Sculpt: Followup change/fix to clay strips brush

A combination of a few changes:
- Don't apply hardness again, the "cube tip" calculation already factors it in.
- Avoid multiplication by brush radius, just use the 0-1 distances from the
  cube tip calculation directly.
- Add filtering by brush radius to fix the second part of #128004.
- Change brush radius filtering to be consistent with previous code using
  less than or equal instead of less than.

Note that the current radius filtering in BKE_brush_calc_curve_factors is
unnecessary since we already filter by the radius in a separate step.

source/blender/editors/sculpt_paint/brushes/clay_strips.cc

@@ -9,6 +9,7 @@
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
 
+#include "BKE_brush.hh"
 #include "BKE_key.hh"
 #include "BKE_mesh.hh"
 #include "BKE_paint.hh"
@@ -69,9 +70,9 @@ static void calc_faces(const Depsgraph &depsgraph,
   tls.distances.resize(verts.size());
   const MutableSpan<float> distances = tls.distances;
   calc_brush_cube_distances(brush, mat, position_data.eval, verts, distances, factors);
-  scale_factors(distances, cache.radius);
-  apply_hardness_to_distances(cache, distances);
-  calc_brush_strength_factors(cache, brush, distances, factors);
+  filter_distances_with_radius(1.0f, distances, factors);
+  BKE_brush_calc_curve_factors(
+      eBrushCurvePreset(brush.curve_preset), brush.curve, distances, 1.0f, factors);
 
   auto_mask::calc_vert_factors(depsgraph, object, cache.automasking.get(), node, verts, factors);
 
@@ -125,9 +126,9 @@ static void calc_grids(const Depsgraph &depsgraph,
   tls.distances.resize(positions.size());
   const MutableSpan<float> distances = tls.distances;
   calc_brush_cube_distances(brush, mat, positions, distances, factors);
-  scale_factors(distances, cache.radius);
-  apply_hardness_to_distances(cache, distances);
-  calc_brush_strength_factors(cache, brush, distances, factors);
+  filter_distances_with_radius(1.0f, distances, factors);
+  BKE_brush_calc_curve_factors(
+      eBrushCurvePreset(brush.curve_preset), brush.curve, distances, 1.0f, factors);
 
   auto_mask::calc_grids_factors(depsgraph, object, cache.automasking.get(), node, grids, factors);
 
@@ -180,9 +181,9 @@ static void calc_bmesh(const Depsgraph &depsgraph,
   tls.distances.resize(verts.size());
   const MutableSpan<float> distances = tls.distances;
   calc_brush_cube_distances(brush, mat, positions, distances, factors);
-  scale_factors(distances, cache.radius);
-  apply_hardness_to_distances(cache, distances);
-  calc_brush_strength_factors(cache, brush, distances, factors);
+  filter_distances_with_radius(1.0f, distances, factors);
+  BKE_brush_calc_curve_factors(
+      eBrushCurvePreset(brush.curve_preset), brush.curve, distances, 1.0f, factors);
 
   auto_mask::calc_vert_factors(depsgraph, object, cache.automasking.get(), node, verts, factors);
 

source/blender/editors/sculpt_paint/sculpt.cc

@@ -6522,7 +6522,7 @@ void filter_distances_with_radius(const float radius,
                                   const MutableSpan<float> factors)
 {
   for (const int i : distances.index_range()) {
-    if (distances[i] > radius) {
+    if (distances[i] >= radius) {
       factors[i] = 0.0f;
     }
   }