int
SWEEP_BASE::trim_line_cb(CGESTUREptr& g, DrawState*&)
{
// Activity occurred to extend the deadline for fading away:
reset_timeout();
// A slash gesture across the guideline trims its tip
static bool debug =
Config::get_var_bool("DEBUG_SWEEP_TRIM",false) || debug_all;
err_adv(debug, "SWEEP_BASE::trim_cb");
// Find where the slash intersects the guideline.
PIXEL p;
if (g->endpt_line().intersect_segs(pix_line(), p)) {
// Reset the endpoint to match screen position p:
reset_endpoint(p);
return 1;
}
// The slash gesture missed the guideline...
// XXX - policy on failure?
err_adv(debug, "SWEEP_BASE::trim_line_cb: Missed the guideline");
return 1; // This means we DID use up the gesture
}
int
SWEEP_BASE::line_cb(CGESTUREptr& g, DrawState*& s)
{
// Activity occurred to extend the deadline for fading away:
reset_timeout();
static bool debug =
Config::get_var_bool("DEBUG_SWEEP_LINE_CB",false) || debug_all;
err_adv(debug, "SWEEP_BASE::line_cb");
// If gesture aligns with guideline:
// if it starts near the end and extends past the end, extend
// if it starts near the beginning, do uniform sweep
// If it's across the gesture, trim
// If it's a trim stroke, it has to be short and run
// across the guideline.
const double TRIM_MAX_LEN = 65;
if (g->length() < TRIM_MAX_LEN) {
const double TRIM_ANGLE_THRESH = 80; // degrees
double angle = line_angle(g->endpt_vec(), pix_line().direction());
if (rad2deg(angle) > TRIM_ANGLE_THRESH) {
// Nice angle. But did it cross?
if (g->endpt_line().intersect_segs(pix_line()))
return trim_line_cb(g, s);
}
}
// do uniform sweep if straight gesture starts at sweep origin
// and ends near the guideline:
if (from_center(g)) {
if (hits_line(g->end()))
return do_uniform_sweep(project_to_guideline(g->end()) - sweep_origin());
return stroke_cb(g,s);
}
// extend the guideline if straight gesture starts near guideline end
// and is nearly parallel:
const double ALIGN_ANGLE_THRESH = 15; // degrees
if (pix_line().endpt().dist(g->start()) < DIST_THRESH_PIXELS &&
rad2deg(g->endpt_vec().angle(pix_line().direction())) < ALIGN_ANGLE_THRESH)
return extend_line_cb(g, s);
return stroke_cb(g,s);
}