From c8ea909811073869094919b2ad3a63f2251396a3 Mon Sep 17 00:00:00 2001
From: peter1138 <peter1138@openttd.org>
Date: Fri, 4 Nov 2005 07:38:26 +0000
Subject: [PATCH] (svn r3130) Calculate shorter wagon lengths more precisely in
 train depot window. This affects wagon position, the scroll bar, and the
 train length counter. No trial and error is required to get the correct
 length now.

---
 train_gui.c | 48 ++++++++++++++++++++++++------------------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/train_gui.c b/train_gui.c
index fcc0cd98f4..9af16a1eef 100644
--- a/train_gui.c
+++ b/train_gui.c
@@ -345,29 +345,38 @@ static void ShowBuildTrainWindow(TileIndex tile)
 	}
 }
 
+/**
+ * Get the number of pixels for the given wagon length.
+ * @param len Length measured in 1/8ths of a standard wagon.
+ * @return Number of pixels across.
+ */
+static int WagonLengthToPixels(int len) {
+	return (len * 29) / 8;
+}
+
 static void DrawTrainImage(const Vehicle *v, int x, int y, int count, int skip, VehicleID selection)
 {
-	int max_x = x + count * 29;
+	int dx = 0;
+	count *= 8;
 
 	do {
 		if (--skip < 0) {
 			int image = GetTrainImage(v, 6);
 			uint32 ormod = SPRITE_PALETTE(PLAYER_SPRITE_COLOR(v->owner));
-			int width = v->u.rail.cached_veh_length * 3;
+			int width = v->u.rail.cached_veh_length;
 
-			if (x + width + 4 <= max_x) {
+			if (dx + width <= count) {
 				if (v->vehstatus & VS_CRASHED)
 					ormod = PALETTE_CRASH;
-				DrawSprite(image | ormod, x + 14, y + 6 + (is_custom_sprite(RailVehInfo(v->engine_type)->image_index) ? _traininfo_vehicle_pitch : 0));
+				DrawSprite(image | ormod, x + 14 + WagonLengthToPixels(dx), y + 6 + (is_custom_sprite(RailVehInfo(v->engine_type)->image_index) ? _traininfo_vehicle_pitch : 0));
 				if (v->index == selection)
-					DrawFrameRect(x - 1, y - 1, x + width + 4, y + 12, 15, FR_BORDERONLY);
+					DrawFrameRect(x - 1 + WagonLengthToPixels(dx), y - 1, x + WagonLengthToPixels(dx + width) - 1, y + 12, 15, FR_BORDERONLY);
 			}
-			x += width + 5;
+			dx += width;
 		}
 
-		if (!(v = v->next))
-			break;
-	} while (x < max_x);
+		v = v->next;
+	} while (dx < count && v != NULL);
 }
 
 static void DrawTrainDepotWindow(Window *w)
@@ -385,7 +394,7 @@ static void DrawTrainDepotWindow(Window *w)
 
 	/* determine amount of items for scroller */
 	num = 0;
-	hnum = 1;
+	hnum = 8;
 	FOR_ALL_VEHICLES(v) {
 		if (v->type == VEH_Train &&
 			  (v->subtype == TS_Front_Engine || v->subtype == TS_Free_Car) &&
@@ -394,10 +403,7 @@ static void DrawTrainDepotWindow(Window *w)
 			num++;
 			// determine number of items in the X direction.
 			if (v->subtype == TS_Front_Engine) {
-				i = 0;
-				u = v;
-				do i++; while ((u = u->next) != NULL);
-				if (i > hnum) hnum = i;
+				hnum = max(hnum, v->u.rail.cached_total_length);
 			}
 		}
 	}
@@ -406,7 +412,7 @@ static void DrawTrainDepotWindow(Window *w)
 	num++;
 
 	SetVScrollCount(w, num);
-	SetHScrollCount(w, hnum);
+	SetHScrollCount(w, (hnum + 7) / 8);
 
 	/* locate the depot struct */
 	depot = GetDepotByTile(tile);
@@ -429,14 +435,8 @@ static void DrawTrainDepotWindow(Window *w)
 			SetDParam(0, v->unitnumber);
 			DrawString(x, y, (v->max_age - 366 < v->age) ? STR_00E3 : STR_00E2, 0);
 
-			/*Draw the train counter */
-			i = 0;
-			u = v;
-			do {
-				i += u->u.rail.cached_veh_length + 1;
-			} while ( (u=u->next) != NULL);			//Determine length of train
-
-			SetDParam(0, (i + 8) / 9);			//Set the counter
+			// Number of wagons relative to a standard length wagon (rounded up)
+			SetDParam(0, (v->u.rail.cached_total_length + 7) / 8);
 			DrawStringRightAligned(w->widget[6].right - 1, y + 4, STR_TINY_BLACK, 0);	//Draw the counter
 
 			/* Draw the pretty flag */
@@ -525,7 +525,7 @@ found_it:
 	while (skip--) v = v->next;
 
 	/* find the vehicle in this row that was clicked */
-	while ((x -= v->u.rail.cached_veh_length * 3 + 5) >= 0) {
+	while ((x -= WagonLengthToPixels(v->u.rail.cached_veh_length)) >= 0) {
 		v = v->next;
 		if (v == NULL) break;
 	}