Roto: Improve spline sliding vs. curvature detection

If the mouse is closer to the spline than to it's center do a
spline curvature correction operator instead.

3 files changed, 24 insertions, 10 deletions

diff --git a/source/blender/editors/mask/mask_add.c b/source/blender/editors/mask/mask_add.c
index b816103de13..cd6e93771c0 100644
--- a/source/blender/editors/mask/mask_add.c
+++ b/source/blender/editors/mask/mask_add.c
@@ -62,7 +62,8 @@ bool ED_mask_find_nearest_diff_point(const bContext *C,
                                      MaskSplinePoint **point_r,
                                      float *u_r, float tangent[2],
                                      const bool use_deform,
-                                     const bool use_project)
+                                     const bool use_project,
+                                     float *score_r)
 {
 	ScrArea *sa = CTX_wm_area(C);
 	ARegion *ar = CTX_wm_region(C);
@@ -171,6 +172,10 @@ bool ED_mask_find_nearest_diff_point(const bContext *C,
 			*u_r = u;
 		}
 
+		if (score_r) {
+			*score_r = dist;
+		}
+
 		return true;
 	}
 
@@ -339,7 +344,7 @@ static bool add_vertex_subdivide(const bContext *C, Mask *mask, const float co[2
 	float tangent[2];
 	float u;
 
-	if (ED_mask_find_nearest_diff_point(C, mask, co, threshold, false, &masklay, &spline, &point, &u, tangent, true, true)) {
+	if (ED_mask_find_nearest_diff_point(C, mask, co, threshold, false, &masklay, &spline, &point, &u, tangent, true, true, NULL)) {
 		MaskSplinePoint *new_point;
 		int point_index = point - spline->points;
 
@@ -624,7 +629,7 @@ static int add_feather_vertex_exec(bContext *C, wmOperator *op)
 	if (point)
 		return OPERATOR_FINISHED;
 
-	if (ED_mask_find_nearest_diff_point(C, mask, co, threshold, true, &masklay, &spline, &point, &u, NULL, true, true)) {
+	if (ED_mask_find_nearest_diff_point(C, mask, co, threshold, true, &masklay, &spline, &point, &u, NULL, true, true, NULL)) {
 		Scene *scene = CTX_data_scene(C);
 		float w = BKE_mask_point_weight(spline, point, u);
 		float weight_scalar = BKE_mask_point_weight_scalar(spline, point, u);
diff --git a/source/blender/editors/mask/mask_intern.h b/source/blender/editors/mask/mask_intern.h
index 6899cf7e6f5..af91afe838a 100644
--- a/source/blender/editors/mask/mask_intern.h
+++ b/source/blender/editors/mask/mask_intern.h
@@ -49,7 +49,8 @@ bool ED_mask_find_nearest_diff_point(const struct bContext *C,
                                      struct MaskSplinePoint **point_r,
                                      float *u_r, float tangent[2],
                                      const bool use_deform,
-                                     const bool use_project);
+                                     const bool use_project,
+                                     float *score_r);
 
 void MASK_OT_add_vertex(struct wmOperatorType *ot);
 void MASK_OT_add_feather_vertex(struct wmOperatorType *ot);
diff --git a/source/blender/editors/mask/mask_ops.c b/source/blender/editors/mask/mask_ops.c
index d322ca931b9..486704c9b9e 100644
--- a/source/blender/editors/mask/mask_ops.c
+++ b/source/blender/editors/mask/mask_ops.c
@@ -510,6 +510,7 @@ static bool spline_under_mouse_get(const bContext *C,
                                    MaskLayer **mask_layer_r,
                                    MaskSpline **mask_spline_r)
 {
+	const float threshold = 19.0f;
 	ScrArea *sa = CTX_wm_area(C);
 	SpaceClip *sc = CTX_wm_space_clip(C);
 	MaskLayer *mask_layer;
@@ -580,10 +581,17 @@ static bool spline_under_mouse_get(const bContext *C,
 			}
 		}
 	}
-	/* TODO(sergey): Chech whether tessellated spline point is closer
-	 * to the mouse than the spline center.
-	 */
-	if (closest_dist_squared < SQUARE(32.0f) && closest_spline != NULL) {
+	if (closest_dist_squared < SQUARE(threshold) && closest_spline != NULL) {
+		float diff_score;
+		if (ED_mask_find_nearest_diff_point(C, mask, co, threshold, false,
+		                                    NULL, NULL, NULL, NULL,
+		                                    NULL, true, false, &diff_score))
+		{
+			if (SQUARE(diff_score) < closest_dist_squared) {
+				return false;
+			}
+		}
+
 		*mask_layer_r = closest_layer;
 		*mask_spline_r = closest_spline;
 		return true;
@@ -1185,7 +1193,7 @@ static bool slide_spline_curvature_check(bContext *C, const wmEvent *event)
 static SlideSplineCurvatureData *slide_spline_curvature_customdata(
 	bContext *C, const wmEvent *event)
 {
-	const float threshold = 19;
+	const float threshold = 19.0f;
 
 	Mask *mask = CTX_data_edit_mask(C);
 	SlideSplineCurvatureData *slide_data;
@@ -1199,7 +1207,7 @@ static SlideSplineCurvatureData *slide_spline_curvature_customdata(
 
 	if (!ED_mask_find_nearest_diff_point(C, mask, co, threshold, false,
 	                                     &mask_layer, &spline, &point, &u,
-	                                     NULL, true, false))
+	                                     NULL, true, false, NULL))
 	{
 		return NULL;
 	}