Below are two captures of a same moving contact separated by 50ms. It shows both the ellipse and bounding box data returned by the API. From the documentation I deduced that the ellipse figure should contained within the bounding box. As can be seen here, this is not the case at all.
Can anybody help me interpret the meaning of the bounding box.
INITIAL CONTACT DATA (Red)
x_pos: 169.96484375 mm
y_pos: 82.55078125 mm
orientation: -0.8125 º
major_axis: 10.0 mm
minor_axis: 10.0 mm
min_x: 165.0 mm
min_y: 80.0 mm
max_x: 170.0 mm
max_y: 85.0 mm
CONTACT DATA 50MS LATER (Blue)
x_pos: 159.82421875 mm
y_pos: 78.6171875 mm
orientation: 8.4375 º
major_axis: 11.578125 mm
minor_axis: 11.13671875 mm
min_x: 135.0 mm
min_y: 70.0 mm
max_x: 160.0 mm
max_y: 80.0 mm
Hello, I am not sure what setup you are using, but I modified the C contact example from GitHub to confirm that bounding boxes are working as expected.
//Handle that references a Sensel device
SENSEL_HANDLE handle = NULL;
//List of all available Sensel devices
SenselDeviceList list;
//SenselFrame data that will hold the contacts
SenselFrameData *frame = NULL;
//Get a list of avaialble Sensel devices
senselGetDeviceList(&list);
if (list.num_devices == 0)
{
fprintf(stdout, "No device found\n");
fprintf(stdout, "Press Enter to exit example\n");
getchar();
return 0;
}
//Open a Sensel device by the id in the SenselDeviceList, handle initialized
senselOpenDeviceByID(&handle, list.devices[0].idx);
//Set the frame content to scan contact data
senselSetFrameContent(handle, FRAME_CONTENT_CONTACTS_MASK);
senselSetContactsMask(handle, 0x0F);
//Allocate a frame of data, must be done before reading frame data
senselAllocateFrameData(handle, &frame);
//Start scanning the Sensel device
senselStartScanning(handle);
fprintf(stdout, "Press Enter to exit example\n");
#ifdef WIN32
HANDLE thread = CreateThread(NULL, 0, waitForEnter, NULL, 0, NULL);
#else
pthread_t thread;
pthread_create(&thread, NULL, waitForEnter, NULL);
#endif
while (!enter_pressed)
{
unsigned int num_frames = 0;
//Read all available data from the Sensel device
senselReadSensor(handle);
//Get number of frames available in the data read from the sensor
senselGetNumAvailableFrames(handle, &num_frames);
for (int f = 0; f < num_frames; f++)
{
//Read one frame of data
senselGetFrame(handle, frame);
//Print out contact data
if (frame->n_contacts > 0) {
fprintf(stdout, "Num Contacts: %d\n", frame->n_contacts);
for (int c = 0; c < frame->n_contacts; c++)
{
unsigned int state = frame->contacts[c].state;
fprintf(stdout, "Contact: X %f MinX %f MaxX %f Y %f MinY %f MaxY %f \n", frame->contacts[c].x_pos, frame->contacts[c].min_x, frame->contacts[c].max_x, frame->contacts[c].y_pos, frame->contacts[c].min_y, frame->contacts[c].max_y );
//fprintf(stdout, "Contact ID: %d State: %s\n", frame->contacts[c].id, CONTACT_STATE_STRING[state]);
//Turn on LED for CONTACT_START
if (state == CONTACT_START) {
senselSetLEDBrightness(handle, frame->contacts[c].id, 100);
}
//Turn off LED for CONTACT_END
else if (state == CONTACT_END) {
senselSetLEDBrightness(handle, frame->contacts[c].id, 0);
}
}
fprintf(stdout, "\n");
}
}
}
return 0;
