Cleanup/Refactor: Split the snap to increments code

Now we have a better distinction of what is snap to grid and what is
snap to increments.

The code also allows the implementation of mixed snap for these modes.

30 files changed, 206 insertions, 178 deletions

diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 1917d9463f4..6356144d77a 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -79,7 +79,6 @@ typedef struct TransSnap {
   bool project;
   bool snap_self;
   bool peel;
-  bool snap_spatial_grid;
   bool use_backface_culling;
   char status;
   /* Snapped Element Type (currently for objects only). */
diff --git a/source/blender/editors/transform/transform_constraints.c b/source/blender/editors/transform/transform_constraints.c
index 4e5eaf4bf51..8a132f89b1c 100644
--- a/source/blender/editors/transform/transform_constraints.c
+++ b/source/blender/editors/transform/transform_constraints.c
@@ -167,7 +167,7 @@ static void postConstraintChecks(TransInfo *t, float vec[3])
 {
   mul_m3_v3(t->spacemtx_inv, vec);
 
-  snapGridIncrement(t, vec);
+  transform_snap_increment(t, vec);
 
   if (t->flag & T_NULL_ONE) {
     if (!(t->con.mode & CON_AXIS0)) {
diff --git a/source/blender/editors/transform/transform_mode.c b/source/blender/editors/transform/transform_mode.c
index 495c21bc755..edc0781e18e 100644
--- a/source/blender/editors/transform/transform_mode.c
+++ b/source/blender/editors/transform/transform_mode.c
@@ -1014,7 +1014,7 @@ void ElementResize(TransInfo *t, TransDataContainer *tc, TransData *td, float ma
 
     /* scale stroke thickness */
     if (td->val) {
-      snapGridIncrement(t, t->values_final);
+      transform_snap_increment(t, t->values_final);
       applyNumInput(&t->num, t->values_final);
 
       float ratio = t->values_final[0];
diff --git a/source/blender/editors/transform/transform_mode_baketime.c b/source/blender/editors/transform/transform_mode_baketime.c
index 4e7fc3578ce..235b04b1858 100644
--- a/source/blender/editors/transform/transform_mode_baketime.c
+++ b/source/blender/editors/transform/transform_mode_baketime.c
@@ -67,7 +67,7 @@ static void applyBakeTime(TransInfo *t, const int mval[2])
     time = (float)(t->center2d[0] - mval[0]) * fac;
   }
 
-  snapGridIncrement(t, &time);
+  transform_snap_increment(t, &time);
 
   applyNumInput(&t->num, &time);
 
diff --git a/source/blender/editors/transform/transform_mode_bbone_resize.c b/source/blender/editors/transform/transform_mode_bbone_resize.c
index 80a5b307a91..d067c9df418 100644
--- a/source/blender/editors/transform/transform_mode_bbone_resize.c
+++ b/source/blender/editors/transform/transform_mode_bbone_resize.c
@@ -124,7 +124,7 @@ static void applyBoneSize(TransInfo *t, const int UNUSED(mval[2]))
 
     copy_v3_fl(t->values_final, ratio);
 
-    snapGridIncrement(t, t->values_final);
+    transform_snap_increment(t, t->values_final);
 
     if (applyNumInput(&t->num, t->values_final)) {
       constraintNumInput(t, t->values_final);
diff --git a/source/blender/editors/transform/transform_mode_bend.c b/source/blender/editors/transform/transform_mode_bend.c
index 3b51626b170..86de40448b7 100644
--- a/source/blender/editors/transform/transform_mode_bend.c
+++ b/source/blender/editors/transform/transform_mode_bend.c
@@ -104,7 +104,7 @@ static void Bend(TransInfo *t, const int UNUSED(mval[2]))
     const float radius_snap = 0.1f;
     const float snap_hack = (t->snap[1] * data->warp_init_dist) / radius_snap;
     values.scale *= snap_hack;
-    snapGridIncrement(t, values.vector);
+    transform_snap_increment(t, values.vector);
     values.scale /= snap_hack;
   }
 #endif
diff --git a/source/blender/editors/transform/transform_mode_boneenvelope.c b/source/blender/editors/transform/transform_mode_boneenvelope.c
index b7a34769f5a..7f5a8fedeef 100644
--- a/source/blender/editors/transform/transform_mode_boneenvelope.c
+++ b/source/blender/editors/transform/transform_mode_boneenvelope.c
@@ -53,7 +53,7 @@ static void applyBoneEnvelope(TransInfo *t, const int UNUSED(mval[2]))
 
   ratio = t->values[0];
 
-  snapGridIncrement(t, &ratio);
+  transform_snap_increment(t, &ratio);
 
   applyNumInput(&t->num, &ratio);
 
diff --git a/source/blender/editors/transform/transform_mode_boneroll.c b/source/blender/editors/transform/transform_mode_boneroll.c
index 1503519c519..8805d54e1f8 100644
--- a/source/blender/editors/transform/transform_mode_boneroll.c
+++ b/source/blender/editors/transform/transform_mode_boneroll.c
@@ -54,7 +54,7 @@ static void applyBoneRoll(TransInfo *t, const int UNUSED(mval[2]))
 
   final = t->values[0];
 
-  snapGridIncrement(t, &final);
+  transform_snap_increment(t, &final);
 
   applyNumInput(&t->num, &final);
 
diff --git a/source/blender/editors/transform/transform_mode_curveshrinkfatten.c b/source/blender/editors/transform/transform_mode_curveshrinkfatten.c
index 84e4e950804..fd65b019fe0 100644
--- a/source/blender/editors/transform/transform_mode_curveshrinkfatten.c
+++ b/source/blender/editors/transform/transform_mode_curveshrinkfatten.c
@@ -53,7 +53,7 @@ static void applyCurveShrinkFatten(TransInfo *t, const int UNUSED(mval[2]))
 
   ratio = t->values[0];
 
-  snapGridIncrement(t, &ratio);
+  transform_snap_increment(t, &ratio);
 
   applyNumInput(&t->num, &ratio);
 
diff --git a/source/blender/editors/transform/transform_mode_edge_bevelweight.c b/source/blender/editors/transform/transform_mode_edge_bevelweight.c
index 399cec2d62c..4d6e25dbe34 100644
--- a/source/blender/editors/transform/transform_mode_edge_bevelweight.c
+++ b/source/blender/editors/transform/transform_mode_edge_bevelweight.c
@@ -55,7 +55,7 @@ static void applyBevelWeight(TransInfo *t, const int UNUSED(mval[2]))
 
   CLAMP_MAX(weight, 1.0f);
 
-  snapGridIncrement(t, &weight);
+  transform_snap_increment(t, &weight);
 
   applyNumInput(&t->num, &weight);
 
diff --git a/source/blender/editors/transform/transform_mode_edge_crease.c b/source/blender/editors/transform/transform_mode_edge_crease.c
index 53c948c742b..a1822d99ff9 100644
--- a/source/blender/editors/transform/transform_mode_edge_crease.c
+++ b/source/blender/editors/transform/transform_mode_edge_crease.c
@@ -55,7 +55,7 @@ static void applyCrease(TransInfo *t, const int UNUSED(mval[2]))
 
   CLAMP_MAX(crease, 1.0f);
 
-  snapGridIncrement(t, &crease);
+  transform_snap_increment(t, &crease);
 
   applyNumInput(&t->num, &crease);
 
diff --git a/source/blender/editors/transform/transform_mode_edge_rotate_normal.c b/source/blender/editors/transform/transform_mode_edge_rotate_normal.c
index fde0d5b187e..5b929c39915 100644
--- a/source/blender/editors/transform/transform_mode_edge_rotate_normal.c
+++ b/source/blender/editors/transform/transform_mode_edge_rotate_normal.c
@@ -99,7 +99,7 @@ static void applyNormalRotation(TransInfo *t, const int UNUSED(mval[2]))
     float angle = t->values[0];
     copy_v3_v3(axis, axis_final);
 
-    snapGridIncrement(t, &angle);
+    transform_snap_increment(t, &angle);
 
     applySnapping(t, &angle);
 
diff --git a/source/blender/editors/transform/transform_mode_edge_seq_slide.c b/source/blender/editors/transform/transform_mode_edge_seq_slide.c
index c1cb4325c09..141f9acdeb4 100644
--- a/source/blender/editors/transform/transform_mode_edge_seq_slide.c
+++ b/source/blender/editors/transform/transform_mode_edge_seq_slide.c
@@ -102,7 +102,7 @@ static void applySeqSlide(TransInfo *t, const int mval[2])
     copy_v3_v3(t->values_final, tvec);
   }
   else {
-    // snapGridIncrement(t, t->values);
+    // transform_snap_increment(t, t->values);
     applyNumInput(&t->num, t->values);
     copy_v3_v3(t->values_final, t->values);
   }
diff --git a/source/blender/editors/transform/transform_mode_edge_slide.c b/source/blender/editors/transform/transform_mode_edge_slide.c
index fe97a9fba87..7d0e555e362 100644
--- a/source/blender/editors/transform/transform_mode_edge_slide.c
+++ b/source/blender/editors/transform/transform_mode_edge_slide.c
@@ -1463,7 +1463,9 @@ static void applyEdgeSlide(TransInfo *t, const int UNUSED(mval[2]))
   final = t->values[0];
 
   applySnapping(t, &final);
-  snapGridIncrement(t, &final);
+  if (!validSnap(t)) {
+    transform_snap_increment(t, &final);
+  }
 
   /* only do this so out of range values are not displayed */
   if (is_constrained) {
diff --git a/source/blender/editors/transform/transform_mode_gpopacity.c b/source/blender/editors/transform/transform_mode_gpopacity.c
index 4712fb7ba01..11c63be156c 100644
--- a/source/blender/editors/transform/transform_mode_gpopacity.c
+++ b/source/blender/editors/transform/transform_mode_gpopacity.c
@@ -53,7 +53,7 @@ static void applyGPOpacity(TransInfo *t, const int UNUSED(mval[2]))
 
   ratio = t->values[0];
 
-  snapGridIncrement(t, &ratio);
+  transform_snap_increment(t, &ratio);
 
   applyNumInput(&t->num, &ratio);
 
diff --git a/source/blender/editors/transform/transform_mode_gpshrinkfatten.c b/source/blender/editors/transform/transform_mode_gpshrinkfatten.c
index ab9a0aa79ed..c025dbcaccb 100644
--- a/source/blender/editors/transform/transform_mode_gpshrinkfatten.c
+++ b/source/blender/editors/transform/transform_mode_gpshrinkfatten.c
@@ -53,7 +53,7 @@ static void applyGPShrinkFatten(TransInfo *t, const int UNUSED(mval[2]))
 
   ratio = t->values[0];
 
-  snapGridIncrement(t, &ratio);
+  transform_snap_increment(t, &ratio);
 
   applyNumInput(&t->num, &ratio);
 
diff --git a/source/blender/editors/transform/transform_mode_maskshrinkfatten.c b/source/blender/editors/transform/transform_mode_maskshrinkfatten.c
index 68f3abda85b..3ac35ae7780 100644
--- a/source/blender/editors/transform/transform_mode_maskshrinkfatten.c
+++ b/source/blender/editors/transform/transform_mode_maskshrinkfatten.c
@@ -54,7 +54,7 @@ static void applyMaskShrinkFatten(TransInfo *t, const int UNUSED(mval[2]))
 
   ratio = t->values[0];
 
-  snapGridIncrement(t, &ratio);
+  transform_snap_increment(t, &ratio);
 
   applyNumInput(&t->num, &ratio);
 
diff --git a/source/blender/editors/transform/transform_mode_push_pull.c b/source/blender/editors/transform/transform_mode_push_pull.c
index 4a2f979ec38..2b17f208e79 100644
--- a/source/blender/editors/transform/transform_mode_push_pull.c
+++ b/source/blender/editors/transform/transform_mode_push_pull.c
@@ -55,7 +55,7 @@ static void applyPushPull(TransInfo *t, const int UNUSED(mval[2]))
 
   distance = t->values[0];
 
-  snapGridIncrement(t, &distance);
+  transform_snap_increment(t, &distance);
 
   applyNumInput(&t->num, &distance);
 
diff --git a/source/blender/editors/transform/transform_mode_resize.c b/source/blender/editors/transform/transform_mode_resize.c
index 5fb46b30e0d..b4245abcc12 100644
--- a/source/blender/editors/transform/transform_mode_resize.c
+++ b/source/blender/editors/transform/transform_mode_resize.c
@@ -91,7 +91,7 @@ static void applyResize(TransInfo *t, const int UNUSED(mval[2]))
 
     copy_v3_fl(t->values_final, ratio);
 
-    snapGridIncrement(t, t->values_final);
+    transform_snap_increment(t, t->values_final);
 
     if (applyNumInput(&t->num, t->values_final)) {
       constraintNumInput(t, t->values_final);
diff --git a/source/blender/editors/transform/transform_mode_rotate.c b/source/blender/editors/transform/transform_mode_rotate.c
index 4fa5dffc473..c0ddd4eb2a6 100644
--- a/source/blender/editors/transform/transform_mode_rotate.c
+++ b/source/blender/editors/transform/transform_mode_rotate.c
@@ -200,7 +200,7 @@ static void applyRotation(TransInfo *t, const int UNUSED(mval[2]))
 
   final = t->values[0];
 
-  snapGridIncrement(t, &final);
+  transform_snap_increment(t, &final);
 
   float axis_final[3];
   /* Use the negative axis to match the default Z axis of the view matrix. */
diff --git a/source/blender/editors/transform/transform_mode_shear.c b/source/blender/editors/transform/transform_mode_shear.c
index e508a1fa4c2..18968494395 100644
--- a/source/blender/editors/transform/transform_mode_shear.c
+++ b/source/blender/editors/transform/transform_mode_shear.c
@@ -128,7 +128,7 @@ static void applyShear(TransInfo *t, const int UNUSED(mval[2]))
 
   value = t->values[0];
 
-  snapGridIncrement(t, &value);
+  transform_snap_increment(t, &value);
 
   applyNumInput(&t->num, &value);
 
diff --git a/source/blender/editors/transform/transform_mode_shrink_fatten.c b/source/blender/editors/transform/transform_mode_shrink_fatten.c
index 6302bc96330..2f221181d12 100644
--- a/source/blender/editors/transform/transform_mode_shrink_fatten.c
+++ b/source/blender/editors/transform/transform_mode_shrink_fatten.c
@@ -56,7 +56,7 @@ static void applyShrinkFatten(TransInfo *t, const int UNUSED(mval[2]))
 
   distance = t->values[0];
 
-  snapGridIncrement(t, &distance);
+  transform_snap_increment(t, &distance);
 
   applyNumInput(&t->num, &distance);
 
diff --git a/source/blender/editors/transform/transform_mode_skin_resize.c b/source/blender/editors/transform/transform_mode_skin_resize.c
index 23d83050613..665c616bc2b 100644
--- a/source/blender/editors/transform/transform_mode_skin_resize.c
+++ b/source/blender/editors/transform/transform_mode_skin_resize.c
@@ -55,7 +55,7 @@ static void applySkinResize(TransInfo *t, const int UNUSED(mval[2]))
   else {
     copy_v3_fl(t->values_final, t->values[0]);
 
-    snapGridIncrement(t, t->values_final);
+    transform_snap_increment(t, t->values_final);
 
     if (applyNumInput(&t->num, t->values_final)) {
       constraintNumInput(t, t->values_final);
diff --git a/source/blender/editors/transform/transform_mode_tilt.c b/source/blender/editors/transform/transform_mode_tilt.c
index ca0a8818477..5ab23000039 100644
--- a/source/blender/editors/transform/transform_mode_tilt.c
+++ b/source/blender/editors/transform/transform_mode_tilt.c
@@ -54,7 +54,7 @@ static void applyTilt(TransInfo *t, const int UNUSED(mval[2]))
 
   final = t->values[0];
 
-  snapGridIncrement(t, &final);
+  transform_snap_increment(t, &final);
 
   applyNumInput(&t->num, &final);
 
diff --git a/source/blender/editors/transform/transform_mode_tosphere.c b/source/blender/editors/transform/transform_mode_tosphere.c
index f6c5448a906..e747f0e75d0 100644
--- a/source/blender/editors/transform/transform_mode_tosphere.c
+++ b/source/blender/editors/transform/transform_mode_tosphere.c
@@ -54,7 +54,7 @@ static void applyToSphere(TransInfo *t, const int UNUSED(mval[2]))
 
   ratio = t->values[0];
 
-  snapGridIncrement(t, &ratio);
+  transform_snap_increment(t, &ratio);
 
   applyNumInput(&t->num, &ratio);
 
diff --git a/source/blender/editors/transform/transform_mode_trackball.c b/source/blender/editors/transform/transform_mode_trackball.c
index ca5a749b275..2656411e8ab 100644
--- a/source/blender/editors/transform/transform_mode_trackball.c
+++ b/source/blender/editors/transform/transform_mode_trackball.c
@@ -93,7 +93,7 @@ static void applyTrackball(TransInfo *t, const int UNUSED(mval[2]))
 
   copy_v2_v2(phi, t->values);
 
-  snapGridIncrement(t, phi);
+  transform_snap_increment(t, phi);
 
   applyNumInput(&t->num, phi);
 
diff --git a/source/blender/editors/transform/transform_mode_translate.c b/source/blender/editors/transform/transform_mode_translate.c
index c083e1654dc..36be26049d3 100644
--- a/source/blender/editors/transform/transform_mode_translate.c
+++ b/source/blender/editors/transform/transform_mode_translate.c
@@ -362,15 +362,28 @@ static void applyTranslation(TransInfo *t, const int UNUSED(mval[2]))
   }
   else {
     copy_v3_v3(global_dir, t->values);
-    if ((t->con.mode & CON_APPLY) == 0) {
-      snapGridIncrement(t, global_dir);
-    }
-
     if (applyNumInput(&t->num, global_dir)) {
       removeAspectRatio(t, global_dir);
     }
+    else {
+      applySnapping(t, global_dir);
+
+      if (!validSnap(t) && !(t->con.mode & CON_APPLY)) {
+        float dist_sq = FLT_MAX;
+        if (transform_snap_grid(t, global_dir)) {
+          dist_sq = len_squared_v3v3(t->values, global_dir);
+        }
 
-    applySnapping(t, global_dir);
+        /* Check the snap distance to the initial value to work with mixed snap. */
+        float increment_loc[3];
+        copy_v3_v3(increment_loc, t->values);
+        if (transform_snap_increment(t, increment_loc)) {
+          if ((dist_sq == FLT_MAX) || (len_squared_v3v3(t->values, increment_loc) < dist_sq)) {
+            copy_v3_v3(global_dir, increment_loc);
+          }
+        }
+      }
+    }
   }
 
   if (t->con.mode & CON_APPLY) {
diff --git a/source/blender/editors/transform/transform_mode_vert_slide.c b/source/blender/editors/transform/transform_mode_vert_slide.c
index 4367dd5ee92..75b973b6b14 100644
--- a/source/blender/editors/transform/transform_mode_vert_slide.c
+++ b/source/blender/editors/transform/transform_mode_vert_slide.c
@@ -587,7 +587,9 @@ static void applyVertSlide(TransInfo *t, const int UNUSED(mval[2]))
   final = t->values[0];
 
   applySnapping(t, &final);
-  snapGridIncrement(t, &final);
+  if (!validSnap(t)) {
+    transform_snap_increment(t, &final);
+  }
 
   /* only do this so out of range values are not displayed */
   if (is_constrained) {
diff --git a/source/blender/editors/transform/transform_snap.c b/source/blender/editors/transform/transform_snap.c
index 5db41570e00..96b7c85713b 100644
--- a/source/blender/editors/transform/transform_snap.c
+++ b/source/blender/editors/transform/transform_snap.c
@@ -378,30 +378,14 @@ void applyProject(TransInfo *t)
 
 void applyGridAbsolute(TransInfo *t)
 {
-  float grid_size = 0.0f;
-  GearsType grid_action;
   int i;
 
   if (!(activeSnap(t) && (t->tsnap.mode & (SCE_SNAP_MODE_INCREMENT | SCE_SNAP_MODE_GRID)))) {
     return;
   }
 
-  grid_action = BIG_GEARS;
-  if (t->modifiers & MOD_PRECISION) {
-    grid_action = SMALL_GEARS;
-  }
+  float grid_size = (t->modifiers & MOD_PRECISION) ? t->snap_spatial[2] : t->snap_spatial[1];
 
-  switch (grid_action) {
-    case NO_GEARS:
-      grid_size = t->snap_spatial[0];
-      break;
-    case BIG_GEARS:
-      grid_size = t->snap_spatial[1];
-      break;
-    case SMALL_GEARS:
-      grid_size = t->snap_spatial[2];
-      break;
-  }
   /* early exit on unusable grid size */
   if (grid_size == 0.0f) {
     return;
@@ -445,7 +429,12 @@ void applyGridAbsolute(TransInfo *t)
 void applySnapping(TransInfo *t, float *vec)
 {
   /* Each Trans Data already makes the snap to face */
-  if (doForceIncrementSnap(t) || (t->tsnap.project && t->tsnap.mode == SCE_SNAP_MODE_FACE)) {
+  if (doForceIncrementSnap(t)) {
+    return;
+  }
+
+  if (t->tsnap.project && t->tsnap.mode == SCE_SNAP_MODE_FACE) {
+    /* The snap has already been resolved for each transdata. */
     return;
   }
 
@@ -559,6 +548,12 @@ static void initSnappingMode(TransInfo *t)
     }
 
     t->tsnap.mode = ts->snap_mode;
+    if ((t->tsnap.mode & SCE_SNAP_MODE_INCREMENT) && (ts->snap_flag & SCE_SNAP_ABS_GRID) &&
+        (t->mode == TFM_TRANSLATION)) {
+      /* Special case in which snap to increments is transformed to snap to grid. */
+      t->tsnap.mode &= ~SCE_SNAP_MODE_INCREMENT;
+      t->tsnap.mode |= SCE_SNAP_MODE_GRID;
+    }
   }
 
   if ((t->spacetype == SPACE_VIEW3D || t->spacetype == SPACE_IMAGE) && (t->flag & T_CAMERA) == 0) {
@@ -600,7 +595,7 @@ static void initSnappingMode(TransInfo *t)
       }
     }
     else {
-      /* Grid if snap is not possible */
+      /* Increment if snap is not possible */
       t->tsnap.mode = SCE_SNAP_MODE_INCREMENT;
     }
   }
@@ -613,7 +608,7 @@ static void initSnappingMode(TransInfo *t)
     t->tsnap.mode = SCE_SNAP_MODE_GRID; /* Dummy, should we rather add a NOP mode? */
   }
   else {
-    /* Always grid outside of 3D view */
+    /* Always increment outside of 3D view */
     t->tsnap.mode = SCE_SNAP_MODE_INCREMENT;
   }
 
@@ -686,11 +681,6 @@ void initSnapping(TransInfo *t, wmOperator *op)
       t->tsnap.snap_self = !((t->settings->snap_flag & SCE_SNAP_NO_SELF) != 0);
       t->tsnap.peel = ((t->settings->snap_flag & SCE_SNAP_PROJECT) != 0);
     }
-
-    /* for now only 3d view (others can be added if we want) */
-    if (t->spacetype == SPACE_VIEW3D) {
-      t->tsnap.snap_spatial_grid = ((t->settings->snap_flag & SCE_SNAP_ABS_GRID) != 0);
-    }
   }
 
   t->tsnap.target = snap_target;
@@ -832,11 +822,6 @@ void getSnapPoint(const TransInfo *t, float vec[3])
 /** \name Calc Snap (Generic)
  * \{ */
 
-static void UNUSED_FUNCTION(CalcSnapGrid)(TransInfo *t, float *UNUSED(vec))
-{
-  snapGridIncrementAction(t, t->tsnap.snapPoint, BIG_GEARS);
-}
-
 static void CalcSnapGeometry(TransInfo *t, float *UNUSED(vec))
 {
   if (t->spacetype == SPACE_VIEW3D) {
@@ -1407,77 +1392,160 @@ void snapFrameTransform(TransInfo *t,
 
 /*================================================================*/
 
-static void applyGridIncrement(
-    TransInfo *t, float *val, int max_index, const float fac[3], GearsType action);
-
-void snapGridIncrementAction(TransInfo *t, float *val, GearsType action)
+void snapSequenceBounds(TransInfo *t, const int mval[2])
 {
-  float fac[3];
+  /* Reuse increment, strictly speaking could be another snap mode, but leave as is. */
+  if (!(t->modifiers & MOD_SNAP_INVERT)) {
+    return;
+  }
+
+  /* Convert to frame range. */
+  float xmouse, ymouse;
+  UI_view2d_region_to_view(&t->region->v2d, mval[0], mval[1], &xmouse, &ymouse);
+  const int frame_curr = round_fl_to_int(xmouse);
 
-  fac[NO_GEARS] = t->snap[0];
-  fac[BIG_GEARS] = t->snap[1];
-  fac[SMALL_GEARS] = t->snap[2];
+  /* Now find the closest sequence. */
+  const int frame_near = BKE_sequencer_find_next_prev_edit(
+      t->scene, frame_curr, SEQ_SIDE_BOTH, true, false, true);
 
-  applyGridIncrement(t, val, t->idx_max, fac, action);
+  const int frame_snap = transform_convert_sequencer_get_snap_bound(t);
+  t->values[0] = frame_near - frame_snap;
 }
 
-void snapGridIncrement(TransInfo *t, float *val)
+static void snap_grid_apply_ex(
+    TransInfo *t, const int max_index, const float grid_dist, const float loc[3], float r_out[3])
 {
-  GearsType action;
+  const float *center_global = t->center_global;
+  const float *asp = t->aspect;
+  bool use_local_axis = false;
 
-  /* only do something if using absolute or incremental grid snapping
-   * and there is no valid snap point */
-  if ((!(t->tsnap.mode & (SCE_SNAP_MODE_INCREMENT | SCE_SNAP_MODE_GRID)) || validSnap(t)) &&
-      !doForceIncrementSnap(t)) {
-    return;
+  /* use a fallback for cursor selection,
+   * this isn't useful as a global center for absolute grid snapping
+   * since its not based on the position of the selection. */
+  if (t->around == V3D_AROUND_CURSOR) {
+    const TransCenterData *cd = transformCenter_from_type(t, V3D_AROUND_CENTER_MEDIAN);
+    center_global = cd->global;
   }
 
-  action = activeSnap(t) ? BIG_GEARS : NO_GEARS;
-
-  if (action == BIG_GEARS && (t->modifiers & MOD_PRECISION)) {
-    action = SMALL_GEARS;
+  if (t->con.mode & (CON_AXIS0 | CON_AXIS1 | CON_AXIS2)) {
+    use_local_axis = true;
   }
 
-  snapGridIncrementAction(t, val, action);
+  for (int i = 0; i <= max_index; i++) {
+    /* do not let unconstrained axis jump to absolute grid increments */
+    if (!(t->con.mode & CON_APPLY) || t->con.mode & (CON_AXIS0 << i)) {
+      const float iter_fac = grid_dist * asp[i];
+
+      if (use_local_axis) {
+        float local_axis[3];
+        float pos_on_axis[3];
+
+        copy_v3_v3(local_axis, t->spacemtx[i]);
+        copy_v3_v3(pos_on_axis, t->spacemtx[i]);
+
+        /* amount of movement on axis from initial pos */
+        mul_v3_fl(pos_on_axis, loc[i]);
+
+        /* actual global position on axis */
+        add_v3_v3(pos_on_axis, center_global);
+
+        float min_dist = INFINITY;
+        for (int j = 0; j < 3; j++) {
+          if (fabs(local_axis[j]) < 0.01f) {
+            /* Ignore very small (normalized) axis changes */
+            continue;
+          }
+
+          /* closest point on grid */
+          float grid_p = iter_fac * roundf(pos_on_axis[j] / iter_fac);
+          float dist_p = fabs((grid_p - pos_on_axis[j]) / local_axis[j]);
+
+          /* The amount of distance needed to travel along the
+           * local axis to snap to the closest grid point */
+          /* in the global j axis direction */
+          float move_dist = (grid_p - center_global[j]) / local_axis[j];
+
+          if (dist_p < min_dist) {
+            min_dist = dist_p;
+            r_out[i] = move_dist;
+          }
+        }
+      }
+      else {
+        r_out[i] = iter_fac * roundf((loc[i] + center_global[i]) / iter_fac) - center_global[i];
+      }
+    }
+  }
 }
 
-void snapSequenceBounds(TransInfo *t, const int mval[2])
+static void snap_grid_apply(TransInfo *t, int max_index, const float grid_dist, float *r_val)
 {
-  /* Reuse increment, strictly speaking could be another snap mode, but leave as is. */
-  if (!(t->modifiers & MOD_SNAP_INVERT)) {
+  BLI_assert(t->tsnap.mode & SCE_SNAP_MODE_GRID);
+  BLI_assert(max_index <= 2);
+
+  /* Early bailing out if no need to snap */
+  if (grid_dist == 0.0f) {
     return;
   }
 
-  /* Convert to frame range. */
-  float xmouse, ymouse;
-  UI_view2d_region_to_view(&t->region->v2d, mval[0], mval[1], &xmouse, &ymouse);
-  const int frame_curr = round_fl_to_int(xmouse);
+  /* absolute snapping on grid based on global center.
+   * for now only 3d view (others can be added if we want) */
+  snap_grid_apply_ex(t, max_index, grid_dist, r_val, r_val);
+}
 
-  /* Now find the closest sequence. */
-  const int frame_near = BKE_sequencer_find_next_prev_edit(
-      t->scene, frame_curr, SEQ_SIDE_BOTH, true, false, true);
+bool transform_snap_grid(TransInfo *t, float *val)
+{
+  if ((!(t->tsnap.mode & SCE_SNAP_MODE_GRID)) || validSnap(t)) {
+    /* Don't do grid snapping if there is a valid snap point. */
+    return false;
+  }
 
-  const int frame_snap = transform_convert_sequencer_get_snap_bound(t);
-  t->values[0] = frame_near - frame_snap;
+  if (t->spacetype != SPACE_VIEW3D) {
+    return false;
+  }
+
+  if (t->mode != TFM_TRANSLATION) {
+    return false;
+  }
+
+  float grid_dist = activeSnap(t) ? (t->modifiers & MOD_PRECISION) ? t->snap[2] : t->snap[1] :
+                                    t->snap[0];
+
+  snap_grid_apply(t, t->idx_max, grid_dist, val);
+  return true;
 }
 
-static void applyGridIncrement(
-    TransInfo *t, float *val, int max_index, const float fac[3], GearsType action)
+static void snap_increment_apply_ex(TransInfo *t,
+                                    const int max_index,
+                                    const float increment_val,
+                                    const float aspect[3],
+                                    const float loc[3],
+                                    float r_out[3])
 {
-  float asp_local[3] = {1, 1, 1};
-  const bool use_aspect = ELEM(t->mode, TFM_TRANSLATION);
-  const float *asp = use_aspect ? t->aspect : asp_local;
-  int i;
+  /* relative snapping in fixed increments */
+  for (int i = 0; i <= max_index; i++) {
+    const float iter_fac = increment_val * aspect[i];
+    r_out[i] = iter_fac * roundf(loc[i] / iter_fac);
+  }
+}
 
-  BLI_assert((t->tsnap.mode & (SCE_SNAP_MODE_INCREMENT | SCE_SNAP_MODE_GRID)) ||
-             doForceIncrementSnap(t));
+static void snap_increment_apply(TransInfo *t,
+                                 int max_index,
+                                 const float increment_dist,
+                                 float *r_val)
+{
+  BLI_assert((t->tsnap.mode & SCE_SNAP_MODE_INCREMENT) || doForceIncrementSnap(t));
   BLI_assert(max_index <= 2);
 
   /* Early bailing out if no need to snap */
-  if (fac[action] == 0.0f) {
+  if (increment_dist == 0.0f) {
     return;
   }
 
+  float asp_local[3] = {1, 1, 1};
+  const bool use_aspect = ELEM(t->mode, TFM_TRANSLATION);
+  const float *asp = use_aspect ? t->aspect : asp_local;
+
   if (use_aspect) {
     /* custom aspect for fcurve */
     if (t->spacetype == SPACE_GRAPH) {
@@ -1491,76 +1559,26 @@ static void applyGridIncrement(
     }
   }
 
-  /* absolute snapping on grid based on global center */
-  if ((t->tsnap.snap_spatial_grid) && (t->mode == TFM_TRANSLATION)) {
-    const float *center_global = t->center_global;
-    bool use_local_axis = false;
-
-    /* use a fallback for cursor selection,
-     * this isn't useful as a global center for absolute grid snapping
-     * since its not based on the position of the selection. */
-    if (t->around == V3D_AROUND_CURSOR) {
-      const TransCenterData *cd = transformCenter_from_type(t, V3D_AROUND_CENTER_MEDIAN);
-      center_global = cd->global;
-    }
-
-    if (t->con.mode & (CON_AXIS0 | CON_AXIS1 | CON_AXIS2)) {
-      use_local_axis = true;
-    }
-
-    for (i = 0; i <= max_index; i++) {
-      /* do not let unconstrained axis jump to absolute grid increments */
-      if (!(t->con.mode & CON_APPLY) || t->con.mode & (CON_AXIS0 << i)) {
-        const float iter_fac = fac[action] * asp[i];
-
-        if (use_local_axis) {
-          float local_axis[3];
-          float pos_on_axis[3];
-
-          copy_v3_v3(local_axis, t->spacemtx[i]);
-          copy_v3_v3(pos_on_axis, t->spacemtx[i]);
-
-          /* amount of movement on axis from initial pos */
-          mul_v3_fl(pos_on_axis, val[i]);
-
-          /* actual global position on axis */
-          add_v3_v3(pos_on_axis, center_global);
+  snap_increment_apply_ex(t, max_index, increment_dist, asp, r_val, r_val);
+}
 
-          float min_dist = INFINITY;
-          for (int j = 0; j < 3; j++) {
-            if (fabs(local_axis[j]) < 0.01f) {
-              /* Ignore very small (normalized) axis changes */
-              continue;
-            }
+bool transform_snap_increment(TransInfo *t, float *val)
+{
+  if (!(t->tsnap.mode & SCE_SNAP_MODE_INCREMENT) && !doForceIncrementSnap(t)) {
+    return false;
+  }
 
-            /* closest point on grid */
-            float grid_p = iter_fac * roundf(pos_on_axis[j] / iter_fac);
-            float dist_p = fabs((grid_p - pos_on_axis[j]) / local_axis[j]);
+  if (t->spacetype != SPACE_VIEW3D && validSnap(t)) {
+    /* Only do something if using absolute or incremental grid snapping
+     * and there is no valid snap point. */
+    return false;
+  }
 
-            /* The amount of distance needed to travel along the
-             * local axis to snap to the closest grid point */
-            /* in the global j axis direction */
-            float move_dist = (grid_p - center_global[j]) / local_axis[j];
+  float increment_dist = activeSnap(t) ? (t->modifiers & MOD_PRECISION) ? t->snap[2] : t->snap[1] :
+                                         t->snap[0];
 
-            if (dist_p < min_dist) {
-              min_dist = dist_p;
-              val[i] = move_dist;
-            }
-          }
-        }
-        else {
-          val[i] = iter_fac * roundf((val[i] + center_global[i]) / iter_fac) - center_global[i];
-        }
-      }
-    }
-  }
-  else {
-    /* relative snapping in fixed increments */
-    for (i = 0; i <= max_index; i++) {
-      const float iter_fac = fac[action] * asp[i];
-      val[i] = iter_fac * roundf(val[i] / iter_fac);
-    }
-  }
+  snap_increment_apply(t, t->idx_max, increment_dist, val);
+  return true;
 }
 
 /** \} */
diff --git a/source/blender/editors/transform/transform_snap.h b/source/blender/editors/transform/transform_snap.h
index b97a9dc882c..5bee572c603 100644
--- a/source/blender/editors/transform/transform_snap.h
+++ b/source/blender/editors/transform/transform_snap.h
@@ -54,16 +54,10 @@ void snapFrameTransform(struct TransInfo *t,
                         /* return args */
                         float *r_val);
 
-typedef enum {
-  NO_GEARS = 0,
-  BIG_GEARS = 1,
-  SMALL_GEARS = 2,
-} GearsType;
-
 bool transformModeUseSnap(const TransInfo *t);
 
-void snapGridIncrement(TransInfo *t, float *val);
-void snapGridIncrementAction(TransInfo *t, float *val, GearsType action);
+bool transform_snap_increment(TransInfo *t, float *val);
+bool transform_snap_grid(TransInfo *t, float *val);
 
 void snapSequenceBounds(TransInfo *t, const int mval[2]);