function create($data)
{
$o = decode($data['data']);
$exists = doesExist($o['id']);
$id = $exists ? 'null' : $o['id'];
$sql = sprintf("insert into `drafts` values(%d, '%s', '%s', %d, %d, %d)", mysql_real_escape_string($id), mysql_real_escape_string($o['timestamp']), mysql_real_escape_string($o['content']), mysql_real_escape_string($o['x']), mysql_real_escape_string($o['y']), mysql_real_escape_string($o['z']));
mysql_query($sql) or die(mysql_error());
headercode(201);
// If there was a conflict, we ignored the existing id, and created
// a new id. Send back the new id.
if ($exists) {
echo mysql_insert_id();
}
}
/**
* function runAstar
*
* traverse the grid useing the A* algorithm
*
* @param Grid $grid will hold the map of the world we are searching
* @param int $start_row the row of the start node
* @param int $start_col the col of the start node
* @param int $goal_row the row of the goal node
* @param int $goal_col the col of the goal node
* @param int $max_row the last row index
* @param int $max_col the last col index
* @return bool true if path exsit, false otherwise
*/
function runAstar($grid, $start_row, $start_col, $goal_row, $goal_col, $max_row, $max_col)
{
//initialize the open list
$open_list = array();
//initialize the closed list
$close_list = array();
$b_end_search = false;
//if true we must end the search
$goal_node =& $grid->nodes[$goal_row][$goal_col];
$start_node =& $grid->nodes[$start_row][$start_col];
$start_node->f = 0;
$open_list[] =& $start_node;
sortNodes($open_list, 'ASCE');
//while the open list is not empty
while (!empty($open_list)) {
$q = null;
//current_node
//find the node with the least f on the open list, call it "q"
//pop q off the open list
sortNodes($open_list, 'ASCE');
pop($open_list, 0, $q);
//generate q's 8 successors and set their parents to q
$successors = findSuccessors($grid->nodes, $q->row, $q->col, $max_row, $max_col);
foreach ($successors as $key => $successor) {
$temp = clone $successor;
$temp->parent_node =& $q;
//if the successor is an obstacle
if (isObstacle($temp)) {
continue;
// skip this successor if it is an obstacle
}
if (isGoal($temp, $goal_node)) {
$successor->parent_node = $temp->parent_node;
$b_end_search = true;
break;
}
$temp->g = $q->g + 1;
//
$temp->h = sqrt(pow($goal_node->row - $temp->row, 2) + pow($goal_node->col - $temp->col, 2));
$temp->f = $temp->g + $temp->h;
//
// $successor->g = $q->g + 1; //
// $successor->h = sqrt(pow(($goal_node->row - $successor->row), 2) + pow(($goal_node->col - $successor->col), 2));
// $successor->f = $successor->g + $successor->h;
//does exist in open list
if (doesExist($successor, $open_list) && $successor->f < $temp->f) {
continue;
}
//does exist in close list
if (doesExist($successor, $close_list) && $successor->f < $temp->f) {
continue;
}
//
$successor->parent_node = $temp->parent_node;
$successor->g = $temp->g;
$successor->h = $temp->h;
$successor->f = $temp->f;
$open_list[] =& $successors[$key];
//&$successor;
}
$close_list[] =& $grid->nodes[$q->row][$q->col];
//&$q;
if ($b_end_search == true) {
break;
}
}
return $b_end_search ? true : false;
//return true if there is a path, false otherwise
}
