/** A callback function that will get called whenever the tracker
* provides us with new data. This may be called repeatedly for each
* record that we have missed if many records have been delivered
* since the last call to the VRPN mainloop() function. */
static void VRPN_CALLBACK handle_tracker(void *name, vrpn_TRACKERCB t)
{
float fps = kuhl_getfps(&fps_state);
if(fps_state.frame == 0)
msg(INFO, "VRPN records per second: %.1f\n", fps);
/* Some tracking systems return large values when a point gets
* lost. If the tracked point seems to be lost, ignore this
* update. */
float pos[3];
vec3f_set(pos, t.pos[0], t.pos[1], t.pos[2]);
long microseconds = (t.msg_time.tv_sec* 1000000L) + t.msg_time.tv_usec;
if(0)
{
printf("Current time %ld; VRPN record time: %ld\n", kuhl_microseconds(), microseconds);
printf("Received position from vrpn: ");
vec3f_print(pos);
}
if(vec3f_norm(pos) > 100)
return;
// Store the data in our map so that someone can use it later.
std::string s = (char*)name;
nameToCallbackData[s] = t;
smooth(nameToCallbackData[s]);
}
/** Performs a sanity check on the IPD to ensure that it is not too small, big, or reversed.
@param viewmatrix View matrix for the viewportID
@param viewportID The viewportID for this particular view matrix.
*/
static void viewmat_validate_ipd(float viewmatrix[16], int viewportID)
{
// First, if viewportID=0, save the matrix so we can do the check when we are called with viewportID=1.
static float viewmatrix0[16];
static long viewmatrix0time;
if(viewportID == 0)
{
mat4f_copy(viewmatrix0, viewmatrix);
viewmatrix0time = kuhl_microseconds();
return;
}
// If rendering viewportID == 1, and if there are two viewports,
// assume that we are running in a stereoscopic configuration and
// validate the IPD value.
if(viewportID == 1 && viewports_size == 2)
{
float flip = 1;
/* In most cases, viewportID=0 is the left eye. However,
* Oculus may cause this to get swapped. */
if(viewmat_viewport_to_eye(0) == VIEWMAT_EYE_RIGHT)
flip = -1;
// Get the position matrix information
float pos1[4], pos2[4];
mat4f_getColumn(pos1, viewmatrix0, 3); // get last column
mat4f_getColumn(pos2, viewmatrix, 3); // get last column
// Get a vector between the eyes
float diff[4];
vec4f_sub_new(diff, pos1, pos2);
vec4f_scalarMult_new(diff, diff, flip); // flip vector if necessary
/* This message may be triggered if a person is moving quickly
* and/or when the FPS is low. This happens because the
* position/orientation of the head changed between the
* rendering of the left and right eyes. */
float ipd = diff[0];
long delay = kuhl_microseconds() - viewmatrix0time;
if(ipd > .07 || ipd < .05)
{
msg(MSG_WARNING, "IPD=%.4f meters, delay=%ld us (IPD validation failed; occasional messages are OK!)\n", ipd, delay);
}
// msg(MSG_INFO, "IPD=%.4f meters, delay=%ld us\n", ipd, delay);
}
}
/** Performs a sanity check on how long it took us to render a
* frame. At 60fps, we have approximately 16 milliseconds or 16000
* microseconds per frame. If the time between two subsequent
* renderings of viewportID 0 is too large, a warning message is
* printed.
*
* Even though the average FPS over a period of time may be above 60,
* the rendering might not appear smooth if an occasional frame misses
* the time budget.
*/
static void viewmat_validate_fps(void)
{
/* Set the time budget. If vblank syncing is turned on, we'd
* expect to always get a FPS close to the monitor. Setting this
* to 55 (instead of 60) will prevent messages from getting
* printed out constantly on such machines. */
#define targetFps 55 // older compilers won't let us use a static const variable to calculate another static const variable.
static const int timeBudget = 1000000.0f / targetFps;
/* Initialize our warning message counter and the time that the
* last frame was rendered. */
static int warnMsgCount = 0;
static long lastTime = -1;
if(lastTime < 0) // if our first time called, initialize time and return.
{
lastTime = kuhl_microseconds();
return;
}
/* If it took too long to render the frame, print a message. */
long delay = kuhl_microseconds() - lastTime;
// msg(MSG_INFO, "Time to render frame %d\n", delay);
if(delay > timeBudget)
{
warnMsgCount++;
/* Don't print the message if the first few frames took too
* long to render. Also, eventually stop printing the
* message. */
if(warnMsgCount > 5 && warnMsgCount <= 100)
msg(MSG_WARNING, "It took %ld microseconds to render a frame. Time budget for %d fps is %d microseconds.\n", delay, targetFps, timeBudget);
if(warnMsgCount == 100)
msg(MSG_WARNING, "That was your last warning about the time budget per frame.\n");
}
lastTime = kuhl_microseconds();
}