// find_path.cpp: implementation of the find_path class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "find_path.h"
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
find_path::find_path()
{
_pf_go_test = NULL;
node_close = NULL;
node_open = NULL;
node_next = NULL;
path_p = NULL;
node_map = NULL;
}
find_path::~find_path()
{
node_close = NULL;
node_open = NULL;
node_next = NULL;
if (NULL != path_p)
{
delete []path_p;
path_p = NULL;
}
if (NULL != node_map)
{
delete []node_map;
node_map = NULL;
}
}
void find_path::reset()
{
path_t = 0;
memset(path_p, 0, path_max*sizeof(path_z));
memset(node_map, 0, path_max*sizeof(path_node));
for (int j = 0; j < h; j++)
{
for (int i = 0; i < w; i++)
{
T * p = node_map + w*j + i;
p->x = i;
p->y = j;
}
}
}
void find_path::init(int width, int height, pf_go_test pf)
{
set_pf(pf);
w = width;
h = height;
path_max = w*h;
path_p = new path_z[path_max];
node_map = new path_node[path_max];
//reset();
}
//--返回找到的最短路径步数
//--返回-1表示无法到达目的地
//--并将找到的最短路径存储在path_p
int find_path::go(int x0, int y0, int x1, int y1, pf_go_test pf)
{
reset();
set_pf(pf);
//reset();
node_open = (T*)(node_map) + w*y0 + x0;
T * root;
//root = node_open;
int xx, yy;//--决定x轴或y轴各自的优先寻路方向
int dx, dy;//--决定x轴与y轴的优先寻路方向
bool find = false;
while (NULL != node_open)
{
root = GetFromOpenQueue();
if (NULL == root) break;
T & t = *root;
if (x1 == t.x && y1 == t.y)
{
find = true;
break; // 达到目的地成功返回
}
//--决定优先寻路方向
if (x1 > t.x)
{
xx = 1;
dx = x1 - t.x;
}
else
{
xx = 0;
dx = t.x - x1;
}
//--
if (y1 > t.y)
{
yy = 1;
dy = y1 - t.y;
}
else
{
yy = 0;
dy = t.y - y1;
}
//--后面的优先
//--y方向优先
if (0 == dx
|| (0 != dy && dx > dy))
{
//--x方向+优先
if (1 == xx)
{
TryTile(t.x - 1, t.y, root);
TryTile(t.x + 1, t.y, root);
}
//--x方向-优先
else
{
TryTile(t.x + 1, t.y, root);
TryTile(t.x - 1, t.y, root);
}
//--y方向+优先
if (1 == yy)
{
TryTile(t.x, t.y - 1, root);
TryTile(t.x, t.y + 1, root);
}
//--y方向-优先
else
{
TryTile(t.x, t.y + 1, root);
TryTile(t.x, t.y - 1, root);
}
}
//--x方向优先
else
{
//--y方向+优先
if (1 == yy)
{
TryTile(t.x, t.y - 1, root);
TryTile(t.x, t.y + 1, root);
}
//--y方向-优先
else
{
TryTile(t.x, t.y + 1, root);
TryTile(t.x, t.y - 1, root);
}
//--x方向+优先
if (1 == xx)
{
TryTile(t.x - 1, t.y, root);
TryTile(t.x + 1, t.y, root);
}
//--x方向-优先
else
{
TryTile(t.x + 1, t.y, root);
TryTile(t.x - 1, t.y, root);
}
}
};
if (false == find)
{
//--无法到达目的地
path_t = -1;
return path_t;
}
//--回溯树
//--将求出的最佳路径(逆向)保存在path_p
for (path_t = 0; root; path_t++)
{
path_p[path_t].x = root->x;
path_p[path_t].y = root->y;
root = root->parent;
}
if (path_t > 0)
{
path_t--;
//--路径反转
int t = path_t/2;
for (int i = 0; i < t; i++)
{
path_z z = path_p[i];
path_p[i] = path_p[path_t - i];
path_p[path_t - i] = z;
}
}
return path_t;
}
