Use backup/restore wrappers for various _cur_dpi changes

src/company_gui.cpp

@@ -37,6 +37,7 @@
 #include "station_func.h"
 #include "zoom_func.h"
 #include "sortlist_type.h"
+#include "core/backup_type.hpp"
 
 #include "widgets/company_widget.h"
 
@@ -2087,8 +2088,7 @@ struct CompanyInfrastructureWindow : Window
 		DrawPixelInfo tmp_dpi;
 		if (!FillDrawPixelInfo(&tmp_dpi, r.left, r.top, width + 1, r.bottom - r.top + 1)) return;
 
-		DrawPixelInfo *old_dpi = _cur_dpi;
+		AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-		_cur_dpi = &tmp_dpi;
 
 		int y = -this->vscroll->GetPosition();
 
@@ -2198,9 +2198,6 @@ struct CompanyInfrastructureWindow : Window
 				break;
 			}
 		}
-
-		/* Restore clipping region. */
-		_cur_dpi = old_dpi;
 	}
 
 	virtual void OnResize() override

src/departures_gui.cpp

@@ -33,6 +33,7 @@
 #include "departures_func.h"
 #include "cargotype.h"
 #include "zoom_func.h"
+#include "core/backup_type.hpp"
 
 #include "table/sprites.h"
 #include "table/strings.h"
@@ -1001,8 +1002,7 @@ void DeparturesWindow<Twaypoint>::DrawDeparturesListItems(const Rect &r) const
 				y += this->entry_height;
 				continue;
 			}
-			DrawPixelInfo *old_dpi = _cur_dpi;
+			AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-			_cur_dpi = &tmp_dpi;
 
 			/* The scrolling text starts out of view at the right of the screen and finishes when it is out of view at the left of the screen. */
 			int pos = ltr
@@ -1011,8 +1011,6 @@ void DeparturesWindow<Twaypoint>::DrawDeparturesListItems(const Rect &r) const
 
 			ltr ? DrawString(       pos, INT16_MAX, 0, buffer, TC_FROMSTRING,  SA_LEFT | SA_FORCE)
 				: DrawString(-INT16_MAX,       pos, 0, buffer, TC_FROMSTRING, SA_RIGHT | SA_FORCE);
-
-			_cur_dpi = old_dpi;
 		}
 
 		y += this->entry_height;

src/gfx.cpp

@@ -1752,9 +1752,8 @@ void DrawDirtyBlocks()
 			cleared_overlays = true;
 		};
 
-		DrawPixelInfo *old_dpi = _cur_dpi;
 		DrawPixelInfo bk;
-		_cur_dpi = &bk;
+		Backup dpi_backup(_cur_dpi, &bk, FILE_LINE);
 
 		for (Window *w : Window::IterateFromBack()) {
 			w->flags &= ~WF_DRAG_DIRTIED;
@@ -1899,7 +1898,7 @@ void DrawDirtyBlocks()
 			}
 		}
 
-		_cur_dpi = old_dpi;
+		dpi_backup.Restore();
 
 		for (const Rect &r : _dirty_blocks) {
 			RedrawScreenRect(r.left, r.top, r.right, r.bottom);

src/order_gui.cpp

@@ -34,6 +34,7 @@
 #include "error.h"
 #include "tracerestrict.h"
 #include "scope.h"
+#include "core/backup_type.hpp"
 
 #include "widgets/order_widget.h"
 
@@ -1171,12 +1172,9 @@ void DrawOrderString(const Vehicle *v, const Order *order, int order_index, int
 		Dimension lock_d = GetSpriteSize(SPR_LOCK);
 		DrawPixelInfo tmp_dpi;
 		if (FillDrawPixelInfo(&tmp_dpi, rtl ? left : middle, y, rtl ? middle - left : right - middle, lock_d.height)) {
-			DrawPixelInfo *old_dpi = _cur_dpi;
+			AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-			_cur_dpi = &tmp_dpi;
 
 			DrawSprite(SPR_LOCK, PAL_NONE, rtl ? edge - 3 - lock_d.width - left : edge + 3 - middle, 0);
-
-			_cur_dpi = old_dpi;
 		}
 	}
 }

src/smallmap_gui.cpp

@@ -1699,20 +1699,17 @@ void SmallMapWindow::TakeScreenshot()
  */
 void SmallMapWindow::ScreenshotCallbackHandler(void *buf, uint y, uint pitch, uint n)
 {
-	DrawPixelInfo dpi, *old_dpi;
+	DrawPixelInfo dpi;
+	AutoRestoreBackup dpi_backup(_cur_dpi, &dpi);
 
 	/* We are no longer rendering to the screen */
-	DrawPixelInfo old_screen = _screen;
+	AutoRestoreBackup screen_backup(_screen, AutoRestoreBackupNoNewValueTag{});
-	bool old_disable_anim = _screen_disable_anim;
+	AutoRestoreBackup screen_disable_anim_backup(_screen_disable_anim, true);
 
 	_screen.dst_ptr = buf;
 	_screen.width = pitch;
 	_screen.height = n;
 	_screen.pitch = pitch;
-	_screen_disable_anim = true;
-
-	old_dpi = _cur_dpi;
-	_cur_dpi = &dpi;
 
 	dpi.dst_ptr = buf;
 	dpi.height = n;
@@ -1728,12 +1725,6 @@ void SmallMapWindow::ScreenshotCallbackHandler(void *buf, uint y, uint pitch, ui
 
 	/* make the screenshot */
 	this->DrawSmallMap(&dpi, false);
-
-	_cur_dpi = old_dpi;
-
-	/* Switch back to rendering to the screen */
-	_screen = old_screen;
-	_screen_disable_anim = old_disable_anim;
 }
 
 SmallMapWindow::SmallMapType SmallMapWindow::map_type = SMT_CONTOUR;

src/tbtr_template_gui_create.cpp

@@ -40,6 +40,7 @@
 #include "company_base.h"
 #include "train.h"
 #include "newgrf_debug.h"
+#include "core/backup_type.hpp"
 
 #include "tbtr_template_gui_create.h"
 #include "tbtr_template_vehicle.h"
@@ -298,12 +299,11 @@ public:
 			}
 			case TCW_INFO_PANEL: {
 				if (this->virtual_train) {
-					DrawPixelInfo tmp_dpi, *old_dpi;
+					DrawPixelInfo tmp_dpi;
 
 					if (!FillDrawPixelInfo(&tmp_dpi, r.left, r.top, r.right - r.left, r.bottom - r.top)) break;
 
-					old_dpi = _cur_dpi;
+					AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-					_cur_dpi = &tmp_dpi;
 
 					int y = ScaleGUITrad(4) - this->vscroll->GetPosition();
 					bool buildable = true;
@@ -380,8 +380,6 @@ public:
 							y += FONT_HEIGHT_NORMAL;
 						}
 					}
-
-					_cur_dpi = old_dpi;
 				}
 				break;
 			}

src/tbtr_template_gui_main.cpp

@@ -28,6 +28,7 @@
 #include "network/network.h"
 #include "zoom_func.h"
 #include "textbuf_gui.h"
+#include "core/backup_type.hpp"
 
 #include "table/sprites.h"
 #include "table/strings.h"
@@ -769,14 +770,13 @@ public:
 			return;
 		}
 
-		DrawPixelInfo tmp_dpi, *old_dpi;
+		DrawPixelInfo tmp_dpi;
 
 		if (!FillDrawPixelInfo(&tmp_dpi, r.left, r.top, r.right - r.left, r.bottom - r.top)) {
 			return;
 		}
 
-		old_dpi = _cur_dpi;
+		AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-		_cur_dpi = &tmp_dpi;
 
 		const TemplateVehicle *tmp = this->templates[this->selected_template_index];
 
@@ -840,8 +840,6 @@ public:
 				}
 			}
 		}
-
-		_cur_dpi = old_dpi;
 	}
 
 	void UpdateButtonState()

src/tbtr_template_vehicle_func.cpp

@@ -124,14 +124,13 @@ void DrawTemplate(const TemplateVehicle *tv, int left, int right, int y, int hei
 {
 	if (!tv) return;
 
-	DrawPixelInfo tmp_dpi, *old_dpi;
+	DrawPixelInfo tmp_dpi;
 	int max_width = right - left + 1;
 	int veh_height = ScaleSpriteTrad(14);
 	int padding = height - veh_height;
 	if (!FillDrawPixelInfo(&tmp_dpi, left, y + (padding / 2), max_width, height)) return;
 
-	old_dpi = _cur_dpi;
+	AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-	_cur_dpi = &tmp_dpi;
 
 	const TemplateVehicle *t = tv;
 	int offset = 0;
@@ -142,8 +141,6 @@ void DrawTemplate(const TemplateVehicle *tv, int left, int right, int y, int hei
 		offset += t->image_dimensions.GetDisplayImageWidth();
 		t = t->Next();
 	}
-
-	_cur_dpi = old_dpi;
 }
 
 // copy important stuff from the virtual vehicle to the template

src/timetable_gui.cpp

@@ -26,6 +26,7 @@
 #include "schdispatch.h"
 #include "vehiclelist.h"
 #include "tracerestrict.h"
+#include "core/backup_type.hpp"
 
 #include "widgets/timetable_widget.h"
 
@@ -723,12 +724,9 @@ struct TimetableWindow : GeneralVehicleWindow {
 							Dimension lock_d = GetSpriteSize(SPR_LOCK);
 							DrawPixelInfo tmp_dpi;
 							if (FillDrawPixelInfo(&tmp_dpi, rtl ? tr.left : middle, tr.top, rtl ? middle : tr.right, lock_d.height)) {
-								DrawPixelInfo *old_dpi = _cur_dpi;
+								AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-								_cur_dpi = &tmp_dpi;
 
 								DrawSprite(SPR_LOCK, PAL_NONE, rtl ? edge - 3 - lock_d.width - tr.left : edge + 3 - middle, 0);
-
-								_cur_dpi = old_dpi;
 							}
 						}
 

src/town_cmd.cpp

@@ -367,8 +367,7 @@ void DrawHouseImage(HouseID house_id, int left, int top, int right, int bottom)
 {
 	DrawPixelInfo tmp_dpi;
 	if (!FillDrawPixelInfo(&tmp_dpi, left, top, right - left + 1, bottom - top + 1)) return;
-	DrawPixelInfo *old_dpi = _cur_dpi;
+	AutoRestoreBackup dpi_backup(_cur_dpi, &tmp_dpi);
-	_cur_dpi = &tmp_dpi;
 
 	const HouseSpec *hs = HouseSpec::Get(house_id);
 
@@ -412,8 +411,6 @@ void DrawHouseImage(HouseID house_id, int left, int top, int right, int bottom)
 		}
 		if (!ground) break;
 	}
-
-	_cur_dpi = old_dpi;
 }
 
 static int GetSlopePixelZ_Town(TileIndex tile, uint x, uint y)

src/viewport.cpp

@@ -115,6 +115,7 @@
 #include "tracerestrict.h"
 #include "worker_thread.h"
 #include "vehiclelist.h"
+#include "core/backup_type.hpp"
 
 #include <map>
 #include <vector>
@@ -2482,10 +2483,9 @@ static inline void DrawRouteStep(const Viewport * const vp, const TileIndex tile
 	DrawSprite(SetBit(s, PALETTE_MODIFIER_TRANSPARENT), PALETTE_TO_TRANSPARENT, _cur_dpi->left + x_bottom_spr, _cur_dpi->top + y2);
 
 	/* Fill with the data. */
-	DrawPixelInfo *old_dpi = _cur_dpi;
 	y2 = y + _vp_route_step_height_top;
 	DrawPixelInfo dpi_for_text = _vdd->MakeDPIForText();
-	_cur_dpi = &dpi_for_text;
+	AutoRestoreBackup dpi_backup(_cur_dpi, &dpi_for_text);
 
 	const int x_str = x_centre - (str_width / 2);
 	if (list.size() > max_rank_order_type_count) {
@@ -2521,7 +2521,6 @@ static inline void DrawRouteStep(const Viewport * const vp, const TileIndex tile
 			}
 		}
 	}
-	_cur_dpi = old_dpi;
 }
 
 static bool ViewportPrepareVehicleRouteSteps(const Vehicle * const veh)
@@ -3325,9 +3324,8 @@ static void ViewportMapDrawScrollingViewportBox(const Viewport * const vp)
 
 static void ViewportMapDrawSelection(const Viewport * const vp)
 {
-	DrawPixelInfo *old_dpi = _cur_dpi;
 	DrawPixelInfo dpi_for_text = _vdd->MakeDPIForText();
-	_cur_dpi = &dpi_for_text;
+	AutoRestoreBackup dpi_backup(_cur_dpi, &dpi_for_text);
 
 	auto draw_line = [&](Point from_pt, Point to_pt) {
 		GfxDrawLine(from_pt.x, from_pt.y, to_pt.x, to_pt.y, PC_WHITE, 2, 0);
@@ -3368,8 +3366,6 @@ static void ViewportMapDrawSelection(const Viewport * const vp)
 	} else {
 		draw_line(start_pt, end_pt);
 	}
-
-	_cur_dpi = old_dpi;
 }
 
 template <bool is_32bpp>
@@ -3627,9 +3623,6 @@ void ViewportDoDraw(Viewport *vp, int left, int top, int right, int bottom, uint
 		_spare_viewport_drawers.pop_back();
 	}
 
-	DrawPixelInfo *old_dpi = _cur_dpi;
-	_cur_dpi = &_vdd->dpi;
-
 	_vdd->display_flags = display_flags;
 	_vdd->transparency_opt = _transparency_opt;
 	_vdd->invisibility_opt = _invisibility_opt;
@@ -3643,7 +3636,7 @@ void ViewportDoDraw(Viewport *vp, int left, int top, int right, int bottom, uint
 	_vdd->dpi.height = (bottom - top) & mask;
 	_vdd->dpi.left = left & mask;
 	_vdd->dpi.top = top & mask;
-	_vdd->dpi.pitch = old_dpi->pitch;
+	_vdd->dpi.pitch = _cur_dpi->pitch;
 	_vd.last_child = nullptr;
 
 	_vdd->offset_x = UnScaleByZoomLower(_vdd->dpi.left - (vp->virtual_left & mask), vp->zoom);
@@ -3651,7 +3644,9 @@ void ViewportDoDraw(Viewport *vp, int left, int top, int right, int bottom, uint
 	int x = _vdd->offset_x + vp->left;
 	int y = _vdd->offset_y + vp->top;
 
-	_vdd->dpi.dst_ptr = BlitterFactory::GetCurrentBlitter()->MoveTo(old_dpi->dst_ptr, x - old_dpi->left, y - old_dpi->top);
+	_vdd->dpi.dst_ptr = BlitterFactory::GetCurrentBlitter()->MoveTo(_cur_dpi->dst_ptr, x - _cur_dpi->left, y - _cur_dpi->top);
+
+	AutoRestoreBackup dpi_backup(_cur_dpi, &_vdd->dpi);
 
 	if (vp->overlay != nullptr && vp->overlay->GetCargoMask() != 0 && vp->overlay->GetCompanyMask() != 0) {
 		vp->overlay->PrepareDraw();
@@ -3698,8 +3693,6 @@ void ViewportDoDraw(Viewport *vp, int left, int top, int right, int bottom, uint
 			}, vp, _vdd.release());
 		}
 	}
-
-	_cur_dpi = old_dpi;
 }
 
 /* This is run in a worker thread */
@@ -3776,9 +3769,10 @@ void ViewportDoDrawProcessAllPending()
 			_viewport_drawer_returns.pop_back();
 			lk.unlock();
 
-			DrawPixelInfo *old_dpi = _cur_dpi;
+			{
-			ViewportDoDrawPhase3(vp);
+				AutoRestoreBackup dpi_backup(_cur_dpi, AutoRestoreBackupNoNewValueTag{});
-			_cur_dpi = old_dpi;
+				ViewportDoDrawPhase3(vp);
+			}
 
 			_viewport_drawer_jobs--;
 			if (_viewport_drawer_jobs == 0) return;