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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "BLI_array.hh"
#include "BLI_span.hh"
#include "BLI_task.hh"
#include "BKE_spline.hh"
using blender::Array;
using blender::float3;
using blender::IndexRange;
using blender::MutableSpan;
using blender::Span;
SplinePtr BezierSpline::copy() const
{
return std::make_unique<BezierSpline>(*this);
}
SplinePtr BezierSpline::copy_settings() const
{
std::unique_ptr<BezierSpline> copy = std::make_unique<BezierSpline>();
copy_base_settings(*this, *copy);
copy->resolution_ = resolution_;
return copy;
}
int BezierSpline::size() const
{
const int size = positions_.size();
BLI_assert(size == handle_types_left_.size());
BLI_assert(size == handle_positions_left_.size());
BLI_assert(size == handle_types_right_.size());
BLI_assert(size == handle_positions_right_.size());
BLI_assert(size == radii_.size());
BLI_assert(size == tilts_.size());
return size;
}
int BezierSpline::resolution() const
{
return resolution_;
}
void BezierSpline::set_resolution(const int value)
{
BLI_assert(value > 0);
resolution_ = value;
this->mark_cache_invalid();
}
/**
* \warning Call #reallocate on the spline's attributes after adding all points.
*/
void BezierSpline::add_point(const float3 position,
const HandleType handle_type_left,
const float3 handle_position_left,
const HandleType handle_type_right,
const float3 handle_position_right,
const float radius,
const float tilt)
{
handle_types_left_.append(handle_type_left);
handle_positions_left_.append(handle_position_left);
positions_.append(position);
handle_types_right_.append(handle_type_right);
handle_positions_right_.append(handle_position_right);
radii_.append(radius);
tilts_.append(tilt);
this->mark_cache_invalid();
}
void BezierSpline::resize(const int size)
{
handle_types_left_.resize(size);
handle_positions_left_.resize(size);
positions_.resize(size);
handle_types_right_.resize(size);
handle_positions_right_.resize(size);
radii_.resize(size);
tilts_.resize(size);
this->mark_cache_invalid();
attributes.reallocate(size);
}
MutableSpan<float3> BezierSpline::positions()
{
return positions_;
}
Span<float3> BezierSpline::positions() const
{
return positions_;
}
MutableSpan<float> BezierSpline::radii()
{
return radii_;
}
Span<float> BezierSpline::radii() const
{
return radii_;
}
MutableSpan<float> BezierSpline::tilts()
{
return tilts_;
}
Span<float> BezierSpline::tilts() const
{
return tilts_;
}
Span<BezierSpline::HandleType> BezierSpline::handle_types_left() const
{
return handle_types_left_;
}
MutableSpan<BezierSpline::HandleType> BezierSpline::handle_types_left()
{
return handle_types_left_;
}
Span<float3> BezierSpline::handle_positions_left() const
{
this->ensure_auto_handles();
return handle_positions_left_;
}
MutableSpan<float3> BezierSpline::handle_positions_left()
{
this->ensure_auto_handles();
return handle_positions_left_;
}
Span<BezierSpline::HandleType> BezierSpline::handle_types_right() const
{
return handle_types_right_;
}
MutableSpan<BezierSpline::HandleType> BezierSpline::handle_types_right()
{
return handle_types_right_;
}
Span<float3> BezierSpline::handle_positions_right() const
{
this->ensure_auto_handles();
return handle_positions_right_;
}
MutableSpan<float3> BezierSpline::handle_positions_right()
{
this->ensure_auto_handles();
return handle_positions_right_;
}
static float3 previous_position(Span<float3> positions, const bool cyclic, const int i)
{
if (i == 0) {
if (cyclic) {
return positions[positions.size() - 1];
}
return 2.0f * positions[i] - positions[i + 1];
}
return positions[i - 1];
}
static float3 next_position(Span<float3> positions, const bool cyclic, const int i)
{
if (i == positions.size() - 1) {
if (cyclic) {
return positions[0];
}
return 2.0f * positions[i] - positions[i - 1];
}
return positions[i + 1];
}
/**
* Recalculate all #Auto and #Vector handles with positions automatically
* derived from the neighboring control points.
*/
void BezierSpline::ensure_auto_handles() const
{
if (!auto_handles_dirty_) {
return;
}
std::lock_guard lock{auto_handle_mutex_};
if (!auto_handles_dirty_) {
return;
}
for (const int i : IndexRange(this->size())) {
if (ELEM(HandleType::Auto, handle_types_left_[i], handle_types_right_[i])) {
const float3 prev_diff = positions_[i] - previous_position(positions_, is_cyclic_, i);
const float3 next_diff = next_position(positions_, is_cyclic_, i) - positions_[i];
float prev_len = prev_diff.length();
float next_len = next_diff.length();
if (prev_len == 0.0f) {
prev_len = 1.0f;
}
if (next_len == 0.0f) {
next_len = 1.0f;
}
const float3 dir = next_diff / next_len + prev_diff / prev_len;
/* This magic number is unfortunate, but comes from elsewhere in Blender. */
const float len = dir.length() * 2.5614f;
if (len != 0.0f) {
if (handle_types_left_[i] == HandleType::Auto) {
const float prev_len_clamped = std::min(prev_len, next_len * 5.0f);
handle_positions_left_[i] = positions_[i] + dir * -(prev_len_clamped / len);
}
if (handle_types_right_[i] == HandleType::Auto) {
const float next_len_clamped = std::min(next_len, prev_len * 5.0f);
handle_positions_right_[i] = positions_[i] + dir * (next_len_clamped / len);
}
}
}
if (handle_types_left_[i] == HandleType::Vector) {
const float3 prev = previous_position(positions_, is_cyclic_, i);
handle_positions_left_[i] = float3::interpolate(positions_[i], prev, 1.0f / 3.0f);
}
if (handle_types_right_[i] == HandleType::Vector) {
const float3 next = next_position(positions_, is_cyclic_, i);
handle_positions_right_[i] = float3::interpolate(positions_[i], next, 1.0f / 3.0f);
}
}
auto_handles_dirty_ = false;
}
void BezierSpline::translate(const blender::float3 &translation)
{
for (float3 &position : this->positions()) {
position += translation;
}
for (float3 &handle_position : this->handle_positions_left()) {
handle_position += translation;
}
for (float3 &handle_position : this->handle_positions_right()) {
handle_position += translation;
}
this->mark_cache_invalid();
}
void BezierSpline::transform(const blender::float4x4 &matrix)
{
for (float3 &position : this->positions()) {
position = matrix * position;
}
for (float3 &handle_position : this->handle_positions_left()) {
handle_position = matrix * handle_position;
}
for (float3 &handle_position : this->handle_positions_right()) {
handle_position = matrix * handle_position;
}
this->mark_cache_invalid();
}
bool BezierSpline::point_is_sharp(const int index) const
{
return ELEM(handle_types_left_[index], HandleType::Vector, HandleType::Free) ||
ELEM(handle_types_right_[index], HandleType::Vector, HandleType::Free);
}
bool BezierSpline::segment_is_vector(const int index) const
{
if (index == this->size() - 1) {
if (is_cyclic_) {
return handle_types_right_.last() == HandleType::Vector &&
handle_types_left_.first() == HandleType::Vector;
}
/* There is actually no segment in this case, but it's nice to avoid
* having a special case for the last segment in calling code. */
return true;
}
return handle_types_right_[index] == HandleType::Vector &&
handle_types_left_[index + 1] == HandleType::Vector;
}
void BezierSpline::mark_cache_invalid()
{
offset_cache_dirty_ = true;
position_cache_dirty_ = true;
mapping_cache_dirty_ = true;
tangent_cache_dirty_ = true;
normal_cache_dirty_ = true;
length_cache_dirty_ = true;
auto_handles_dirty_ = true;
}
int BezierSpline::evaluated_points_size() const
{
BLI_assert(this->size() > 0);
return this->control_point_offsets().last();
}
/**
* If the spline is not cyclic, the direction for the first and last points is just the
* direction formed by the corresponding handles and control points. In the unlikely situation
* that the handles define a zero direction, fallback to using the direction defined by the
* first and last evaluated segments already calculated in #Spline::evaluated_tangents().
*/
void BezierSpline::correct_end_tangents() const
{
if (is_cyclic_) {
return;
}
MutableSpan<float3> tangents(evaluated_tangents_cache_);
if (handle_positions_right_.first() != positions_.first()) {
tangents.first() = (handle_positions_right_.first() - positions_.first()).normalized();
}
if (handle_positions_left_.last() != positions_.last()) {
tangents.last() = (positions_.last() - handle_positions_left_.last()).normalized();
}
}
static void bezier_forward_difference_3d(const float3 &point_0,
const float3 &point_1,
const float3 &point_2,
const float3 &point_3,
MutableSpan<float3> result)
{
BLI_assert(result.size() > 0);
const float inv_len = 1.0f / static_cast<float>(result.size());
const float inv_len_squared = inv_len * inv_len;
const float inv_len_cubed = inv_len_squared * inv_len;
const float3 rt1 = 3.0f * (point_1 - point_0) * inv_len;
const float3 rt2 = 3.0f * (point_0 - 2.0f * point_1 + point_2) * inv_len_squared;
const float3 rt3 = (point_3 - point_0 + 3.0f * (point_1 - point_2)) * inv_len_cubed;
float3 q0 = point_0;
float3 q1 = rt1 + rt2 + rt3;
float3 q2 = 2.0f * rt2 + 6.0f * rt3;
float3 q3 = 6.0f * rt3;
for (const int i : result.index_range()) {
result[i] = q0;
q0 += q1;
q1 += q2;
q2 += q3;
}
}
void BezierSpline::evaluate_bezier_segment(const int index,
const int next_index,
MutableSpan<float3> positions) const
{
if (this->segment_is_vector(index)) {
BLI_assert(positions.size() == 1);
positions.first() = positions_[index];
}
else {
bezier_forward_difference_3d(positions_[index],
handle_positions_right_[index],
handle_positions_left_[next_index],
positions_[next_index],
positions);
}
}
/**
* Returns access to a cache of offsets into the evaluated point array for each control point.
* While most control point edges generate the number of edges specified by the resolution, vector
* segments only generate one edge.
*
* \note The length of the result is one greater than the number of points, so that the last item
* is the total number of evaluated points. This is useful to avoid recalculating the size of the
* last segment everywhere.
*/
Span<int> BezierSpline::control_point_offsets() const
{
if (!offset_cache_dirty_) {
return offset_cache_;
}
std::lock_guard lock{offset_cache_mutex_};
if (!offset_cache_dirty_) {
return offset_cache_;
}
const int points_len = this->size();
offset_cache_.resize(points_len + 1);
MutableSpan<int> offsets = offset_cache_;
int offset = 0;
for (const int i : IndexRange(points_len)) {
offsets[i] = offset;
offset += this->segment_is_vector(i) ? 1 : resolution_;
}
offsets.last() = offset;
offset_cache_dirty_ = false;
return offsets;
}
static void calculate_mappings_linear_resolution(Span<int> offsets,
const int size,
const int resolution,
const bool is_cyclic,
MutableSpan<float> r_mappings)
{
const float first_segment_len_inv = 1.0f / offsets[1];
for (const int i : IndexRange(0, offsets[1])) {
r_mappings[i] = i * first_segment_len_inv;
}
const int grain_size = std::max(2048 / resolution, 1);
parallel_for(IndexRange(1, size - 2), grain_size, [&](IndexRange range) {
for (const int i_control_point : range) {
const int segment_len = offsets[i_control_point + 1] - offsets[i_control_point];
const float segment_len_inv = 1.0f / segment_len;
for (const int i : IndexRange(segment_len)) {
r_mappings[offsets[i_control_point] + i] = i_control_point + i * segment_len_inv;
}
}
});
if (is_cyclic) {
const int last_segment_len = offsets[size] - offsets[size - 1];
const float last_segment_len_inv = 1.0f / last_segment_len;
for (const int i : IndexRange(last_segment_len)) {
r_mappings[offsets[size - 1] + i] = size - 1 + i * last_segment_len_inv;
}
}
else {
r_mappings.last() = size - 1;
}
}
/**
* Returns non-owning access to an array of values containing the information necessary to
* interpolate values from the original control points to evaluated points. The control point
* index is the integer part of each value, and the factor used for interpolating to the next
* control point is the remaining factional part.
*/
Span<float> BezierSpline::evaluated_mappings() const
{
if (!mapping_cache_dirty_) {
return evaluated_mapping_cache_;
}
std::lock_guard lock{mapping_cache_mutex_};
if (!mapping_cache_dirty_) {
return evaluated_mapping_cache_;
}
const int size = this->size();
const int eval_size = this->evaluated_points_size();
evaluated_mapping_cache_.resize(eval_size);
MutableSpan<float> mappings = evaluated_mapping_cache_;
if (eval_size == 1) {
mappings.first() = 0.0f;
mapping_cache_dirty_ = false;
return mappings;
}
Span<int> offsets = this->control_point_offsets();
calculate_mappings_linear_resolution(offsets, size, resolution_, is_cyclic_, mappings);
mapping_cache_dirty_ = false;
return mappings;
}
Span<float3> BezierSpline::evaluated_positions() const
{
if (!position_cache_dirty_) {
return evaluated_position_cache_;
}
std::lock_guard lock{position_cache_mutex_};
if (!position_cache_dirty_) {
return evaluated_position_cache_;
}
this->ensure_auto_handles();
const int size = this->size();
const int eval_size = this->evaluated_points_size();
evaluated_position_cache_.resize(eval_size);
MutableSpan<float3> positions = evaluated_position_cache_;
Span<int> offsets = this->control_point_offsets();
const int grain_size = std::max(512 / resolution_, 1);
parallel_for(IndexRange(size - 1), grain_size, [&](IndexRange range) {
for (const int i : range) {
this->evaluate_bezier_segment(
i, i + 1, positions.slice(offsets[i], offsets[i + 1] - offsets[i]));
}
});
if (is_cyclic_) {
this->evaluate_bezier_segment(
size - 1, 0, positions.slice(offsets[size - 1], offsets[size] - offsets[size - 1]));
}
else {
/* Since evaluating the bezier segment doesn't add the final point,
* it must be added manually in the non-cyclic case. */
positions.last() = positions_.last();
}
position_cache_dirty_ = false;
return positions;
}
/**
* Convert the data encoded in #evaulated_mappings into its parts-- the information necessary
* to interpolate data from control points to evaluated points between them. The next control
* point index result will not overflow the size of the control point vectors.
*/
BezierSpline::InterpolationData BezierSpline::interpolation_data_from_index_factor(
const float index_factor) const
{
const int points_len = this->size();
if (is_cyclic_) {
if (index_factor < points_len) {
const int index = std::floor(index_factor);
const int next_index = (index < points_len - 1) ? index + 1 : 0;
return InterpolationData{index, next_index, index_factor - index};
}
return InterpolationData{points_len - 1, 0, 1.0f};
}
if (index_factor < points_len - 1) {
const int index = std::floor(index_factor);
const int next_index = index + 1;
return InterpolationData{index, next_index, index_factor - index};
}
return InterpolationData{points_len - 2, points_len - 1, 1.0f};
}
/* Use a spline argument to avoid adding this to the header. */
template<typename T>
static void interpolate_to_evaluated_points_impl(const BezierSpline &spline,
const blender::VArray<T> &source_data,
MutableSpan<T> result_data)
{
Span<float> mappings = spline.evaluated_mappings();
for (const int i : result_data.index_range()) {
BezierSpline::InterpolationData interp = spline.interpolation_data_from_index_factor(
mappings[i]);
const T &value = source_data[interp.control_point_index];
const T &next_value = source_data[interp.next_control_point_index];
result_data[i] = blender::attribute_math::mix2(interp.factor, value, next_value);
}
}
blender::fn::GVArrayPtr BezierSpline::interpolate_to_evaluated_points(
const blender::fn::GVArray &source_data) const
{
BLI_assert(source_data.size() == this->size());
if (source_data.is_single()) {
return source_data.shallow_copy();
}
const int eval_size = this->evaluated_points_size();
if (eval_size == 1) {
return source_data.shallow_copy();
}
blender::fn::GVArrayPtr new_varray;
blender::attribute_math::convert_to_static_type(source_data.type(), [&](auto dummy) {
using T = decltype(dummy);
if constexpr (!std::is_void_v<blender::attribute_math::DefaultMixer<T>>) {
Array<T> values(eval_size);
interpolate_to_evaluated_points_impl<T>(*this, source_data.typed<T>(), values);
new_varray = std::make_unique<blender::fn::GVArray_For_ArrayContainer<Array<T>>>(
std::move(values));
}
});
return new_varray;
}
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