treewars/graph.cpp

#include "graph.h"
#include "mathutils.h"
#include "debug.h"
#include <list>
#include <algorithm>
#include <cassert>

using std::list;

Graph::Graph(bool planar)
{
    this->planar = planar;
}

Graph::~Graph()
{
    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex* v = *cursor;
	delete v;
    }
}

bool Graph::point_in_vertex(int x, int y)
{
    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex* v = *cursor;
	if (MathUtils::distance(v->x, v->y, x, y) <= v->r) return true;
    }

    return false;
}


Vertex * Graph::vertex_at(int x, int y)
{
    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex* v = *cursor;
	if (MathUtils::distance(v->x, v->y, x, y) <= v->r) return v;
    }

    return NULL;
}


bool Graph::vertex_would_overlap(int x, int y, int r)
{
    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex* v = *cursor;
	if (MathUtils::distance(v->x, v->y, x, y) <= v->r + r) return true;
    }

    return false;
}


bool Graph::crosses_edge(Edge e)
{
    for (list<Edge>::iterator cursor = edges.begin();
	 cursor != edges.end(); cursor++)
    {
	Edge c = *cursor;
	if (MathUtils::lines_intersect(c.a->x, c.a->y, c.b->x, c.b->y,
				       e.a->x, e.a->y, e.b->x, e.b->y))
	    return true;
    }

    return false;
}


bool Graph::add_vertex(int x, int y, int r, int colour, int score, Vertex* src)
{
    Vertex* v = new Vertex(x, y, r, colour, score);

    // Make sure the nodes won't overlap
    if (vertex_would_overlap(v->x, v->y, v->r))
    {
#ifdef DEBUG
	fprintf(stderr, "debug: Graph::add_vertex(): failed to add due to vertex collision: x=%d, y=%d, r=%d\n", v->x, v->y, v->r);
#endif
	delete v;
	return false;
    }

    if (src != NULL)
    {
	Edge e;
	e.a = src;
	e.b = v;

	if (planar && crosses_edge(e))
	{
#ifdef DEBUG
    fprintf(stderr, "debug: Graph::add_vertex(): failed to add due to edge collision: x1=%d, y1=%d, x2=%d, y2=%d\n", e.a->x, e.a->y, e.b->x, e.b->y);
#endif
            delete v;
            return false;
	}

	edges.push_back(e);
    }

    vertices.push_back(v);

#ifdef DEBUG
    fprintf(stderr, "debug: Graph::add_vertex(): added: x=%d, y=%d, r=%d, score=%d\n", v->x, v->y, v->r, v->score);
#endif

    return true;
}


list<Vertex*> Graph::get_colour(int colour)
{
    list<Vertex*> answer;

    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex* v = *cursor;
	if (v->colour == colour) answer.push_back(v);
    }

    return answer;
}


list<Edge> Graph::get_edges(Vertex* v)
{
    list<Edge> answer;

    for (list<Edge>::iterator cursor = edges.begin();
	 cursor != edges.end(); cursor++)
    {
	Edge e = *cursor;
	if (e.a == v || e.b == v) answer.push_back(e);
    }

    return answer;
}


list<Vertex*> Graph::get_neighbors(Vertex* v)
{
    list<Vertex*> answer;

    for (list<Edge>::iterator cursor = edges.begin();
	 cursor != edges.end(); cursor++)
    {
	Edge e = *cursor;
	if (e.a == v) answer.push_back(e.b);
	else if (e.b == v) answer.push_back(e.a);
    }

    return answer;
}


void Graph::remove_vertex(Vertex* target)
{
    list<Edge> dead_edges = get_edges(target);

    for (list<Edge>::iterator cursor = dead_edges.begin();
	 cursor != dead_edges.end(); cursor++)
    {
	Edge e = *cursor;
	list<Edge>::iterator to_del = find(edges.begin(), edges.end(), e);

	if (to_del != edges.end())
	{
	    edges.erase(to_del);
	}
    }

    list<Vertex*>::iterator to_del = find(vertices.begin(), vertices.end(),
					  target);

    assert(to_del != vertices.end());
    vertices.erase(to_del);
    delete target;
}


Vertex::Vertex(int x, int y, int r, int colour, int score)
{
    this->x = x;
    this->y = y;
    this->r = r;
    this->colour = colour;
    this->score = score;
}


Edge::Edge()
{
    a = NULL;
    b = NULL;
    score = 0;
}


Edge::Edge(Vertex* a, Vertex* b, int score)
{
    this->a = a;
    this->b = b;
    this->score = score;
}


bool Edge::operator==(const Edge e) const
{
    return (this->a == e.a &&
	    this->b == e.b &&
	    this->score == e.score);
}