(svn r6758) -Feature: Add a measurement tool that will show dimensions and height

 differences of various draggable tools (inspiration, concept and double
 checking by MeusH).

8 files changed, 279 insertions, 45 deletions

diff --git a/lang/english.txt b/lang/english.txt
index 0de6b0ed2..35d197f62 100644
--- a/lang/english.txt
+++ b/lang/english.txt
@@ -1065,6 +1065,7 @@ STR_CONFIG_PATCHES_STATION_SPREAD                               :{LTBLUE}Max sta
 STR_CONFIG_PATCHES_SERVICEATHELIPAD                             :{LTBLUE}Service helicopters at helipads automatically: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_LINK_TERRAFORM_TOOLBAR                       :{LTBLUE}Link landscape toolbar to rail/road/water/airport toolbars: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_REVERSE_SCROLLING                            :{LTBLUE}Reverse scroll direction: {ORANGE}{STRING1}
+STR_CONFIG_PATCHES_MEASURE_TOOLTIP                              :{LTBLUE}Show a measurement tooltip when using various build-tools: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_LIVERIES                                     :{LTBLUE}Show company liveries: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_LIVERIES_NONE                                :None
 STR_CONFIG_PATCHES_LIVERIES_OWN                                 :Own company
@@ -3093,4 +3094,11 @@ STR_LARGE_AIRPORTS                                              :{BLACK}Large ai
 STR_HUB_AIRPORTS                                                :{BLACK}Hub airports
 STR_HELIPORTS                                                   :{BLACK}Helicopter airports
 
+############ Tooltip measurment
+
+STR_MEASURE_LENGTH                                              :{BLACK}Length: {NUM}
+STR_MEASURE_AREA                                                :{BLACK}Area: {NUM} x {NUM}
+STR_MEASURE_LENGTH_HEIGHTDIFF                                   :{BLACK}Length: {NUM}{}Height difference: {NUM} m
+STR_MEASURE_AREA_HEIGHTDIFF                                     :{BLACK}Area: {NUM} x {NUM}{}Height difference: {NUM} m
+
 ########
diff --git a/macros.h b/macros.h
index f5c78cc35..8e310c07e 100644
--- a/macros.h
+++ b/macros.h
@@ -148,6 +148,7 @@ static inline int64 myabs64(int64 a) { if (a<0) a = -a; return a; }
 static inline void swap_byte(byte *a, byte *b) { byte t = *a; *a = *b; *b = t; }
 static inline void swap_uint16(uint16 *a, uint16 *b) { uint16 t = *a; *a = *b; *b = t; }
 static inline void swap_int16(int16 *a, int16 *b) { int16 t = *a; *a = *b; *b = t; }
+static inline void swap_uint32(uint32 *a, uint32 *b) { uint32 t = *a; *a = *b; *b = t; }
 static inline void swap_int32(int32 *a, int32 *b) { int32 t = *a; *a = *b; *b = t; }
 static inline void swap_tile(TileIndex *a, TileIndex *b) { TileIndex t = *a; *a = *b; *b = t; }
 
diff --git a/misc_gui.c b/misc_gui.c
index 047866eab..a812d5210 100644
--- a/misc_gui.c
+++ b/misc_gui.c
@@ -636,57 +636,77 @@ static const Widget _tooltips_widgets[] = {
 static void TooltipsWndProc(Window *w, WindowEvent *e)
 {
 	switch (e->event) {
-		case WE_PAINT:
+		case WE_PAINT: {
+			uint arg;
 			GfxFillRect(0, 0, w->width - 1, w->height - 1, 0);
 			GfxFillRect(1, 1, w->width - 2, w->height - 2, 0x44);
-			DrawStringMultiCenter((w->width >> 1), (w->height >> 1) - 5, WP(w,tooltips_d).string_id, 197);
+
+			for (arg = 0; arg < WP(w, tooltips_d).paramcount; arg++) {
+				SetDParam(arg, WP(w, tooltips_d).params[arg]);
+			}
+			DrawStringMultiCenter((w->width >> 1), (w->height >> 1) - 5, WP(w, tooltips_d).string_id, 197);
 			break;
+		}
 
 		case WE_MOUSELOOP:
-			if (!_right_button_down) DeleteWindow(w);
+			/* We can show tooltips while dragging tools. These are shown as long as
+			 * we are dragging the tool. Normal tooltips work with rmb */
+			if (WP(w, tooltips_d).paramcount == 0 ) {
+				if (!_right_button_down) DeleteWindow(w);
+			} else {
+				if (!_left_button_down) DeleteWindow(w);
+			}
+
 			break;
 	}
 }
 
-void GuiShowTooltips(StringID string_id)
+/** Shows a tooltip
+* @param str String to be displayed
+* @param params (optional) up to 5 pieces of additional information that may be
+* added to a tooltip; currently only supports parameters of {NUM} (integer) */
+void GuiShowTooltipsWithArgs(StringID str, uint paramcount, uint32 params[])
 {
 	char buffer[512];
-	Window *w;
-	int right,bottom;
-	int x,y;
+	BoundingRect br;
+	uint i;
+	int x, y;
 
-	if (string_id == 0) return;
+	Window *w = FindWindowById(WC_TOOLTIPS, 0);
+	if (w != NULL) DeleteWindow(w);
 
-	w = FindWindowById(WC_TOOLTIPS, 0);
-	if (w != NULL) {
-		if (WP(w,tooltips_d).string_id == string_id)
-			return;
-		DeleteWindow(w);
-	}
+	/* We only show measurement tooltips with shift pressed down */
+	if (paramcount != 0 && !_patches.measure_tooltip) return;
 
-	GetString(buffer, string_id);
+	for (i = 0; i != paramcount; i++) SetDParam(i, params[i]);
+	GetString(buffer, str);
 
-	right = GetStringBoundingBox(buffer).width + 6;
+	br = GetStringBoundingBox(buffer);
+	br.width += 6; br.height += 4; // increase slightly to have some space around the box
 
 	/* Cut tooltip length to 200 pixels max, wrap to new line if longer */
-	bottom = 14;
-	if (right > 200) {
-		bottom += ((right - 4) / 176) * 10;
-		right = 200;
+	if (br.width > 200) {
+		br.height += ((br.width - 4) / 176) * 10;
+		br.width = 200;
 	}
 
 	/* Correctly position the tooltip position, watch out for window and cursor size
 	 * Clamp value to below main toolbar and above statusbar. If tooltip would
 	 * go below window, flip it so it is shown above the cursor */
 	y = clamp(_cursor.pos.y + _cursor.size.y + _cursor.offs.y + 5, 22, _screen.height - 12);
-	if (y + bottom > _screen.height - 12) y = _cursor.pos.y + _cursor.offs.y - bottom - 5;
-	x = clamp(_cursor.pos.x - (right >> 1), 0, _screen.width - right);
+	if (y + br.height > _screen.height - 12) y = _cursor.pos.y + _cursor.offs.y - br.height - 5;
+	x = clamp(_cursor.pos.x - (br.width >> 1), 0, _screen.width - br.width);
+
+	w = AllocateWindow(x, y, br.width, br.height, TooltipsWndProc, WC_TOOLTIPS, _tooltips_widgets);
+
+	WP(w, tooltips_d).string_id = str;
+	assert(sizeof(WP(w, tooltips_d).params[0]) == sizeof(params[0]));
+	memcpy(WP(w, tooltips_d).params, params, sizeof(WP(w, tooltips_d).params[0]) * paramcount);
+	WP(w, tooltips_d).paramcount = paramcount;
 
-	w = AllocateWindow(x, y, right, bottom, TooltipsWndProc, WC_TOOLTIPS, _tooltips_widgets);
-	WP(w,tooltips_d).string_id = string_id;
 	w->flags4 &= ~WF_WHITE_BORDER_MASK; // remove white-border from tooltip
-	w->widget[0].right = right;
-	w->widget[0].bottom = bottom;
+	w->widget[0].right = br.width;
+	w->widget[0].bottom = br.height;
 }
 
 
diff --git a/settings.c b/settings.c
index b8b72dd54..06a4870ba 100644
--- a/settings.c
+++ b/settings.c
@@ -1254,6 +1254,7 @@ const SettingDesc _patch_settings[] = {
 	SDT_BOOL(Patches, show_finances,                 S, 0,  true,        STR_CONFIG_PATCHES_SHOWFINANCES,          NULL),
 	SDT_BOOL(Patches, autoscroll,                    S, 0, false,        STR_CONFIG_PATCHES_AUTOSCROLL,            NULL),
 	SDT_BOOL(Patches, reverse_scroll,                S, 0, false,        STR_CONFIG_PATCHES_REVERSE_SCROLLING,     NULL),
+	SDT_BOOL(Patches, measure_tooltip,               S, 0, false,        STR_CONFIG_PATCHES_MEASURE_TOOLTIP,       NULL),
 	 SDT_VAR(Patches, errmsg_duration,    SLE_UINT8, S, 0,  5, 0, 20, 0, STR_CONFIG_PATCHES_ERRMSG_DURATION,       NULL),
 	 SDT_VAR(Patches, toolbar_pos,        SLE_UINT8, S,MS,  0, 0,  2, 0, STR_CONFIG_PATCHES_TOOLBAR_POS,           v_PositionMainToolbar),
 	 SDT_VAR(Patches, window_snap_radius, SLE_UINT8, S,D0, 10, 1, 32, 0, STR_CONFIG_PATCHES_SNAP_RADIUS,           NULL),
diff --git a/settings_gui.c b/settings_gui.c
index 6530aa137..b93a480c8 100644
--- a/settings_gui.c
+++ b/settings_gui.c
@@ -566,6 +566,7 @@ static const char *_patches_ui[] = {
 	"reverse_scroll",
 	"errmsg_duration",
 	"toolbar_pos",
+	"measure_tooltip",
 	"window_snap_radius",
 	"invisible_trees",
 	"population_in_label",
diff --git a/variables.h b/variables.h
index b7a1071cd..ef3d04b42 100644
--- a/variables.h
+++ b/variables.h
@@ -126,6 +126,7 @@ typedef struct Patches {
 	bool no_servicing_if_no_breakdowns; // dont send vehicles to depot when breakdowns are disabled
 	bool link_terraform_toolbar;        // display terraform toolbar when displaying rail, road, water and airport toolbars
 	bool reverse_scroll;                // Right-Click-Scrolling scrolls in the opposite direction
+	bool measure_tooltip;               // Show a permanent tooltip when dragging tools
 	byte liveries;                      // Options for displaying company liveries, 0=none, 1=self, 2=all
 
 	uint8 toolbar_pos;                  // position of toolbars, 0=left, 1=center, 2=right
diff --git a/viewport.c b/viewport.c
index 5db949401..1053c0c21 100644
--- a/viewport.c
+++ b/viewport.c
@@ -1937,13 +1937,22 @@ void VpSetPlaceSizingLimit(int limit)
 	_thd.sizelimit = limit;
 }
 
-void VpSetPresizeRange(uint from, uint to)
+/**
+* Highlights all tiles between a set of two tiles. Used in dock and tunnel placement
+* @param from TileIndex of the first tile to highlight
+* @param to TileIndex of the last tile to highlight */
+void VpSetPresizeRange(TileIndex from, TileIndex to)
 {
+	uint distance = DistanceManhattan(from, to) + 1;
+
 	_thd.selend.x = TileX(to) * TILE_SIZE;
 	_thd.selend.y = TileY(to) * TILE_SIZE;
 	_thd.selstart.x = TileX(from) * TILE_SIZE;
 	_thd.selstart.y = TileY(from) * TILE_SIZE;
 	_thd.next_drawstyle = HT_RECT;
+
+	/* show measurement only if there is any length to speak of */
+	if (distance > 1) GuiShowTooltipsWithArgs(STR_MEASURE_LENGTH, 1, &distance);
 }
 
 static void VpStartPreSizing(void)
@@ -1986,6 +1995,120 @@ static byte Check2x1AutoRail(int mode)
 	return 0; // avoids compiler warnings
 }
 
+/** Check if the direction of start and end tile should be swapped based on
+ * the dragging-style. Default directions are:
+ * in the case of a line (HT_RAIL, HT_LINE):  DIR_NE, DIR_NW, DIR_N, DIR_E
+ * in the case of a rect (HT_RECT, HT_POINT): DIR_S, DIR_E
+ * For example dragging a rectangle area from south to north should be swapped to
+ * north-south (DIR_S) to obtain the same results with less code. This is what
+ * the return value signifies.
+ * @param style HighLightStyle dragging style
+ * @param start_tile, end_tile start and end tile of drag
+ * @param boolean value which when true means start/end should be swapped */
+static bool SwapDirection(HighLightStyle style, TileIndex start_tile, TileIndex end_tile)
+{
+	uint start_x = TileX(start_tile);
+	uint start_y = TileY(start_tile);
+	uint end_x = TileX(end_tile);
+	uint end_y = TileY(end_tile);
+
+	switch (style & HT_DRAG_MASK) {
+		case HT_RAIL:
+		case HT_LINE: return (end_x > start_x || (end_x == start_x && end_y > start_y));
+
+		case HT_RECT:
+		case HT_POINT: return (end_x != start_x && end_y < start_y);
+		default: NOT_REACHED();
+	}
+
+	return false;
+}
+
+/** Calculates height difference between one tile and another
+* Multiplies the result to suit the standard given by minimap - 50 meters high
+* To correctly get the height difference we need the direction we are dragging
+* in, as well as with what kind of tool we are dragging. For example a horizontal
+* autorail tool that starts in bottom and ends at the top of a tile will need the
+* maximum of SW,S and SE,N corners respectively. This is handled by the lookup table below
+* See _tileoffs_by_dir in map.c for the direction enums if you can't figure out
+* the values yourself.
+* @param style HightlightStyle of drag. This includes direction and style (autorail, rect, etc.)
+* @param distance amount of tiles dragged, important for horizontal/vertical drags
+*        ignored for others
+* @param start_tile, end_tile start and end tile of drag operation
+* @return height difference between two tiles. Tile measurement tool utilizes
+* this value in its tooltips */
+static int CalcHeightdiff(HighLightStyle style, uint distance, TileIndex start_tile, TileIndex end_tile)
+{
+	bool swap = SwapDirection(style, start_tile, end_tile);
+	byte style_t;
+	uint h0, h1, ht; // start heigth, end height, and temp variable
+
+	if (start_tile == end_tile) return 0;
+	if (swap) swap_tile(&start_tile, &end_tile);
+
+	switch (style & HT_DRAG_MASK) {
+		case HT_RECT: {
+			static const TileIndexDiffC heightdiff_area_by_dir[] = {
+				/* Start */ {1, 0}, /* Dragging east */ {0, 0}, /* Dragging south */
+				/* End   */ {0, 1}, /* Dragging east */ {1, 1}  /* Dragging south */
+			};
+
+			/* In the case of an area we can determine whether we were dragging south or
+			 * east by checking the X-coordinates of the tiles */
+			style_t = (byte)(TileX(end_tile) > TileX(start_tile));
+			start_tile = TILE_ADD(start_tile, ToTileIndexDiff(heightdiff_area_by_dir[style_t]));
+			end_tile   = TILE_ADD(end_tile, ToTileIndexDiff(heightdiff_area_by_dir[2 + style_t]));
+		}
+		/* Fallthrough */
+		case HT_POINT:
+			h0 = TileHeight(start_tile);
+			h1 = TileHeight(end_tile);
+			break;
+		default: { /* All other types, this is mostly only line/autorail */
+			static const HighLightStyle flip_style_direction[] = {
+				HT_DIR_X, HT_DIR_Y, HT_DIR_HL, HT_DIR_HU, HT_DIR_VR, HT_DIR_VL
+			};
+			static const TileIndexDiffC heightdiff_line_by_dir[] = {
+				/* Start */ {1, 0}, {1, 1}, /* HT_DIR_X  */ {0, 1}, {1, 1}, /* HT_DIR_Y  */
+				/* Start */ {1, 0}, {0, 0}, /* HT_DIR_HU */ {1, 0}, {1, 1}, /* HT_DIR_HL */
+				/* Start */ {1, 0}, {1, 1}, /* HT_DIR_VL */ {0, 1}, {1, 1}, /* HT_DIR_VR */
+
+				/* Start */ {0, 1}, {0, 0}, /* HT_DIR_X  */ {1, 0}, {0, 0}, /* HT_DIR_Y  */
+				/* End   */ {0, 1}, {0, 0}, /* HT_DIR_HU */ {1, 1}, {0, 1}, /* HT_DIR_HL */
+				/* End   */ {1, 0}, {0, 0}, /* HT_DIR_VL */ {0, 0}, {0, 1}, /* HT_DIR_VR */
+			};
+
+			distance %= 2; // we're only interested if the distance is even or uneven
+			style &= HT_DIR_MASK;
+
+			/* To handle autorail, we do some magic to be able to use a lookup table.
+			 * Firstly if we drag the other way around, we switch start&end, and if needed
+			 * also flip the drag-position. Eg if it was on the left, and the distance is even
+			 * that means the end, which is now the start is on the right */
+			if (swap && distance == 0) style = flip_style_direction[style];
+
+			/* Use lookup table for start-tile based on HighLightStyle direction */
+			style_t = style * 2;
+			assert(style_t < lengthof(heightdiff_line_by_dir) - 13);
+			h0 = TileHeight(TILE_ADD(start_tile, ToTileIndexDiff(heightdiff_line_by_dir[style_t])));
+			ht = TileHeight(TILE_ADD(start_tile, ToTileIndexDiff(heightdiff_line_by_dir[style_t + 1])));
+			h0 = maxu(h0, ht);
+
+			/* Use lookup table for end-tile based on HighLightStyle direction
+			 * flip around side (lower/upper, left/right) based on distance */
+			if (distance == 0) style_t = flip_style_direction[style] * 2;
+			assert(style_t < lengthof(heightdiff_line_by_dir) - 13);
+			h1 = TileHeight(TILE_ADD(end_tile, ToTileIndexDiff(heightdiff_line_by_dir[12 + style_t])));
+			ht = TileHeight(TILE_ADD(end_tile, ToTileIndexDiff(heightdiff_line_by_dir[12 + style_t + 1])));
+			h1 = maxu(h1, ht);
+		} break;
+	}
+
+	if (swap) swap_uint32(&h0, &h1);
+	/* Minimap shows height in intervals of 50 meters, let's do the same */
+	return (int)(h1 - h0) * 50;
+}
 
 // while dragging
 static void CalcRaildirsDrawstyle(TileHighlightData *thd, int x, int y, int method)
@@ -2087,6 +2210,30 @@ static void CalcRaildirsDrawstyle(TileHighlightData *thd, int x, int y, int meth
 			}
 		}
 	}
+
+	if (_patches.measure_tooltip) {
+		TileIndex t0 = TileVirtXY(thd->selstart.x, thd->selstart.y);
+		TileIndex t1 = TileVirtXY(x, y);
+		uint distance = DistanceManhattan(t0, t1) + 1;
+		int heightdiff = CalcHeightdiff(b, distance, t0, t1);
+		uint params[2];
+
+		/* If we are showing a tooltip for horizontal or vertical drags,
+		 * 2 tiles have a length of 1. To bias towards the ceiling we add
+		 * one before division. It feels more natural to count 3 lengths as 2 */
+		if ((b & HT_DIR_MASK) != HT_DIR_X && (b & HT_DIR_MASK) != HT_DIR_Y) {
+			distance = (distance + 1) / 2;
+		}
+
+		params[0] = distance;
+		if (heightdiff == 0) {
+			GuiShowTooltipsWithArgs(STR_MEASURE_LENGTH, 1, params);
+		} else {
+			params[1] = heightdiff;
+			GuiShowTooltipsWithArgs(STR_MEASURE_LENGTH_HEIGHTDIFF, 2, params);
+		}
+	}
+
 	thd->selend.x = x;
 	thd->selend.y = y;
 	thd->next_drawstyle = b;
@@ -2101,6 +2248,7 @@ static void CalcRaildirsDrawstyle(TileHighlightData *thd, int x, int y, int meth
 void VpSelectTilesWithMethod(int x, int y, int method)
 {
 	int sx, sy;
+	HighLightStyle style;
 
 	if (x == -1) {
 		_thd.selend.x = -1;
@@ -2124,32 +2272,80 @@ void VpSelectTilesWithMethod(int x, int y, int method)
 	sy = _thd.selstart.y;
 
 	switch (method) {
-		case VPM_FIX_X:
-			x = sx;
-			break;
-
-		case VPM_FIX_Y:
-			y = sy;
-			break;
-
-		case VPM_X_OR_Y:
+		case VPM_X_OR_Y: /* drag in X or Y direction */
 			if (myabs(sy - y) < myabs(sx - x)) {
 				y = sy;
+				style = HT_DIR_X;
 			} else {
 				x = sx;
+				style = HT_DIR_Y;
 			}
-			break;
-
-		case VPM_X_AND_Y:
-			break;
+			goto calc_heightdiff_single_direction;
+		case VPM_FIX_X: /* drag in Y direction */
+			x = sx;
+			style = HT_DIR_Y;
+			goto calc_heightdiff_single_direction;
+		case VPM_FIX_Y: /* drag in X direction */
+			y = sy;
+			style = HT_DIR_X;
+
+calc_heightdiff_single_direction:;
+			if (_patches.measure_tooltip) {
+				TileIndex t0 = TileVirtXY(sx, sy);
+				TileIndex t1 = TileVirtXY(x, y);
+				uint distance = DistanceManhattan(t0, t1) + 1;
+				int heightdiff = CalcHeightdiff((_thd.next_drawstyle & HT_DRAG_MASK) | style, 0, t0, t1);
+				uint params[2];
+
+				params[0] = distance;
+				if (heightdiff == 0) {
+					GuiShowTooltipsWithArgs(STR_MEASURE_LENGTH, 1, params);
+				} else {
+					params[1] = heightdiff;
+					GuiShowTooltipsWithArgs(STR_MEASURE_LENGTH_HEIGHTDIFF, 2, params);
+				}
+			} break;
 
-		// limit the selected area to a 10x10 rect.
-		case VPM_X_AND_Y_LIMITED: {
-			int limit = (_thd.sizelimit - 1) * 16;
+		case VPM_X_AND_Y_LIMITED: { /* drag an X by Y constrained rect area */
+			int limit = (_thd.sizelimit - 1) * TILE_SIZE;
 			x = sx + clamp(x - sx, -limit, limit);
 			y = sy + clamp(y - sy, -limit, limit);
-			break;
+			/* Fallthrough */
+		case VPM_X_AND_Y: { /* drag an X by Y area */
+			if (_patches.measure_tooltip) {
+				TileIndex t0 = TileVirtXY(sx, sy);
+				TileIndex t1 = TileVirtXY(x, y);
+				uint dx = abs(TileX(t0) - TileX(t1)) + 1;
+				uint dy = abs(TileY(t0) - TileY(t1)) + 1;
+				HighLightStyle style = _thd.next_drawstyle;
+				int heightdiff;
+				uint params[3];
+
+				/* If dragging an area (eg dynamite tool) and it is actually a single
+				 * row/column, change the type to 'line' to get proper calculation for height */
+				if (style & HT_RECT) {
+					if (dx == 1) {
+						style = HT_LINE | HT_DIR_Y;
+					} else if (dy == 1) {
+						style = HT_LINE | HT_DIR_X;
+					}
+				}
+
+				heightdiff = CalcHeightdiff(style, 0, t0, t1);
+
+				params[0] = dx;
+				params[1] = dy;
+				if (heightdiff == 0) {
+					GuiShowTooltipsWithArgs(STR_MEASURE_AREA, 2, params);
+				} else {
+					params[2] = heightdiff;
+					GuiShowTooltipsWithArgs(STR_MEASURE_AREA_HEIGHTDIFF, 3, params);
+				}
+			}
+		} break;
+
 		}
+		default: NOT_REACHED();
 	}
 
 	_thd.selend.x = x;
diff --git a/window.h b/window.h
index 086c32d68..876f6a2a4 100644
--- a/window.h
+++ b/window.h
@@ -387,6 +387,8 @@ assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(tree_d));
 
 typedef struct {
 	StringID string_id;
+	byte paramcount;
+	uint32 params[5];
 } tooltips_d;
 assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(tooltips_d));
 
@@ -805,7 +807,11 @@ void CDECL SetWindowWidgetsHiddenState(Window *w, bool hidden_stat, int widgets,
 void CDECL SetWindowWidgetsLoweredState(Window *w, bool lowered_stat, int widgets, ...);
 
 /* misc_gui.c*/
-void GuiShowTooltips(StringID string_id);
+void GuiShowTooltipsWithArgs(StringID str, uint paramcount, uint params[]);
+static inline void GuiShowTooltips(StringID str)
+{
+	GuiShowTooltipsWithArgs(str, 0, NULL);
+}
 
 /* widget.c */
 int GetWidgetFromPos(const Window *w, int x, int y);