fix for knife tool when the mouse was moved outside the clipped area the mouse line would reset to 0/0/0

a few areas that use ED_view3d_win_to_segment_clip() didnt take into account the case where the segment was filly clipped, some callers even needed the segment not to be clipped.
- added ED_view3d_win_to_segment()
- ED_view3d_win_to_segment_clip() now returns FALSE if the segment is totally clipped, but the start/ends of the line are not zero'd as they were before.

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index b4679bd1c69..f15f2418707 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -193,7 +193,8 @@ void ED_view3d_global_to_vector(struct RegionView3D *rv3d, const float coord[3],
 void ED_view3d_win_to_3d(struct ARegion *ar, const float depth_pt[3], const float mval[2], float out[3]);
 void ED_view3d_win_to_delta(struct ARegion *ar, const float mval[2], float out[3]);
 void ED_view3d_win_to_vector(struct ARegion *ar, const float mval[2], float out[3]);
-void ED_view3d_win_to_segment_clip(struct ARegion *ar, struct View3D *v3d, const float mval[2], float ray_start[3], float ray_end[3]);
+void ED_view3d_win_to_segment(struct ARegion *ar, struct View3D *v3d, const float mval[2], float ray_start[3], float ray_end[3]);
+int  ED_view3d_win_to_segment_clip(struct ARegion *ar, struct View3D *v3d, const float mval[2], float ray_start[3], float ray_end[3]);
 void ED_view3d_ob_project_mat_get(struct RegionView3D *v3d, struct Object *ob, float pmat[4][4]);
 void ED_view3d_unproject(struct bglMats *mats, float out[3], const float x, const float y, const float z);