Fix T87173: wrong Auto-Snap in animation editors

This was partially broken with {rBde9ea94fc6f}.

The `Frame Step` and `Second Step` snapping options were working as if
they were `Nearest Frame` and `Nearest Second` respectively in the
`Dope Sheet` and `NLA` editors.

In the `Graph Editor` the problem was more serious:
"Second Step: ... The keyframe itself moves along as though in snapping
were active at all, while its handles 'stay behind' until it reaches
the next second boundary, at which point the teleport handles to
'catch up'".

The snapping code for these modes was spread across the transform
mode code and `recalcData` of each data type. Therefore, create a
unified snapping code for these options so that all issues are fixed in
one place.

Differetial Revision: https://developer.blender.org/D12241

1 files changed, 6 insertions, 53 deletions

diff --git a/source/blender/editors/transform/transform_convert_graph.c b/source/blender/editors/transform/transform_convert_graph.c
index c0acdd89b02..d22277f9d91 100644
--- a/source/blender/editors/transform/transform_convert_graph.c
+++ b/source/blender/editors/transform/transform_convert_graph.c
@@ -40,6 +40,8 @@
 #include "UI_view2d.h"
 
 #include "transform.h"
+#include "transform_snap.h"
+
 #include "transform_convert.h"
 #include "transform_snap.h"
 
@@ -662,10 +664,9 @@ static void flushTransGraphData(TransInfo *t)
   TransData *td;
   TransData2D *td2d;
   TransDataGraph *tdg;
-  Scene *scene = t->scene;
-  double secf = FPS;
   int a;
 
+  const short autosnap = getAnimEdit_SnapMode(t);
   TransDataContainer *tc = TRANS_DATA_CONTAINER_FIRST_SINGLE(t);
 
   /* flush to 2d vector from internally used 3d vector */
@@ -681,22 +682,8 @@ static void flushTransGraphData(TransInfo *t)
      * - Only apply to keyframes (but never to handles).
      * - Don't do this when canceling, or else these changes won't go away.
      */
-    if ((t->state != TRANS_CANCEL) && (td->flag & TD_NOTIMESNAP) == 0) {
-      const short autosnap = getAnimEdit_SnapMode(t);
-      switch (autosnap) {
-        case SACTSNAP_FRAME: /* snap to nearest frame */
-          td2d->loc[0] = floor((double)td2d->loc[0] + 0.5);
-          break;
-
-        case SACTSNAP_SECOND: /* snap to nearest second */
-          td2d->loc[0] = floor(((double)td2d->loc[0] / secf) + 0.5) * secf;
-          break;
-
-        case SACTSNAP_MARKER: /* snap to nearest marker */
-          td2d->loc[0] = (float)ED_markers_find_nearest_marker_time(&t->scene->markers,
-                                                                    td2d->loc[0]);
-          break;
-      }
+    if ((autosnap != SACTSNAP_OFF) && (t->state != TRANS_CANCEL) && !(td->flag & TD_NOTIMESNAP)) {
+      transform_snap_anim_flush_data(t, td, autosnap, td->loc);
     }
 
     /* we need to unapply the nla-mapping from the time in some situations */
@@ -707,32 +694,6 @@ static void flushTransGraphData(TransInfo *t)
       td2d->loc2d[0] = td2d->loc[0];
     }
 
-    /** Time-stepping auto-snapping modes don't get applied for Graph Editor transforms,
-     * as these use the generic transform modes which don't account for this sort of thing.
-     * These ones aren't affected by NLA mapping, so we do this after the conversion...
-     *
-     * \note We also have to apply to td->loc,
-     * as that's what the handle-adjustment step below looks to,
-     * otherwise we get "swimming handles".
-     *
-     * \note We don't do this when canceling transforms, or else these changes don't go away.
-     */
-    if ((t->state != TRANS_CANCEL) && (td->flag & TD_NOTIMESNAP) == 0) {
-      const short autosnap = getAnimEdit_SnapMode(t);
-      switch (autosnap) {
-        case SACTSNAP_STEP: /* frame step */
-          td2d->loc2d[0] = floor((double)td2d->loc[0] + 0.5);
-          td->loc[0] = floor((double)td->loc[0] + 0.5);
-          break;
-
-        case SACTSNAP_TSTEP: /* second step */
-          /* XXX: the handle behavior in this case is still not quite right... */
-          td2d->loc[0] = floor(((double)td2d->loc[0] / secf) + 0.5) * secf;
-          td->loc[0] = floor(((double)td->loc[0] / secf) + 0.5) * secf;
-          break;
-      }
-    }
-
     /* if int-values only, truncate to integers */
     if (td->flag & TD_INTVALUES) {
       td2d->loc2d[1] = floorf(td2d->loc[1] * inv_unit_scale - tdg->offset + 0.5f);
@@ -741,15 +702,7 @@ static void flushTransGraphData(TransInfo *t)
       td2d->loc2d[1] = td2d->loc[1] * inv_unit_scale - tdg->offset;
     }
 
-    if ((td->flag & TD_MOVEHANDLE1) && td2d->h1) {
-      td2d->h1[0] = td2d->ih1[0] + td->loc[0] - td->iloc[0];
-      td2d->h1[1] = td2d->ih1[1] + (td->loc[1] - td->iloc[1]) * inv_unit_scale;
-    }
-
-    if ((td->flag & TD_MOVEHANDLE2) && td2d->h2) {
-      td2d->h2[0] = td2d->ih2[0] + td->loc[0] - td->iloc[0];
-      td2d->h2[1] = td2d->ih2[1] + (td->loc[1] - td->iloc[1]) * inv_unit_scale;
-    }
+    transform_convert_flush_handle2D(td, td2d, inv_unit_scale);
   }
 }