(svn r11399) -Feature(ette): transparency settings can now be saved and thus remembered.

-Codechange: Wrap all transparency settings in accessors, hiding the implementation
-Change: Clicking "transparent building" menu will toggle Houses And Trees only.  The other options can be used in the transparency gui.
Initial patch by Smatz (FS#1349), with some rework by BigBB and your humble servant.

25 files changed, 165 insertions, 102 deletions

diff --git a/projects/openttd.vcproj b/projects/openttd.vcproj
index a821044e0..7ee50b846 100644
--- a/projects/openttd.vcproj
+++ b/projects/openttd.vcproj
@@ -685,6 +685,9 @@
 				RelativePath=".\..\src\train.h">
 			</File>
 			<File
+				RelativePath=".\..\src\transparency.h">
+			</File>
+			<File
 				RelativePath=".\..\src\transparency_gui.h">
 			</File>
 			<File
diff --git a/projects/openttd_vs80.vcproj b/projects/openttd_vs80.vcproj
index e8559486b..f4e9bf89c 100644
--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -1144,6 +1144,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\..\src\transparency.h"
+				>
+			</File>
+			<File
 				RelativePath=".\..\src\transparency_gui.h"
 				>
 			</File>
diff --git a/source.list b/source.list
index 68d5433cd..a4cc2da0a 100644
--- a/source.list
+++ b/source.list
@@ -194,6 +194,7 @@ tile.h
 timetable.h
 town.h
 train.h
+transparency.h
 transparency_gui.h
 variables.h
 vehicle.h
diff --git a/src/elrail.cpp b/src/elrail.cpp
index 8a0e7854c..47f854ddf 100644
--- a/src/elrail.cpp
+++ b/src/elrail.cpp
@@ -65,6 +65,7 @@
 #include "vehicle.h"
 #include "train.h"
 #include "gui.h"
+#include "transparency.h"
 
 static inline TLG GetTLG(TileIndex t)
 {
@@ -195,7 +196,7 @@ void DrawCatenaryOnTunnel(const TileInfo *ti)
 		sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
 		BB_data[2] - sss->x_offset, BB_data[3] - sss->y_offset, BB_Z_SEPARATOR - sss->z_offset + 1,
 		GetTileZ(ti->tile) + sss->z_offset,
-		HASBIT(_transparent_opt, TO_BUILDINGS),
+		IsTransparencySet(TO_BUILDINGS),
 		BB_data[0] - sss->x_offset, BB_data[1] - sss->y_offset, BB_Z_SEPARATOR - sss->z_offset
 	);
 }
@@ -342,7 +343,7 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 
 					AddSortableSpriteToDraw(pylon_sprites[temp], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE,
 							GetPCPElevation(ti->tile, i),
-							HASBIT(_transparent_opt, TO_BUILDINGS), -1, -1);
+							IsTransparencySet(TO_BUILDINGS), -1, -1);
 					break; /* We already have drawn a pylon, bail out */
 				}
 			}
@@ -350,7 +351,7 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 	}
 
 	/* Don't draw a wire under a low bridge */
-	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !HASBIT(_transparent_opt, TO_BUILDINGS)) {
+	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !IsTransparencySet(TO_BUILDINGS)) {
 		uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));
 
 		if (height <= GetTileMaxZ(ti->tile) + TILE_HEIGHT) return;
@@ -377,7 +378,7 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 			 */
 			AddSortableSpriteToDraw(sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
 				sss->x_size, sss->y_size, sss->z_size, GetSlopeZ(ti->x + sss->x_offset, ti->y + sss->y_offset) + sss->z_offset,
-				HASBIT(_transparent_opt, TO_BUILDINGS));
+				IsTransparencySet(TO_BUILDINGS));
 		}
 	}
 }
@@ -410,7 +411,7 @@ static void DrawCatenaryOnBridge(const TileInfo *ti)
 
 	AddSortableSpriteToDraw(sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
 		sss->x_size, sss->y_size, sss->z_size, height + sss->z_offset,
-		HASBIT(_transparent_opt, TO_BUILDINGS)
+		IsTransparencySet(TO_BUILDINGS)
 	);
 
 	/* Finished with wires, draw pylons */
@@ -421,7 +422,7 @@ static void DrawCatenaryOnBridge(const TileInfo *ti)
 		if (HASBIT(tlg, (axis == AXIS_X ? 0 : 1))) PPPpos = ReverseDir(PPPpos);
 		uint x = ti->x + x_pcp_offsets[PCPpos] + x_ppp_offsets[PPPpos];
 		uint y = ti->y + y_pcp_offsets[PCPpos] + y_ppp_offsets[PPPpos];
-		AddSortableSpriteToDraw(pylon_sprites[PPPpos], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, height, HASBIT(_transparent_opt, TO_BUILDINGS), -1, -1);
+		AddSortableSpriteToDraw(pylon_sprites[PPPpos], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, height, IsTransparencySet(TO_BUILDINGS), -1, -1);
 	}
 
 	/* need a pylon on the southern end of the bridge */
@@ -431,7 +432,7 @@ static void DrawCatenaryOnBridge(const TileInfo *ti)
 		if (HASBIT(tlg, (axis == AXIS_X ? 0 : 1))) PPPpos = ReverseDir(PPPpos);
 		uint x = ti->x + x_pcp_offsets[PCPpos] + x_ppp_offsets[PPPpos];
 		uint y = ti->y + y_pcp_offsets[PCPpos] + y_ppp_offsets[PPPpos];
-		AddSortableSpriteToDraw(pylon_sprites[PPPpos], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, height, HASBIT(_transparent_opt, TO_BUILDINGS), -1, -1);
+		AddSortableSpriteToDraw(pylon_sprites[PPPpos], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, height, IsTransparencySet(TO_BUILDINGS), -1, -1);
 	}
 }
 
@@ -457,7 +458,7 @@ void DrawCatenary(const TileInfo *ti)
 					sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
 					sss->x_size, sss->y_size, sss->z_size,
 					GetTileMaxZ(ti->tile) + sss->z_offset,
-					HASBIT(_transparent_opt, TO_BUILDINGS)
+					IsTransparencySet(TO_BUILDINGS)
 				);
 				return;
 			}
diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index 4e846cec5..621495b94 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -38,6 +38,7 @@
 #include "newgrf_callbacks.h"
 #include "misc/autoptr.hpp"
 #include "autoslope.h"
+#include "transparency.h"
 
 void ShowIndustryViewWindow(int industry);
 void BuildOilRig(TileIndex tile);
@@ -310,9 +311,9 @@ static void DrawTile_Industry(TileInfo *ti)
 			dits->height,
 			dits->dz,
 			ti->z,
-			HASBIT(_transparent_opt, TO_INDUSTRIES));
+			IsTransparencySet(TO_INDUSTRIES));
 
-		if (HASBIT(_transparent_opt, TO_INDUSTRIES)) return;
+		if (IsTransparencySet(TO_INDUSTRIES)) return;
 	}
 
 	{
diff --git a/src/main_gui.cpp b/src/main_gui.cpp
index 9d25e6354..d84c6c2d1 100644
--- a/src/main_gui.cpp
+++ b/src/main_gui.cpp
@@ -47,6 +47,7 @@
 #include "network/network_server.h"
 #include "network/network_gui.h"
 #include "industry.h"
+#include "transparency.h"
 
 static int _rename_id = 1;
 static int _rename_what = -1;
@@ -156,22 +157,6 @@ static void ToolbarFastForwardClick(Window *w)
 }
 
 
-/** Toggle all transparency options, except for signs */
-static void ToggleTransparency()
-{
-	static byte trans_opt = ~0;
-
-	if (GB(_transparent_opt, 1, 7) == 0) {
-		SB(_transparent_opt, 1, 7, GB(trans_opt, 1, 7));
-	} else {
-		trans_opt = _transparent_opt;
-		SB(_transparent_opt, 1, 7, 0);
-	}
-
-	MarkWholeScreenDirty();
-}
-
-
 static void MenuClickSettings(int index)
 {
 	switch (index) {
@@ -187,8 +172,11 @@ static void MenuClickSettings(int index)
 		case  9: TOGGLEBIT(_display_opt, DO_WAYPOINTS);          break;
 		case 10: TOGGLEBIT(_display_opt, DO_FULL_ANIMATION);     break;
 		case 11: TOGGLEBIT(_display_opt, DO_FULL_DETAIL);        break;
-		case 12: ToggleTransparency(); break;
-		case 13: TOGGLEBIT(_transparent_opt, TO_SIGNS); break;
+		case 12:
+			ToggleTransparency(TO_TREES);
+			ToggleTransparency(TO_HOUSES);
+			break;
+		case 13: ToggleTransparency(TO_SIGNS);                   break;
 	}
 	MarkWholeScreenDirty();
 }
@@ -988,8 +976,8 @@ static void ToolbarOptionsClick(Window *w)
 	if (HASBIT(_display_opt, DO_WAYPOINTS))          SETBIT(x,  9);
 	if (HASBIT(_display_opt, DO_FULL_ANIMATION))     SETBIT(x, 10);
 	if (HASBIT(_display_opt, DO_FULL_DETAIL))        SETBIT(x, 11);
-	if (GB(_transparent_opt, 1, 7) != 0)      SETBIT(x, 12);
-	if (HASBIT(_transparent_opt, TO_SIGNS))   SETBIT(x, 13);
+	if (IsTransparencySet(TO_HOUSES) && IsTransparencySet(TO_TREES)) SETBIT(x, 12);
+	if (IsTransparencySet(TO_SIGNS))                     SETBIT(x, 13);
 	WP(w,menu_d).checked_items = x;
 }
 
@@ -2259,8 +2247,9 @@ static void MainWindowWndProc(Window *w, WindowEvent *e)
 			case '5' | WKC_CTRL:
 			case '6' | WKC_CTRL:
 			case '7' | WKC_CTRL:
+			case '8' | WKC_CTRL:
 				/* Transparency toggle hot keys */
-				TOGGLEBIT(_transparent_opt, e->we.keypress.keycode - ('1' | WKC_CTRL));
+				ToggleTransparency((TransparencyOption)(e->we.keypress.keycode - ('1' | WKC_CTRL)));
 				MarkWholeScreenDirty();
 				break;
 
@@ -2269,7 +2258,7 @@ static void MainWindowWndProc(Window *w, WindowEvent *e)
 				break;
 
 			case 'X':
-				ToggleTransparency();
+				ResetRestoreAllTransparency();
 				break;
 
 #ifdef ENABLE_NETWORK
diff --git a/src/newgrf_house.cpp b/src/newgrf_house.cpp
index 568225667..a284abb67 100644
--- a/src/newgrf_house.cpp
+++ b/src/newgrf_house.cpp
@@ -25,6 +25,7 @@
 #include "newgrf_town.h"
 #include "newgrf_sound.h"
 #include "newgrf_commons.h"
+#include "transparency.h"
 
 static BuildingCounts    _building_counts;
 static HouseClassMapping _class_mapping[HOUSE_CLASS_MAX];
@@ -320,7 +321,7 @@ void DrawTileLayout(const TileInfo *ti, const SpriteGroup *group, byte stage, Ho
 
 		if (IS_CUSTOM_SPRITE(image)) image += stage;
 
-		if ((HASBIT(image, SPRITE_MODIFIER_OPAQUE) || !HASBIT(_transparent_opt, TO_HOUSES)) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
+		if ((HASBIT(image, SPRITE_MODIFIER_OPAQUE) || !IsTransparencySet(TO_HOUSES)) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
 			if (pal == 0) {
 				const HouseSpec *hs = GetHouseSpecs(house_id);
 				if (HASBIT(hs->callback_mask, CBM_HOUSE_COLOUR)) {
@@ -343,10 +344,10 @@ void DrawTileLayout(const TileInfo *ti, const SpriteGroup *group, byte stage, Ho
 				ti->x + dtss->delta_x, ti->y + dtss->delta_y,
 				dtss->size_x, dtss->size_y,
 				dtss->size_z, ti->z + dtss->delta_z,
-				HASBIT(_transparent_opt, TO_HOUSES)
+				IsTransparencySet(TO_HOUSES)
 			);
 		} else {
-			AddChildSpriteScreen(image, pal, (byte)dtss->delta_x, (byte)dtss->delta_y, HASBIT(_transparent_opt, TO_HOUSES));
+			AddChildSpriteScreen(image, pal, (byte)dtss->delta_x, (byte)dtss->delta_y, IsTransparencySet(TO_HOUSES));
 		}
 	}
 }
diff --git a/src/newgrf_industrytiles.cpp b/src/newgrf_industrytiles.cpp
index 6a28d350e..70420915b 100644
--- a/src/newgrf_industrytiles.cpp
+++ b/src/newgrf_industrytiles.cpp
@@ -22,6 +22,7 @@
 #include "table/sprites.h"
 #include "table/strings.h"
 #include "sprite.h"
+#include "transparency.h"
 
 /**
  * Based on newhouses equivalent, but adapted for newindustries
@@ -195,10 +196,10 @@ void IndustryDrawTileLayout(const TileInfo *ti, const SpriteGroup *group, byte r
 				ti->x + dtss->delta_x, ti->y + dtss->delta_y,
 				dtss->size_x, dtss->size_y,
 				dtss->size_z, ti->z + dtss->delta_z,
-				!HASBIT(image, SPRITE_MODIFIER_OPAQUE) && HASBIT(_transparent_opt, TO_INDUSTRIES)
+				!HASBIT(image, SPRITE_MODIFIER_OPAQUE) && IsTransparencySet(TO_INDUSTRIES)
 			);
 		} else {
-			AddChildSpriteScreen(image, pal, (byte)dtss->delta_x, (byte)dtss->delta_y, HASBIT(_transparent_opt, TO_INDUSTRIES));
+			AddChildSpriteScreen(image, pal, (byte)dtss->delta_x, (byte)dtss->delta_y, IsTransparencySet(TO_INDUSTRIES));
 		}
 	}
 }
diff --git a/src/news_gui.cpp b/src/news_gui.cpp
index a8d8b0e36..724ec1e78 100644
--- a/src/news_gui.cpp
+++ b/src/news_gui.cpp
@@ -17,6 +17,7 @@
 #include "variables.h"
 #include "date.h"
 #include "string.h"
+#include "transparency.h"
 
 /** @file news_gui.cpp
  *
@@ -137,10 +138,10 @@ static void NewsWindowProc(Window *w, WindowEvent *e)
 						ni->string_id, w->width - 4);
 				} else {
 					/* Back up transparency options to draw news view */
-					byte to_backup = _transparent_opt;
-					_transparent_opt = 0;
+					TransparencyOptionBits to_backup = _transparency_opt;
+					_transparency_opt = 0;
 					DrawWindowViewport(w);
-					_transparent_opt = to_backup;
+					_transparency_opt = to_backup;
 
 					/* Shade the viewport into gray, or color*/
 					vp = w->viewport;
diff --git a/src/openttd.cpp b/src/openttd.cpp
index d2285a318..0ab4dc4c0 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -321,9 +321,6 @@ static void LoadIntroGame()
 {
 	_game_mode = GM_MENU;
 
-	/* Clear transparency options */
-	_transparent_opt = 0;
-
 	_opt_ptr = &_opt_newgame;
 	ResetGRFConfig(false);
 
diff --git a/src/openttd.h b/src/openttd.h
index 2fdf8e0a9..79cfb5783 100644
--- a/src/openttd.h
+++ b/src/openttd.h
@@ -187,17 +187,6 @@ enum {
 	DO_WAYPOINTS          = 6,
 };
 
-enum {
-	TO_SIGNS,
-	TO_TREES,
-	TO_HOUSES,
-	TO_INDUSTRIES,
-	TO_BUILDINGS,
-	TO_BRIDGES,
-	TO_STRUCTURES,
-	TO_LOADING,
-};
-
 /* Landscape types */
 enum {
 	LT_TEMPERATE  = 0,
diff --git a/src/rail_cmd.cpp b/src/rail_cmd.cpp
index f0e16edf5..957c37b07 100644
--- a/src/rail_cmd.cpp
+++ b/src/rail_cmd.cpp
@@ -40,6 +40,7 @@
 #include "train.h"
 #include "misc/autoptr.hpp"
 #include "autoslope.h"
+#include "transparency.h"
 
 const byte _track_sloped_sprites[14] = {
 	14, 15, 22, 13,
@@ -1755,7 +1756,7 @@ default_waypoint:
 				image += relocation;
 			}
 
-			if (!HASBIT(_transparent_opt, TO_BUILDINGS) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
+			if (!IsTransparencySet(TO_BUILDINGS) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
 				pal = _drawtile_track_palette;
 			} else {
 				pal = dtss->pal;
@@ -1767,7 +1768,7 @@ default_waypoint:
 					ti->x + dtss->delta_x, ti->y + dtss->delta_y,
 					dtss->size_x, dtss->size_y,
 					dtss->size_z, ti->z + dtss->delta_z,
-					HASBIT(_transparent_opt, TO_BUILDINGS)
+					IsTransparencySet(TO_BUILDINGS)
 				);
 			} else {
 				AddChildSpriteScreen(image, pal, dtss->delta_x, dtss->delta_y);
diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp
index 886593b33..68ec7d957 100644
--- a/src/road_cmd.cpp
+++ b/src/road_cmd.cpp
@@ -33,6 +33,7 @@
 #include "tunnel_map.h"
 #include "misc/autoptr.hpp"
 #include "autoslope.h"
+#include "transparency.h"
 
 #define M(x) (1 << (x))
 /* Level crossings may only be built on these slopes */
@@ -946,7 +947,7 @@ static bool AlwaysDrawUnpavedRoads(TileIndex tile, Roadside roadside)
 void DrawTramCatenary(TileInfo *ti, RoadBits tram)
 {
 	/* Don't draw the catenary under a low bridge */
-	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !HASBIT(_transparent_opt, TO_BUILDINGS)) {
+	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !IsTransparencySet(TO_BUILDINGS)) {
 		uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));
 
 		if (height <= GetTileMaxZ(ti->tile) + TILE_HEIGHT) return;
@@ -963,8 +964,8 @@ void DrawTramCatenary(TileInfo *ti, RoadBits tram)
 		front = SPR_TRAMWAY_BASE + _road_frontwire_sprites_1[tram];
 	}
 
-	AddSortableSpriteToDraw(back,  PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, HASBIT(_transparent_opt, TO_BUILDINGS));
-	AddSortableSpriteToDraw(front, PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, HASBIT(_transparent_opt, TO_BUILDINGS));
+	AddSortableSpriteToDraw(back,  PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, IsTransparencySet(TO_BUILDINGS));
+	AddSortableSpriteToDraw(front, PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, IsTransparencySet(TO_BUILDINGS));
 }
 
 /**
@@ -1120,7 +1121,7 @@ static void DrawTile_Road(TileInfo *ti)
 				SpriteID image = dtss->image;
 				SpriteID pal;
 
-				if (!HASBIT(_transparent_opt, TO_BUILDINGS) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
+				if (!IsTransparencySet(TO_BUILDINGS) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
 					pal = palette;
 				} else {
 					pal = PAL_NONE;
@@ -1131,7 +1132,7 @@ static void DrawTile_Road(TileInfo *ti)
 					ti->x + dtss->delta_x, ti->y + dtss->delta_y,
 					dtss->size_x, dtss->size_y,
 					dtss->size_z, ti->z,
-					HASBIT(_transparent_opt, TO_BUILDINGS)
+					IsTransparencySet(TO_BUILDINGS)
 				);
 			}
 			break;
diff --git a/src/settings.cpp b/src/settings.cpp
index 4e35b1954..d268ff1df 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -49,6 +49,7 @@
 #include "fontcache.h"
 #endif
 #include "spritecache.h"
+#include "transparency.h"
 
 /** The patch values that are used for new games and/or modified in config file */
 Patches _patches_newgame;
@@ -1275,6 +1276,7 @@ static const SettingDescGlobVarList _misc_settings[] = {
 #endif
 	  SDTG_VAR("sprite_cache_size",SLE_UINT, S, 0, _sprite_cache_size,     4, 1, 64, 0, STR_NULL, NULL),
 	  SDTG_VAR("player_face",    SLE_UINT32, S, 0, _player_face,      0,0,0xFFFFFFFF,0, STR_NULL, NULL),
+	  SDTG_VAR("transparency_options", SLE_UINT8, S, 0, _transparency_opt, 0, 0,0xFF,0, STR_NULL, NULL),
 	  SDTG_END()
 };
 
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 9bc18c759..dcf3f1f53 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -43,6 +43,7 @@
 #include "cargotype.h"
 #include "strings.h"
 #include "autoslope.h"
+#include "transparency.h"
 
 DEFINE_OLD_POOL_GENERIC(Station, Station)
 DEFINE_OLD_POOL_GENERIC(RoadStop, RoadStop)
@@ -2138,7 +2139,7 @@ static void DrawTile_Station(TileInfo *ti)
 		}
 
 		SpriteID pal;
-		if (!HASBIT(_transparent_opt, TO_BUILDINGS) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
+		if (!IsTransparencySet(TO_BUILDINGS) && HASBIT(image, PALETTE_MODIFIER_COLOR)) {
 			pal = palette;
 		} else {
 			pal = dtss->pal;
@@ -2150,10 +2151,10 @@ static void DrawTile_Station(TileInfo *ti)
 				ti->x + dtss->delta_x, ti->y + dtss->delta_y,
 				dtss->size_x, dtss->size_y,
 				dtss->size_z, ti->z + dtss->delta_z,
-				HASBIT(_transparent_opt, TO_BUILDINGS)
+				IsTransparencySet(TO_BUILDINGS)
 			);
 		} else {
-			AddChildSpriteScreen(image, pal, dtss->delta_x, dtss->delta_y, HASBIT(_transparent_opt, TO_BUILDINGS));
+			AddChildSpriteScreen(image, pal, dtss->delta_x, dtss->delta_y, IsTransparencySet(TO_BUILDINGS));
 		}
 	}
 }
diff --git a/src/texteff.cpp b/src/texteff.cpp
index f42a650e4..eae4e0aed 100644
--- a/src/texteff.cpp
+++ b/src/texteff.cpp
@@ -20,6 +20,7 @@
 #include "date.h"
 #include "texteff.hpp"
 #include "video/video_driver.hpp"
+#include "transparency.h"
 
 enum {
 	MAX_TEXTMESSAGE_LENGTH = 200,
@@ -390,7 +391,7 @@ void DrawTextEffects(DrawPixelInfo *dpi)
 						dpi->top  <= te->bottom &&
 						dpi->left + dpi->width  > te->x &&
 						dpi->top  + dpi->height > te->y) {
-					if (te->mode == TE_RISING || (_patches.loading_indicators && !HASBIT(_transparent_opt, TO_LOADING))) {
+					if (te->mode == TE_RISING || (_patches.loading_indicators && !IsTransparencySet(TO_LOADING))) {
 						AddStringToDraw(te->x, te->y, te->string_id, te->params_1, te->params_2);
 					}
 				}
@@ -405,7 +406,7 @@ void DrawTextEffects(DrawPixelInfo *dpi)
 						dpi->top  <= te->bottom * 2 - te->y &&
 						dpi->left + dpi->width  > te->x &&
 						dpi->top  + dpi->height > te->y) {
-					if (te->mode == TE_RISING || (_patches.loading_indicators && !HASBIT(_transparent_opt, TO_LOADING))) {
+					if (te->mode == TE_RISING || (_patches.loading_indicators && !IsTransparencySet(TO_LOADING))) {
 						AddStringToDraw(te->x, te->y, (StringID)(te->string_id - 1), te->params_1, te->params_2);
 					}
 				}
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 8a9e00dd5..e6891accd 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -43,6 +43,7 @@
 #include "misc/autoptr.hpp"
 #include "autoslope.h"
 #include "waypoint.h"
+#include "transparency.h"
 
 /* Initialize the town-pool */
 DEFINE_OLD_POOL_GENERIC(Town, Town)
@@ -183,10 +184,10 @@ static void DrawTile_Town(TileInfo *ti)
 			dcts->height,
 			dcts->dz,
 			ti->z,
-			HASBIT(_transparent_opt, TO_HOUSES)
+			IsTransparencySet(TO_HOUSES)
 		);
 
-		if (HASBIT(_transparent_opt, TO_HOUSES)) return;
+		if (IsTransparencySet(TO_HOUSES)) return;
 	}
 
 	{
diff --git a/src/transparency.h b/src/transparency.h
new file mode 100644
index 000000000..3dae9cecc
--- /dev/null
+++ b/src/transparency.h
@@ -0,0 +1,69 @@
+/* $Id$ */
+
+/** @file transparency.h */
+
+#ifndef TRANSPARENCY_H
+#define TRANSPARENCY_H
+
+/**
+ * Transparency option bits: which position in _transparency_opt stands for which transparency.
+ * If you change the order, change the order of the ShowTransparencyToolbar() stuff in transparency_gui.cpp too.
+ * If you add or remove an option don't forget to change the transparency 'hot keys' in main_gui.cpp.
+ * If you add an option and have more then 8, change the typedef TransparencyOptionBits and
+ * the save stuff (e.g. SLE_UINT8 to SLE_UINT16) in settings.cpp .
+ */
+enum TransparencyOption {
+	TO_SIGNS = 0,  ///< signs
+	TO_TREES,      ///< trees
+	TO_HOUSES,     ///< town buildings
+	TO_INDUSTRIES, ///< industries
+	TO_BUILDINGS,  ///< player buildings - depots, stations, HQ, ...
+	TO_BRIDGES,    ///< bridges
+	TO_STRUCTURES, ///< unmovable structures
+	TO_LOADING,    ///< loading indicators
+	TO_END,
+};
+
+typedef byte TransparencyOptionBits; ///< transparency option bits
+extern TransparencyOptionBits _transparency_opt;
+
+/**
+ * Check if the transparency option bit is set
+ * and if we aren't in the game menu (there's never transparency)
+ *
+ * @param to the structure which transparency option is ask for
+ */
+static inline bool IsTransparencySet(TransparencyOption to)
+{
+	return (HASBIT(_transparency_opt, to) && _game_mode != GM_MENU);
+}
+
+/**
+ * Toggle the transparency option bit
+ *
+ * @param to the structure which transparency option is toggle
+ */
+static inline void ToggleTransparency(TransparencyOption to)
+{
+	TOGGLEBIT(_transparency_opt, to);
+}
+
+/** Toggle all transparency options (except signs) or restore the stored transparencies */
+static inline void ResetRestoreAllTransparency()
+{
+	/* backup of the original transparencies or if all transparencies false toggle them to true */
+	static TransparencyOptionBits trans_opt = ~0;
+
+	if (_transparency_opt == 0) {
+		/* no structure is transparent, so restore the old transparency if present otherwise set all true */
+		_transparency_opt = trans_opt;
+	} else {
+		/* any structure is transparent, so store current transparency settings and reset it */
+		trans_opt = _transparency_opt;
+		_transparency_opt = 0;
+	}
+
+	MarkWholeScreenDirty();
+}
+
+#endif /* TRANSPARENCY_H */
diff --git a/src/transparency_gui.cpp b/src/transparency_gui.cpp
index bebb18fa1..d66f494b9 100644
--- a/src/transparency_gui.cpp
+++ b/src/transparency_gui.cpp
@@ -11,6 +11,9 @@
 #include "gfx.h"
 #include "sound.h"
 #include "variables.h"
+#include "transparency.h"
+
+TransparencyOptionBits _transparency_opt;
 
 enum TransparencyToolbarWidgets{
 	/* Widgets not toggled when pressing the X key */
@@ -27,16 +30,6 @@ enum TransparencyToolbarWidgets{
 	TTW_WIDGET_END,          ///< End of toggle buttons
 };
 
-/** Toggle the bits of the transparencies variable
- * when clicking on a widget, and play a sound
- * @param widget been clicked.
- */
-static void Transparent_Click(byte widget)
-{
-	TOGGLEBIT(_transparent_opt, widget);
-	SndPlayFx(SND_15_BEEP);
-}
-
 static void TransparencyToolbWndProc(Window *w, WindowEvent *e)
 {
 	switch (e->event) {
@@ -44,14 +37,16 @@ static void TransparencyToolbWndProc(Window *w, WindowEvent *e)
 			/* must be sure that the widgets show the transparency variable changes
 			 * also when we use shortcuts */
 			for (uint i = TTW_WIDGET_SIGNS; i < TTW_WIDGET_END; i++) {
-				SetWindowWidgetLoweredState(w, i, HASBIT(_transparent_opt, i - TTW_WIDGET_SIGNS));
+				SetWindowWidgetLoweredState(w, i, IsTransparencySet((TransparencyOption)(i - TTW_WIDGET_SIGNS)));
 			}
 			DrawWindowWidgets(w);
 			break;
 
 		case WE_CLICK:
 			if (e->we.click.widget >= TTW_WIDGET_SIGNS) {
-				Transparent_Click(e->we.click.widget - TTW_WIDGET_SIGNS);
+				/* toggle the bit of the transparencies variable when clicking on a widget, and play a sound */
+				ToggleTransparency((TransparencyOption)(e->we.click.widget - TTW_WIDGET_SIGNS));
+				SndPlayFx(SND_15_BEEP);
 				MarkWholeScreenDirty();
 			}
 			break;
diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
index a901143a3..3e53fbee7 100644
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -20,6 +20,7 @@
 #include "sound.h"
 #include "variables.h"
 #include "genworld.h"
+#include "transparency.h"
 
 /**
  * List of tree placer algorithm.
@@ -427,7 +428,7 @@ static void DrawTile_Trees(TileInfo *ti)
 
 	StartSpriteCombine();
 
-	if (!HASBIT(_transparent_opt, TO_TREES) || !_patches.invisible_trees) {
+	if (!IsTransparencySet(TO_TREES) || !_patches.invisible_trees) {
 		TreeListEnt te[4];
 		uint i;
 
@@ -460,7 +461,7 @@ static void DrawTile_Trees(TileInfo *ti)
 
 			if (tep == NULL) break;
 
-			AddSortableSpriteToDraw(tep->image, tep->pal, ti->x + tep->x, ti->y + tep->y, 16 - tep->x, 16 - tep->y, 0x30, z, HASBIT(_transparent_opt, TO_TREES), -tep->x, -tep->y);
+			AddSortableSpriteToDraw(tep->image, tep->pal, ti->x + tep->x, ti->y + tep->y, 16 - tep->x, 16 - tep->y, 0x30, z, IsTransparencySet(TO_TREES), -tep->x, -tep->y);
 			tep->image = 0;
 		}
 	}
diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
index 1145913e2..d5ff51d95 100644
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -33,6 +33,7 @@
 #include "date.h"
 #include "newgrf_sound.h"
 #include "autoslope.h"
+#include "transparency.h"
 
 #include "table/bridge_land.h"
 
@@ -858,12 +859,12 @@ static void DrawBridgePillars(const PalSpriteID *psid, const TileInfo* ti, Axis
 		for (int cur_z = z_bridge; cur_z >= front_height || cur_z >= back_height; cur_z -= TILE_HEIGHT) {
 			/* Draw front facing pillar */
 			if (cur_z >= front_height) {
-				AddSortableSpriteToDraw(image, psid->pal, x, y, w, h, BB_HEIGHT_UNDER_BRIDGE - 5, cur_z, HASBIT(_transparent_opt, TO_BRIDGES), 0, 0, -5);
+				AddSortableSpriteToDraw(image, psid->pal, x, y, w, h, BB_HEIGHT_UNDER_BRIDGE - 5, cur_z, IsTransparencySet(TO_BRIDGES), 0, 0, -5);
 			}
 
 			/* Draw back facing pillar, but not the highest part directly under the bridge-floor */
 			if (drawfarpillar && cur_z >= back_height && cur_z < z_bridge - TILE_HEIGHT) {
-				AddSortableSpriteToDraw(image, psid->pal, x_back, y_back, w, h, BB_HEIGHT_UNDER_BRIDGE - 5, cur_z, HASBIT(_transparent_opt, TO_BRIDGES), 0, 0, -5);
+				AddSortableSpriteToDraw(image, psid->pal, x_back, y_back, w, h, BB_HEIGHT_UNDER_BRIDGE - 5, cur_z, IsTransparencySet(TO_BRIDGES), 0, 0, -5);
 			}
 		}
 	}
@@ -897,16 +898,16 @@ static void DrawBridgeTramBits(int x, int y, byte z, int offset, bool overlay)
 
 	/* The sprites under the vehicles are drawn as SpriteCombine. StartSpriteCombine() has already been called
 	 * The bounding boxes here are the same as for bridge front/roof */
-	AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + tram_offsets[overlay][offset], PAL_NONE, x, y, size_x[offset], size_y[offset], 0x28, z, HASBIT(_transparent_opt, TO_BRIDGES));
+	AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + tram_offsets[overlay][offset], PAL_NONE, x, y, size_x[offset], size_y[offset], 0x28, z, IsTransparencySet(TO_BRIDGES));
 
-	AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + back_offsets[offset],  PAL_NONE, x, y, size_x[offset], size_y[offset], 0x28, z, HASBIT(_transparent_opt, TO_BUILDINGS));
+	AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + back_offsets[offset],  PAL_NONE, x, y, size_x[offset], size_y[offset], 0x28, z, IsTransparencySet(TO_BUILDINGS));
 
 	/* Start a new SpriteCombine for the front part */
 	EndSpriteCombine();
 	StartSpriteCombine();
 
 	/* For sloped sprites the bounding box needs to be higher, as the pylons stop on a higher point */
-	AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + front_offsets[offset], PAL_NONE, x, y, size_x[offset] + front_bb_offset_x[offset], size_y[offset] + front_bb_offset_y[offset], 0x28, z, HASBIT(_transparent_opt, TO_BUILDINGS), front_bb_offset_x[offset], front_bb_offset_y[offset]);
+	AddSortableSpriteToDraw(SPR_TRAMWAY_BASE + front_offsets[offset], PAL_NONE, x, y, size_x[offset] + front_bb_offset_x[offset], size_y[offset] + front_bb_offset_y[offset], 0x28, z, IsTransparencySet(TO_BUILDINGS), front_bb_offset_x[offset], front_bb_offset_y[offset]);
 }
 
 /**
@@ -969,7 +970,7 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 
 				catenary = true;
 				StartSpriteCombine();
-				AddSortableSpriteToDraw(SPR_TRAMWAY_TUNNEL_WIRES + dir, PAL_NONE, ti->x, ti->y, BB_data[10], BB_data[11], TILE_HEIGHT, ti->z, HASBIT(_transparent_opt, TO_BUILDINGS), BB_data[8], BB_data[9], BB_Z_SEPARATOR);
+				AddSortableSpriteToDraw(SPR_TRAMWAY_TUNNEL_WIRES + dir, PAL_NONE, ti->x, ti->y, BB_data[10], BB_data[11], TILE_HEIGHT, ti->z, IsTransparencySet(TO_BUILDINGS), BB_data[8], BB_data[9], BB_Z_SEPARATOR);
 			}
 		} else if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) {
 			DrawCatenary(ti);
@@ -1028,7 +1029,7 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		 * it doesn't disappear behind it
 		 */
 		AddSortableSpriteToDraw(
-			psid->sprite, psid->pal, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 0 : 8, ti->z, HASBIT(_transparent_opt, TO_BRIDGES)
+			psid->sprite, psid->pal, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 0 : 8, ti->z, IsTransparencySet(TO_BRIDGES)
 		);
 
 		if (GetBridgeTransportType(ti->tile) == TRANSPORT_ROAD) {
@@ -1156,9 +1157,9 @@ void DrawBridgeMiddle(const TileInfo* ti)
 
 	/* Draw floor and far part of bridge*/
 	if (axis == AXIS_X) {
-		AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 1, 0x28, z, HASBIT(_transparent_opt, TO_BRIDGES), 0, 0, BRIDGE_Z_START);
+		AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 1, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 0, BRIDGE_Z_START);
 	} else {
-		AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 1, 16, 0x28, z, HASBIT(_transparent_opt, TO_BRIDGES), 0, 0, BRIDGE_Z_START);
+		AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 1, 16, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 0, BRIDGE_Z_START);
 	}
 
 	psid++;
@@ -1180,10 +1181,10 @@ void DrawBridgeMiddle(const TileInfo* ti)
 	/* draw roof, the component of the bridge which is logically between the vehicle and the camera */
 	if (axis == AXIS_X) {
 		y += 12;
-		if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 4, 0x28, z, HASBIT(_transparent_opt, TO_BRIDGES), 0, 3, BRIDGE_Z_START);
+		if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 16, 4, 0x28, z, IsTransparencySet(TO_BRIDGES), 0, 3, BRIDGE_Z_START);
 	} else {
 		x += 12;
-		if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 4, 16, 0x28, z, HASBIT(_transparent_opt, TO_BRIDGES), 3, 0, BRIDGE_Z_START);
+		if (psid->sprite & SPRITE_MASK) AddSortableSpriteToDraw(psid->sprite, psid->pal, x, y, 4, 16, 0x28, z, IsTransparencySet(TO_BRIDGES), 3, 0, BRIDGE_Z_START);
 	}
 
 	/* Draw TramFront as SpriteCombine */
@@ -1195,7 +1196,7 @@ void DrawBridgeMiddle(const TileInfo* ti)
 		if (psid->sprite != 0) {
 			SpriteID image = psid->sprite;
 			SpriteID pal   = psid->pal;
-			if (HASBIT(_transparent_opt, TO_BRIDGES)) {
+			if (IsTransparencySet(TO_BRIDGES)) {
 				SETBIT(image, PALETTE_MODIFIER_TRANSPARENT);
 				pal = PALETTE_TO_TRANSPARENT;
 			}
diff --git a/src/unmovable_cmd.cpp b/src/unmovable_cmd.cpp
index b5b9fe4c6..f711e8aab 100644
--- a/src/unmovable_cmd.cpp
+++ b/src/unmovable_cmd.cpp
@@ -25,6 +25,7 @@
 #include "genworld.h"
 #include "bridge.h"
 #include "autoslope.h"
+#include "transparency.h"
 
 /** Destroy a HQ.
  * During normal gameplay you can only implicitely destroy a HQ when you are
@@ -129,7 +130,7 @@ static void DrawTile_Unmovable(TileInfo *ti)
 			AddSortableSpriteToDraw(
 				dtus->image, PAL_NONE, ti->x | dtus->subcoord_x, ti->y | dtus->subcoord_y,
 				dtus->width, dtus->height, dtus->z_size, ti->z,
-				HASBIT(_transparent_opt, TO_STRUCTURES)
+				IsTransparencySet(TO_STRUCTURES)
 			);
 			break;
 		}
@@ -140,7 +141,7 @@ static void DrawTile_Unmovable(TileInfo *ti)
 
 			DrawGroundSprite(SPR_CONCRETE_GROUND, PAL_NONE);
 
-			AddSortableSpriteToDraw(SPR_STATUE_COMPANY, PLAYER_SPRITE_COLOR(GetTileOwner(ti->tile)), ti->x, ti->y, 16, 16, 25, ti->z, HASBIT(_transparent_opt, TO_STRUCTURES));
+			AddSortableSpriteToDraw(SPR_STATUE_COMPANY, PLAYER_SPRITE_COLOR(GetTileOwner(ti->tile)), ti->x, ti->y, 16, 16, 25, ti->z, IsTransparencySet(TO_STRUCTURES));
 			break;
 
 		case UNMOVABLE_OWNED_LAND:
@@ -172,7 +173,7 @@ static void DrawTile_Unmovable(TileInfo *ti)
 					ti->x + dtss->delta_x, ti->y + dtss->delta_y,
 					dtss->size_x, dtss->size_y,
 					dtss->size_z, ti->z + dtss->delta_z,
-					HASBIT(_transparent_opt, TO_STRUCTURES)
+					IsTransparencySet(TO_STRUCTURES)
 				);
 			}
 			break;
diff --git a/src/variables.h b/src/variables.h
index 02e18885f..da7b46f8d 100644
--- a/src/variables.h
+++ b/src/variables.h
@@ -290,7 +290,6 @@ VARDEF bool _do_autosave;
 VARDEF int _autosave_ctr;
 
 VARDEF byte _display_opt;
-VARDEF byte _transparent_opt;
 VARDEF int _caret_timer;
 VARDEF uint32 _news_display_opt;
 VARDEF bool _news_ticker_sound;
diff --git a/src/viewport.cpp b/src/viewport.cpp
index e03a3b948..fa816b6fb 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -26,6 +26,7 @@
 #include "roadveh.h"
 #include "vehicle_gui.h"
 #include "blitter/factory.hpp"
+#include "transparency.h"
 
 #define VIEWPORT_DRAW_MEM (65536 * 2)
 
@@ -1483,10 +1484,10 @@ static void ViewportDrawStrings(DrawPixelInfo *dpi, const StringSpriteToDraw *ss
 
 		/* Draw the rectangle if 'tranparent station signs' is off,
 		 * or if we are drawing a general text sign (STR_2806) */
-			if (!HASBIT(_transparent_opt, TO_SIGNS) || ss->string == STR_2806) {
+			if (!IsTransparencySet(TO_SIGNS) || ss->string == STR_2806) {
 				DrawFrameRect(
 					x, y, x + w, bottom, ss->color,
-					HASBIT(_transparent_opt, TO_SIGNS) ? FR_TRANSPARENT : FR_NONE
+					IsTransparencySet(TO_SIGNS) ? FR_TRANSPARENT : FR_NONE
 				);
 			}
 		}
@@ -1495,7 +1496,7 @@ static void ViewportDrawStrings(DrawPixelInfo *dpi, const StringSpriteToDraw *ss
 		SetDParam(1, ss->params[1]);
 		/* if we didn't draw a rectangle, or if transparant building is on,
 		 * draw the text in the color the rectangle would have */
-		if (HASBIT(_transparent_opt, TO_SIGNS) && ss->string != STR_2806 && ss->width != 0) {
+		if (IsTransparencySet(TO_SIGNS) && ss->string != STR_2806 && ss->width != 0) {
 			/* Real colors need the IS_PALETTE_COLOR flag
 			 * otherwise colors from _string_colormap are assumed. */
 			colour = _colour_gradient[ss->color][6] | IS_PALETTE_COLOR;
diff --git a/src/water_cmd.cpp b/src/water_cmd.cpp
index 87eaa675f..14b570dd7 100644
--- a/src/water_cmd.cpp
+++ b/src/water_cmd.cpp
@@ -30,6 +30,7 @@
 #include "newgrf.h"
 #include "newgrf_canal.h"
 #include "misc/autoptr.hpp"
+#include "transparency.h"
 
 /** Array for the shore sprites */
 static const SpriteID _water_shore_sprites[] = {
@@ -449,7 +450,7 @@ static void DrawWaterStuff(const TileInfo *ti, const WaterDrawTileStruct *wdts,
 			ti->x + wdts->delta_x, ti->y + wdts->delta_y,
 			wdts->width, wdts->height,
 			wdts->unk, ti->z + wdts->delta_z,
-			HASBIT(_transparent_opt, TO_BUILDINGS));
+			IsTransparencySet(TO_BUILDINGS));
 	}
 }