tracking_plane_tracker.c

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/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2011 Blender Foundation.
 * All rights reserved.
 */
 
#include "MEM_guardedalloc.h"
 
#include "DNA_movieclip_types.h"
 
#include "BLI_math.h"
#include "BLI_utildefines.h"
 
#include "BKE_tracking.h"
 
#include "libmv-capi.h"
 
typedef double Vec2[2];
 
static int point_markers_correspondences_on_both_image(
    MovieTrackingPlaneTrack *plane_track, int frame1, int frame2, Vec2 **x1_r, Vec2 **x2_r)
{
  Vec2 *x1, *x2;
 
  *x1_r = x1 = MEM_mallocN(sizeof(*x1) * plane_track->point_tracksnr, "point correspondences x1");
  *x2_r = x2 = MEM_mallocN(sizeof(*x1) * plane_track->point_tracksnr, "point correspondences x2");
 
  int correspondence_index = 0;
  for (int i = 0; i < plane_track->point_tracksnr; i++) {
    MovieTrackingTrack *point_track = plane_track->point_tracks[i];
    MovieTrackingMarker *point_marker1, *point_marker2;
 
    point_marker1 = BKE_tracking_marker_get_exact(point_track, frame1);
    point_marker2 = BKE_tracking_marker_get_exact(point_track, frame2);
 
    if (point_marker1 != NULL && point_marker2 != NULL) {
      /* Here conversion from float to double happens. */
      x1[correspondence_index][0] = point_marker1->pos[0];
      x1[correspondence_index][1] = point_marker1->pos[1];
 
      x2[correspondence_index][0] = point_marker2->pos[0];
      x2[correspondence_index][1] = point_marker2->pos[1];
 
      correspondence_index++;
    }
  }
 
  return correspondence_index;
}
 
/* NOTE: frame number should be in clip space, not scene space */
static void track_plane_from_existing_motion(MovieTrackingPlaneTrack *plane_track,
                                             int start_frame,
                                             int direction,
                                             bool retrack)
{
  MovieTrackingPlaneMarker *start_plane_marker = BKE_tracking_plane_marker_get(plane_track,
                                                                               start_frame);
  MovieTrackingPlaneMarker *keyframe_plane_marker = NULL;
  MovieTrackingPlaneMarker new_plane_marker;
  int frame_delta = direction > 0 ? 1 : -1;
 
  if (plane_track->flag & PLANE_TRACK_AUTOKEY) {
    /* Find a keyframe in given direction. */
    for (int current_frame = start_frame;; current_frame += frame_delta) {
      MovieTrackingPlaneMarker *next_plane_marker = BKE_tracking_plane_marker_get_exact(
          plane_track, current_frame + frame_delta);
 
      if (next_plane_marker == NULL) {
        break;
      }
 
      if ((next_plane_marker->flag & PLANE_MARKER_TRACKED) == 0) {
        keyframe_plane_marker = next_plane_marker;
        break;
      }
    }
  }
  else {
    start_plane_marker->flag |= PLANE_MARKER_TRACKED;
  }
 
  new_plane_marker = *start_plane_marker;
  new_plane_marker.flag |= PLANE_MARKER_TRACKED;
 
  for (int current_frame = start_frame;; current_frame += frame_delta) {
    MovieTrackingPlaneMarker *next_plane_marker = BKE_tracking_plane_marker_get_exact(
        plane_track, current_frame + frame_delta);
    Vec2 *x1, *x2;
    double H_double[3][3];
    float H[3][3];
 
    /* As soon as we meet keyframed plane, we stop updating the sequence. */
    if (next_plane_marker && (next_plane_marker->flag & PLANE_MARKER_TRACKED) == 0) {
      /* Don't override keyframes if track is in auto-keyframe mode */
      if (plane_track->flag & PLANE_TRACK_AUTOKEY) {
        break;
      }
    }
 
    const int num_correspondences = point_markers_correspondences_on_both_image(
        plane_track, current_frame, current_frame + frame_delta, &x1, &x2);
    if (num_correspondences < 4) {
      MEM_freeN(x1);
      MEM_freeN(x2);
      break;
    }
 
    libmv_homography2DFromCorrespondencesEuc(x1, x2, num_correspondences, H_double);
 
    copy_m3_m3d(H, H_double);
 
    for (int i = 0; i < 4; i++) {
      float vec[3] = {0.0f, 0.0f, 1.0f}, vec2[3];
      copy_v2_v2(vec, new_plane_marker.corners[i]);
 
      /* Apply homography */
      mul_v3_m3v3(vec2, H, vec);
 
      /* Normalize. */
      vec2[0] /= vec2[2];
      vec2[1] /= vec2[2];
 
      copy_v2_v2(new_plane_marker.corners[i], vec2);
    }
 
    new_plane_marker.framenr = current_frame + frame_delta;
 
    if (!retrack && keyframe_plane_marker && next_plane_marker &&
        (plane_track->flag & PLANE_TRACK_AUTOKEY)) {
      float fac = ((float)next_plane_marker->framenr - start_plane_marker->framenr) /
                  ((float)keyframe_plane_marker->framenr - start_plane_marker->framenr);
 
      fac = 3 * fac * fac - 2 * fac * fac * fac;
 
      for (int i = 0; i < 4; i++) {
        interp_v2_v2v2(new_plane_marker.corners[i],
                       new_plane_marker.corners[i],
                       next_plane_marker->corners[i],
                       fac);
      }
    }
 
    BKE_tracking_plane_marker_insert(plane_track, &new_plane_marker);
 
    MEM_freeN(x1);
    MEM_freeN(x2);
  }
}
 
/* NOTE: frame number should be in clip space, not scene space */
void BKE_tracking_track_plane_from_existing_motion(MovieTrackingPlaneTrack *plane_track,
                                                   int start_frame)
{
  track_plane_from_existing_motion(plane_track, start_frame, 1, false);
  track_plane_from_existing_motion(plane_track, start_frame, -1, false);
}
 
static MovieTrackingPlaneMarker *find_plane_keyframe(MovieTrackingPlaneTrack *plane_track,
                                                     int start_frame,
                                                     int direction)
{
  MovieTrackingPlaneMarker *plane_marker = BKE_tracking_plane_marker_get(plane_track, start_frame);
  int index = plane_marker - plane_track->markers;
  int frame_delta = direction > 0 ? 1 : -1;
 
  while (index >= 0 && index < plane_track->markersnr) {
    if ((plane_marker->flag & PLANE_MARKER_TRACKED) == 0) {
      return plane_marker;
    }
    plane_marker += frame_delta;
  }
 
  return NULL;
}
 
void BKE_tracking_retrack_plane_from_existing_motion_at_segment(
    MovieTrackingPlaneTrack *plane_track, int start_frame)
{
  MovieTrackingPlaneMarker *prev_plane_keyframe, *next_plane_keyframe;
 
  prev_plane_keyframe = find_plane_keyframe(plane_track, start_frame, -1);
  next_plane_keyframe = find_plane_keyframe(plane_track, start_frame, 1);
 
  if (prev_plane_keyframe != NULL && next_plane_keyframe != NULL) {
    /* First we track from left keyframe to the right one without any blending. */
    track_plane_from_existing_motion(plane_track, prev_plane_keyframe->framenr, 1, true);
 
    /* And then we track from the right keyframe to the left one, so shape blends in nicely */
    track_plane_from_existing_motion(plane_track, next_plane_keyframe->framenr, -1, false);
  }
  else if (prev_plane_keyframe != NULL) {
    track_plane_from_existing_motion(plane_track, prev_plane_keyframe->framenr, 1, true);
  }
  else if (next_plane_keyframe != NULL) {
    track_plane_from_existing_motion(plane_track, next_plane_keyframe->framenr, -1, true);
  }
}
 
BLI_INLINE void float_corners_to_double(/*const*/ float corners[4][2], double double_corners[4][2])
{
  copy_v2db_v2fl(double_corners[0], corners[0]);
  copy_v2db_v2fl(double_corners[1], corners[1]);
  copy_v2db_v2fl(double_corners[2], corners[2]);
  copy_v2db_v2fl(double_corners[3], corners[3]);
}
 
void BKE_tracking_homography_between_two_quads(/*const*/ float reference_corners[4][2],
                                               /*const*/ float corners[4][2],
                                               float H[3][3])
{
  Vec2 x1[4], x2[4];
  double H_double[3][3];
 
  float_corners_to_double(reference_corners, x1);
  float_corners_to_double(corners, x2);
 
  libmv_homography2DFromCorrespondencesEuc(x1, x2, 4, H_double);
 
  copy_m3_m3d(H, H_double);
}