NDOF: define 2 default navigation modes: free & orbit

After some discussion it seems both are valid defaults but useful for
very different purposes.

- 'free' lets you explore the scene with full 6dof (like fly mode)
- 'orbit' is closer to typical mouse view orbit, constraining to orbiting about a central location.

This doesn't effect orbit/pan which are available with modifier keys.

3 files changed, 70 insertions, 28 deletions

diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index 8fce5e7e7c0..a42b352ad51 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -335,6 +335,7 @@ void ED_view3D_background_image_clear(struct View3D *v3d);
 #define VIEW3D_MARGIN 1.4f
 #define VIEW3D_DIST_FALLBACK 1.0f
 float ED_view3d_offset_distance(float mat[4][4], const float ofs[3], const float dist_fallback);
+void  ED_view3d_distance_set(struct RegionView3D *rv3d, const float dist);
 
 float ED_scene_grid_scale(struct Scene *scene, const char **grid_unit);
 float ED_view3d_grid_scale(struct Scene *scene, struct View3D *v3d, const char **grid_unit);
diff --git a/source/blender/editors/space_view3d/view3d_camera_control.c b/source/blender/editors/space_view3d/view3d_camera_control.c
index 2797125485c..230df49f386 100644
--- a/source/blender/editors/space_view3d/view3d_camera_control.c
+++ b/source/blender/editors/space_view3d/view3d_camera_control.c
@@ -185,7 +185,6 @@ struct View3DCameraControl *ED_view3d_cameracontrol_aquire(
 		rv3d->dist = 0.0;
 	}
 	else {
-		float tvec[3];
 		/* perspective or ortho */
 		if (rv3d->persp == RV3D_ORTHO)
 			rv3d->persp = RV3D_PERSP;  /* if ortho projection, make perspective */
@@ -200,11 +199,7 @@ struct View3DCameraControl *ED_view3d_cameracontrol_aquire(
 		 * but to correct the dist removal we must
 		 * alter offset so the view doesn't jump. */
 
-		rv3d->dist = 0.0f;
-
-		copy_v3_fl3(tvec, 0.0f, 0.0f, vctrl->dist_backup);
-		mul_mat3_m4_v3(rv3d->viewinv, tvec);
-		sub_v3_v3(rv3d->ofs, tvec);
+		ED_view3d_distance_set(rv3d, 0.0f);
 		/* Done with correcting for the dist */
 	}
 
@@ -316,7 +311,6 @@ void ED_view3d_cameracontrol_release(
 	View3D *v3d        = vctrl->ctx_v3d;
 	RegionView3D *rv3d = vctrl->ctx_rv3d;
 
-	rv3d->dist = vctrl->dist_backup;
 	if (restore) {
 		/* Revert to original view? */
 		if (vctrl->persp_backup == RV3D_CAMOB) { /* a camera view */
@@ -334,21 +328,19 @@ void ED_view3d_cameracontrol_release(
 		}
 		/* always, is set to zero otherwise */
 		copy_v3_v3(rv3d->ofs, vctrl->ofs_backup);
+		rv3d->dist = vctrl->dist_backup;
 	}
 	else if (vctrl->persp_backup == RV3D_CAMOB) { /* camera */
 		DAG_id_tag_update((ID *)view3d_cameracontrol_object(vctrl), OB_RECALC_OB);
 
 		/* always, is set to zero otherwise */
 		copy_v3_v3(rv3d->ofs, vctrl->ofs_backup);
+		rv3d->dist = vctrl->dist_backup;
 	}
 	else { /* not camera */
-		float tvec[3];
-
 		/* Apply the fly mode view */
 		/* restore the dist */
-		copy_v3_fl3(tvec, 0.0f, 0.0f, vctrl->dist_backup);
-		mul_mat3_m4_v3(rv3d->viewinv, tvec);
-		add_v3_v3(rv3d->ofs, tvec);
+		ED_view3d_distance_set(rv3d, vctrl->dist_backup);
 		/* Done with correcting for the dist */
 	}
 
diff --git a/source/blender/editors/space_view3d/view3d_edit.c b/source/blender/editors/space_view3d/view3d_edit.c
index 03c0063babe..faee6514616 100644
--- a/source/blender/editors/space_view3d/view3d_edit.c
+++ b/source/blender/editors/space_view3d/view3d_edit.c
@@ -1219,15 +1219,18 @@ static void view3d_ndof_pan_zoom(const struct wmNDOFMotionData *ndof, ScrArea *s
 }
 
 
-static void view3d_ndof_orbit(const struct wmNDOFMotionData *ndof, RegionView3D *rv3d, const float dt,
+static void view3d_ndof_orbit(const struct wmNDOFMotionData *ndof, ScrArea *sa, ARegion *ar,
                               /* optional, can be NULL*/
                               ViewOpsData *vod)
 {
+	View3D *v3d = sa->spacedata.first;
+	RegionView3D *rv3d = ar->regiondata;
+
 	float view_inv[4];
 
 	BLI_assert((rv3d->viewlock & RV3D_LOCKED) == 0);
 
-	view3d_ensure_persp(vod->v3d, vod->ar);
+	view3d_ensure_persp(v3d, ar);
 
 	rv3d->view = RV3D_VIEW_USER;
 
@@ -1247,13 +1250,13 @@ static void view3d_ndof_orbit(const struct wmNDOFMotionData *ndof, RegionView3D
 		mul_qt_v3(view_inv, xvec);
 
 		/* Perform the up/down rotation */
-		angle = dt * rot[0];
+		angle = ndof->dt * rot[0];
 		quat[0] = cosf(angle);
 		mul_v3_v3fl(quat + 1, xvec, sin(angle));
 		mul_qt_qtqt(rv3d->viewquat, rv3d->viewquat, quat);
 
 		/* Perform the orbital rotation */
-		angle = dt * rot[1];
+		angle = ndof->dt * rot[1];
 
 		/* update the onscreen doo-dad */
 		rv3d->rot_angle = angle;
@@ -1432,7 +1435,7 @@ static int ndof_orbit_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 		View3D *v3d;
 		RegionView3D *rv3d;
 
-		wmNDOFMotionData *ndof = (wmNDOFMotionData *) event->customdata;
+		const wmNDOFMotionData *ndof = event->customdata;
 
 		viewops_data_alloc(C, op);
 		viewops_data_create(C, op, event);
@@ -1457,7 +1460,7 @@ static int ndof_orbit_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 			}
 
 			if (has_rotation) {
-				view3d_ndof_orbit(ndof, rv3d, ndof->dt, vod);
+				view3d_ndof_orbit(ndof, vod->sa, vod->ar, vod);
 			}
 		}
 
@@ -1497,7 +1500,7 @@ static int ndof_orbit_zoom_invoke(bContext *C, wmOperator *op, const wmEvent *ev
 		View3D *v3d;
 		RegionView3D *rv3d;
 
-		wmNDOFMotionData *ndof = (wmNDOFMotionData *) event->customdata;
+		const wmNDOFMotionData *ndof = event->customdata;
 
 		viewops_data_alloc(C, op);
 		viewops_data_create(C, op, event);
@@ -1511,21 +1514,49 @@ static int ndof_orbit_zoom_invoke(bContext *C, wmOperator *op, const wmEvent *ev
 
 		ED_view3d_camera_lock_init(v3d, rv3d);
 
-		if (ndof->progress != P_FINISHING) {
-			const bool has_rotation = NDOF_HAS_ROTATE && (RV3D_VIEW_IS_AXIS(rv3d->view) == false);
+		if (ndof->progress == P_FINISHING) {
+			/* pass */
+		}
+		else if (RV3D_VIEW_IS_AXIS(rv3d->view)) {
 			/* if we can't rotate, fallback to translate (locked axis views) */
 			const bool has_translate = NDOF_HAS_TRANSLATE;
-			/* always zoom since this is the main purpose of the function */
-			const bool has_zoom = true;
 
-			if (has_translate || has_zoom) {
+			if (has_translate) {
 				view3d_ndof_pan_zoom(ndof, vod->sa, vod->ar, has_translate, true);
 			}
+		}
+		else if (U.ndof_flag & NDOF_MODE_ORBIT) {
+			const bool has_rotation = NDOF_HAS_ROTATE;
+			const bool has_zoom = (ndof->tvec[2] != 0.0f);
+
+			if (has_zoom) {
+				view3d_ndof_pan_zoom(ndof, vod->sa, vod->ar, false, has_zoom);
+			}
 
 			if (has_rotation) {
-				view3d_ndof_orbit(ndof, rv3d, ndof->dt, vod);
+				view3d_ndof_orbit(ndof, vod->sa, vod->ar, vod);
 			}
 		}
+		else {  /* free/explore (like fly mode) */
+			Scene *scene = CTX_data_scene(C);
+			const bool has_rotation = NDOF_HAS_ROTATE;
+			const bool has_translate = NDOF_HAS_TRANSLATE;
+
+			const float dist_backup = rv3d->dist;
+
+			if (has_translate) {
+				view3d_ndof_pan_zoom(ndof, vod->sa, vod->ar, true, false);
+			}
+
+			ED_view3d_distance_set(rv3d, 0.0f);
+
+			if (has_rotation) {
+				view3d_ndof_orbit(ndof, vod->sa, vod->ar, NULL);
+			}
+
+			ED_view3d_update_viewmat(scene, v3d, vod->ar, NULL, NULL);
+			ED_view3d_distance_set(rv3d, dist_backup);
+		}
 
 		ED_view3d_camera_lock_sync(v3d, rv3d);
 
@@ -1563,7 +1594,7 @@ static int ndof_pan_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent *e
 	else {
 		View3D *v3d = CTX_wm_view3d(C);
 		RegionView3D *rv3d = CTX_wm_region_view3d(C);
-		wmNDOFMotionData *ndof = (wmNDOFMotionData *) event->customdata;
+		const wmNDOFMotionData *ndof = event->customdata;
 
 		const bool has_translate = NDOF_HAS_TRANSLATE;
 		const bool has_zoom = !rv3d->is_persp;
@@ -1622,7 +1653,7 @@ static int ndof_all_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 		View3D *v3d;
 		RegionView3D *rv3d;
 		
-		wmNDOFMotionData *ndof = (wmNDOFMotionData *) event->customdata;
+		const wmNDOFMotionData *ndof = event->customdata;
 
 		viewops_data_alloc(C, op);
 		viewops_data_create(C, op, event);
@@ -1646,7 +1677,7 @@ static int ndof_all_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 			}
 
 			if (has_rotation) {
-				view3d_ndof_orbit(ndof, rv3d, ndof->dt, vod);
+				view3d_ndof_orbit(ndof, vod->sa, vod->ar, vod);
 			}
 		}
 
@@ -4562,6 +4593,24 @@ float ED_view3d_offset_distance(float mat[4][4], const float ofs[3], const float
 }
 
 /**
+ * Set the dist without moving the view (compensate with #RegionView3D.ofs)
+ *
+ * \note take care that viewinv is up to date, #ED_view3d_update_viewmat first.
+ */
+void ED_view3d_distance_set(RegionView3D *rv3d, const float dist)
+{
+	float tvec[3];
+
+	BLI_assert(dist >= 0.0f);
+
+	copy_v3_fl3(tvec, 0.0f, 0.0f, rv3d->dist - dist);
+	mul_mat3_m4_v3(rv3d->viewinv, tvec);
+	sub_v3_v3(rv3d->ofs, tvec);
+
+	rv3d->dist = dist;
+}
+
+/**
  * Set the view transformation from a 4x4 matrix.
  *
  * \param mat The view 4x4 transformation matrix to assign.