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require_once("../inc/bossa.inc");
// Bossa example #2.
// Show the user an image and ask them to click on the ellipse
// This version does replication;
// a job is considered done if either
// - 2 instances are positive and match within +- 20 pixels
// - 2 instances are negative
// - there are 10 finished instances
// (in which case the job is marked as inconclusive)
function job_show($job, $inst, $user) {
$info = $job->get_opaque_data($job);
$path = $info->path;
echo "
Find the Ellipse!
";
}
function job_issued($job, $inst, $user) {
$insts = $job->get_instances();
if (count($insts) == 1) {
$job->set_priority(2);
} else {
$job->set_priority(0);
}
}
function job_finished($job, $inst) {
// record the user's response
//
$response = null;
if (get_str('submit', true)) {
$response->have_ellipse = 0;
} else {
$response->have_ellipse = 1;
$response->cx = get_int('pic_x');
$response->cy = get_int('pic_y');
}
$inst->set_opaque_data($response);
// see whether we have a consensus
//
$insts = $job->get_finished_instances();
$n = count($insts);
$results = null;
foreach ($insts as $inst) {
$results[] = $inst->get_opaque_data();
}
for ($i=0; $i<$n-1; $i++) {
$r1 = $results[$i];
for ($j=$i+1; $j<$n; $j++) {
$r2 = $results[$j];
if (compatible($r1, $r2)) {
$job->set_state(BOSSA_JOB_DONE);
return;
}
}
}
// no consensus - see whether we've reached replication limit
//
if ($n >= 10) {
$job->set_state(BOSSA_JOB_INCONCLUSIVE);
return;
}
// still looking for consensus - get another instance
//
$job->set_priority(2);
}
// two results are compatible if neither found an ellipse,
// or they both did and centers are within 20 pixels
//
function compatible($r1, $r2) {
if ($r1->have_ellipse) {
if ($r2->have_ellipse) {
$dx = ($r1->cx - $r2->cx);
$dy = ($r1->cy - $r2->cy);
$dsq = $dx*$dx + $dy*$dy;
return ($dsq < 400);
} else return false;
} else {
return !$r2->have_ellipse;
}
}
function job_timed_out($job, $inst, $user) {
$job->set_priority(2);
}
function job_summary($job) {
$info = $job->get_opaque_data();
return "path>View image";
}
function instance_summary($info) {
if ($info->have_ellipse) {
return "ellipse ($info->cx, $info->cy)";
} else {
return "no ellipse";
}
}
function user_summary($user) {
return "";
}