(svn r16872) -Codechange: Add RoadVehicle::GetDisplayImageWidth and simplify DrawRoadVehImage.

src/roadveh.h

@@ -117,6 +117,7 @@ struct RoadVehicle : public SpecializedVehicle<RoadVehicle, VEH_ROAD> {
 	int GetDisplaySpeed() const { return this->cur_speed / 2; }
 	int GetDisplayMaxSpeed() const { return this->max_speed / 2; }
 	Money GetRunningCost() const { return RoadVehInfo(this->engine_type)->running_cost * GetPriceByIndex(RoadVehInfo(this->engine_type)->running_cost_class); }
+	int GetDisplayImageWidth(Point *offset = NULL) const;
 	bool IsInDepot() const { return this->state == RVSB_IN_DEPOT; }
 	bool IsStoppedInDepot() const;
 	bool Tick();

src/roadveh_cmd.cpp

@@ -85,6 +85,22 @@ static const Trackdir _roadveh_depot_exit_trackdir[DIAGDIR_END] = {
 	TRACKDIR_X_NE, TRACKDIR_Y_SE, TRACKDIR_X_SW, TRACKDIR_Y_NW
 };
 
+/**
+ * Get the width of a road vehicle image in the GUI.
+ * @param offset Additional offset for positioning the sprite; set to NULL if not needed
+ * @return Width in pixels
+ */
+int RoadVehicle::GetDisplayImageWidth(Point *offset) const
+{
+	int reference_width = ROADVEHINFO_DEFAULT_VEHICLE_WIDTH;
+
+	if (offset != NULL) {
+		offset->x = reference_width / 2;
+		offset->y = 0;
+	}
+	return this->rcache.cached_veh_length * reference_width / 8;
+}
+
 static SpriteID GetRoadVehIcon(EngineID engine)
 {
 	uint8 spritenum = RoadVehInfo(engine)->image_index;

src/roadveh_gui.cpp

@@ -6,7 +6,6 @@
 #include "roadveh.h"
 #include "window_gui.h"
 #include "gfx_func.h"
-#include "newgrf_engine.h"
 #include "vehicle_gui.h"
 #include "strings_func.h"
 #include "vehicle_func.h"
@@ -115,12 +114,6 @@ void DrawRoadVehDetails(const Vehicle *v, int left, int right, int y)
 	DrawString(left, right, y + 33 + y_offset, STR_FEEDER_CARGO_VALUE);
 }
 
-
-static inline int RoadVehLengthToPixels(int length)
-{
-	return (length * ROADVEHINFO_DEFAULT_VEHICLE_WIDTH) / 8;
-}
-
 /**
  * Draws an image of a road vehicle chain
  * @param v Front vehicle
@@ -131,31 +124,19 @@ static inline int RoadVehLengthToPixels(int length)
  */
 void DrawRoadVehImage(const Vehicle *v, int x, int y, VehicleID selection, int max_width)
 {
-	int max_length = max_width / ROADVEHINFO_DEFAULT_VEHICLE_WIDTH;
-
-	/* Width of highlight box */
-	int highlight_w = 0;
-
-	for (int dx = 0; v != NULL && dx < max_length ; v = v->Next()) {
-		int width = RoadVehicle::From(v)->rcache.cached_veh_length;
-
-		if (dx + width > 0 && dx <= max_length) {
-			SpriteID pal = (v->vehstatus & VS_CRASHED) ? PALETTE_CRASH : GetVehiclePalette(v);
-			DrawSprite(v->GetImage(DIR_W), pal, x + 14 + RoadVehLengthToPixels(dx), y + 6);
-
-			if (v->index == selection) {
-				/* Set the highlight position */
-				highlight_w = RoadVehLengthToPixels(width);
-			} else if (_cursor.vehchain && highlight_w != 0) {
-				highlight_w += RoadVehLengthToPixels(width);
-			}
-		}
-
-		dx += width;
+	const RoadVehicle *u = RoadVehicle::From(v);
+	int x_pos = 0;
+	for (; u != NULL && x_pos < max_width; u = u->Next()) {
+		Point offset;
+		int width = u->GetDisplayImageWidth(&offset);
+
+		SpriteID pal = (u->vehstatus & VS_CRASHED) ? PALETTE_CRASH : GetVehiclePalette(u);
+		DrawSprite(u->GetImage(DIR_W), pal, x + x_pos + offset.x, y + 6 + offset.y);
+		x_pos += width;
 	}
 
-	if (highlight_w != 0) {
-		DrawFrameRect(x - 1, y - 1, x - 1 + highlight_w, y + 12, COLOUR_WHITE, FR_BORDERONLY);
+	if (v->index == selection) {
+		DrawFrameRect(x - 1, y - 1, x - 1 + x_pos, y + 12, COLOUR_WHITE, FR_BORDERONLY);
 	}
 }