Camera tracking: more accurate track preview widget

- Added 1px extra margin to deal with bicubic interpolation nicely
- Code should be a bit more clear now

2 files changed, 25 insertions, 12 deletions

diff --git a/source/blender/blenkernel/intern/movieclip.c b/source/blender/blenkernel/intern/movieclip.c
index ab963f1e78c..4c78ab13874 100644
--- a/source/blender/blenkernel/intern/movieclip.c
+++ b/source/blender/blenkernel/intern/movieclip.c
@@ -860,7 +860,9 @@ void BKE_movieclip_update_scopes(MovieClip *clip, MovieClipUser *user, MovieClip
 						undist_marker.pos[1]/= height*aspy;
 					}
 
-					tmpibuf= BKE_tracking_get_pattern_imbuf(ibuf, track, &undist_marker, 1, 1, scopes->track_pos, NULL);
+					/* NOTE: margin should be kept in sync with value from ui_draw_but_TRACKPREVIEW */
+					tmpibuf= BKE_tracking_get_pattern_imbuf(ibuf, track, &undist_marker, 2 /* margin */,
+							1 /* anchor */, scopes->track_pos, NULL);
 
 					if(tmpibuf->rect_float)
 						IMB_rect_from_float(tmpibuf);
diff --git a/source/blender/blenkernel/intern/tracking.c b/source/blender/blenkernel/intern/tracking.c
index 7bfc7a8ef87..ff76fc14755 100644
--- a/source/blender/blenkernel/intern/tracking.c
+++ b/source/blender/blenkernel/intern/tracking.c
@@ -999,17 +999,24 @@ static ImBuf *get_area_imbuf(ImBuf *ibuf, MovieTrackingTrack *track, MovieTracki
 	if(anchored)
 		add_v2_v2(mpos, track->offset);
 
+	if(pos)
+		zero_v2(pos);
+
 	x= mpos[0]*ibuf->x;
 	y= mpos[1]*ibuf->y;
-	x1= x-(int)(-min[0]*ibuf->x);
-	y1= y-(int)(-min[1]*ibuf->y);
-	x2= x+(int)(max[0]*ibuf->x);
-	y2= y+(int)(max[1]*ibuf->y);
 
-	/* dimensions should be odd */
-	w= (x2-x1)|1;
-	h= (y2-y1)|1;
+	w= (max[0]-min[0])*ibuf->x;
+	h= (max[1]-min[1])*ibuf->y;
+
+	w= w|1;
+	h= h|1;
 
+	x1= x-(int)(w/2.0f);
+	y1= y-(int)(h/2.0f);
+	x2= x+(int)(w/2.0f);
+	y2= y+(int)(h/2.0f);
+
+	/* dimensions should be odd */
 	tmpibuf= IMB_allocImBuf(w+margin*2, h+margin*2, 32, IB_rect);
 	IMB_rectcpy(tmpibuf, ibuf, 0, 0, x1-margin, y1-margin, w+margin*2, h+margin*2);
 
@@ -1023,13 +1030,17 @@ static ImBuf *get_area_imbuf(ImBuf *ibuf, MovieTrackingTrack *track, MovieTracki
 		origin[1]= y1-margin;
 	}
 
-	if ((track->flag & TRACK_PREVIEW_GRAYSCALE) ||
-			(track->flag & TRACK_DISABLE_RED)       ||
-			(track->flag & TRACK_DISABLE_GREEN)     ||
-			(track->flag & TRACK_DISABLE_BLUE) ) {
+	if((track->flag & TRACK_PREVIEW_GRAYSCALE) ||
+	   (track->flag & TRACK_DISABLE_RED)       ||
+	   (track->flag & TRACK_DISABLE_GREEN)     ||
+	   (track->flag & TRACK_DISABLE_BLUE))
+	{
 		disable_imbuf_channels(tmpibuf, track, 1 /* grayscale */);
 	}
 
+	tmpibuf->ftype= PNG;
+	IMB_saveiff(tmpibuf, "/tmp/1.png", IB_rect);
+
 	return tmpibuf;
 }