GPencil: Improve Cyclic operator to generate geometry

Now, when close a geometry with cyclic is possible generate new geometry for the gap.

The cyclic operator now supports multiframe edition too. Before only worked with active frame.

Also added the corresponding missing menu options and the new F keymap. All these features were missing, pending of the fix of the alpha glitches in stroke already done.

1 files changed, 80 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/gpencil.c b/source/blender/blenkernel/intern/gpencil.c
index 842fa85bf76..ff638eaf082 100644
--- a/source/blender/blenkernel/intern/gpencil.c
+++ b/source/blender/blenkernel/intern/gpencil.c
@@ -1958,3 +1958,83 @@ bool BKE_gpencil_trim_stroke(bGPDstroke *gps)
   }
   return intersect;
 }
+
+/**
+ * Close stroke
+ * \param gps: Stroke to close
+ */
+bool BKE_gpencil_close_stroke(bGPDstroke *gps)
+{
+  bGPDspoint *pt1 = NULL;
+  bGPDspoint *pt2 = NULL;
+
+  /* Only can close a stroke with 3 points or more. */
+  if (gps->totpoints < 3) {
+    return false;
+  }
+
+  /* Calc average distance between points to get same level of sampling. */
+  float dist_tot = 0.0f;
+  for (int i = 0; i < gps->totpoints - 1; i++) {
+    pt1 = &gps->points[i];
+    pt2 = &gps->points[i + 1];
+    dist_tot += len_v3v3(&pt1->x, &pt2->x);
+  }
+  /* Calc the average distance. */
+  float dist_avg = dist_tot / (gps->totpoints - 1);
+
+  /* Calc distance between last and first point. */
+  pt1 = &gps->points[gps->totpoints - 1];
+  pt2 = &gps->points[0];
+  float dist_close = len_v3v3(&pt1->x, &pt2->x);
+
+  /* Calc number of points required using the average distance. */
+  int tot_newpoints = MAX2(dist_close / dist_avg, 1);
+
+  /* Resize stroke array. */
+  int old_tot = gps->totpoints;
+  gps->totpoints += tot_newpoints;
+  gps->points = MEM_recallocN(gps->points, sizeof(*gps->points) * gps->totpoints);
+  if (gps->dvert != NULL) {
+    gps->dvert = MEM_recallocN(gps->dvert, sizeof(*gps->dvert) * gps->totpoints);
+  }
+
+  /* Generate new points */
+  pt1 = &gps->points[old_tot - 1];
+  pt2 = &gps->points[0];
+  bGPDspoint *pt = &gps->points[old_tot];
+  for (int i = 1; i < tot_newpoints + 1; i++, pt++) {
+    float step = ((float)i / (float)tot_newpoints);
+    /* Clamp last point to be near, but not on top of first point. */
+    CLAMP(step, 0.0f, 0.99f);
+
+    /* Average point. */
+    interp_v3_v3v3(&pt->x, &pt1->x, &pt2->x, step);
+    pt->pressure = interpf(pt2->pressure, pt1->pressure, step);
+    pt->strength = interpf(pt2->strength, pt1->strength, step);
+    pt->flag = 0;
+
+    /* Set weights. */
+    if (gps->dvert != NULL) {
+      MDeformVert *dvert1 = &gps->dvert[old_tot - 1];
+      MDeformWeight *dw1 = defvert_verify_index(dvert1, 0);
+      float weight_1 = dw1 ? dw1->weight : 0.0f;
+
+      MDeformVert *dvert2 = &gps->dvert[0];
+      MDeformWeight *dw2 = defvert_verify_index(dvert2, 0);
+      float weight_2 = dw2 ? dw2->weight : 0.0f;
+
+      MDeformVert *dvert_final = &gps->dvert[old_tot + i - 1];
+      dvert_final->totweight = 0;
+      MDeformWeight *dw = defvert_verify_index(dvert_final, 0);
+      if (dvert_final->dw) {
+        dw->weight = interpf(weight_2, weight_1, step);
+      }
+    }
+  }
+
+  /* Enable cyclic flag. */
+  gps->flag |= GP_STROKE_CYCLIC;
+
+  return true;
+}