From 3b0e00e2f91c524153f804a6a53946d3b555f021 Mon Sep 17 00:00:00 2001 From: rubidium Date: Mon, 12 Feb 2007 22:46:10 +0000 Subject: [PATCH] (svn r8692) -Cleanup: add comments to RoadVehController. Patch by mart3p. --- src/roadveh_cmd.cpp | 51 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 45 insertions(+), 6 deletions(-) diff --git a/src/roadveh_cmd.cpp b/src/roadveh_cmd.cpp index 8eb454f62a..3a898373ed 100644 --- a/src/roadveh_cmd.cpp +++ b/src/roadveh_cmd.cpp @@ -1273,6 +1273,7 @@ static void RoadVehController(Vehicle *v) if (v->current_order.type == OT_LOADING) return; if (IsRoadVehInDepot(v)) { + /* Vehicle is about to leave a depot */ DiagDirection dir; const RoadDriveEntry* rdp; byte rd2; @@ -1308,6 +1309,7 @@ static void RoadVehController(Vehicle *v) return; } + /* Check if vehicle needs to proceed, return if it doesn't */ if (!RoadVehAccelerate(v)) return; if (v->u.road.overtaking != 0) { @@ -1323,9 +1325,11 @@ static void RoadVehController(Vehicle *v) } } + /* Save old vehicle position to use at end of move to set viewport area dirty */ BeginVehicleMove(v); if (v->u.road.state == 255) { + /* Vehicle is on a bridge or in a tunnel */ GetNewVehiclePosResult gp; GetNewVehiclePos(v, &gp); @@ -1337,7 +1341,7 @@ static void RoadVehController(Vehicle *v) } if ((IsTunnelTile(gp.new_tile) || IsBridgeTile(gp.new_tile)) && VehicleEnterTile(v, gp.new_tile, gp.x, gp.y) & 4) { - //new_dir = RoadGetNewDirection(v, gp.x, gp.y) + /* Vehicle has just entered a bridge or tunnel */ v->cur_image = GetRoadVehImage(v, v->direction); UpdateRoadVehDeltaXY(v); SetRoadVehPosition(v,gp.x,gp.y); @@ -1351,10 +1355,11 @@ static void RoadVehController(Vehicle *v) return; } + /* Get move position data for next frame */ rd = _road_drive_data[(v->u.road.state + (_opt.road_side << 4)) ^ v->u.road.overtaking][v->u.road.frame + 1]; -// switch to another tile if (rd.x & 0x80) { + /* Vehicle is moving to the next tile */ TileIndex tile = v->tile + TileOffsByDiagDir(rd.x & 3); int dir = RoadFindPathToDest(v, tile, (DiagDirection)(rd.x & 3)); uint32 r; @@ -1362,6 +1367,7 @@ static void RoadVehController(Vehicle *v) const RoadDriveEntry *rdp; if (dir == -1) { + /* No path was found to destination */ v->cur_speed = 0; return; } @@ -1372,6 +1378,7 @@ again: tile = v->tile; } + /* Get position data for first frame on the new tile */ rdp = _road_drive_data[(dir + (_opt.road_side << 4)) ^ v->u.road.overtaking]; x = TileX(tile) * TILE_SIZE + rdp[0].x; @@ -1382,29 +1389,35 @@ again: r = VehicleEnterTile(v, tile, x, y); if (r & 8) { + /* Vehicle cannot enter the tile */ if (!IsTileType(tile, MP_TUNNELBRIDGE)) { v->cur_speed = 0; return; } + /* Try an about turn to re-enter the previous tile */ dir = _road_reverse_table[rd.x&3]; goto again; } if (IS_BYTE_INSIDE(v->u.road.state, 0x20, 0x30) && IsTileType(v->tile, MP_STATION)) { if ((dir & 7) >= 6) { + /* New direction is trying to turn vehicle around. + * We can't turn at the exit of a road stop so wait.*/ v->cur_speed = 0; return; } if (IsRoadStop(v->tile)) { + /* The tile that the vehicle is leaving is a road stop */ RoadStop *rs = GetRoadStopByTile(v->tile, GetRoadStopType(v->tile)); - // reached a loading bay, mark it as used and clear the usage bit - SETBIT(rs->status, v->u.road.state & 2 ? 1 : 0); // occupied bay + /* Vehicle is leaving a road stop tile, mark bay as free and clear the usage bit */ + SETBIT(rs->status, v->u.road.state & 2 ? 1 : 0); // set bay as free CLRBIT(rs->status, 7); // usage bit } } if (!(r & 4)) { + /* Set vehicle to first frame on new tile */ v->tile = tile; v->u.road.state = (byte)dir; v->u.road.frame = 0; @@ -1421,6 +1434,7 @@ again: } if (rd.x & 0x40) { + /* Vehicle has finished turning around, it will now head back onto the same tile */ int dir = RoadFindPathToDest(v, v->tile, (DiagDirection)(rd.x & 3)); uint32 r; int tmp; @@ -1428,6 +1442,7 @@ again: const RoadDriveEntry *rdp; if (dir == -1) { + /* No path was found to destination */ v->cur_speed = 0; return; } @@ -1443,10 +1458,12 @@ again: r = VehicleEnterTile(v, v->tile, x, y); if (r & 8) { + /* Vehicle cannot enter the tile */ v->cur_speed = 0; return; } + /* Set vehicle to second frame on the tile */ v->u.road.state = tmp & ~16; v->u.road.frame = 1; @@ -1461,15 +1478,19 @@ again: return; } + /* Calculate new position for the vehicle */ x = (v->x_pos & ~15) + (rd.x & 15); y = (v->y_pos & ~15) + (rd.y & 15); new_dir = RoadVehGetSlidingDirection(v, x, y); if (!IS_BYTE_INSIDE(v->u.road.state, 0x20, 0x30)) { + /* Vehicle is not in a road stop. + * Check for another vehicle to overtake */ Vehicle* u = RoadVehFindCloseTo(v, x, y, new_dir); if (u != NULL) { + /* There is a vehicle in front overtake it if possible */ if (v->u.road.overtaking == 0) RoadVehCheckOvertake(v, u); return; } @@ -1477,12 +1498,17 @@ again: old_dir = v->direction; if (new_dir != old_dir) { + /* The vehicle's direction has changed. */ v->direction = new_dir; v->cur_speed -= (v->cur_speed >> 2); if (old_dir != v->u.road.state) { + /* The vehicle is in a road stop */ v->cur_image = GetRoadVehImage(v, new_dir); UpdateRoadVehDeltaXY(v); SetRoadVehPosition(v, v->x_pos, v->y_pos); + /* Note, return here means that the frame counter is not incremented + * for vehicles changing direction in a road stop. This causes frames to + * be repeated. Is this intended? */ return; } } @@ -1492,10 +1518,15 @@ again: RoadStop *rs = GetRoadStopByTile(v->tile, GetRoadStopType(v->tile)); Station* st = GetStationByTile(v->tile); + /* Vehicle is at the stop position (at a bay) in a road stop. + * Note, if vehicle is loading/unloading it has already been handled, + * so if we get here the vehicle has just arrived or is just ready to leave. */ if (v->current_order.type != OT_LEAVESTATION && v->current_order.type != OT_GOTO_DEPOT) { + /* Vehicle has arrived at a bay in a road stop */ Order old_order; + /* Clear road stop busy bit to allow another vehicle to enter or leave */ CLRBIT(rs->status, 7); v->last_station_visited = GetStationIndex(v->tile); @@ -1521,8 +1552,10 @@ again: return; } + /* Vehicle is ready to leave a bay in a road stop */ if (v->current_order.type != OT_GOTO_DEPOT) { if (HASBIT(rs->status, 7)) { + /* Road stop is busy, so wait */ v->cur_speed = 0; return; } @@ -1530,13 +1563,14 @@ again: v->current_order.flags = 0; ClearSlot(v); } + /* Set road stop busy bit to prevent another vehicle trying to enter or leave */ SETBIT(rs->status, 7); if (rs == v->u.road.slot) { - //we have arrived at the correct station + /* We are leaving the correct station */ ClearSlot(v); } else if (v->u.road.slot != NULL) { - //we have arrived at the wrong station + /* We are leaving the wrong station */ //XXX The question is .. what to do? Actually we shouldn't be here //but I guess we need to clear the slot DEBUG(ms, 0, "Vehicle %d (index %d) arrived at wrong stop", v->unitnumber, v->index); @@ -1562,12 +1596,17 @@ again: InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR); } + /* Check tile position conditions - i.e. stop position in depot, + * entry onto bridge or into tunnel */ r = VehicleEnterTile(v, v->tile, x, y); if (r & 8) { + /* Vehicle cannot continue */ v->cur_speed = 0; return; } + /* Move to next frame unless vehicle arrived at a stop position + * in a depot or entered a tunnel/bridge */ if ((r & 4) == 0) v->u.road.frame++; v->cur_image = GetRoadVehImage(v, v->direction);