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/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <algorithm>
#include "curves_sculpt_intern.hh"
#include "BLI_float4x4.hh"
#include "BLI_kdtree.h"
#include "BLI_rand.hh"
#include "BLI_vector.hh"
#include "PIL_time.h"
#include "DEG_depsgraph.h"
#include "BKE_attribute_math.hh"
#include "BKE_brush.h"
#include "BKE_bvhutils.h"
#include "BKE_context.h"
#include "BKE_curves.hh"
#include "BKE_mesh.h"
#include "BKE_mesh_runtime.h"
#include "BKE_paint.h"
#include "BKE_spline.hh"
#include "DNA_brush_enums.h"
#include "DNA_brush_types.h"
#include "DNA_curves_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_object_types.h"
#include "DNA_screen_types.h"
#include "DNA_space_types.h"
#include "ED_screen.h"
#include "ED_view3d.h"
/**
* The code below uses a prefix naming convention to indicate the coordinate space:
* cu: Local space of the curves object that is being edited.
* su: Local space of the surface object.
* wo: World space.
* re: 2D coordinates within the region.
*/
namespace blender::ed::sculpt_paint {
using bke::CurvesGeometry;
class AddOperation : public CurvesSculptStrokeOperation {
private:
/** Used when some data should be interpolated from existing curves. */
KDTree_3d *curve_roots_kdtree_ = nullptr;
friend struct AddOperationExecutor;
public:
~AddOperation() override
{
if (curve_roots_kdtree_ != nullptr) {
BLI_kdtree_3d_free(curve_roots_kdtree_);
}
}
void on_stroke_extended(bContext *C, const StrokeExtension &stroke_extension) override;
};
static void initialize_straight_curve_positions(const float3 &p1,
const float3 &p2,
MutableSpan<float3> r_positions)
{
const float step = 1.0f / (float)(r_positions.size() - 1);
for (const int i : r_positions.index_range()) {
r_positions[i] = math::interpolate(p1, p2, i * step);
}
}
/**
* Utility class that actually executes the update when the stroke is updated. That's useful
* because it avoids passing a very large number of parameters between functions.
*/
struct AddOperationExecutor {
AddOperation *self_ = nullptr;
Depsgraph *depsgraph_ = nullptr;
Scene *scene_ = nullptr;
Object *object_ = nullptr;
ARegion *region_ = nullptr;
View3D *v3d_ = nullptr;
Curves *curves_id_ = nullptr;
CurvesGeometry *curves_ = nullptr;
Object *surface_ob_ = nullptr;
Mesh *surface_ = nullptr;
Span<MLoopTri> surface_looptris_;
Span<float3> corner_normals_su_;
CurvesSculpt *curves_sculpt_ = nullptr;
Brush *brush_ = nullptr;
BrushCurvesSculptSettings *brush_settings_ = nullptr;
float brush_radius_re_;
float2 brush_pos_re_;
bool use_front_face_;
bool interpolate_length_;
bool interpolate_shape_;
bool use_interpolation_;
float new_curve_length_;
int add_amount_;
int points_per_curve_;
/** Various matrices to convert between coordinate spaces. */
float4x4 curves_to_world_mat_;
float4x4 world_to_curves_mat_;
float4x4 world_to_surface_mat_;
float4x4 surface_to_world_mat_;
float4x4 surface_to_curves_mat_;
float4x4 surface_to_curves_normal_mat_;
BVHTreeFromMesh surface_bvh_;
int tot_old_curves_;
int tot_old_points_;
struct AddedPoints {
Vector<float3> positions_cu;
Vector<float3> bary_coords;
Vector<int> looptri_indices;
};
void execute(AddOperation &self, bContext *C, const StrokeExtension &stroke_extension)
{
self_ = &self;
depsgraph_ = CTX_data_depsgraph_pointer(C);
scene_ = CTX_data_scene(C);
object_ = CTX_data_active_object(C);
region_ = CTX_wm_region(C);
v3d_ = CTX_wm_view3d(C);
curves_id_ = static_cast<Curves *>(object_->data);
curves_ = &CurvesGeometry::wrap(curves_id_->geometry);
if (curves_id_->surface == nullptr || curves_id_->surface->type != OB_MESH) {
return;
}
curves_to_world_mat_ = object_->obmat;
world_to_curves_mat_ = curves_to_world_mat_.inverted();
surface_ob_ = curves_id_->surface;
surface_ = static_cast<Mesh *>(surface_ob_->data);
surface_to_world_mat_ = surface_ob_->obmat;
world_to_surface_mat_ = surface_to_world_mat_.inverted();
surface_to_curves_mat_ = world_to_curves_mat_ * surface_to_world_mat_;
surface_to_curves_normal_mat_ = surface_to_curves_mat_.inverted().transposed();
if (!CustomData_has_layer(&surface_->ldata, CD_NORMAL)) {
BKE_mesh_calc_normals_split(surface_);
}
corner_normals_su_ = {
reinterpret_cast<const float3 *>(CustomData_get_layer(&surface_->ldata, CD_NORMAL)),
surface_->totloop};
curves_sculpt_ = scene_->toolsettings->curves_sculpt;
brush_ = BKE_paint_brush(&curves_sculpt_->paint);
brush_settings_ = brush_->curves_sculpt_settings;
brush_radius_re_ = BKE_brush_size_get(scene_, brush_);
brush_pos_re_ = stroke_extension.mouse_position;
use_front_face_ = brush_->flag & BRUSH_FRONTFACE;
const eBrushFalloffShape falloff_shape = static_cast<eBrushFalloffShape>(
brush_->falloff_shape);
add_amount_ = std::max(0, brush_settings_->add_amount);
points_per_curve_ = std::max(2, brush_settings_->points_per_curve);
interpolate_length_ = brush_settings_->flag & BRUSH_CURVES_SCULPT_FLAG_INTERPOLATE_LENGTH;
interpolate_shape_ = brush_settings_->flag & BRUSH_CURVES_SCULPT_FLAG_INTERPOLATE_SHAPE;
use_interpolation_ = interpolate_length_ || interpolate_shape_;
new_curve_length_ = brush_settings_->curve_length;
tot_old_curves_ = curves_->curves_num();
tot_old_points_ = curves_->points_num();
if (add_amount_ == 0) {
return;
}
const double time = PIL_check_seconds_timer() * 1000000.0;
/* Use a pointer cast to avoid overflow warnings. */
RandomNumberGenerator rng{*(uint32_t *)(&time)};
BKE_bvhtree_from_mesh_get(&surface_bvh_, surface_, BVHTREE_FROM_LOOPTRI, 2);
BLI_SCOPED_DEFER([&]() { free_bvhtree_from_mesh(&surface_bvh_); });
surface_looptris_ = {BKE_mesh_runtime_looptri_ensure(surface_),
BKE_mesh_runtime_looptri_len(surface_)};
/* Sample points on the surface using one of multiple strategies. */
AddedPoints added_points;
if (add_amount_ == 1) {
this->sample_in_center_with_symmetry(added_points);
}
else if (falloff_shape == PAINT_FALLOFF_SHAPE_TUBE) {
this->sample_projected_with_symmetry(rng, added_points);
}
else if (falloff_shape == PAINT_FALLOFF_SHAPE_SPHERE) {
this->sample_spherical_with_symmetry(rng, added_points);
}
else {
BLI_assert_unreachable();
}
if (added_points.bary_coords.is_empty()) {
/* No new points have been added. */
return;
}
if (use_interpolation_) {
this->ensure_curve_roots_kdtree();
}
const int tot_added_curves = added_points.bary_coords.size();
const int tot_added_points = tot_added_curves * points_per_curve_;
curves_->resize(curves_->points_num() + tot_added_points,
curves_->curves_num() + tot_added_curves);
threading::parallel_invoke([&]() { this->initialize_curve_offsets(tot_added_curves); },
[&]() { this->initialize_attributes(added_points); });
DEG_id_tag_update(&curves_id_->id, ID_RECALC_GEOMETRY);
ED_region_tag_redraw(region_);
}
float3 get_bary_coords(const Mesh &mesh, const MLoopTri &looptri, const float3 position) const
{
const float3 &v0 = mesh.mvert[mesh.mloop[looptri.tri[0]].v].co;
const float3 &v1 = mesh.mvert[mesh.mloop[looptri.tri[1]].v].co;
const float3 &v2 = mesh.mvert[mesh.mloop[looptri.tri[2]].v].co;
float3 bary_coords;
interp_weights_tri_v3(bary_coords, v0, v1, v2, position);
return bary_coords;
}
/**
* Sample a single point exactly at the mouse position.
*/
void sample_in_center_with_symmetry(AddedPoints &r_added_points)
{
float3 ray_start_wo, ray_end_wo;
ED_view3d_win_to_segment_clipped(
depsgraph_, region_, v3d_, brush_pos_re_, ray_start_wo, ray_end_wo, true);
const float3 ray_start_su = world_to_surface_mat_ * ray_start_wo;
const float3 ray_end_su = world_to_surface_mat_ * ray_end_wo;
const Vector<float4x4> symmetry_brush_transforms = get_symmetry_brush_transforms(
eCurvesSymmetryType(curves_id_->symmetry));
for (const float4x4 &brush_transform : symmetry_brush_transforms) {
this->sample_in_center(
r_added_points, brush_transform * ray_start_su, brush_transform * ray_end_su);
}
}
void sample_in_center(AddedPoints &r_added_points,
const float3 &ray_start_su,
const float3 &ray_end_su)
{
const float3 ray_direction_su = math::normalize(ray_end_su - ray_start_su);
BVHTreeRayHit ray_hit;
ray_hit.dist = FLT_MAX;
ray_hit.index = -1;
BLI_bvhtree_ray_cast(surface_bvh_.tree,
ray_start_su,
ray_direction_su,
0.0f,
&ray_hit,
surface_bvh_.raycast_callback,
&surface_bvh_);
if (ray_hit.index == -1) {
return;
}
const int looptri_index = ray_hit.index;
const float3 brush_pos_su = ray_hit.co;
const float3 bary_coords = this->get_bary_coords(
*surface_, surface_looptris_[looptri_index], brush_pos_su);
const float3 brush_pos_cu = surface_to_curves_mat_ * brush_pos_su;
r_added_points.positions_cu.append(brush_pos_cu);
r_added_points.bary_coords.append(bary_coords);
r_added_points.looptri_indices.append(looptri_index);
}
/**
* Sample points by shooting rays within the brush radius in the 3D view.
*/
void sample_projected_with_symmetry(RandomNumberGenerator &rng, AddedPoints &r_added_points)
{
const Vector<float4x4> symmetry_brush_transforms = get_symmetry_brush_transforms(
eCurvesSymmetryType(curves_id_->symmetry));
for (const float4x4 &brush_transform : symmetry_brush_transforms) {
this->sample_projected(rng, r_added_points, brush_transform);
}
}
void sample_projected(RandomNumberGenerator &rng,
AddedPoints &r_added_points,
const float4x4 &brush_transform)
{
const int old_amount = r_added_points.bary_coords.size();
const int max_iterations = std::max(100'000, add_amount_ * 10);
int current_iteration = 0;
while (r_added_points.bary_coords.size() < old_amount + add_amount_) {
if (current_iteration++ >= max_iterations) {
break;
}
const float r = brush_radius_re_ * std::sqrt(rng.get_float());
const float angle = rng.get_float() * 2.0f * M_PI;
const float2 pos_re = brush_pos_re_ + r * float2(std::cos(angle), std::sin(angle));
float3 ray_start_wo, ray_end_wo;
ED_view3d_win_to_segment_clipped(
depsgraph_, region_, v3d_, pos_re, ray_start_wo, ray_end_wo, true);
const float3 ray_start_su = brush_transform * (world_to_surface_mat_ * ray_start_wo);
const float3 ray_end_su = brush_transform * (world_to_surface_mat_ * ray_end_wo);
const float3 ray_direction_su = math::normalize(ray_end_su - ray_start_su);
BVHTreeRayHit ray_hit;
ray_hit.dist = FLT_MAX;
ray_hit.index = -1;
BLI_bvhtree_ray_cast(surface_bvh_.tree,
ray_start_su,
ray_direction_su,
0.0f,
&ray_hit,
surface_bvh_.raycast_callback,
&surface_bvh_);
if (ray_hit.index == -1) {
continue;
}
if (use_front_face_) {
const float3 normal_su = ray_hit.no;
if (math::dot(ray_direction_su, normal_su) >= 0.0f) {
continue;
}
}
const int looptri_index = ray_hit.index;
const float3 pos_su = ray_hit.co;
const float3 bary_coords = this->get_bary_coords(
*surface_, surface_looptris_[looptri_index], pos_su);
const float3 pos_cu = surface_to_curves_mat_ * pos_su;
r_added_points.positions_cu.append(pos_cu);
r_added_points.bary_coords.append(bary_coords);
r_added_points.looptri_indices.append(looptri_index);
}
}
/**
* Sample points in a 3D sphere around the surface position that the mouse hovers over.
*/
void sample_spherical_with_symmetry(RandomNumberGenerator &rng, AddedPoints &r_added_points)
{
/* Find ray that starts in the center of the brush. */
float3 brush_ray_start_wo, brush_ray_end_wo;
ED_view3d_win_to_segment_clipped(
depsgraph_, region_, v3d_, brush_pos_re_, brush_ray_start_wo, brush_ray_end_wo, true);
const float3 brush_ray_start_su = world_to_surface_mat_ * brush_ray_start_wo;
const float3 brush_ray_end_su = world_to_surface_mat_ * brush_ray_end_wo;
/* Find ray that starts on the boundary of the brush. That is used to compute the brush radius
* in 3D. */
float3 brush_radius_ray_start_wo, brush_radius_ray_end_wo;
ED_view3d_win_to_segment_clipped(depsgraph_,
region_,
v3d_,
brush_pos_re_ + float2(brush_radius_re_, 0),
brush_radius_ray_start_wo,
brush_radius_ray_end_wo,
true);
const float3 brush_radius_ray_start_su = world_to_surface_mat_ * brush_radius_ray_start_wo;
const float3 brush_radius_ray_end_su = world_to_surface_mat_ * brush_radius_ray_end_wo;
const Vector<float4x4> symmetry_brush_transforms = get_symmetry_brush_transforms(
eCurvesSymmetryType(curves_id_->symmetry));
for (const float4x4 &brush_transform : symmetry_brush_transforms) {
this->sample_spherical(rng,
r_added_points,
brush_transform * brush_ray_start_su,
brush_transform * brush_ray_end_su,
brush_transform * brush_radius_ray_start_su,
brush_transform * brush_radius_ray_end_su);
}
}
void sample_spherical(RandomNumberGenerator &rng,
AddedPoints &r_added_points,
const float3 &brush_ray_start_su,
const float3 &brush_ray_end_su,
const float3 &brush_radius_ray_start_su,
const float3 &brush_radius_ray_end_su)
{
const float3 brush_ray_direction_su = math::normalize(brush_ray_end_su - brush_ray_start_su);
BVHTreeRayHit ray_hit;
ray_hit.dist = FLT_MAX;
ray_hit.index = -1;
BLI_bvhtree_ray_cast(surface_bvh_.tree,
brush_ray_start_su,
brush_ray_direction_su,
0.0f,
&ray_hit,
surface_bvh_.raycast_callback,
&surface_bvh_);
if (ray_hit.index == -1) {
return;
}
/* Compute brush radius. */
const float3 brush_pos_su = ray_hit.co;
const float brush_radius_su = dist_to_line_v3(
brush_pos_su, brush_radius_ray_start_su, brush_radius_ray_end_su);
const float brush_radius_sq_su = pow2f(brush_radius_su);
/* Find surface triangles within brush radius. */
Vector<int> looptri_indices;
if (use_front_face_) {
BLI_bvhtree_range_query_cpp(
*surface_bvh_.tree,
brush_pos_su,
brush_radius_su,
[&](const int index, const float3 &UNUSED(co), const float UNUSED(dist_sq)) {
const MLoopTri &looptri = surface_looptris_[index];
const float3 v0_su = surface_->mvert[surface_->mloop[looptri.tri[0]].v].co;
const float3 v1_su = surface_->mvert[surface_->mloop[looptri.tri[1]].v].co;
const float3 v2_su = surface_->mvert[surface_->mloop[looptri.tri[2]].v].co;
float3 normal_su;
normal_tri_v3(normal_su, v0_su, v1_su, v2_su);
if (math::dot(normal_su, brush_ray_direction_su) >= 0.0f) {
return;
}
looptri_indices.append(index);
});
}
else {
BLI_bvhtree_range_query_cpp(
*surface_bvh_.tree,
brush_pos_su,
brush_radius_su,
[&](const int index, const float3 &UNUSED(co), const float UNUSED(dist_sq)) {
looptri_indices.append(index);
});
}
/* Density used for sampling points. This does not have to be exact, because the loop below
* automatically runs until enough samples have been found. If too many samples are found, some
* will be discarded afterwards. */
const float brush_plane_area_su = M_PI * brush_radius_sq_su;
const float approximate_density_su = add_amount_ / brush_plane_area_su;
/* Used for switching between two triangle sampling strategies. */
const float area_threshold = brush_plane_area_su;
/* Usually one or two iterations should be enough. */
const int max_iterations = 5;
int current_iteration = 0;
const int old_amount = r_added_points.bary_coords.size();
while (r_added_points.bary_coords.size() < old_amount + add_amount_) {
if (current_iteration++ >= max_iterations) {
break;
}
for (const int looptri_index : looptri_indices) {
const MLoopTri &looptri = surface_looptris_[looptri_index];
const float3 v0_su = surface_->mvert[surface_->mloop[looptri.tri[0]].v].co;
const float3 v1_su = surface_->mvert[surface_->mloop[looptri.tri[1]].v].co;
const float3 v2_su = surface_->mvert[surface_->mloop[looptri.tri[2]].v].co;
const float looptri_area_su = area_tri_v3(v0_su, v1_su, v2_su);
if (looptri_area_su < area_threshold) {
/* The triangle is small compared to the brush radius. Sample by generating random
* barycentric coordinates. */
const int amount = rng.round_probabilistic(approximate_density_su * looptri_area_su);
for ([[maybe_unused]] const int i : IndexRange(amount)) {
const float3 bary_coord = rng.get_barycentric_coordinates();
const float3 point_pos_su = attribute_math::mix3(bary_coord, v0_su, v1_su, v2_su);
const float distance_to_brush_sq_su = math::distance_squared(point_pos_su,
brush_pos_su);
if (distance_to_brush_sq_su > brush_radius_sq_su) {
continue;
}
r_added_points.bary_coords.append(bary_coord);
r_added_points.looptri_indices.append(looptri_index);
r_added_points.positions_cu.append(surface_to_curves_mat_ * point_pos_su);
}
}
else {
/* The triangle is large compared to the brush radius. Sample by generating random points
* on the triangle plane within the brush radius. */
float3 normal_su;
normal_tri_v3(normal_su, v0_su, v1_su, v2_su);
float3 brush_pos_proj_su = brush_pos_su;
project_v3_plane(brush_pos_proj_su, normal_su, v0_su);
const float proj_distance_sq_su = math::distance_squared(brush_pos_proj_su,
brush_pos_su);
const float brush_radius_factor_sq = 1.0f -
std::min(1.0f,
proj_distance_sq_su / brush_radius_sq_su);
const float radius_proj_sq_su = brush_radius_sq_su * brush_radius_factor_sq;
const float radius_proj_su = std::sqrt(radius_proj_sq_su);
const float circle_area_su = M_PI * radius_proj_su;
const int amount = rng.round_probabilistic(approximate_density_su * circle_area_su);
const float3 axis_1_su = math::normalize(v1_su - v0_su) * radius_proj_su;
const float3 axis_2_su = math::normalize(math::cross(
axis_1_su, math::cross(axis_1_su, v2_su - v0_su))) *
radius_proj_su;
for ([[maybe_unused]] const int i : IndexRange(amount)) {
const float r = std::sqrt(rng.get_float());
const float angle = rng.get_float() * 2.0f * M_PI;
const float x = r * std::cos(angle);
const float y = r * std::sin(angle);
const float3 point_pos_su = brush_pos_proj_su + axis_1_su * x + axis_2_su * y;
if (!isect_point_tri_prism_v3(point_pos_su, v0_su, v1_su, v2_su)) {
/* Sampled point is not in the triangle. */
continue;
}
float3 bary_coord;
interp_weights_tri_v3(bary_coord, v0_su, v1_su, v2_su, point_pos_su);
r_added_points.bary_coords.append(bary_coord);
r_added_points.looptri_indices.append(looptri_index);
r_added_points.positions_cu.append(surface_to_curves_mat_ * point_pos_su);
}
}
}
}
/* Remove samples when there are too many. */
while (r_added_points.bary_coords.size() > old_amount + add_amount_) {
const int index_to_remove = rng.get_int32(add_amount_) + old_amount;
r_added_points.bary_coords.remove_and_reorder(index_to_remove);
r_added_points.looptri_indices.remove_and_reorder(index_to_remove);
r_added_points.positions_cu.remove_and_reorder(index_to_remove);
}
}
void ensure_curve_roots_kdtree()
{
if (self_->curve_roots_kdtree_ == nullptr) {
self_->curve_roots_kdtree_ = BLI_kdtree_3d_new(curves_->curves_num());
for (const int curve_i : curves_->curves_range()) {
const int root_point_i = curves_->offsets()[curve_i];
const float3 &root_pos_cu = curves_->positions()[root_point_i];
BLI_kdtree_3d_insert(self_->curve_roots_kdtree_, curve_i, root_pos_cu);
}
BLI_kdtree_3d_balance(self_->curve_roots_kdtree_);
}
}
void initialize_curve_offsets(const int tot_added_curves)
{
MutableSpan<int> offsets = curves_->offsets_for_write();
threading::parallel_for(IndexRange(tot_added_curves), 1024, [&](const IndexRange range) {
for (const int i : range) {
const int curve_i = tot_old_curves_ + i;
offsets[curve_i + 1] = tot_old_points_ + (i + 1) * points_per_curve_;
}
});
}
struct NeighborInfo {
/* Curve index of the neighbor. */
int index;
/* The weights of all neighbors of a new curve add up to 1. */
float weight;
};
static constexpr int max_neighbors = 5;
using NeighborsVector = Vector<NeighborInfo, max_neighbors>;
void initialize_attributes(const AddedPoints &added_points)
{
Array<NeighborsVector> neighbors_per_curve;
if (use_interpolation_) {
neighbors_per_curve = this->find_curve_neighbors(added_points);
}
Array<float> new_lengths_cu(added_points.bary_coords.size());
if (interpolate_length_) {
this->interpolate_lengths(neighbors_per_curve, new_lengths_cu);
}
else {
new_lengths_cu.fill(new_curve_length_);
}
Array<float3> new_normals_su = this->compute_normals_for_added_curves_su(added_points);
this->initialize_surface_attachment(added_points);
if (interpolate_shape_) {
this->initialize_position_with_interpolation(
added_points, neighbors_per_curve, new_normals_su, new_lengths_cu);
}
else {
this->initialize_position_without_interpolation(
added_points, new_lengths_cu, new_normals_su);
}
}
Array<NeighborsVector> find_curve_neighbors(const AddedPoints &added_points)
{
const int tot_added_curves = added_points.bary_coords.size();
Array<NeighborsVector> neighbors_per_curve(tot_added_curves);
threading::parallel_for(IndexRange(tot_added_curves), 128, [&](const IndexRange range) {
for (const int i : range) {
const float3 root_cu = added_points.positions_cu[i];
std::array<KDTreeNearest_3d, max_neighbors> nearest_n;
const int found_neighbors = BLI_kdtree_3d_find_nearest_n(
self_->curve_roots_kdtree_, root_cu, nearest_n.data(), max_neighbors);
float tot_weight = 0.0f;
for (const int neighbor_i : IndexRange(found_neighbors)) {
KDTreeNearest_3d &nearest = nearest_n[neighbor_i];
const float weight = 1.0f / std::max(nearest.dist, 0.00001f);
tot_weight += weight;
neighbors_per_curve[i].append({nearest.index, weight});
}
/* Normalize weights. */
for (NeighborInfo &neighbor : neighbors_per_curve[i]) {
neighbor.weight /= tot_weight;
}
}
});
return neighbors_per_curve;
}
void interpolate_lengths(const Span<NeighborsVector> neighbors_per_curve,
MutableSpan<float> r_lengths)
{
const Span<float3> positions_cu = curves_->positions();
threading::parallel_for(r_lengths.index_range(), 128, [&](const IndexRange range) {
for (const int added_curve_i : range) {
const Span<NeighborInfo> neighbors = neighbors_per_curve[added_curve_i];
float length_sum = 0.0f;
for (const NeighborInfo &neighbor : neighbors) {
const IndexRange neighbor_points = curves_->points_for_curve(neighbor.index);
float neighbor_length = 0.0f;
const int tot_segments = neighbor_points.size() - 1;
for (const int segment_i : IndexRange(tot_segments)) {
const float3 &p1 = positions_cu[neighbor_points[segment_i]];
const float3 &p2 = positions_cu[neighbor_points[segment_i] + 1];
neighbor_length += math::distance(p1, p2);
}
length_sum += neighbor.weight * neighbor_length;
}
const float length = neighbors.is_empty() ? new_curve_length_ : length_sum;
r_lengths[added_curve_i] = length;
}
});
}
float3 compute_point_normal_su(const int looptri_index, const float3 &bary_coord)
{
const MLoopTri &looptri = surface_looptris_[looptri_index];
const int l0 = looptri.tri[0];
const int l1 = looptri.tri[1];
const int l2 = looptri.tri[2];
const float3 &l0_normal_su = corner_normals_su_[l0];
const float3 &l1_normal_su = corner_normals_su_[l1];
const float3 &l2_normal_su = corner_normals_su_[l2];
const float3 normal_su = math::normalize(
attribute_math::mix3(bary_coord, l0_normal_su, l1_normal_su, l2_normal_su));
return normal_su;
}
Array<float3> compute_normals_for_added_curves_su(const AddedPoints &added_points)
{
Array<float3> normals_su(added_points.bary_coords.size());
threading::parallel_for(normals_su.index_range(), 256, [&](const IndexRange range) {
for (const int i : range) {
const int looptri_index = added_points.looptri_indices[i];
const float3 &bary_coord = added_points.bary_coords[i];
normals_su[i] = this->compute_point_normal_su(looptri_index, bary_coord);
}
});
return normals_su;
}
void initialize_surface_attachment(const AddedPoints &added_points)
{
MutableSpan<int> surface_triangle_indices = curves_->surface_triangle_indices_for_write();
MutableSpan<float2> surface_triangle_coords = curves_->surface_triangle_coords_for_write();
threading::parallel_for(
added_points.bary_coords.index_range(), 1024, [&](const IndexRange range) {
for (const int i : range) {
const int curve_i = tot_old_curves_ + i;
surface_triangle_indices[curve_i] = added_points.looptri_indices[i];
surface_triangle_coords[curve_i] = float2(added_points.bary_coords[i]);
}
});
}
/**
* Initialize new curves so that they are just a straight line in the normal direction.
*/
void initialize_position_without_interpolation(const AddedPoints &added_points,
const Span<float> lengths_cu,
const MutableSpan<float3> normals_su)
{
MutableSpan<float3> positions_cu = curves_->positions_for_write();
threading::parallel_for(
added_points.bary_coords.index_range(), 256, [&](const IndexRange range) {
for (const int i : range) {
const int first_point_i = tot_old_points_ + i * points_per_curve_;
const float3 &root_cu = added_points.positions_cu[i];
const float length = lengths_cu[i];
const float3 &normal_su = normals_su[i];
const float3 normal_cu = math::normalize(surface_to_curves_normal_mat_ * normal_su);
const float3 tip_cu = root_cu + length * normal_cu;
initialize_straight_curve_positions(
root_cu, tip_cu, positions_cu.slice(first_point_i, points_per_curve_));
}
});
}
/**
* Use neighboring curves to determine the shape.
*/
void initialize_position_with_interpolation(const AddedPoints &added_points,
const Span<NeighborsVector> neighbors_per_curve,
const Span<float3> new_normals_su,
const Span<float> new_lengths_cu)
{
MutableSpan<float3> positions_cu = curves_->positions_for_write();
const VArray_Span<int> surface_triangle_indices{curves_->surface_triangle_indices()};
const Span<float2> surface_triangle_coords = curves_->surface_triangle_coords();
threading::parallel_for(
added_points.bary_coords.index_range(), 256, [&](const IndexRange range) {
for (const int i : range) {
const Span<NeighborInfo> neighbors = neighbors_per_curve[i];
const float length_cu = new_lengths_cu[i];
const float3 &normal_su = new_normals_su[i];
const float3 normal_cu = math::normalize(surface_to_curves_normal_mat_ * normal_su);
const float3 &root_cu = added_points.positions_cu[i];
const int first_point_i = tot_old_points_ + i * points_per_curve_;
if (neighbors.is_empty()) {
/* If there are no neighbors, just make a straight line. */
const float3 tip_cu = root_cu + length_cu * normal_cu;
initialize_straight_curve_positions(
root_cu, tip_cu, positions_cu.slice(first_point_i, points_per_curve_));
continue;
}
positions_cu.slice(first_point_i, points_per_curve_).fill(root_cu);
for (const NeighborInfo &neighbor : neighbors) {
const int neighbor_curve_i = neighbor.index;
const int neighbor_looptri_index = surface_triangle_indices[neighbor_curve_i];
float3 neighbor_bary_coord{surface_triangle_coords[neighbor_curve_i]};
neighbor_bary_coord.z = 1.0f - neighbor_bary_coord.x - neighbor_bary_coord.y;
const float3 neighbor_normal_su = this->compute_point_normal_su(
neighbor_looptri_index, neighbor_bary_coord);
const float3 neighbor_normal_cu = math::normalize(surface_to_curves_normal_mat_ *
neighbor_normal_su);
/* The rotation matrix used to transform relative coordinates of the neighbor curve
* to the new curve. */
float normal_rotation_cu[3][3];
rotation_between_vecs_to_mat3(normal_rotation_cu, neighbor_normal_cu, normal_cu);
const IndexRange neighbor_points = curves_->points_for_curve(neighbor_curve_i);
const float3 &neighbor_root_cu = positions_cu[neighbor_points[0]];
/* Use a temporary #PolySpline, because that's the easiest way to resample an
* existing curve right now. Resampling is necessary if the length of the new curve
* does not match the length of the neighbors or the number of handle points is
* different. */
PolySpline neighbor_spline;
neighbor_spline.resize(neighbor_points.size());
neighbor_spline.positions().copy_from(positions_cu.slice(neighbor_points));
neighbor_spline.mark_cache_invalid();
const float neighbor_length_cu = neighbor_spline.length();
const float length_factor = std::min(1.0f, length_cu / neighbor_length_cu);
const float resample_factor = (1.0f / (points_per_curve_ - 1.0f)) * length_factor;
for (const int j : IndexRange(points_per_curve_)) {
const Spline::LookupResult lookup = neighbor_spline.lookup_evaluated_factor(
j * resample_factor);
const float index_factor = lookup.evaluated_index + lookup.factor;
float3 p;
neighbor_spline.sample_with_index_factors<float3>(
neighbor_spline.positions(), {&index_factor, 1}, {&p, 1});
const float3 relative_coord = p - neighbor_root_cu;
float3 rotated_relative_coord = relative_coord;
mul_m3_v3(normal_rotation_cu, rotated_relative_coord);
positions_cu[first_point_i + j] += neighbor.weight * rotated_relative_coord;
}
}
}
});
}
};
void AddOperation::on_stroke_extended(bContext *C, const StrokeExtension &stroke_extension)
{
AddOperationExecutor executor;
executor.execute(*this, C, stroke_extension);
}
std::unique_ptr<CurvesSculptStrokeOperation> new_add_operation()
{
return std::make_unique<AddOperation>();
}
} // namespace blender::ed::sculpt_paint
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