Files @ r25014:e1f1bf3a062e
Branch filter:

Location: cpp/openttd-patchpack/source/src/linkgraph/flowmapper.cpp

Patric Stout
Add: [Video] move GameLoop into its own thread

This allows drawing to happen while the GameLoop is doing an
iteration too.

Sadly, not much drawing currently can be done while the GameLoop
is running, as for example PollEvent() or UpdateWindows() can
influence the game-state. As such, they first need to acquire a
lock on the game-state before they can be called.

Currently, the main advantage is the time spend in Paint(), which
for non-OpenGL drivers can be a few milliseconds. For OpenGL this
is more like 0.05 milliseconds; in these instances this change
doesn't add any benefits for now.

This is an alternative to the former "draw-thread", which moved
the drawing in a thread for some OSes. It has similar performance
gain as this does, although this implementation allows for more
finer control over what suffers when the GameLoop takes too
long: drawing or the next GameLoop. For now they both suffer
equally.
/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file flowmapper.cpp Definition of flowmapper. */

#include "../stdafx.h"
#include "flowmapper.h"

#include "../safeguards.h"

/**
 * Map the paths generated by the MCF solver into flows associated with nodes.
 * @param job the link graph component to be used.
 */
void FlowMapper::Run(LinkGraphJob &job) const
{
	for (NodeID node_id = 0; node_id < job.Size(); ++node_id) {
		Node prev_node = job[node_id];
		StationID prev = prev_node.Station();
		PathList &paths = prev_node.Paths();
		for (PathList::iterator i = paths.begin(); i != paths.end(); ++i) {
			Path *path = *i;
			uint flow = path->GetFlow();
			if (flow == 0) break;
			Node node = job[path->GetNode()];
			StationID via = node.Station();
			StationID origin = job[path->GetOrigin()].Station();
			assert(prev != via && via != origin);
			/* Mark all of the flow for local consumption at "first". */
			node.Flows().AddFlow(origin, via, flow);
			if (prev != origin) {
				/* Pass some of the flow marked for local consumption at "prev" on
				 * to this node. */
				prev_node.Flows().PassOnFlow(origin, via, flow);
			} else {
				/* Prev node is origin. Simply add flow. */
				prev_node.Flows().AddFlow(origin, via, flow);
			}
		}
	}

	for (NodeID node_id = 0; node_id < job.Size(); ++node_id) {
		/* Remove local consumption shares marked as invalid. */
		Node node = job[node_id];
		FlowStatMap &flows = node.Flows();
		flows.FinalizeLocalConsumption(node.Station());
		if (this->scale) {
			/* Scale by time the graph has been running without being compressed. Add 1 to avoid
			 * division by 0 if spawn date == last compression date. This matches
			 * LinkGraph::Monthly(). */
			uint runtime = job.JoinDate() - job.Settings().recalc_time - job.LastCompression() + 1;
			for (FlowStatMap::iterator i = flows.begin(); i != flows.end(); ++i) {
				i->second.ScaleToMonthly(runtime);
			}
		}
		/* Clear paths. */
		PathList &paths = node.Paths();
		for (PathList::iterator i = paths.begin(); i != paths.end(); ++i) {
			delete *i;
		}
		paths.clear();
	}
}