Fix T53850: Lock to Cursor breaks 3D manipulators

3 files changed, 29 insertions, 6 deletions

diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 250e6559b8f..f614f235c66 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -2744,10 +2744,17 @@ void ED_view3d_update_viewmat(
 		view3d_winmatrix_set(ar, v3d, rect);
 
 	/* setup view matrix */
-	if (viewmat)
+	if (viewmat) {
 		copy_m4_m4(rv3d->viewmat, viewmat);
-	else
-		view3d_viewmatrix_set(scene, v3d, rv3d);  /* note: calls BKE_object_where_is_calc for camera... */
+	}
+	else {
+		float rect_scale[2];
+		if (rect) {
+			rect_scale[0] = (float)BLI_rcti_size_x(rect) / (float)ar->winx;
+			rect_scale[1] = (float)BLI_rcti_size_y(rect) / (float)ar->winy;
+		}
+		view3d_viewmatrix_set(scene, v3d, rv3d, rect ? rect_scale : NULL);  /* note: calls BKE_object_where_is_calc for camera... */
+	}
 
 	/* update utility matrices */
 	mul_m4_m4m4(rv3d->persmat, rv3d->winmat, rv3d->viewmat);
diff --git a/source/blender/editors/space_view3d/view3d_intern.h b/source/blender/editors/space_view3d/view3d_intern.h
index 7a106a27833..b1ccb508e50 100644
--- a/source/blender/editors/space_view3d/view3d_intern.h
+++ b/source/blender/editors/space_view3d/view3d_intern.h
@@ -248,7 +248,7 @@ void ED_view3d_smooth_view_force_finish(
         struct View3D *v3d, struct ARegion *ar);
 
 void view3d_winmatrix_set(ARegion *ar, const View3D *v3d, const rcti *rect);
-void view3d_viewmatrix_set(Scene *scene, const View3D *v3d, RegionView3D *rv3d);
+void view3d_viewmatrix_set(Scene *scene, const View3D *v3d, RegionView3D *rv3d, const float rect_scale[2]);
 
 void fly_modal_keymap(struct wmKeyConfig *keyconf);
 void walk_modal_keymap(struct wmKeyConfig *keyconf);
diff --git a/source/blender/editors/space_view3d/view3d_view.c b/source/blender/editors/space_view3d/view3d_view.c
index 5c13fd37dda..6ebd19aba85 100644
--- a/source/blender/editors/space_view3d/view3d_view.c
+++ b/source/blender/editors/space_view3d/view3d_view.c
@@ -1024,8 +1024,18 @@ bool ED_view3d_lock(RegionView3D *rv3d)
 	return ED_view3d_quat_from_axis_view(rv3d->view, rv3d->viewquat);
 }
 
-/* don't set windows active in here, is used by renderwin too */
-void view3d_viewmatrix_set(Scene *scene, const View3D *v3d, RegionView3D *rv3d)
+/**
+ * Sets #RegionView3D.viewmat
+ *
+ * \param scene: Scene for camera and cursor location.
+ * \param v3d: View 3D space data.
+ * \param rv3d: 3D region which stores the final matrices.
+ * \param rect_scale: Optional 2D scale argument,
+ * Use when displaying a sub-region, eg: when #view3d_winmatrix_set takes a 'rect' argument.
+ *
+ * \note don't set windows active in here, is used by renderwin too.
+ * */
+void view3d_viewmatrix_set(Scene *scene, const View3D *v3d, RegionView3D *rv3d, const float rect_scale[2])
 {
 	if (rv3d->persp == RV3D_CAMOB) {      /* obs/camera */
 		if (v3d->camera) {
@@ -1084,6 +1094,12 @@ void view3d_viewmatrix_set(Scene *scene, const View3D *v3d, RegionView3D *rv3d)
 
 			mul_v2_v2fl(vec, rv3d->ofs_lock, rv3d->is_persp ? rv3d->dist : 1.0f);
 			vec[2] = 0.0f;
+
+			if (rect_scale) {
+				vec[0] /= rect_scale[0];
+				vec[1] /= rect_scale[1];
+			}
+
 			mul_mat3_m4_v3(persinv, vec);
 			translate_m4(rv3d->viewmat, vec[0], vec[1], vec[2]);
 		}