderWidget(this->GetWidget<NWidgetBase>(widget)->GetCurrentRect(), pt, MIN_INTERFACE_SCALE, MAX_INTERFACE_SCALE, this->gui_scale)) {
+					if (!_ctrl_pressed) this->gui_scale = ((this->gui_scale + 12) / 25) * 25;
+					this->SetWidgetDirty(widget);
+				}
+
+				if (click_count > 0) this->mouse_capture_widget = widget;
+				break;
+
+			case WID_GO_GUI_SCALE_AUTO:
+			{
+				if (_gui_scale_cfg == -1) {
+					_gui_scale_cfg = _gui_scale;
+					this->SetWidgetLoweredState(WID_GO_GUI_SCALE_AUTO, false);
+				} else {
+					_gui_scale_cfg = -1;
+					this->SetWidgetLoweredState(WID_GO_GUI_SCALE_AUTO, true);
+					if (AdjustGUIZoom(false)) ReInitAllWindows(true);
+					this->gui_scale = _gui_scale;
+				}
+				this->SetWidgetDirty(widget);
+				break;
+			}
+
 			case WID_GO_BASE_SFX_VOLUME:
 			case WID_GO_BASE_MUSIC_VOLUME: {
 				byte &vol = (widget == WID_GO_BASE_MUSIC_VOLUME) ? _settings_client.music.music_vol : _settings_client.music.effect_vol;
@@ -517,6 +531,19 @@ struct GameOptionsWindow : Window {
 		}
 	}
 
+	void OnMouseLoop() override
+	{
+		if (_left_button_down || this->gui_scale == _gui_scale) return;
+
+		_gui_scale_cfg = this->gui_scale;
+
+		if (AdjustGUIZoom(false)) {
+			ReInitAllWindows(true);
+			this->SetWidgetLoweredState(WID_GO_GUI_SCALE_AUTO, false);
+			this->SetDirty();
+		}
+	}
+
 	/**
 	 * Set the base media set.
 	 * @param index the index of the media set
@@ -576,36 +603,6 @@ struct GameOptionsWindow : Window {
 				break;
 			}
 
-			case WID_GO_GUI_ZOOM_DROPDOWN: {
-				int8 new_zoom = index > 0 ? ZOOM_LVL_OUT_4X - index + 1 : ZOOM_LVL_CFG_AUTO;
-				if (new_zoom != _gui_zoom_cfg) {
-					GfxClearSpriteCache();
-					_gui_zoom_cfg = new_zoom;
-					UpdateGUIZoom();
-					UpdateCursorSize();
-					SetupWidgetDimensions();
-					UpdateAllVirtCoords();
-					FixTitleGameZoom();
-					ReInitAllWindows(true);
-				}
-				break;
-			}
-
-			case WID_GO_FONT_ZOOM_DROPDOWN: {
-				int8 new_zoom = index > 0 ? ZOOM_LVL_OUT_4X - index + 1 : ZOOM_LVL_CFG_AUTO;
-				if (new_zoom != _font_zoom_cfg) {
-					GfxClearSpriteCache();
-					_font_zoom_cfg = new_zoom;
-					UpdateGUIZoom();
-					ClearFontCache();
-					LoadStringWidthTable();
-					SetupWidgetDimensions();
-					UpdateAllVirtCoords();
-					ReInitAllWindows(true);
-				}
-				break;
-			}
-
 			case WID_GO_BASE_GRF_DROPDOWN:
 				this->SetMediaSet<BaseGraphics>(index);
 				break;
@@ -637,6 +634,7 @@ struct GameOptionsWindow : Window {
 		this->SetWidgetDisabledState(WID_GO_VIDEO_VSYNC_BUTTON, !_video_hw_accel);
 #endif
 
+		this->SetWidgetLoweredState(WID_GO_GUI_SCALE_AUTO, _gui_scale_cfg == -1);
 		this->SetWidgetLoweredState(WID_GO_GUI_SCALE_BEVEL_BUTTON, _settings_client.gui.scale_bevels);
 
 		bool missing_files = BaseGraphics::GetUsedSet()->GetNumMissing() == 0;
@@ -664,16 +662,6 @@ static const NWidgetPart _nested_game_options_widgets[] = {
 				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_AUTOSAVE_FRAME, STR_NULL),
 					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_AUTOSAVE_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_AUTOSAVE_DROPDOWN_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
-				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_GUI_ZOOM_FRAME, STR_NULL),
-					NWidget(NWID_VERTICAL), SetPIP(0, WidgetDimensions::unscaled.vsep_normal, 0),
-						NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_GUI_ZOOM_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_GUI_ZOOM_DROPDOWN_TOOLTIP), SetFill(1, 0),
-						NWidget(NWID_HORIZONTAL),
-							NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetDataTip(STR_GAME_OPTIONS_GUI_SCALE_BEVELS, STR_NULL),
-							NWidget(NWID_SPACER), SetMinimalSize(1, 0), SetFill(1, 0),
-							NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_GO_GUI_SCALE_BEVEL_BUTTON), SetMinimalSize(21, 9), SetDataTip(STR_EMPTY, STR_GAME_OPTIONS_GUI_SCALE_BEVELS_TOOLTIP),
-						EndContainer(),
-					EndContainer(),
-				EndContainer(),
 				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_CURRENCY_UNITS_FRAME, STR_NULL),
 					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_CURRENCY_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_CURRENCY_UNITS_DROPDOWN_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
@@ -683,8 +671,20 @@ static const NWidgetPart _nested_game_options_widgets[] = {
 				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_LANGUAGE, STR_NULL),
 					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_LANG_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_RAW_STRING, STR_GAME_OPTIONS_LANGUAGE_TOOLTIP), SetFill(1, 0),
 				EndContainer(),
-				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_FONT_ZOOM, STR_NULL),
+				NWidget(WWT_FRAME, COLOUR_GREY), SetDataTip(STR_GAME_OPTIONS_GUI_SCALE_FRAME, STR_NULL),
-					NWidget(WWT_DROPDOWN, COLOUR_GREY, WID_GO_FONT_ZOOM_DROPDOWN), SetMinimalSize(150, 12), SetDataTip(STR_BLACK_STRING, STR_GAME_OPTIONS_FONT_ZOOM_DROPDOWN_TOOLTIP), SetFill(1, 0),
+					NWidget(NWID_VERTICAL), SetPIP(0, WidgetDimensions::unscaled.vsep_normal, 0),
+						NWidget(WWT_EMPTY, COLOUR_GREY, WID_GO_GUI_SCALE), SetMinimalSize(67, 0), SetMinimalTextLines(1, 12 + WidgetDimensions::unscaled.vsep_normal, FS_SMALL), SetFill(0, 0), SetDataTip(0x0, STR_GAME_OPTIONS_GUI_SCALE_TOOLTIP),
+						NWidget(NWID_HORIZONTAL),
+							NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetDataTip(STR_GAME_OPTIONS_GUI_SCALE_AUTO, STR_NULL),
+							NWidget(NWID_SPACER), SetMinimalSize(1, 0), SetFill(1, 0),
+							NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_GO_GUI_SCALE_AUTO), SetMinimalSize(21, 9), SetDataTip(STR_EMPTY, STR_GAME_OPTIONS_GUI_SCALE_AUTO_TOOLTIP),
+						EndContainer(),
+						NWidget(NWID_HORIZONTAL),
+							NWidget(WWT_TEXT, COLOUR_GREY), SetMinimalSize(0, 12), SetDataTip(STR_GAME_OPTIONS_GUI_SCALE_BEVELS, STR_NULL),
+							NWidget(NWID_SPACER), SetMinimalSize(1, 0), SetFill(1, 0),
+							NWidget(WWT_TEXTBTN, COLOUR_GREY, WID_GO_GUI_SCALE_BEVEL_BUTTON), SetMinimalSize(21, 9), SetDataTip(STR_EMPTY, STR_GAME_OPTIONS_GUI_SCALE_BEVELS_TOOLTIP),
+						EndContainer(),
+					EndContainer(),
 				EndContainer(),
 			EndContainer(),
 		EndContainer(),

src/smallmap_gui.cpp

@@ -1188,7 +1188,7 @@ void SmallMapWindow::RebuildColourIndexIfNecessary()
 	}
 
 	/* Width of the legend blob. */
-	this->legend_width = (FONT_HEIGHT_SMALL - ScaleFontTrad(1)) * 8 / 5;
+	this->legend_width = (FONT_HEIGHT_SMALL - ScaleGUITrad(1)) * 8 / 5;
 
 	/* The width of a column is the minimum width of all texts + the size of the blob + some spacing */
 	this->column_width = min_width + this->legend_width + WidgetDimensions::scaled.framerect.Horizontal();

src/spritecache.cpp

@@ -517,14 +517,14 @@ static void *ReadSprite(const SpriteCache *sc, SpriteID id, SpriteType sprite_ty
 		return (void*)GetRawSprite(SPR_IMG_QUERY, ST_NORMAL, allocator, encoder);
 	}
 
-	if (sprite->type == ST_FONT && ZOOM_LVL_FONT != ZOOM_LVL_NORMAL) {
+	if (sprite->type == ST_FONT && ZOOM_LVL_GUI != ZOOM_LVL_NORMAL) {
-		/* Make ZOOM_LVL_NORMAL be ZOOM_LVL_FONT */
+		/* Make ZOOM_LVL_NORMAL be ZOOM_LVL_GUI */
-		sprite[ZOOM_LVL_NORMAL].width  = sprite[ZOOM_LVL_FONT].width;
+		sprite[ZOOM_LVL_NORMAL].width  = sprite[ZOOM_LVL_GUI].width;
-		sprite[ZOOM_LVL_NORMAL].height = sprite[ZOOM_LVL_FONT].height;
+		sprite[ZOOM_LVL_NORMAL].height = sprite[ZOOM_LVL_GUI].height;
-		sprite[ZOOM_LVL_NORMAL].x_offs = sprite[ZOOM_LVL_FONT].x_offs;
+		sprite[ZOOM_LVL_NORMAL].x_offs = sprite[ZOOM_LVL_GUI].x_offs;
-		sprite[ZOOM_LVL_NORMAL].y_offs = sprite[ZOOM_LVL_FONT].y_offs;
+		sprite[ZOOM_LVL_NORMAL].y_offs = sprite[ZOOM_LVL_GUI].y_offs;
-		sprite[ZOOM_LVL_NORMAL].data   = sprite[ZOOM_LVL_FONT].data;
+		sprite[ZOOM_LVL_NORMAL].data   = sprite[ZOOM_LVL_GUI].data;
-		sprite[ZOOM_LVL_NORMAL].colours = sprite[ZOOM_LVL_FONT].colours;
+		sprite[ZOOM_LVL_NORMAL].colours = sprite[ZOOM_LVL_GUI].colours;
 	}
 
 	return encoder->Encode(sprite, allocator);

src/station_gui.cpp

@@ -163,7 +163,7 @@ static void StationsWndShowStationRating(int left, int right, int y, CargoID typ
 	const CargoSpec *cs = CargoSpec::Get(type);
 	if (!cs->IsValid()) return;
 
-	int padding = ScaleFontTrad(1);
+	int padding = ScaleGUITrad(1);
 	int width = right - left;
 	int colour = cs->rating_colour;
 	TextColour tc = GetContrastColour(colour);
@@ -177,7 +177,7 @@ static void StationsWndShowStationRating(int left, int right, int y, CargoID typ
 	} else {
 		/* Draw a (scaled) one pixel-wide bar of additional cargo meter, useful
 		 * for stations with only a small amount (<=30) */
-		uint rest = ScaleFontTrad(amount) / 5;
+		uint rest = ScaleGUITrad(amount) / 5;
 		if (rest != 0) {
 			GfxFillRect(left, y + height - rest, left + padding - 1, y + height, colour);
 		}
@@ -391,7 +391,7 @@ public:
 			}
 
 			case WID_STL_LIST:
-				resize->height = std::max(FONT_HEIGHT_NORMAL, FONT_HEIGHT_SMALL + ScaleFontTrad(3));
+				resize->height = std::max(FONT_HEIGHT_NORMAL, FONT_HEIGHT_SMALL + ScaleGUITrad(3));
 				size->height = padding.height + 5 * resize->height;
 
 				/* Determine appropriate width for mini station rating graph */

src/table/settings/misc_settings.ini

@@ -334,21 +334,12 @@ max      = UINT32_MAX
 cat      = SC_EXPERT
 
 [SDTG_VAR]
-name     = ""gui_zoom""
+name     = ""gui_scale""
-type     = SLE_INT8
+type     = SLE_INT32
-var      = _gui_zoom_cfg
+var      = _gui_scale_cfg
-def      = ZOOM_LVL_CFG_AUTO
+def      = -1
-min      = ZOOM_LVL_CFG_AUTO
+min      = -1
-max      = ZOOM_LVL_OUT_4X
+max      = MAX_INTERFACE_SCALE
-cat      = SC_BASIC
-
-[SDTG_VAR]
-name     = ""font_zoom""
-type     = SLE_INT8
-var      = _font_zoom_cfg
-def      = ZOOM_LVL_CFG_AUTO
-min      = ZOOM_LVL_CFG_AUTO
-max      = ZOOM_LVL_OUT_4X
 cat      = SC_BASIC
 
 [SDTG_BOOL]

src/video/cocoa/cocoa_wnd.mm

@@ -1269,7 +1269,7 @@ void CocoaDialog(const char *title, const char *message, const char *buttonLabel
 /** Screen the window is on changed. */
 - (void)windowDidChangeBackingProperties:(NSNotification *)notification
 {
-	bool did_adjust = AdjustGUIZoom();
+	bool did_adjust = AdjustGUIZoom(true);
 
 	/* Reallocate screen buffer if necessary. */
 	driver->AllocateBackingStore();

src/video/video_driver.hpp

@@ -167,15 +167,13 @@ public:
 	}
 
 	/**
-	 * Get a suggested default GUI zoom taking screen DPI into account.
+	 * Get a suggested default GUI scale taking screen DPI into account.
 	 */
-	virtual ZoomLevel GetSuggestedUIZoom()
+	virtual int GetSuggestedUIScale()
 	{
 		float dpi_scale = this->GetDPIScale();
 
-		if (dpi_scale >= 3.0f) return ZOOM_LVL_NORMAL;
+		return Clamp(dpi_scale * 100, MIN_INTERFACE_SCALE, MAX_INTERFACE_SCALE);
-		if (dpi_scale >= 1.5f) return ZOOM_LVL_OUT_2X;
-		return ZOOM_LVL_OUT_4X;
 	}
 
 	virtual const char *GetInfoString() const

src/video/win32_v.cpp

@@ -675,7 +675,7 @@ LRESULT CALLBACK WndProcGdi(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 		}
 
 		case WM_DPICHANGED: {
-			auto did_adjust = AdjustGUIZoom();
+			auto did_adjust = AdjustGUIZoom(true);
 
 			/* Resize the window to match the new DPI setting. */
 			RECT *prcNewWindow = (RECT *)lParam;

src/widgets/settings_widget.h

@@ -19,7 +19,8 @@ enum GameOptionsWidgets {
 	WID_GO_LANG_DROPDOWN,          ///< Language dropdown.
 	WID_GO_RESOLUTION_DROPDOWN,    ///< Dropdown for the resolution.
 	WID_GO_FULLSCREEN_BUTTON,      ///< Toggle fullscreen.
-	WID_GO_GUI_ZOOM_DROPDOWN,      ///< Dropdown for the GUI zoom level.
+	WID_GO_GUI_SCALE,              ///< GUI Scale slider.
+	WID_GO_GUI_SCALE_AUTO,         ///< Autodetect GUI scale button.
 	WID_GO_GUI_SCALE_BEVEL_BUTTON, ///< Toggle for chunky bevels.
 	WID_GO_BASE_GRF_DROPDOWN,      ///< Use to select a base GRF.
 	WID_GO_BASE_GRF_STATUS,        ///< Info about missing files etc.
@@ -35,7 +36,6 @@ enum GameOptionsWidgets {
 	WID_GO_BASE_MUSIC_STATUS,      ///< Info about corrupted files etc.
 	WID_GO_BASE_MUSIC_TEXTFILE,    ///< Open base music readme, changelog (+1) or license (+2).
 	WID_GO_BASE_MUSIC_DESCRIPTION = WID_GO_BASE_MUSIC_TEXTFILE + TFT_END, ///< Description of selected base music set.
-	WID_GO_FONT_ZOOM_DROPDOWN,     ///< Dropdown for the font zoom level.
 	WID_GO_VIDEO_ACCEL_BUTTON,     ///< Toggle for video acceleration.
 	WID_GO_VIDEO_VSYNC_BUTTON,     ///< Toggle for video vsync.
 	WID_GO_REFRESH_RATE_DROPDOWN,  ///< Dropdown for all available refresh rates.

src/zoom_func.h

@@ -116,27 +116,7 @@ static inline int ScaleSpriteTrad(int value)
  */
 static inline int ScaleGUITrad(int value)
 {
-	return UnScaleGUI(value * ZOOM_LVL_BASE);
+	return value * _gui_scale / 100;
-}
-
-/**
- * Short-hand to apply font zoom level.
- * @param value Pixel amount at #ZOOM_LVL_BEGIN (full zoom in).
- * @return Pixel amount at #ZOOM_LVL_FONT (current interface size).
- */
-static inline int UnScaleFont(int value)
-{
-	return UnScaleByZoom(value, ZOOM_LVL_FONT);
-}
-
-/**
- * Scale traditional pixel dimensions to Font zoom level.
- * @param value Pixel amount at #ZOOM_LVL_BASE (traditional "normal" interface size).
- * @return Pixel amount at #ZOOM_LVL_FONT (current interface size).
- */
-static inline int ScaleFontTrad(int value)
-{
-	return UnScaleFont(value * ZOOM_LVL_BASE);
 }
 
 #endif /* ZOOM_FUNC_H */

src/zoom_type.h

@@ -15,8 +15,6 @@
 static uint const ZOOM_LVL_SHIFT = 2;
 static uint const ZOOM_LVL_BASE  = 1 << ZOOM_LVL_SHIFT;
 
-static const int8 ZOOM_LVL_CFG_AUTO = -1;
-
 /** All zoom levels we know. */
 enum ZoomLevel : byte {
 	/* Our possible zoom-levels */
@@ -50,12 +48,13 @@ enum ZoomLevel : byte {
 };
 DECLARE_POSTFIX_INCREMENT(ZoomLevel)
 
-extern int8 _gui_zoom_cfg;
+extern int _gui_scale;
-extern int8 _font_zoom_cfg;
+extern int _gui_scale_cfg;
 
 extern ZoomLevel _gui_zoom;
-extern ZoomLevel _font_zoom;
 #define ZOOM_LVL_GUI (_gui_zoom)
-#define ZOOM_LVL_FONT (_font_zoom)
+
+static const int MIN_INTERFACE_SCALE = 100;
+static const int MAX_INTERFACE_SCALE = 500;
 
 #endif /* ZOOM_TYPE_H */