Curves: Implement Handles for selected points only

When editing a complex curve is very annoying to have all handles at a time. Also, this is a requirement for the current GSoC Edit Grease Pencil using curves.
I have seen that this improvement can be used in any other area of blender, so I have decided to publish the option in the overlay panel..

Reviewed By: fclem, #user_interface, billreynish, Severin

Differential Revision: https://developer.blender.org/D7754

3 files changed, 19 insertions, 6 deletions

diff --git a/source/blender/makesdna/DNA_curve_types.h b/source/blender/makesdna/DNA_curve_types.h
index 6a081a7f5a7..b2902407a15 100644
--- a/source/blender/makesdna/DNA_curve_types.h
+++ b/source/blender/makesdna/DNA_curve_types.h
@@ -496,11 +496,11 @@ typedef enum eBezTriple_KeyframeType {
 #define BEZT_ISSEL_ALL(bezt) \
   (((bezt)->f2 & SELECT) && ((bezt)->f1 & SELECT) && ((bezt)->f3 & SELECT))
 #define BEZT_ISSEL_ALL_HIDDENHANDLES(v3d, bezt) \
-  ((((v3d) != NULL) && ((v3d)->overlay.edit_flag & V3D_OVERLAY_EDIT_CU_HANDLES) == 0) ? \
+  ((((v3d) != NULL) && ((v3d)->overlay.handle_display == CURVE_HANDLE_NONE)) ? \
        (bezt)->f2 & SELECT : \
        BEZT_ISSEL_ALL(bezt))
 #define BEZT_ISSEL_ANY_HIDDENHANDLES(v3d, bezt) \
-  ((((v3d) != NULL) && ((v3d)->overlay.edit_flag & V3D_OVERLAY_EDIT_CU_HANDLES) == 0) ? \
+  ((((v3d) != NULL) && ((v3d)->overlay.handle_display == CURVE_HANDLE_NONE)) ? \
        (bezt)->f2 & SELECT : \
        BEZT_ISSEL_ANY(bezt))
 
diff --git a/source/blender/makesdna/DNA_view3d_defaults.h b/source/blender/makesdna/DNA_view3d_defaults.h
index 20b491c47f2..10eadf368ef 100644
--- a/source/blender/makesdna/DNA_view3d_defaults.h
+++ b/source/blender/makesdna/DNA_view3d_defaults.h
@@ -64,8 +64,8 @@
     .edit_flag = V3D_OVERLAY_EDIT_FACES | V3D_OVERLAY_EDIT_SEAMS | \
                              V3D_OVERLAY_EDIT_SHARP | V3D_OVERLAY_EDIT_FREESTYLE_EDGE | \
                              V3D_OVERLAY_EDIT_FREESTYLE_FACE | V3D_OVERLAY_EDIT_EDGES | \
-                             V3D_OVERLAY_EDIT_CREASES | V3D_OVERLAY_EDIT_BWEIGHTS | \
-                             V3D_OVERLAY_EDIT_CU_HANDLES, \
+                             V3D_OVERLAY_EDIT_CREASES | V3D_OVERLAY_EDIT_BWEIGHTS, \
+    .handle_display = CURVE_HANDLE_SELECTED, \
  \
     .gpencil_paper_opacity = 0.5f, \
     .gpencil_grid_opacity = 0.9f, \
diff --git a/source/blender/makesdna/DNA_view3d_types.h b/source/blender/makesdna/DNA_view3d_types.h
index 6d8d16c4313..ef174f5858f 100644
--- a/source/blender/makesdna/DNA_view3d_types.h
+++ b/source/blender/makesdna/DNA_view3d_types.h
@@ -228,9 +228,20 @@ typedef struct View3DOverlay {
 
   /** Factor for mixing vertex paint with original color */
   float gpencil_vertex_paint_opacity;
-  char _pad4[4];
+  /** Handles display type for curves. */
+  int handle_display;
 } View3DOverlay;
 
+/* View3DOverlay->handle_display */
+typedef enum eHandleDisplay {
+  /* Display only selected points. */
+  CURVE_HANDLE_SELECTED = 0,
+  /* Display all handles. */
+  CURVE_HANDLE_ALL = 1,
+  /* No display handles. */
+  CURVE_HANDLE_NONE = 2,
+} eHandleDisplay;
+
 typedef struct View3D_Runtime {
   /** Nkey panel stores stuff here. */
   void *properties_storage;
@@ -522,7 +533,9 @@ enum {
   V3D_OVERLAY_EDIT_FACE_AREA = (1 << 18),
   V3D_OVERLAY_EDIT_INDICES = (1 << 19),
 
-  V3D_OVERLAY_EDIT_CU_HANDLES = (1 << 20),
+  /* Deprecated. */
+  /* V3D_OVERLAY_EDIT_CU_HANDLES = (1 << 20),  */
+
   V3D_OVERLAY_EDIT_CU_NORMALS = (1 << 21),
 };