(svn r9846) -Codechange: introduced ZOOM_LVL_MIN and ZOOM_LVL_MAX for the obvious reasons

-Codechange: introduced ZOOM_LVL_DETAIL to show/remove details
-Codechange: changed << and >> operator with ZoomLevel to a simple wrapper (that in theory also allows zoom-in besides the current zoom-out)
-Fix r9845: missed some int -> ZoomLevel

13 files changed, 79 insertions, 60 deletions

diff --git a/src/gfx.cpp b/src/gfx.cpp
index 02974d155..84cfe2830 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -1426,7 +1426,7 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 	const DrawPixelInfo *dpi = _cur_dpi;
 	int start_x, start_y;
 	BlitterParams bp;
-	int zoom_mask = ~((1 << dpi->zoom) - 1);
+	int zoom_mask = ~(ScaleByZoom(1, dpi->zoom) - 1);
 
 	/* decode sprite header */
 	x += sprite->x_offs;
@@ -1458,7 +1458,7 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 			start_y -= y;
 			y = 0;
 		} else {
-			bp.dst += bp.pitch * (y >> dpi->zoom);
+			bp.dst += bp.pitch * UnScaleByZoom(y, dpi->zoom);
 		}
 		bp.start_y = start_y;
 
@@ -1476,7 +1476,7 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 			x = 0;
 		}
 		bp.start_x = start_x;
-		bp.dst += x >> dpi->zoom;
+		bp.dst += UnScaleByZoom(x, dpi->zoom);
 
 		if ( (x = x + bp.width - dpi->width) > 0) {
 			bp.width -= x;
@@ -1485,9 +1485,9 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 
 		switch (dpi->zoom) {
 			default: NOT_REACHED();
-			case 0: GfxBlitTileZoomIn(&bp);     break;
-			case 1: GfxBlitTileZoomMedium(&bp); break;
-			case 2: GfxBlitTileZoomOut(&bp);    break;
+			case ZOOM_LVL_NORMAL: GfxBlitTileZoomIn(&bp);     break;
+			case ZOOM_LVL_OUT_2X: GfxBlitTileZoomMedium(&bp); break;
+			case ZOOM_LVL_OUT_4X: GfxBlitTileZoomOut(&bp);    break;
 		}
 	} else {
 		bp.sprite += bp.width * (bp.height & ~zoom_mask);
@@ -1502,7 +1502,7 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 			bp.sprite -= bp.width * y;
 			y = 0;
 		} else {
-			bp.dst += bp.pitch * (y >> dpi->zoom);
+			bp.dst += bp.pitch * UnScaleByZoom(y, dpi->zoom);
 		}
 
 		if (bp.height > dpi->height - y) {
@@ -1518,7 +1518,7 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 			bp.sprite -= x;
 			x = 0;
 		}
-		bp.dst += x >> dpi->zoom;
+		bp.dst += UnScaleByZoom(x, dpi->zoom);
 
 		if (bp.width > dpi->width - x) {
 			bp.width = dpi->width - x;
@@ -1527,9 +1527,9 @@ static void GfxMainBlitter(const Sprite *sprite, int x, int y, BlitterMode mode)
 
 		switch (dpi->zoom) {
 			default: NOT_REACHED();
-			case 0: GfxBlitZoomInUncomp(&bp);     break;
-			case 1: GfxBlitZoomMediumUncomp(&bp); break;
-			case 2: GfxBlitZoomOutUncomp(&bp);    break;
+			case ZOOM_LVL_NORMAL: GfxBlitZoomInUncomp(&bp);     break;
+			case ZOOM_LVL_OUT_2X: GfxBlitZoomMediumUncomp(&bp); break;
+			case ZOOM_LVL_OUT_4X: GfxBlitZoomOutUncomp(&bp);    break;
 		}
 	}
 }
diff --git a/src/main_gui.cpp b/src/main_gui.cpp
index b090e69df..5fc4b3f97 100644
--- a/src/main_gui.cpp
+++ b/src/main_gui.cpp
@@ -880,7 +880,7 @@ bool DoZoomInOutWindow(int how, Window *w)
 
 	switch (how) {
 		case ZOOM_IN:
-			if (vp->zoom == ZOOM_LVL_NORMAL) return false;
+			if (vp->zoom == ZOOM_LVL_MIN) return false;
 			vp->zoom = (ZoomLevel)((byte)vp->zoom - 1);
 			vp->virtual_width >>= 1;
 			vp->virtual_height >>= 1;
@@ -889,7 +889,7 @@ bool DoZoomInOutWindow(int how, Window *w)
 			WP(w,vp_d).scrollpos_y += vp->virtual_height >> 1;
 			break;
 		case ZOOM_OUT:
-			if (vp->zoom == ZOOM_LVL_OUT_4X) return false;
+			if (vp->zoom == ZOOM_LVL_MAX) return false;
 			vp->zoom = (ZoomLevel)((byte)vp->zoom + 1);
 
 			WP(w,vp_d).scrollpos_x -= vp->virtual_width >> 1;
@@ -1049,7 +1049,7 @@ void ZoomInOrOutToCursorWindow(bool in, Window *w)
 	vp = w->viewport;
 
 	if (_game_mode != GM_MENU) {
-		if ((in && vp->zoom == ZOOM_LVL_NORMAL) || (!in && vp->zoom == ZOOM_LVL_OUT_4X))
+		if ((in && vp->zoom == ZOOM_LVL_MIN) || (!in && vp->zoom == ZOOM_LVL_MAX))
 			return;
 
 		pt = GetTileZoomCenterWindow(in,w);
diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
index c63e3d6bd..2336d5332 100644
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -579,11 +579,11 @@ void ShowErrorMessage(StringID msg_1, StringID msg_2, int x, int y)
 			vp = FindWindowById(WC_MAIN_WINDOW, 0)->viewport;
 
 			/* move x pos to opposite corner */
-			pt.x = ((pt.x - vp->virtual_left) >> vp->zoom) + vp->left;
+			pt.x = UnScaleByZoom(pt.x - vp->virtual_left, vp->zoom) + vp->left;
 			pt.x = (pt.x < (_screen.width >> 1)) ? _screen.width - 260 : 20;
 
 			/* move y pos to opposite corner */
-			pt.y = ((pt.y - vp->virtual_top) >> vp->zoom) + vp->top;
+			pt.y = UnScaleByZoom(pt.y - vp->virtual_top, vp->zoom) + vp->top;
 			pt.y = (pt.y < (_screen.height >> 1)) ? _screen.height - 80 : 100;
 
 		} else {
@@ -595,8 +595,8 @@ void ShowErrorMessage(StringID msg_1, StringID msg_2, int x, int y)
 		if ( (x|y) != 0) {
 			pt = RemapCoords2(x, y);
 			vp = FindWindowById(WC_MAIN_WINDOW, 0)->viewport;
-			pt.x = clamp(((pt.x - vp->virtual_left) >> vp->zoom) + vp->left - (334/2), 0, _screen.width - 334);
-			pt.y = clamp(((pt.y - vp->virtual_top) >> vp->zoom) + vp->top - (137/2), 22, _screen.height - 137);
+			pt.x = clamp(UnScaleByZoom(pt.x - vp->virtual_left, vp->zoom) + vp->left - (334/2), 0, _screen.width - 334);
+			pt.y = clamp(UnScaleByZoom(pt.y - vp->virtual_top, vp->zoom) + vp->top - (137/2), 22, _screen.height - 137);
 		} else {
 			pt.x = (_screen.width - 334) >> 1;
 			pt.y = (_screen.height - 137) >> 1;
diff --git a/src/openttd.cpp b/src/openttd.cpp
index 0cd1d5b49..088d9fce5 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -986,8 +986,8 @@ static void ScrollMainViewport(int x, int y)
 		Window *w = FindWindowById(WC_MAIN_WINDOW, 0);
 		assert(w);
 
-		WP(w,vp_d).scrollpos_x += x << w->viewport->zoom;
-		WP(w,vp_d).scrollpos_y += y << w->viewport->zoom;
+		WP(w,vp_d).scrollpos_x += ScaleByZoom(x, w->viewport->zoom);
+		WP(w,vp_d).scrollpos_y += ScaleByZoom(y, w->viewport->zoom);
 	}
 }
 
@@ -1282,8 +1282,8 @@ bool AfterLoadGame()
 
 	vp = w->viewport;
 	vp->zoom = _saved_scrollpos_zoom;
-	vp->virtual_width = vp->width << vp->zoom;
-	vp->virtual_height = vp->height << vp->zoom;
+	vp->virtual_width = ScaleByZoom(vp->width, vp->zoom);
+	vp->virtual_height = ScaleByZoom(vp->height, vp->zoom);
 
 	/* in version 4.1 of the savegame, is_active was introduced to determine
 	 * if a player does exist, rather then checking name_1 */
diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp
index 2b6881887..1ad5ce9e7 100644
--- a/src/road_cmd.cpp
+++ b/src/road_cmd.cpp
@@ -725,7 +725,7 @@ static void DrawRoadBits(TileInfo* ti)
 	}
 
 	/* Return if full detail is disabled, or we are zoomed fully out. */
-	if (!HASBIT(_display_opt, DO_FULL_DETAIL) || _cur_dpi->zoom == ZOOM_LVL_OUT_4X) return;
+	if (!HASBIT(_display_opt, DO_FULL_DETAIL) || _cur_dpi->zoom > ZOOM_LVL_DETAIL) return;
 
 	/* Draw extra details. */
 	for (drts = _road_display_table[roadside][road]; drts->image != 0; drts++) {
diff --git a/src/screenshot.cpp b/src/screenshot.cpp
index a6d3153c0..5948f29d3 100644
--- a/src/screenshot.cpp
+++ b/src/screenshot.cpp
@@ -479,10 +479,10 @@ static void LargeWorldCallback(void *userdata, Pixel *buf, uint y, uint pitch, u
 		left += wx;
 
 		ViewportDoDraw(vp,
-			((left - wx - vp->left) << vp->zoom) + vp->virtual_left,
-			((y - vp->top) << vp->zoom) + vp->virtual_top,
-			((left - vp->left) << vp->zoom) + vp->virtual_left,
-			(((y + n) - vp->top) << vp->zoom) + vp->virtual_top
+			ScaleByZoom(left - wx - vp->left, vp->zoom) + vp->virtual_left,
+			ScaleByZoom(y - vp->top, vp->zoom) + vp->virtual_top,
+			ScaleByZoom(left - vp->left, vp->zoom) + vp->virtual_left,
+			ScaleByZoom((y + n) - vp->top, vp->zoom) + vp->virtual_top
 		);
 	}
 
diff --git a/src/smallmap_gui.cpp b/src/smallmap_gui.cpp
index 2b1868288..2035a8a96 100644
--- a/src/smallmap_gui.cpp
+++ b/src/smallmap_gui.cpp
@@ -1016,8 +1016,8 @@ static void ExtraViewPortWndProc(Window *w, WindowEvent *e)
 				_scrolling_viewport = false;
 			}
 
-			WP(w, vp_d).scrollpos_x += e->we.scroll.delta.x << vp->zoom;
-			WP(w, vp_d).scrollpos_y += e->we.scroll.delta.y << vp->zoom;
+			WP(w, vp_d).scrollpos_x += ScaleByZoom(e->we.scroll.delta.x, vp->zoom);
+			WP(w, vp_d).scrollpos_y += ScaleByZoom(e->we.scroll.delta.y, vp->zoom);
 		} break;
 
 		case WE_MOUSEWHEEL:
diff --git a/src/sound.cpp b/src/sound.cpp
index 5700125d0..2245e8c0e 100644
--- a/src/sound.cpp
+++ b/src/sound.cpp
@@ -152,7 +152,7 @@ static void StartSound(uint sound, int panning, uint volume)
 }
 
 
-static const byte _vol_factor_by_zoom[] = {255, 190, 134};
+static const byte _vol_factor_by_zoom[ZOOM_LVL_END] = {255, 190, 134};
 
 static const byte _sound_base_vol[] = {
 	128,  90, 128, 128, 128, 128, 128, 128,
diff --git a/src/texteff.cpp b/src/texteff.cpp
index 692641be5..bb187ac15 100644
--- a/src/texteff.cpp
+++ b/src/texteff.cpp
@@ -351,8 +351,10 @@ void DrawTextEffects(DrawPixelInfo *dpi)
 			}
 			break;
 
-		default:
+		case ZOOM_LVL_OUT_4X:
 			break;
+
+		default: NOT_REACHED();
 	}
 }
 
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 724cd3428..1b5b720b9 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -1425,8 +1425,8 @@ Vehicle *CheckClickOnVehicle(const ViewPort *vp, int x, int y)
 			 (uint)(y -= vp->top) >= (uint)vp->height)
 				return NULL;
 
-	x = (x << vp->zoom) + vp->virtual_left;
-	y = (y << vp->zoom) + vp->virtual_top;
+	x = ScaleByZoom(x, vp->zoom) + vp->virtual_left;
+	y = ScaleByZoom(y, vp->zoom) + vp->virtual_top;
 
 	FOR_ALL_VEHICLES(v) {
 		if ((v->vehstatus & (VS_HIDDEN|VS_UNCLICKABLE)) == 0 &&
diff --git a/src/viewport.cpp b/src/viewport.cpp
index e5f6279cf..3320519bb 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -269,10 +269,10 @@ static void SetViewportPosition(Window *w, int x, int y)
 	vp->virtual_left = x;
 	vp->virtual_top = y;
 
-	old_left >>= vp->zoom;
-	old_top >>= vp->zoom;
-	x >>= vp->zoom;
-	y >>= vp->zoom;
+	old_left = UnScaleByZoom(old_left, vp->zoom);
+	old_top = UnScaleByZoom(old_top, vp->zoom);
+	x = UnScaleByZoom(x, vp->zoom);
+	y = UnScaleByZoom(y, vp->zoom);
 
 	old_left -= x;
 	old_top -= y;
@@ -333,8 +333,8 @@ static Point TranslateXYToTileCoord(const ViewPort *vp, int x, int y)
 				return pt;
 	}
 
-	x = ((x << vp->zoom) + vp->virtual_left) >> 2;
-	y = ((y << vp->zoom) + vp->virtual_top) >> 1;
+	x = (ScaleByZoom(x, vp->zoom) + vp->virtual_left) >> 2;
+	y = (ScaleByZoom(y, vp->zoom) + vp->virtual_top) >> 1;
 
 	a = y-x;
 	b = y+x;
@@ -406,10 +406,10 @@ Point GetTileZoomCenterWindow(bool in, Window * w)
  * @param widget_zoom_out widget index for window with zoom-out button */
 void HandleZoomMessage(Window *w, const ViewPort *vp, byte widget_zoom_in, byte widget_zoom_out)
 {
-	SetWindowWidgetDisabledState(w, widget_zoom_in, vp->zoom == ZOOM_LVL_NORMAL);
+	SetWindowWidgetDisabledState(w, widget_zoom_in, vp->zoom == ZOOM_LVL_MIN);
 	InvalidateWidget(w, widget_zoom_in);
 
-	SetWindowWidgetDisabledState(w, widget_zoom_out, vp->zoom == ZOOM_LVL_OUT_4X);
+	SetWindowWidgetDisabledState(w, widget_zoom_out, vp->zoom == ZOOM_LVL_MAX);
 	InvalidateWidget(w, widget_zoom_out);
 }
 
@@ -671,7 +671,7 @@ static void DrawTileSelection(const TileInfo *ti)
 				z += TILE_HEIGHT;
 				if (ti->tileh == SLOPE_STEEP_N) z += TILE_HEIGHT;
 			}
-			DrawGroundSpriteAt(_cur_dpi->zoom != ZOOM_LVL_OUT_4X ? SPR_DOT : SPR_DOT_SMALL, PAL_NONE, ti->x, ti->y, z);
+			DrawGroundSpriteAt(_cur_dpi->zoom <= ZOOM_LVL_DETAIL ? SPR_DOT : SPR_DOT_SMALL, PAL_NONE, ti->x, ti->y, z);
 		} else if (_thd.drawstyle & HT_RAIL /*&& _thd.place_mode == VHM_RAIL*/) {
 			/* autorail highlight piece under cursor */
 			uint type = _thd.drawstyle & 0xF;
@@ -1241,7 +1241,7 @@ void ViewportDoDraw(const ViewPort *vp, int left, int top, int right, int bottom
 	_cur_dpi = &vd.dpi;
 
 	vd.dpi.zoom = vp->zoom;
-	mask = (-1) << vp->zoom;
+	mask = ScaleByZoom(-1, vp->zoom);
 
 	vd.combine_sprites = 0;
 
@@ -1251,8 +1251,8 @@ void ViewportDoDraw(const ViewPort *vp, int left, int top, int right, int bottom
 	vd.dpi.top = top & mask;
 	vd.dpi.pitch = old_dpi->pitch;
 
-	x = ((vd.dpi.left - (vp->virtual_left&mask)) >> vp->zoom) + vp->left;
-	y = ((vd.dpi.top - (vp->virtual_top&mask)) >> vp->zoom) + vp->top;
+	x = UnScaleByZoom(vd.dpi.left - (vp->virtual_left & mask), vp->zoom) + vp->left;
+	y = UnScaleByZoom(vd.dpi.top - (vp->virtual_top & mask), vp->zoom) + vp->top;
 
 	vd.dpi.dst_ptr = old_dpi->dst_ptr + x - old_dpi->left + (y - old_dpi->top) * old_dpi->pitch;
 
@@ -1295,7 +1295,7 @@ void ViewportDoDraw(const ViewPort *vp, int left, int top, int right, int bottom
  * If we do, the sprite memory will overflow. */
 static void ViewportDrawChk(const ViewPort *vp, int left, int top, int right, int bottom)
 {
-	if (((bottom - top) * (right - left) << (2 * vp->zoom)) > 180000) {
+	if (ScaleByZoom(bottom - top, vp->zoom) * ScaleByZoom(right - left, vp->zoom) > 180000) {
 		if ((bottom - top) > (right - left)) {
 			int t = (top + bottom) >> 1;
 			ViewportDrawChk(vp, left, top, right, t);
@@ -1307,10 +1307,10 @@ static void ViewportDrawChk(const ViewPort *vp, int left, int top, int right, in
 		}
 	} else {
 		ViewportDoDraw(vp,
-			((left - vp->left) << vp->zoom) + vp->virtual_left,
-			((top - vp->top) << vp->zoom) + vp->virtual_top,
-			((right - vp->left) << vp->zoom) + vp->virtual_left,
-			((bottom - vp->top) << vp->zoom) + vp->virtual_top
+			ScaleByZoom(left - vp->left, vp->zoom) + vp->virtual_left,
+			ScaleByZoom(top - vp->top, vp->zoom) + vp->virtual_top,
+			ScaleByZoom(right - vp->left, vp->zoom) + vp->virtual_left,
+			ScaleByZoom(bottom - vp->top, vp->zoom) + vp->virtual_top
 		);
 	}
 }
@@ -1398,10 +1398,10 @@ static void MarkViewportDirty(const ViewPort *vp, int left, int top, int right,
 	if (top >= vp->virtual_height) return;
 
 	SetDirtyBlocks(
-		(left >> vp->zoom) + vp->left,
-		(top >> vp->zoom) + vp->top,
-		(right >> vp->zoom) + vp->left,
-		(bottom >> vp->zoom) + vp->top
+		UnScaleByZoom(left, vp->zoom) + vp->left,
+		UnScaleByZoom(top, vp->zoom) + vp->top,
+		UnScaleByZoom(right, vp->zoom) + vp->left,
+		UnScaleByZoom(bottom, vp->zoom) + vp->top
 	);
 }
 
diff --git a/src/window.cpp b/src/window.cpp
index 34ccb70aa..f4309971a 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -1618,14 +1618,14 @@ static void HandleAutoscroll()
 			/* here allows scrolling in both x and y axis */
 #define scrollspeed 3
 			if (x - 15 < 0) {
-				WP(w, vp_d).scrollpos_x += (x - 15) * scrollspeed << vp->zoom;
+				WP(w, vp_d).scrollpos_x += ScaleByZoom((x - 15) * scrollspeed, vp->zoom);
 			} else if (15 - (vp->width - x) > 0) {
-				WP(w, vp_d).scrollpos_x += (15 - (vp->width - x)) * scrollspeed << vp->zoom;
+				WP(w, vp_d).scrollpos_x += ScaleByZoom((15 - (vp->width - x)) * scrollspeed, vp->zoom);
 			}
 			if (y - 15 < 0) {
-				WP(w, vp_d).scrollpos_y += (y - 15) * scrollspeed << vp->zoom;
+				WP(w, vp_d).scrollpos_y += ScaleByZoom((y - 15) * scrollspeed, vp->zoom);
 			} else if (15 - (vp->height - y) > 0) {
-				WP(w,vp_d).scrollpos_y += (15 - (vp->height - y)) * scrollspeed << vp->zoom;
+				WP(w,vp_d).scrollpos_y += ScaleByZoom((15 - (vp->height - y)) * scrollspeed, vp->zoom);
 			}
 #undef scrollspeed
 		}
@@ -1970,8 +1970,8 @@ void RelocateAllWindows(int neww, int newh)
 			ViewPort *vp = w->viewport;
 			vp->width = w->width = neww;
 			vp->height = w->height = newh;
-			vp->virtual_width = neww << vp->zoom;
-			vp->virtual_height = newh << vp->zoom;
+			vp->virtual_width = ScaleByZoom(neww, vp->zoom);
+			vp->virtual_height = ScaleByZoom(newh, vp->zoom);
 			continue; // don't modify top,left
 		}
 
diff --git a/src/zoom.hpp b/src/zoom.hpp
index 64a2a1397..fc57b0139 100644
--- a/src/zoom.hpp
+++ b/src/zoom.hpp
@@ -22,8 +22,25 @@ enum ZoomLevel {
 	ZOOM_LVL_TRAIN    = ZOOM_LVL_NORMAL,
 	ZOOM_LVL_ROADVEH  = ZOOM_LVL_NORMAL,
 	ZOOM_LVL_WORLD_SCREENSHOT = ZOOM_LVL_NORMAL,
+
+	ZOOM_LVL_DETAIL   = ZOOM_LVL_OUT_2X, //! All zoomlevels below or equal to this, will result in details on the screen, like road-work, ...
+
+	ZOOM_LVL_MIN      = ZOOM_LVL_NORMAL,
+	ZOOM_LVL_MAX      = ZOOM_LVL_OUT_4X,
 };
 
 extern ZoomLevel _saved_scrollpos_zoom;
 
+static inline int ScaleByZoom(int value, ZoomLevel zoom)
+{
+	int izoom = (int)zoom - (int)ZOOM_LVL_NORMAL;
+	return (zoom > ZOOM_LVL_NORMAL) ? value >> izoom : value << izoom;
+}
+
+static inline int UnScaleByZoom(int value, ZoomLevel zoom)
+{
+	int izoom = (int)zoom - (int)ZOOM_LVL_NORMAL;
+	return (zoom > ZOOM_LVL_NORMAL) ? value << izoom : value >> izoom;
+}
+
 #endif /* ZOOM_HPP */