Cleanup: Move curveprofile.c to C++

1 files changed, 1125 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/curveprofile.cc b/source/blender/blenkernel/intern/curveprofile.cc
new file mode 100644
index 00000000000..0adce991d0f
--- /dev/null
+++ b/source/blender/blenkernel/intern/curveprofile.cc
@@ -0,0 +1,1125 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2019 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup bke
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_curve_types.h"
+#include "DNA_curveprofile_types.h"
+
+#include "BLI_math_vector.h"
+#include "BLI_rect.h"
+#include "BLI_utildefines.h"
+
+#include "BKE_curve.h"
+#include "BKE_curveprofile.h"
+
+#include "BLO_read_write.h"
+
+void BKE_curveprofile_free_data(CurveProfile *profile)
+{
+  MEM_SAFE_FREE(profile->path);
+  MEM_SAFE_FREE(profile->table);
+  MEM_SAFE_FREE(profile->segments);
+}
+
+void BKE_curveprofile_free(CurveProfile *profile)
+{
+  if (profile) {
+    BKE_curveprofile_free_data(profile);
+    MEM_freeN(profile);
+  }
+}
+
+void BKE_curveprofile_copy_data(CurveProfile *target, const CurveProfile *profile)
+{
+  *target = *profile;
+
+  target->path = (CurveProfilePoint *)MEM_dupallocN(profile->path);
+  target->table = (CurveProfilePoint *)MEM_dupallocN(profile->table);
+  target->segments = (CurveProfilePoint *)MEM_dupallocN(profile->segments);
+
+  /* Update the reference the points have to the profile. */
+  for (int i = 0; i < target->path_len; i++) {
+    target->path[i].profile = target;
+  }
+}
+
+CurveProfile *BKE_curveprofile_copy(const CurveProfile *profile)
+{
+  if (profile) {
+    CurveProfile *new_prdgt = (CurveProfile *)MEM_dupallocN(profile);
+    BKE_curveprofile_copy_data(new_prdgt, profile);
+    return new_prdgt;
+  }
+  return nullptr;
+}
+
+/**
+ * Move a point's handle, accounting for the alignment of handles with the #HD_ALIGN type.
+ *
+ * \param handle_1: Whether to move the 1st or 2nd control point.
+ * \param delta: The *relative* change in the handle's position.
+ * \note Requires #BKE_curveprofile_update call after.
+ * \return Whether the handle moved from its start position.
+ */
+bool BKE_curveprofile_move_handle(struct CurveProfilePoint *point,
+                                  const bool handle_1,
+                                  const bool snap,
+                                  const float delta[2])
+{
+  short handle_type = (handle_1) ? point->h1 : point->h2;
+  float *handle_location = (handle_1) ? &point->h1_loc[0] : &point->h2_loc[0];
+
+  float start_position[2];
+  copy_v2_v2(start_position, handle_location);
+
+  /* Don't move the handle if it's not a free handle type. */
+  if (!ELEM(handle_type, HD_FREE, HD_ALIGN)) {
+    return false;
+  }
+
+  /* Move the handle. */
+  handle_location[0] += delta ? delta[0] : 0.0f;
+  handle_location[1] += delta ? delta[1] : 0.0f;
+  if (snap) {
+    handle_location[0] = 0.125f * roundf(8.0f * handle_location[0]);
+    handle_location[1] = 0.125f * roundf(8.0f * handle_location[1]);
+  }
+
+  /* Move the other handle if they are aligned. */
+  if (handle_type == HD_ALIGN) {
+    short other_handle_type = (handle_1) ? point->h2 : point->h1;
+    if (other_handle_type == HD_ALIGN) {
+      float *other_handle_location = (handle_1) ? &point->h2_loc[0] : &point->h1_loc[0];
+      other_handle_location[0] = 2.0f * point->x - handle_location[0];
+      other_handle_location[1] = 2.0f * point->y - handle_location[1];
+    }
+  }
+
+  if (!equals_v2v2(handle_location, start_position)) {
+    return true;
+  }
+  return false;
+}
+
+/**
+ * Moves a control point, accounting for clipping and snapping, and moving free handles.
+ *
+ * \param snap: Whether to snap the point to the grid
+ * \param delta: The *relative* change of the point's location.
+ * \return Whether the point moved from its start position.
+ * \note Requires #BKE_curveprofile_update call after.
+ */
+bool BKE_curveprofile_move_point(struct CurveProfile *profile,
+                                 struct CurveProfilePoint *point,
+                                 const bool snap,
+                                 const float delta[2])
+{
+  /* Don't move the final point. */
+  if (point == &profile->path[profile->path_len - 1]) {
+    return false;
+  }
+  /* Don't move the first point. */
+  if (point == profile->path) {
+    return false;
+  }
+  float origx = point->x;
+  float origy = point->y;
+
+  point->x += delta[0];
+  point->y += delta[1];
+  if (snap) {
+    point->x = 0.125f * roundf(8.0f * point->x);
+    point->y = 0.125f * roundf(8.0f * point->y);
+  }
+
+  /* Clip here instead to test clipping here to stop handles from moving too. */
+  if (profile->flag & PROF_USE_CLIP) {
+    point->x = max_ff(point->x, profile->clip_rect.xmin);
+    point->x = min_ff(point->x, profile->clip_rect.xmax);
+    point->y = max_ff(point->y, profile->clip_rect.ymin);
+    point->y = min_ff(point->y, profile->clip_rect.ymax);
+  }
+
+  /* Also move free handles even when they aren't selected. */
+  if (ELEM(point->h1, HD_FREE, HD_ALIGN)) {
+    point->h1_loc[0] += point->x - origx;
+    point->h1_loc[1] += point->y - origy;
+  }
+  if (ELEM(point->h2, HD_FREE, HD_ALIGN)) {
+    point->h2_loc[0] += point->x - origx;
+    point->h2_loc[1] += point->y - origy;
+  }
+
+  if (point->x != origx || point->y != origy) {
+    return true;
+  }
+  return false;
+}
+
+/**
+ * Removes a specific point from the path of control points.
+ * \note Requires #BKE_curveprofile_update call after.
+ */
+bool BKE_curveprofile_remove_point(CurveProfile *profile, CurveProfilePoint *point)
+{
+  /* Must have 2 points minimum. */
+  if (profile->path_len <= 2) {
+    return false;
+  }
+
+  /* Input point must be within the array. */
+  if (!(point > profile->path && point < profile->path + profile->path_len)) {
+    return false;
+  }
+
+  CurveProfilePoint *new_path = (CurveProfilePoint *)MEM_mallocN(
+      sizeof(CurveProfilePoint) * profile->path_len, __func__);
+
+  int i_delete = (int)(point - profile->path);
+  BLI_assert(i_delete > 0);
+
+  /* Copy the before and after the deleted point. */
+  memcpy(new_path, profile->path, sizeof(CurveProfilePoint) * i_delete);
+  memcpy(new_path + i_delete,
+         profile->path + i_delete + 1,
+         sizeof(CurveProfilePoint) * (profile->path_len - i_delete - 1));
+
+  MEM_freeN(profile->path);
+  profile->path = new_path;
+  profile->path_len -= 1;
+  return true;
+}
+
+/**
+ * Removes every point in the widget with the supplied flag set, except for the first and last.
+ *
+ * \param flag: #CurveProfilePoint.flag.
+ *
+ * \note Requires #BKE_curveprofile_update call after.
+ */
+void BKE_curveprofile_remove_by_flag(CurveProfile *profile, const short flag)
+{
+  /* Copy every point without the flag into the new path. */
+  CurveProfilePoint *new_path = (CurveProfilePoint *)MEM_mallocN(
+      sizeof(CurveProfilePoint) * profile->path_len, __func__);
+
+  /* Build the new list without any of the points with the flag. Keep the first and last points. */
+  int i_new = 1;
+  int i_old = 1;
+  int n_removed = 0;
+  new_path[0] = profile->path[0];
+  for (; i_old < profile->path_len - 1; i_old++) {
+    if (!(profile->path[i_old].flag & flag)) {
+      new_path[i_new] = profile->path[i_old];
+      i_new++;
+    }
+    else {
+      n_removed++;
+    }
+  }
+  new_path[i_new] = profile->path[i_old];
+
+  MEM_freeN(profile->path);
+  profile->path = new_path;
+  profile->path_len -= n_removed;
+}
+
+/**
+ * Shorthand helper function for setting location and interpolation of a point.
+ */
+static void point_init(CurveProfilePoint *point, float x, float y, short flag, char h1, char h2)
+{
+  point->x = x;
+  point->y = y;
+  point->flag = flag;
+  point->h1 = h1;
+  point->h2 = h2;
+}
+
+/**
+ * Adds a new point at the specified location. The choice for which points to place the new vertex
+ * between is made by checking which control point line segment is closest to the new point and
+ * placing the new vertex in between that segment's points.
+ *
+ * \note Requires #BKE_curveprofile_update call after.
+ */
+CurveProfilePoint *BKE_curveprofile_insert(CurveProfile *profile, float x, float y)
+{
+  const float new_loc[2] = {x, y};
+
+  /* Don't add more control points  than the maximum size of the higher resolution table. */
+  if (profile->path_len == PROF_TABLE_MAX - 1) {
+    return nullptr;
+  }
+
+  /* Find the index at the line segment that's closest to the new position. */
+  float min_distance = FLT_MAX;
+  int i_insert = 0;
+  for (int i = 0; i < profile->path_len - 1; i++) {
+    const float loc1[2] = {profile->path[i].x, profile->path[i].y};
+    const float loc2[2] = {profile->path[i + 1].x, profile->path[i + 1].y};
+
+    float distance = dist_squared_to_line_segment_v2(new_loc, loc1, loc2);
+    if (distance < min_distance) {
+      min_distance = distance;
+      i_insert = i + 1;
+    }
+  }
+
+  /* Insert the new point at the location we found and copy all of the old points in as well. */
+  profile->path_len++;
+  CurveProfilePoint *new_path = (CurveProfilePoint *)MEM_mallocN(
+      sizeof(CurveProfilePoint) * profile->path_len, __func__);
+  CurveProfilePoint *new_pt = nullptr;
+  for (int i_new = 0, i_old = 0; i_new < profile->path_len; i_new++) {
+    if (i_new != i_insert) {
+      /* Insert old points. */
+      new_path[i_new] = profile->path[i_old];
+      new_path[i_new].flag &= ~PROF_SELECT; /* Deselect old points. */
+      i_old++;
+    }
+    else {
+      /* Insert new point. */
+      /* Set handles of new point based on its neighbors. */
+      char new_handle_type = (new_path[i_new - 1].h2 == HD_VECT &&
+                              profile->path[i_insert].h1 == HD_VECT) ?
+                                 HD_VECT :
+                                 HD_AUTO;
+      point_init(&new_path[i_new], x, y, PROF_SELECT, new_handle_type, new_handle_type);
+      new_pt = &new_path[i_new];
+      /* Give new point a reference to the profile. */
+      new_pt->profile = profile;
+    }
+  }
+
+  /* Free the old path and use the new one. */
+  MEM_freeN(profile->path);
+  profile->path = new_path;
+  return new_pt;
+}
+
+/**
+ * Sets the handle type of the selected control points.
+ * \param type_1, type_2: Handle type for the first handle. HD_VECT, HD_AUTO, HD_FREE, or HD_ALIGN.
+ * \note Requires #BKE_curveprofile_update call after.
+ */
+void BKE_curveprofile_selected_handle_set(CurveProfile *profile, int type_1, int type_2)
+{
+  for (int i = 0; i < profile->path_len; i++) {
+    if (ELEM(profile->path[i].flag, PROF_SELECT, PROF_H1_SELECT, PROF_H2_SELECT)) {
+      profile->path[i].h1 = type_1;
+      profile->path[i].h2 = type_2;
+
+      if (type_1 == HD_ALIGN && type_2 == HD_ALIGN) {
+        /* Align the handles. */
+        BKE_curveprofile_move_handle(&profile->path[i], true, false, nullptr);
+      }
+    }
+  }
+}
+
+static CurveProfilePoint mirror_point(const CurveProfilePoint *point)
+{
+  CurveProfilePoint new_point = *point;
+  point_init(&new_point, point->y, point->x, point->flag, point->h2, point->h1);
+  return new_point;
+}
+
+/**
+ * Flips the profile across the diagonal so that its orientation is reversed.
+ *
+ * \note Requires #BKE_curveprofile_update call after.
+ */
+void BKE_curveprofile_reverse(CurveProfile *profile)
+{
+  /* When there are only two points, reversing shouldn't do anything. */
+  if (profile->path_len == 2) {
+    return;
+  }
+  CurveProfilePoint *new_path = (CurveProfilePoint *)MEM_mallocN(
+      sizeof(CurveProfilePoint) * profile->path_len, __func__);
+  /* Mirror the new points across the y = x line */
+  for (int i = 0; i < profile->path_len; i++) {
+    int i_reversed = profile->path_len - i - 1;
+    BLI_assert(i_reversed >= 0);
+    new_path[i_reversed] = mirror_point(&profile->path[i]);
+    new_path[i_reversed].profile = profile;
+
+    /* Mirror free handles, they can't be recalculated. */
+    if (ELEM(profile->path[i].h1, HD_FREE, HD_ALIGN)) {
+      new_path[i_reversed].h1_loc[0] = profile->path[i].h2_loc[1];
+      new_path[i_reversed].h1_loc[1] = profile->path[i].h2_loc[0];
+    }
+    if (ELEM(profile->path[i].h2, HD_FREE, HD_ALIGN)) {
+      new_path[i_reversed].h2_loc[0] = profile->path[i].h1_loc[1];
+      new_path[i_reversed].h2_loc[1] = profile->path[i].h1_loc[0];
+    }
+  }
+
+  /* Free the old points and use the new ones */
+  MEM_freeN(profile->path);
+  profile->path = new_path;
+}
+
+/**
+ * Builds a quarter circle profile with space on each side for 'support loops.'
+ */
+static void curveprofile_build_supports(CurveProfile *profile)
+{
+  int n = profile->path_len;
+
+  point_init(&profile->path[0], 1.0f, 0.0f, 0, HD_VECT, HD_VECT);
+  point_init(&profile->path[1], 1.0f, 0.5f, 0, HD_VECT, HD_VECT);
+  for (int i = 1; i < n - 2; i++) {
+    const float x = 1.0f - (0.5f * (1.0f - cosf((float)((i / (float)(n - 3))) * M_PI_2)));
+    const float y = 0.5f + 0.5f * sinf((float)((i / (float)(n - 3)) * M_PI_2));
+    point_init(&profile->path[i], x, y, 0, HD_AUTO, HD_AUTO);
+  }
+  point_init(&profile->path[n - 2], 0.5f, 1.0f, 0, HD_VECT, HD_VECT);
+  point_init(&profile->path[n - 1], 0.0f, 1.0f, 0, HD_VECT, HD_VECT);
+}
+
+/**
+ * Puts the widgets control points in a step pattern.
+ * Uses vector handles for each point.
+ */
+static void curveprofile_build_steps(CurveProfile *profile)
+{
+  int n = profile->path_len;
+
+  /* Special case for two points to avoid dividing by zero later. */
+  if (n == 2) {
+    point_init(&profile->path[0], 1.0f, 0.0f, 0, HD_VECT, HD_VECT);
+    point_init(&profile->path[0], 0.0f, 1.0f, 0, HD_VECT, HD_VECT);
+    return;
+  }
+
+  float n_steps_x = (n % 2 == 0) ? n : (n - 1);
+  float n_steps_y = (n % 2 == 0) ? (n - 2) : (n - 1);
+
+  for (int i = 0; i < n; i++) {
+    int step_x = (i + 1) / 2;
+    int step_y = i / 2;
+    const float x = 1.0f - ((float)(2 * step_x) / n_steps_x);
+    const float y = (float)(2 * step_y) / n_steps_y;
+    point_init(&profile->path[i], x, y, 0, HD_VECT, HD_VECT);
+  }
+}
+
+/**
+ * Reset the view to the clipping rectangle.
+ */
+void BKE_curveprofile_reset_view(CurveProfile *profile)
+{
+  profile->view_rect = profile->clip_rect;
+}
+
+/**
+ * Resets the profile to the current preset.
+ *
+ * \note Requires #BKE_curveprofile_update call after.
+ */
+void BKE_curveprofile_reset(CurveProfile *profile)
+{
+  MEM_SAFE_FREE(profile->path);
+
+  eCurveProfilePresets preset = static_cast<eCurveProfilePresets>(profile->preset);
+  switch (preset) {
+    case PROF_PRESET_LINE:
+      profile->path_len = 2;
+      break;
+    case PROF_PRESET_SUPPORTS:
+      /* Use a dynamic number of control points for the widget's profile. */
+      if (profile->segments_len < 4) {
+        /* But always use enough points to at least build the support points. */
+        profile->path_len = 5;
+      }
+      else {
+        profile->path_len = profile->segments_len + 1;
+      }
+      break;
+    case PROF_PRESET_CORNICE:
+      profile->path_len = 13;
+      break;
+    case PROF_PRESET_CROWN:
+      profile->path_len = 11;
+      break;
+    case PROF_PRESET_STEPS:
+      /* Also use dynamic number of control points based on the set number of segments. */
+      if (profile->segments_len == 0) {
+        /* totsegments hasn't been set-- use the number of control points for 8 steps. */
+        profile->path_len = 17;
+      }
+      else {
+        profile->path_len = profile->segments_len + 1;
+      }
+      break;
+  }
+
+  profile->path = (CurveProfilePoint *)MEM_callocN(sizeof(CurveProfilePoint) * profile->path_len,
+                                                   __func__);
+
+  switch (preset) {
+    case PROF_PRESET_LINE:
+      point_init(&profile->path[0], 1.0f, 0.0f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[1], 0.0f, 1.0f, 0, HD_AUTO, HD_AUTO);
+      break;
+    case PROF_PRESET_SUPPORTS:
+      curveprofile_build_supports(profile);
+      break;
+    case PROF_PRESET_CORNICE:
+      point_init(&profile->path[0], 1.0f, 0.0f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[1], 1.0f, 0.125f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[2], 0.92f, 0.16f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[3], 0.875f, 0.25f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[4], 0.8f, 0.25f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[5], 0.733f, 0.433f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[6], 0.582f, 0.522f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[7], 0.4f, 0.6f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[8], 0.289f, 0.727f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[9], 0.25f, 0.925f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[10], 0.175f, 0.925f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[11], 0.175f, 1.0f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[12], 0.0f, 1.0f, 0, HD_VECT, HD_VECT);
+      break;
+    case PROF_PRESET_CROWN:
+      point_init(&profile->path[0], 1.0f, 0.0f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[1], 1.0f, 0.25f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[2], 0.75f, 0.25f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[3], 0.75f, 0.325f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[4], 0.925f, 0.4f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[5], 0.975f, 0.5f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[6], 0.94f, 0.65f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[7], 0.85f, 0.75f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[8], 0.75f, 0.875f, 0, HD_AUTO, HD_AUTO);
+      point_init(&profile->path[9], 0.7f, 1.0f, 0, HD_VECT, HD_VECT);
+      point_init(&profile->path[10], 0.0f, 1.0f, 0, HD_VECT, HD_VECT);
+      break;
+    case PROF_PRESET_STEPS:
+      curveprofile_build_steps(profile);
+      break;
+  }
+
+  profile->flag &= ~PROF_DIRTY_PRESET;
+
+  /* Ensure each point has a reference to the profile. */
+  for (int i = 0; i < profile->path_len; i++) {
+    profile->path[i].profile = profile;
+  }
+
+  MEM_SAFE_FREE(profile->table);
+  profile->table = nullptr;
+}
+
+/**
+ * Helper for 'curve_profile_create' samples.
+ * Returns whether both handles that make up the edge are vector handles.
+ */
+static bool is_curved_edge(CurveProfilePoint *path, int i)
+{
+  return (path[i].h2 != HD_VECT || path[i + 1].h1 != HD_VECT);
+}
+
+/**
+ * Used to set bezier handle locations in the sample creation process. Reduced copy of
+ * #calchandleNurb_intern code in curve.c, mostly changed by removing the third dimension.
+ */
+static void point_calculate_handle(CurveProfilePoint *point,
+                                   const CurveProfilePoint *prev,
+                                   const CurveProfilePoint *next)
+{
+  if (point->h1 == HD_FREE && point->h2 == HD_FREE) {
+    return;
+  }
+
+  float *point_loc = &point->x;
+
+  float pt[2];
+  const float *prev_loc, *next_loc;
+  if (prev == nullptr) {
+    next_loc = &next->x;
+    pt[0] = 2.0f * point_loc[0] - next_loc[0];
+    pt[1] = 2.0f * point_loc[1] - next_loc[1];
+    prev_loc = pt;
+  }
+  else {
+    prev_loc = &prev->x;
+  }
+
+  if (next == nullptr) {
+    prev_loc = &prev->x;
+    pt[0] = 2.0f * point_loc[0] - prev_loc[0];
+    pt[1] = 2.0f * point_loc[1] - prev_loc[1];
+    next_loc = pt;
+  }
+  else {
+    next_loc = &next->x;
+  }
+
+  float dvec_a[2], dvec_b[2];
+  sub_v2_v2v2(dvec_a, point_loc, prev_loc);
+  sub_v2_v2v2(dvec_b, next_loc, point_loc);
+
+  float len_a = len_v2(dvec_a);
+  float len_b = len_v2(dvec_b);
+  if (len_a == 0.0f) {
+    len_a = 1.0f;
+  }
+  if (len_b == 0.0f) {
+    len_b = 1.0f;
+  }
+
+  if (point->h1 == HD_AUTO || point->h2 == HD_AUTO) {
+    float tvec[2];
+    tvec[0] = dvec_b[0] / len_b + dvec_a[0] / len_a;
+    tvec[1] = dvec_b[1] / len_b + dvec_a[1] / len_a;
+
+    float len = len_v2(tvec) * 2.5614f;
+    if (len != 0.0f) {
+      if (point->h1 == HD_AUTO) {
+        len_a /= len;
+        madd_v2_v2v2fl(point->h1_loc, point_loc, tvec, -len_a);
+      }
+      if (point->h2 == HD_AUTO) {
+        len_b /= len;
+        madd_v2_v2v2fl(point->h2_loc, point_loc, tvec, len_b);
+      }
+    }
+  }
+
+  if (point->h1 == HD_VECT) {
+    madd_v2_v2v2fl(point->h1_loc, point_loc, dvec_a, -1.0f / 3.0f);
+  }
+  if (point->h2 == HD_VECT) {
+    madd_v2_v2v2fl(point->h2_loc, point_loc, dvec_b, 1.0f / 3.0f);
+  }
+}
+
+static void calculate_path_handles(CurveProfilePoint *path, int path_len)
+{
+  point_calculate_handle(&path[0], nullptr, &path[1]);
+  for (int i = 1; i < path_len - 1; i++) {
+    point_calculate_handle(&path[i], &path[i - 1], &path[i + 1]);
+  }
+  point_calculate_handle(&path[path_len - 1], &path[path_len - 2], nullptr);
+}
+
+/**
+ * Helper function for 'BKE_curveprofile_create_samples.' Calculates the angle between the
+ * handles on the inside of the edge starting at index i. A larger angle means the edge is
+ * more curved.
+ * \param i_edge: The start index of the edge to calculate the angle for.
+ */
+static float bezt_edge_handle_angle(const CurveProfilePoint *path, int i_edge)
+{
+  /* Find the direction of the handles that define this edge along the direction of the path. */
+  float start_handle_direction[2], end_handle_direction[2];
+  /* Handle 2 - point location. */
+  sub_v2_v2v2(start_handle_direction, path[i_edge].h2_loc, &path[i_edge].x);
+  /* Point location - handle 1. */
+  sub_v2_v2v2(end_handle_direction, &path[i_edge + 1].x, path[i_edge + 1].h1_loc);
+
+  return angle_v2v2(start_handle_direction, end_handle_direction);
+}
+
+/** Struct to sort curvature of control point edges. */
+struct CurvatureSortPoint {
+  /** The index of the corresponding profile point. */
+  int point_index;
+  /** The curvature of the edge with the above index. */
+  float point_curvature;
+};
+
+/**
+ * Helper function for 'BKE_curveprofile_create_samples' for sorting edges based on curvature.
+ */
+static int sort_points_curvature(const void *in_a, const void *in_b)
+{
+  const CurvatureSortPoint *a = (const CurvatureSortPoint *)in_a;
+  const CurvatureSortPoint *b = (const CurvatureSortPoint *)in_b;
+
+  if (a->point_curvature > b->point_curvature) {
+    return 0;
+  }
+
+  return 1;
+}
+
+/**
+ * Used for sampling curves along the profile's path. Any points more than the number of
+ * user-defined points will be evenly distributed among the curved edges.
+ * Then the remainders will be distributed to the most curved edges.
+ *
+ * \param n_segments: The number of segments to sample along the path. Ideally it is higher than
+ * the number of points used to define the profile (profile->path_len).
+ * \param sample_straight_edges: Whether to sample points between vector handle control points.
+ * If this is true and there are only vector edges the straight edges will still be sampled.
+ * \param r_samples: Return array of points to put the sampled positions. Must have length
+ * n_segments. Fill the array with the sampled locations and if the point corresponds to a
+ * control point, its handle type.
+ */
+void BKE_curveprofile_create_samples(CurveProfile *profile,
+                                     int n_segments,
+                                     bool sample_straight_edges,
+                                     CurveProfilePoint *r_samples)
+{
+  CurveProfilePoint *path = profile->path;
+  int totpoints = profile->path_len;
+  BLI_assert(n_segments > 0);
+
+  int totedges = totpoints - 1;
+
+  calculate_path_handles(path, totpoints);
+
+  /* Create a list of edge indices with the most curved at the start, least curved at the end. */
+  CurvatureSortPoint *curve_sorted = (CurvatureSortPoint *)MEM_callocN(
+      sizeof(CurvatureSortPoint) * totedges, __func__);
+  for (int i = 0; i < totedges; i++) {
+    curve_sorted[i].point_index = i;
+    /* Calculate the curvature of each edge once for use when sorting for curvature. */
+    curve_sorted[i].point_curvature = bezt_edge_handle_angle(path, i);
+  }
+  qsort(curve_sorted, totedges, sizeof(CurvatureSortPoint), sort_points_curvature);
+
+  /* Assign the number of sampled points for each edge. */
+  int16_t *n_samples = (int16_t *)MEM_callocN(sizeof(int16_t) * totedges, "samples numbers");
+  int n_added = 0;
+  int n_left;
+  if (n_segments >= totedges) {
+    if (sample_straight_edges) {
+      /* Assign an even number to each edge if it’s possible, then add the remainder of sampled
+       * points starting with the most curved edges. */
+      int n_common = n_segments / totedges;
+      n_left = n_segments % totedges;
+
+      /* Assign the points that fill fit evenly to the edges. */
+      if (n_common > 0) {
+        BLI_assert(n_common < INT16_MAX);
+        for (int i = 0; i < totedges; i++) {
+          n_samples[i] = n_common;
+          n_added += n_common;
+        }
+      }
+    }
+    else {
+      /* Count the number of curved edges */
+      int n_curved_edges = 0;
+      for (int i = 0; i < totedges; i++) {
+        if (is_curved_edge(path, i)) {
+          n_curved_edges++;
+        }
+      }
+      /* Just sample all of the edges if there are no curved edges. */
+      n_curved_edges = (n_curved_edges == 0) ? totedges : n_curved_edges;
+
+      /* Give all of the curved edges the same number of points and straight edges one point. */
+      n_left = n_segments - (totedges - n_curved_edges); /* Left after 1 for each straight edge. */
+      int n_common = n_left / n_curved_edges;            /* Number assigned to all curved edges */
+      if (n_common > 0) {
+        for (int i = 0; i < totedges; i++) {
+          /* Add the common number if it's a curved edge or if edges are curved. */
+          if (is_curved_edge(path, i) || n_curved_edges == totedges) {
+            BLI_assert(n_common + n_samples[i] < INT16_MAX);
+            n_samples[i] += n_common;
+            n_added += n_common;
+          }
+          else {
+            n_samples[i] = 1;
+            n_added++;
+          }
+        }
+      }
+      n_left -= n_common * n_curved_edges;
+    }
+  }
+  else {
+    /* Not enough segments to give one to each edge, so just give them to the most curved edges. */
+    n_left = n_segments;
+  }
+  /* Assign the remainder of the points that couldn't be spread out evenly. */
+  BLI_assert(n_left < totedges);
+  for (int i = 0; i < n_left; i++) {
+    BLI_assert(n_samples[curve_sorted[i].point_index] < INT16_MAX);
+    n_samples[curve_sorted[i].point_index]++;
+    n_added++;
+  }
+
+  BLI_assert(n_added == n_segments); /* n_added is just used for this assert, could remove it. */
+
+  /* Sample the points and add them to the locations table. */
+  for (int i_sample = 0, i = 0; i < totedges; i++) {
+    if (n_samples[i] > 0) {
+      /* Carry over the handle types from the control point to its first corresponding sample. */
+      r_samples[i_sample].h1 = path[i].h1;
+      r_samples[i_sample].h2 = path[i].h2;
+      /* All extra sample points for this control point get "auto" handles. */
+      for (int j = i_sample + 1; j < i_sample + n_samples[i]; j++) {
+        r_samples[j].flag = 0;
+        r_samples[j].h1 = HD_AUTO;
+        r_samples[j].h2 = HD_AUTO;
+        BLI_assert(j < n_segments);
+      }
+
+      /* Sample from the bezier points. X then Y values. */
+      BKE_curve_forward_diff_bezier(path[i].x,
+                                    path[i].h2_loc[0],
+                                    path[i + 1].h1_loc[0],
+                                    path[i + 1].x,
+                                    &r_samples[i_sample].x,
+                                    n_samples[i],
+                                    sizeof(CurveProfilePoint));
+      BKE_curve_forward_diff_bezier(path[i].y,
+                                    path[i].h2_loc[1],
+                                    path[i + 1].h1_loc[1],
+                                    path[i + 1].y,
+                                    &r_samples[i_sample].y,
+                                    n_samples[i],
+                                    sizeof(CurveProfilePoint));
+    }
+    i_sample += n_samples[i]; /* Add the next set of points after the ones we just added. */
+    BLI_assert(i_sample <= n_segments);
+  }
+
+  MEM_freeN(curve_sorted);
+  MEM_freeN(n_samples);
+}
+
+/**
+ * Creates a higher resolution table by sampling the curved points.
+ * This table is used for display and evenly spaced evaluation.
+ */
+static void curveprofile_make_table(CurveProfile *profile)
+{
+  int n_samples = PROF_TABLE_LEN(profile->path_len);
+  CurveProfilePoint *new_table = (CurveProfilePoint *)MEM_callocN(
+      sizeof(CurveProfilePoint) * (n_samples + 1), __func__);
+
+  BKE_curveprofile_create_samples(profile, n_samples - 1, false, new_table);
+  /* Manually add last point at the end of the profile */
+  new_table[n_samples - 1].x = 0.0f;
+  new_table[n_samples - 1].y = 1.0f;
+
+  MEM_SAFE_FREE(profile->table);
+  profile->table = new_table;
+}
+
+/**
+ * Creates the table of points used for displaying a preview of the sampled segment locations on
+ * the widget itself.
+ */
+static void curveprofile_make_segments_table(CurveProfile *profile)
+{
+  int n_samples = profile->segments_len;
+  if (n_samples <= 0) {
+    return;
+  }
+  CurveProfilePoint *new_table = (CurveProfilePoint *)MEM_callocN(
+      sizeof(CurveProfilePoint) * (n_samples + 1), __func__);
+
+  if (profile->flag & PROF_SAMPLE_EVEN_LENGTHS) {
+    /* Even length sampling incompatible with only straight edge sampling for now. */
+    BKE_curveprofile_create_samples_even_spacing(profile, n_samples, new_table);
+  }
+  else {
+    BKE_curveprofile_create_samples(
+        profile, n_samples, profile->flag & PROF_SAMPLE_STRAIGHT_EDGES, new_table);
+  }
+
+  MEM_SAFE_FREE(profile->segments);
+  profile->segments = new_table;
+}
+
+/**
+ * Sets the default settings and clip range for the profile widget.
+ * Does not generate either table.
+ */
+void BKE_curveprofile_set_defaults(CurveProfile *profile)
+{
+  profile->flag = PROF_USE_CLIP;
+
+  BLI_rctf_init(&profile->view_rect, 0.0f, 1.0f, 0.0f, 1.0f);
+  profile->clip_rect = profile->view_rect;
+
+  profile->path_len = 2;
+  profile->path = (CurveProfilePoint *)MEM_callocN(2 * sizeof(CurveProfilePoint), __func__);
+
+  profile->path[0].x = 1.0f;
+  profile->path[0].y = 0.0f;
+  profile->path[0].profile = profile;
+  profile->path[1].x = 1.0f;
+  profile->path[1].y = 1.0f;
+  profile->path[1].profile = profile;
+
+  profile->changed_timestamp = 0;
+}
+
+/**
+ * Returns a pointer to a newly allocated curve profile, using the given preset.
+ */
+struct CurveProfile *BKE_curveprofile_add(eCurveProfilePresets preset)
+{
+  CurveProfile *profile = (CurveProfile *)MEM_callocN(sizeof(CurveProfile), __func__);
+
+  BKE_curveprofile_set_defaults(profile);
+  profile->preset = preset;
+  BKE_curveprofile_reset(profile);
+  curveprofile_make_table(profile);
+
+  return profile;
+}
+
+/**
+ * Should be called after the widget is changed. Does profile and remove double checks and more
+ * importantly, recreates the display / evaluation and segments tables.
+ * \param update_flags: Bitfield with fields defined in header file. Controls removing doubles and
+ * clipping.
+ */
+void BKE_curveprofile_update(CurveProfile *profile, const int update_flags)
+{
+  CurveProfilePoint *points = profile->path;
+  rctf *clipr = &profile->clip_rect;
+
+  profile->changed_timestamp++;
+
+  /* Clamp with the clipping rect in case something got past. */
+  if (profile->flag & PROF_USE_CLIP) {
+    /* Move points inside the clip rectangle. */
+    if (update_flags & PROF_UPDATE_CLIP) {
+      for (int i = 0; i < profile->path_len; i++) {
+        points[i].x = clamp_f(points[i].x, clipr->xmin, clipr->xmax);
+        points[i].y = clamp_f(points[i].y, clipr->ymin, clipr->ymax);
+
+        /* Extra sanity assert to make sure the points have the right profile pointer. */
+        BLI_assert(points[i].profile == profile);
+      }
+    }
+    /* Ensure zoom-level respects clipping. */
+    if (BLI_rctf_size_x(&profile->view_rect) > BLI_rctf_size_x(&profile->clip_rect)) {
+      profile->view_rect.xmin = profile->clip_rect.xmin;
+      profile->view_rect.xmax = profile->clip_rect.xmax;
+    }
+    if (BLI_rctf_size_y(&profile->view_rect) > BLI_rctf_size_y(&profile->clip_rect)) {
+      profile->view_rect.ymin = profile->clip_rect.ymin;
+      profile->view_rect.ymax = profile->clip_rect.ymax;
+    }
+  }
+
+  /* Remove doubles with a threshold set at 1% of default range. */
+  float thresh = pow2f(0.01f * BLI_rctf_size_x(clipr));
+  if (update_flags & PROF_UPDATE_REMOVE_DOUBLES && profile->path_len > 2) {
+    for (int i = 0; i < profile->path_len - 1; i++) {
+      if (len_squared_v2v2(&points[i].x, &points[i + 1].x) < thresh) {
+        if (i == 0) {
+          BKE_curveprofile_remove_point(profile, &points[1]);
+        }
+        else {
+          BKE_curveprofile_remove_point(profile, &points[i]);
+        }
+        break; /* Assumes 1 deletion per update call is ok. */
+      }
+    }
+  }
+
+  /* Create the high resolution table for drawing and some evaluation functions. */
+  curveprofile_make_table(profile);
+
+  /* Store a table of samples for the segment locations for a preview and the table's user. */
+  if (profile->segments_len > 0) {
+    curveprofile_make_segments_table(profile);
+  }
+}
+
+/**
+ * Refreshes the higher resolution table sampled from the input points. A call to this or
+ * #BKE_curveprofile_update is needed before evaluation functions that use the table.
+ * Also sets the number of segments used for the display preview of the locations
+ * of the sampled points.
+ */
+void BKE_curveprofile_init(CurveProfile *profile, short segments_len)
+{
+  if (segments_len != profile->segments_len) {
+    profile->flag |= PROF_DIRTY_PRESET;
+  }
+  profile->segments_len = segments_len;
+
+  /* Calculate the higher resolution / segments tables for display and evaluation. */
+  BKE_curveprofile_update(profile, PROF_UPDATE_NONE);
+}
+
+/**
+ * Gives the distance to the next point in the widgets sampled table, in other words the length
+ * of the \a 'i' edge of the table.
+ *
+ * \note Requires #BKE_curveprofile_init or #BKE_curveprofile_update call before to fill table.
+ */
+static float curveprofile_distance_to_next_table_point(const CurveProfile *profile, int i)
+{
+  BLI_assert(i < PROF_TABLE_LEN(profile->path_len));
+
+  return len_v2v2(&profile->table[i].x, &profile->table[i + 1].x);
+}
+
+/**
+ * Calculates the total length of the profile from the curves sampled in the table.
+ *
+ * \note Requires #BKE_curveprofile_init or #BKE_curveprofile_update call before to fill table.
+ */
+float BKE_curveprofile_total_length(const CurveProfile *profile)
+{
+  float total_length = 0;
+  for (int i = 0; i < PROF_TABLE_LEN(profile->path_len) - 1; i++) {
+    total_length += len_v2v2(&profile->table[i].x, &profile->table[i + 1].x);
+  }
+  return total_length;
+}
+
+/**
+ * Samples evenly spaced positions along the curve profile's table (generated from path). Fills
+ * an entire table at once for a speedup if all of the results are going to be used anyway.
+ *
+ * \note Requires #BKE_curveprofile_init or #BKE_curveprofile_update call before to fill table.
+ * \note Working, but would conflict with "Sample Straight Edges" option, so this is unused for
+ * now.
+ */
+void BKE_curveprofile_create_samples_even_spacing(CurveProfile *profile,
+                                                  int n_segments,
+                                                  CurveProfilePoint *r_samples)
+{
+  const float total_length = BKE_curveprofile_total_length(profile);
+  const float segment_length = total_length / n_segments;
+  float distance_to_next_table_point = curveprofile_distance_to_next_table_point(profile, 0);
+  float distance_to_previous_table_point = 0.0f;
+  int i_table = 0;
+
+  /* Set the location for the first point. */
+  r_samples[0].x = profile->table[0].x;
+  r_samples[0].y = profile->table[0].y;
+
+  /* Travel along the path, recording the locations of segments as we pass them. */
+  float segment_left = segment_length;
+  for (int i = 1; i < n_segments; i++) {
+    /* Travel over all of the points that fit inside this segment. */
+    while (distance_to_next_table_point < segment_left) {
+      segment_left -= distance_to_next_table_point;
+      i_table++;
+      distance_to_next_table_point = curveprofile_distance_to_next_table_point(profile, i_table);
+      distance_to_previous_table_point = 0.0f;
+    }
+    /* We're at the last table point that fits inside the current segment, use interpolation. */
+    float factor = (distance_to_previous_table_point + segment_left) /
+                   (distance_to_previous_table_point + distance_to_next_table_point);
+    r_samples[i].x = interpf(profile->table[i_table + 1].x, profile->table[i_table].x, factor);
+    r_samples[i].y = interpf(profile->table[i_table + 1].y, profile->table[i_table].y, factor);
+    BLI_assert(factor <= 1.0f && factor >= 0.0f);
+#ifdef DEBUG_CURVEPROFILE_EVALUATE
+    printf("segment_left: %.3f\n", segment_left);
+    printf("i_table: %d\n", i_table);
+    printf("distance_to_previous_table_point: %.3f\n", distance_to_previous_table_point);
+    printf("distance_to_next_table_point: %.3f\n", distance_to_next_table_point);
+    printf("Interpolating with factor %.3f from (%.3f, %.3f) to (%.3f, %.3f)\n\n",
+           factor,
+           profile->table[i_table].x,
+           profile->table[i_table].y,
+           profile->table[i_table + 1].x,
+           profile->table[i_table + 1].y);
+#endif
+
+    /* We sampled in between this table point and the next, so the next travel step is smaller. */
+    distance_to_next_table_point -= segment_left;
+    distance_to_previous_table_point += segment_left;
+    segment_left = segment_length;
+  }
+}
+
+/**
+ * Does a single evaluation along the profile's path.
+ * Travels down (length_portion * path) length and returns the position at that point.
+ *
+ * \param length_portion: The portion (0 to 1) of the path's full length to sample at.
+ * \note Requires #BKE_curveprofile_init or #BKE_curveprofile_update call before to fill table.
+ */
+void BKE_curveprofile_evaluate_length_portion(const CurveProfile *profile,
+                                              float length_portion,
+                                              float *x_out,
+                                              float *y_out)
+{
+  const float total_length = BKE_curveprofile_total_length(profile);
+  const float requested_length = length_portion * total_length;
+
+  /* Find the last point along the path with a lower length portion than the input. */
+  int i = 0;
+  float length_travelled = 0.0f;
+  while (length_travelled < requested_length) {
+    /* Check if we reached the last point before the final one. */
+    if (i == PROF_TABLE_LEN(profile->path_len) - 2) {
+      break;
+    }
+    float new_length = curveprofile_distance_to_next_table_point(profile, i);
+    if (length_travelled + new_length >= requested_length) {
+      break;
+    }
+    length_travelled += new_length;
+    i++;
+  }
+
+  /* Now travel the remaining distance of length portion down the path to the next point and
+   * find the location where we stop. */
+  float distance_to_next_point = curveprofile_distance_to_next_table_point(profile, i);
+  float lerp_factor = (requested_length - length_travelled) / distance_to_next_point;
+
+#ifdef DEBUG_CURVEPROFILE_EVALUATE
+  printf("CURVEPROFILE EVALUATE\n");
+  printf("  length portion input: %f\n", (double)length_portion);
+  printf("  requested path length: %f\n", (double)requested_length);
+  printf("  distance to next point: %f\n", (double)distance_to_next_point);
+  printf("  length travelled: %f\n", (double)length_travelled);
+  printf("  lerp-factor: %f\n", (double)lerp_factor);
+  printf("  ith point (%f, %f)\n", (double)profile->path[i].x, (double)profile->path[i].y);
+  printf("  next point(%f, %f)\n", (double)profile->path[i + 1].x, (double)profile->path[i + 1].y);
+#endif
+
+  *x_out = interpf(profile->table[i].x, profile->table[i + 1].x, lerp_factor);
+  *y_out = interpf(profile->table[i].y, profile->table[i + 1].y, lerp_factor);
+}
+
+void BKE_curveprofile_blend_write(struct BlendWriter *writer, const struct CurveProfile *profile)
+{
+  BLO_write_struct(writer, CurveProfile, profile);
+  BLO_write_struct_array(writer, CurveProfilePoint, profile->path_len, profile->path);
+}
+
+/* Expects that the curve profile itself has been read already. */
+void BKE_curveprofile_blend_read(struct BlendDataReader *reader, struct CurveProfile *profile)
+{
+  BLO_read_data_address(reader, &profile->path);
+  profile->table = nullptr;
+  profile->segments = nullptr;
+
+  /* Reset the points' pointers to the profile. */
+  for (int i = 0; i < profile->path_len; i++) {
+    profile->path[i].profile = profile;
+  }
+
+  BKE_curveprofile_init(profile, profile->segments_len);
+}