treewars/graph.cpp

#include "graph.h"
#include <cmath>

using std::abs;

#ifdef DEBUG
#include <iostream>
using std::cerr;
#endif


Graph::Graph()
{
    last_vertex = NULL;
}

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

bool Graph::vertex_present(int x, int y, int size)
{
    int delta = size / 2;

    int x_min = x - delta;
    int x_max = x + delta;
    int y_min = y - delta;
    int y_max = y + delta;

    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex v = *(*cursor);
	if (((x_min >= v.x_min && x_min <= v.x_max) &&
	     ((y_min >= v.y_min && y_min <= v.y_max) ||
	      (y_max >= v.y_min && y_max <= v.y_max))) ||
	    ((x_max >= v.x_min && x_max <= v.x_max) &&
	     ((y_min >= v.y_min && y_min <= v.y_max) ||
	      (y_max >= v.y_min && y_max <= v.y_max))))
	{
#ifdef DEBUG
    cerr << "debug: Graph::vertex_present(): vertex present at x=" << v.x << ", y=" << v.y << "\n";
#endif
	    return true;
	}
    }

	return false;
}

void Graph::add_vertex(int x, int y, int size)
{
    Vertex* v = new Vertex();
    v->x = x;
    v->y = y;

    v->x_min = x - size/2;
    v->x_max = x + size/2;
    v->y_min = y - size/2;
    v->y_max = y + size/2;

    if (vertex_present(v->x, v->y, 25)) return;

    vertices.push_back(v);

    if (last_vertex == NULL)
    {
	last_vertex = v;
	return;
    }

    Edge e;
    e.a = last_vertex;
    e.b = v;
    edges.push_back(e);
    last_vertex = v;
}


float Vertex::distance(Vertex a, Vertex b)
{
    float dy = abs(static_cast<float>(b.y) - a.y);
    float dx = abs(static_cast<float>(b.x) - a.x);
    if (dx == 0) return 0;
    return dy/dx;
}