Tracking: Fix jump when sliding tild/scale of marker

Was a mistake in coordinate handling: need to take possible offset
from the sliding area.

Mouse us still not fully perfectly follows changes of the tilt slide
area, but that is a separate issue.

1 files changed, 2 insertions, 11 deletions

diff --git a/source/blender/editors/space_clip/tracking_ops.c b/source/blender/editors/space_clip/tracking_ops.c
index 6660ff3b78b..1a497a35b6f 100644
--- a/source/blender/editors/space_clip/tracking_ops.c
+++ b/source/blender/editors/space_clip/tracking_ops.c
@@ -876,22 +876,13 @@ static int slide_marker_modal(bContext *C, wmOperator *op, const wmEvent *event)
           BKE_tracking_marker_clamp(data->marker, CLAMP_PAT_DIM);
         }
         else if (data->action == SLIDE_ACTION_TILT_SIZE) {
+          const float mouse_delta[2] = {dx, dy};
           float start[2], end[2];
           float scale = 1.0f, angle = 0.0f;
-          float mval[2];
-
-          if (data->accurate) {
-            mval[0] = data->mval[0] + (event->mval[0] - data->mval[0]) / 5.0f;
-            mval[1] = data->mval[1] + (event->mval[1] - data->mval[1]) / 5.0f;
-          }
-          else {
-            mval[0] = event->mval[0];
-            mval[1] = event->mval[1];
-          }
 
           sub_v2_v2v2(start, data->spos, data->old_pos);
 
-          ED_clip_point_stable_pos(sc, region, mval[0], mval[1], &end[0], &end[1]);
+          add_v2_v2v2(end, data->spos, mouse_delta);
           sub_v2_v2(end, data->old_pos);
 
           if (len_squared_v2(start) != 0.0f) {