blender-archive/source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp

/*
 * 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.
 */

/** \file
 * \ingroup freestyle
 */

#include <iostream>
#include <map>
#include <set>

#include "../application/AppCanvas.h"
#include "../application/AppConfig.h"
#include "../application/AppView.h"
#include "../application/Controller.h"

#include "BlenderStrokeRenderer.h"

using namespace std;
using namespace Freestyle;

#include "MEM_guardedalloc.h"

#include "DNA_camera_types.h"
#include "DNA_collection_types.h"
#include "DNA_freestyle_types.h"
#include "DNA_material_types.h"
#include "DNA_text_types.h"

#include "BKE_callbacks.h"
#include "BKE_context.h"
#include "BKE_freestyle.h"
#include "BKE_global.h"
#include "BKE_lib_id.h"
#include "BKE_linestyle.h"
#include "BKE_scene.h"
#include "BKE_text.h"

#include "BLT_translation.h"

#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_math_color_blend.h"

#include "BPY_extern.h"

#include "DEG_depsgraph_query.h"

#include "pipeline.h"

#include "FRS_freestyle.h"

extern "C" {

#define DEFAULT_SPHERE_RADIUS 1.0f
#define DEFAULT_DKR_EPSILON 0.0f

struct FreestyleGlobals g_freestyle;

// Freestyle configuration
static bool freestyle_is_initialized = false;
static Config::Path *pathconfig = nullptr;
static Controller *controller = nullptr;
static AppView *view = nullptr;

// line set buffer for copy & paste
static FreestyleLineSet lineset_buffer;
static bool lineset_copied = false;

static void load_post_callback(struct Main * /*main*/,
                               struct PointerRNA ** /*pointers*/,
                               const int /*num_pointers*/,
                               void * /*arg*/)
{
  lineset_copied = false;
}

static bCallbackFuncStore load_post_callback_funcstore = {
    nullptr,
    nullptr,            /* next, prev */
    load_post_callback, /* func */
    nullptr,            /* arg */
    0                   /* alloc */
};

//=======================================================
//   Initialization
//=======================================================

void FRS_init()
{
  if (freestyle_is_initialized) {
    return;
  }

  pathconfig = new Config::Path;
  controller = new Controller();
  view = new AppView;
  controller->setView(view);
  controller->Clear();
  g_freestyle.scene = nullptr;
  lineset_copied = false;

  BKE_callback_add(&load_post_callback_funcstore, BKE_CB_EVT_LOAD_POST);

  freestyle_is_initialized = true;
}

void FRS_set_context(bContext *C)
{
  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << "FRS_set_context: context 0x" << C << " scene 0x" << CTX_data_scene(C) << endl;
  }
  controller->setContext(C);
}

void FRS_exit()
{
  delete pathconfig;
  delete controller;
  delete view;
}

//=======================================================
//   Rendering
//=======================================================

static void init_view(Render *re)
{
  int width = re->winx;
  int height = re->winy;
  int xmin = re->disprect.xmin;
  int ymin = re->disprect.ymin;
  int xmax = re->disprect.xmax;
  int ymax = re->disprect.ymax;

  float thickness = 1.0f;
  switch (re->r.line_thickness_mode) {
    case R_LINE_THICKNESS_ABSOLUTE:
      thickness = re->r.unit_line_thickness * (re->r.size / 100.0f);
      break;
    case R_LINE_THICKNESS_RELATIVE:
      thickness = height / 480.0f;
      break;
  }

  g_freestyle.viewport[0] = g_freestyle.viewport[1] = 0;
  g_freestyle.viewport[2] = width;
  g_freestyle.viewport[3] = height;

  view->setWidth(width);
  view->setHeight(height);
  view->setBorder(xmin, ymin, xmax, ymax);
  view->setThickness(thickness);

  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << "\n===  Dimensions of the 2D image coordinate system  ===" << endl;
    cout << "Width  : " << width << endl;
    cout << "Height : " << height << endl;
    if (re->r.mode & R_BORDER) {
      cout << "Border : (" << xmin << ", " << ymin << ") - (" << xmax << ", " << ymax << ")"
           << endl;
    }
    cout << "Unit line thickness : " << thickness << " pixel(s)" << endl;
  }
}

static char *escape_quotes(char *name)
{
  char *s = (char *)MEM_mallocN(strlen(name) * 2 + 1, "escape_quotes");
  char *p = s;
  while (*name) {
    if (*name == '\'') {
      *(p++) = '\\';
    }
    *(p++) = *(name++);
  }
  *p = '\0';
  return s;
}

static char *create_lineset_handler(char *layer_name, char *lineset_name)
{
  const char *fmt = "__import__('parameter_editor').process('%s', '%s')\n";
  char *s1 = escape_quotes(layer_name);
  char *s2 = escape_quotes(lineset_name);
  char *text = BLI_sprintfN(fmt, s1, s2);
  MEM_freeN(s1);
  MEM_freeN(s2);
  return text;
}

struct edge_type_condition {
  int edge_type, value;
};

// examines the conditions and returns true if the target edge type needs to be computed
static bool test_edge_type_conditions(struct edge_type_condition *conditions,
                                      int num_edge_types,
                                      bool logical_and,
                                      int target,
                                      bool distinct)
{
  int target_condition = 0;
  int num_non_target_positive_conditions = 0;
  int num_non_target_negative_conditions = 0;

  for (int i = 0; i < num_edge_types; i++) {
    if (conditions[i].edge_type == target) {
      target_condition = conditions[i].value;
    }
    else if (conditions[i].value > 0) {
      ++num_non_target_positive_conditions;
    }
    else if (conditions[i].value < 0) {
      ++num_non_target_negative_conditions;
    }
  }
  if (distinct) {
    // In this case, the 'target' edge type is assumed to appear on distinct edge
    // of its own and never together with other edge types.
    if (logical_and) {
      if (num_non_target_positive_conditions > 0) {
        return false;
      }
      if (target_condition > 0) {
        return true;
      }
      if (target_condition < 0) {
        return false;
      }
      if (num_non_target_negative_conditions > 0) {
        return true;
      }
    }
    else {
      if (target_condition > 0) {
        return true;
      }
      if (num_non_target_negative_conditions > 0) {
        return true;
      }
      if (target_condition < 0) {
        return false;
      }
      if (num_non_target_positive_conditions > 0) {
        return false;
      }
    }
  }
  else {
    // In this case, the 'target' edge type may appear together with other edge types.
    if (target_condition > 0) {
      return true;
    }
    if (target_condition < 0) {
      return true;
    }
    if (logical_and) {
      if (num_non_target_positive_conditions > 0) {
        return false;
      }
      if (num_non_target_negative_conditions > 0) {
        return true;
      }
    }
    else {
      if (num_non_target_negative_conditions > 0) {
        return true;
      }
      if (num_non_target_positive_conditions > 0) {
        return false;
      }
    }
  }
  return true;
}

static void prepare(Render *re, ViewLayer *view_layer, Depsgraph *depsgraph)
{
  // load mesh
  re->i.infostr = TIP_("Freestyle: Mesh loading");
  re->stats_draw(re->sdh, &re->i);
  re->i.infostr = nullptr;
  if (controller->LoadMesh(
          re, view_layer, depsgraph)) {  // returns if scene cannot be loaded or if empty
    return;
  }
  if (re->test_break(re->tbh)) {
    return;
  }

  // add style modules
  FreestyleConfig *config = &view_layer->freestyle_config;

  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << "\n===  Rendering options  ===" << endl;
  }
  int layer_count = 0;

  switch (config->mode) {
    case FREESTYLE_CONTROL_SCRIPT_MODE:
      if (G.debug & G_DEBUG_FREESTYLE) {
        cout << "Modules :" << endl;
      }
      for (FreestyleModuleConfig *module_conf = (FreestyleModuleConfig *)config->modules.first;
           module_conf;
           module_conf = module_conf->next) {
        if (module_conf->script && module_conf->is_displayed) {
          const char *id_name = module_conf->script->id.name + 2;
          if (G.debug & G_DEBUG_FREESTYLE) {
            cout << "  " << layer_count + 1 << ": " << id_name;
            if (module_conf->script->filepath) {
              cout << " (" << module_conf->script->filepath << ")";
            }
            cout << endl;
          }
          controller->InsertStyleModule(layer_count, id_name, module_conf->script);
          controller->toggleLayer(layer_count, true);
          layer_count++;
        }
      }
      if (G.debug & G_DEBUG_FREESTYLE) {
        cout << endl;
      }
      controller->setComputeRidgesAndValleysFlag(
          (config->flags & FREESTYLE_RIDGES_AND_VALLEYS_FLAG) ? true : false);
      controller->setComputeSuggestiveContoursFlag(
          (config->flags & FREESTYLE_SUGGESTIVE_CONTOURS_FLAG) ? true : false);
      controller->setComputeMaterialBoundariesFlag(
          (config->flags & FREESTYLE_MATERIAL_BOUNDARIES_FLAG) ? true : false);
      break;
    case FREESTYLE_CONTROL_EDITOR_MODE:
      int use_ridges_and_valleys = 0;
      int use_suggestive_contours = 0;
      int use_material_boundaries = 0;
      struct edge_type_condition conditions[] = {
          {FREESTYLE_FE_SILHOUETTE, 0},
          {FREESTYLE_FE_BORDER, 0},
          {FREESTYLE_FE_CREASE, 0},
          {FREESTYLE_FE_RIDGE_VALLEY, 0},
          {FREESTYLE_FE_SUGGESTIVE_CONTOUR, 0},
          {FREESTYLE_FE_MATERIAL_BOUNDARY, 0},
          {FREESTYLE_FE_CONTOUR, 0},
          {FREESTYLE_FE_EXTERNAL_CONTOUR, 0},
          {FREESTYLE_FE_EDGE_MARK, 0},
      };
      int num_edge_types = ARRAY_SIZE(conditions);
      if (G.debug & G_DEBUG_FREESTYLE) {
        cout << "Linesets:" << endl;
      }
      for (FreestyleLineSet *lineset = (FreestyleLineSet *)config->linesets.first; lineset;
           lineset = lineset->next) {
        if (lineset->flags & FREESTYLE_LINESET_ENABLED) {
          if (G.debug & G_DEBUG_FREESTYLE) {
            cout << "  " << layer_count + 1 << ": " << lineset->name << " - "
                 << (lineset->linestyle ? (lineset->linestyle->id.name + 2) : "<NULL>") << endl;
          }
          char *buffer = create_lineset_handler(view_layer->name, lineset->name);
          controller->InsertStyleModule(layer_count, lineset->name, buffer);
          controller->toggleLayer(layer_count, true);
          MEM_freeN(buffer);
          if (!(lineset->selection & FREESTYLE_SEL_EDGE_TYPES) || !lineset->edge_types) {
            ++use_ridges_and_valleys;
            ++use_suggestive_contours;
            ++use_material_boundaries;
          }
          else {
            // conditions for feature edge selection by edge types
            for (int i = 0; i < num_edge_types; i++) {
              if (!(lineset->edge_types & conditions[i].edge_type)) {
                conditions[i].value = 0;  // no condition specified
              }
              else if (!(lineset->exclude_edge_types & conditions[i].edge_type)) {
                conditions[i].value = 1;  // condition: X
              }
              else {
                conditions[i].value = -1;  // condition: NOT X
              }
            }
            // logical operator for the selection conditions
            bool logical_and = ((lineset->flags & FREESTYLE_LINESET_FE_AND) != 0);
            // negation operator
            if (lineset->flags & FREESTYLE_LINESET_FE_NOT) {
              // convert an Exclusive condition into an
              // Inclusive equivalent using De Morgan's laws:
              // - NOT (X OR Y) --> (NOT X) AND (NOT Y)
              // - NOT (X AND Y) --> (NOT X) OR (NOT Y)
              for (int i = 0; i < num_edge_types; i++) {
                conditions[i].value *= -1;
              }
              logical_and = !logical_and;
            }
            if (test_edge_type_conditions(
                    conditions, num_edge_types, logical_and, FREESTYLE_FE_RIDGE_VALLEY, true)) {
              ++use_ridges_and_valleys;
            }
            if (test_edge_type_conditions(conditions,
                                          num_edge_types,
                                          logical_and,
                                          FREESTYLE_FE_SUGGESTIVE_CONTOUR,
                                          true)) {
              ++use_suggestive_contours;
            }
            if (test_edge_type_conditions(conditions,
                                          num_edge_types,
                                          logical_and,
                                          FREESTYLE_FE_MATERIAL_BOUNDARY,
                                          true)) {
              ++use_material_boundaries;
            }
          }
          layer_count++;
        }
      }
      controller->setComputeRidgesAndValleysFlag(use_ridges_and_valleys > 0);
      controller->setComputeSuggestiveContoursFlag(use_suggestive_contours > 0);
      controller->setComputeMaterialBoundariesFlag(use_material_boundaries > 0);
      break;
  }

  // set parameters
  if (config->flags & FREESTYLE_ADVANCED_OPTIONS_FLAG) {
    controller->setSphereRadius(config->sphere_radius);
    controller->setSuggestiveContourKrDerivativeEpsilon(config->dkr_epsilon);
  }
  else {
    controller->setSphereRadius(DEFAULT_SPHERE_RADIUS);
    controller->setSuggestiveContourKrDerivativeEpsilon(DEFAULT_DKR_EPSILON);
  }
  controller->setFaceSmoothness((config->flags & FREESTYLE_FACE_SMOOTHNESS_FLAG) ? true : false);
  controller->setCreaseAngle(RAD2DEGF(config->crease_angle));
  controller->setVisibilityAlgo((config->flags & FREESTYLE_CULLING) ?
                                    FREESTYLE_ALGO_CULLED_ADAPTIVE_CUMULATIVE :
                                    FREESTYLE_ALGO_ADAPTIVE_CUMULATIVE);

  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << "Crease angle : " << controller->getCreaseAngle() << endl;
    cout << "Sphere radius : " << controller->getSphereRadius() << endl;
    cout << "Face smoothness : " << (controller->getFaceSmoothness() ? "enabled" : "disabled")
         << endl;
    cout << "Ridges and valleys : "
         << (controller->getComputeRidgesAndValleysFlag() ? "enabled" : "disabled") << endl;
    cout << "Suggestive contours : "
         << (controller->getComputeSuggestiveContoursFlag() ? "enabled" : "disabled") << endl;
    cout << "Suggestive contour Kr derivative epsilon : "
         << controller->getSuggestiveContourKrDerivativeEpsilon() << endl;
    cout << "Material boundaries : "
         << (controller->getComputeMaterialBoundariesFlag() ? "enabled" : "disabled") << endl;
    cout << endl;
  }

  // set diffuse and z depth passes
  RenderLayer *rl = RE_GetRenderLayer(re->result, view_layer->name);
  bool diffuse = false, z = false;
  for (RenderPass *rpass = (RenderPass *)rl->passes.first; rpass; rpass = rpass->next) {
    if (STREQ(rpass->name, RE_PASSNAME_DIFFUSE_COLOR)) {
      controller->setPassDiffuse(rpass->rect, rpass->rectx, rpass->recty);
      diffuse = true;
    }
    if (STREQ(rpass->name, RE_PASSNAME_Z)) {
      controller->setPassZ(rpass->rect, rpass->rectx, rpass->recty);
      z = true;
    }
  }
  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << "Passes :" << endl;
    cout << "  Diffuse = " << (diffuse ? "enabled" : "disabled") << endl;
    cout << "  Z = " << (z ? "enabled" : "disabled") << endl;
  }

  if (controller->hitViewMapCache()) {
    return;
  }

  // compute view map
  re->i.infostr = TIP_("Freestyle: View map creation");
  re->stats_draw(re->sdh, &re->i);
  re->i.infostr = nullptr;
  controller->ComputeViewMap();
}

void FRS_composite_result(Render *re, ViewLayer *view_layer, Render *freestyle_render)
{
  RenderLayer *rl;
  float *src, *dest, *pixSrc, *pixDest;
  int x, y, rectx, recty;

  if (freestyle_render == nullptr || freestyle_render->result == nullptr) {
    if (view_layer->freestyle_config.flags & FREESTYLE_AS_RENDER_PASS) {
      // Create a blank render pass output.
      RE_create_render_pass(
          re->result, RE_PASSNAME_FREESTYLE, 4, "RGBA", view_layer->name, re->viewname);
    }
    return;
  }

  rl = render_get_active_layer(freestyle_render, freestyle_render->result);
  if (!rl) {
    if (G.debug & G_DEBUG_FREESTYLE) {
      cout << "No source render layer to composite" << endl;
    }
    return;
  }

  src = RE_RenderLayerGetPass(rl, RE_PASSNAME_COMBINED, freestyle_render->viewname);
  if (!src) {
    if (G.debug & G_DEBUG_FREESTYLE) {
      cout << "No source result image to composite" << endl;
    }
    return;
  }
#if 0
  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << "src: " << rl->rectx << " x " << rl->recty << endl;
  }
#endif

  rl = RE_GetRenderLayer(re->result, view_layer->name);
  if (!rl) {
    if (G.debug & G_DEBUG_FREESTYLE) {
      cout << "No destination render layer to composite to" << endl;
    }
    return;
  }

  if (view_layer->freestyle_config.flags & FREESTYLE_AS_RENDER_PASS) {
    RE_create_render_pass(
        re->result, RE_PASSNAME_FREESTYLE, 4, "RGBA", view_layer->name, re->viewname);
    dest = RE_RenderLayerGetPass(rl, RE_PASSNAME_FREESTYLE, re->viewname);
  }
  else {
    dest = RE_RenderLayerGetPass(rl, RE_PASSNAME_COMBINED, re->viewname);
  }
  if (!dest) {
    if (G.debug & G_DEBUG_FREESTYLE) {
      cout << "No destination result image to composite to" << endl;
    }
    return;
  }
#if 0
  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << "dest: " << rl->rectx << " x " << rl->recty << endl;
  }
#endif

  rectx = re->rectx;
  recty = re->recty;
  for (y = 0; y < recty; y++) {
    for (x = 0; x < rectx; x++) {
      pixSrc = src + 4 * (rectx * y + x);
      if (pixSrc[3] > 0.0) {
        pixDest = dest + 4 * (rectx * y + x);
        blend_color_mix_float(pixDest, pixDest, pixSrc);
      }
    }
  }
}

static int displayed_layer_count(ViewLayer *view_layer)
{
  int count = 0;

  switch (view_layer->freestyle_config.mode) {
    case FREESTYLE_CONTROL_SCRIPT_MODE:
      for (FreestyleModuleConfig *module =
               (FreestyleModuleConfig *)view_layer->freestyle_config.modules.first;
           module;
           module = module->next) {
        if (module->script && module->is_displayed) {
          count++;
        }
      }
      break;
    case FREESTYLE_CONTROL_EDITOR_MODE:
      for (FreestyleLineSet *lineset =
               (FreestyleLineSet *)view_layer->freestyle_config.linesets.first;
           lineset;
           lineset = lineset->next) {
        if (lineset->flags & FREESTYLE_LINESET_ENABLED) {
          count++;
        }
      }
      break;
  }
  return count;
}

int FRS_is_freestyle_enabled(ViewLayer *view_layer)
{
  return ((view_layer->flag & VIEW_LAYER_RENDER) && (view_layer->flag & VIEW_LAYER_FREESTYLE) &&
          displayed_layer_count(view_layer) > 0);
}

void FRS_init_stroke_renderer(Render *re)
{
  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << endl;
    cout << "#===============================================================" << endl;
    cout << "#  Freestyle" << endl;
    cout << "#===============================================================" << endl;
  }

  init_view(re);

  controller->ResetRenderCount();
}

void FRS_begin_stroke_rendering(Render *UNUSED(re))
{
}

void FRS_do_stroke_rendering(Render *re, ViewLayer *view_layer)
{
  RenderMonitor monitor(re);
  controller->setRenderMonitor(&monitor);
  controller->setViewMapCache(
      (view_layer->freestyle_config.flags & FREESTYLE_VIEW_MAP_CACHE) ? true : false);

  if (G.debug & G_DEBUG_FREESTYLE) {
    cout << endl;
    cout << "----------------------------------------------------------" << endl;
    cout << "|  " << (re->scene->id.name + 2) << "|" << view_layer->name << endl;
    cout << "----------------------------------------------------------" << endl;
  }

  /* Create depsgraph and evaluate scene. */
  ViewLayer *scene_view_layer = (ViewLayer *)BLI_findstring(
      &re->scene->view_layers, view_layer->name, offsetof(ViewLayer, name));
  Depsgraph *depsgraph = DEG_graph_new(re->main, re->scene, scene_view_layer, DAG_EVAL_RENDER);
  BKE_scene_graph_update_for_newframe(depsgraph);

  /* Init camera
   * Objects are transformed into camera coordinate system, therefore the camera position
   * is zero and the modelview matrix is the identity matrix. */
  Object *ob_camera_orig = RE_GetCamera(re);
  Object *ob_camera_eval = DEG_get_evaluated_object(depsgraph, ob_camera_orig);
  zero_v3(g_freestyle.viewpoint);
  unit_m4(g_freestyle.mv);
  RE_GetCameraWindow(re, ob_camera_eval, g_freestyle.proj);

  // prepare Freestyle:
  //   - load mesh
  //   - add style modules
  //   - set parameters
  //   - compute view map
  prepare(re, view_layer, depsgraph);

  if (re->test_break(re->tbh)) {
    controller->CloseFile();
    if (G.debug & G_DEBUG_FREESTYLE) {
      cout << "Break" << endl;
    }
  }
  else {
    // render and composite Freestyle result
    if (controller->_ViewMap) {
      // render strokes
      re->i.infostr = TIP_("Freestyle: Stroke rendering");
      re->stats_draw(re->sdh, &re->i);
      re->i.infostr = nullptr;
      g_freestyle.scene = DEG_get_evaluated_scene(depsgraph);
      int strokeCount = controller->DrawStrokes();
      Render *freestyle_render = nullptr;
      if (strokeCount > 0) {
        freestyle_render = controller->RenderStrokes(re, true);
      }
      controller->CloseFile();
      g_freestyle.scene = nullptr;

      // composite result
      FRS_composite_result(re, view_layer, freestyle_render);
      if (freestyle_render) {
        RE_FreeRender(freestyle_render);
      }
    }
  }

  DEG_graph_free(depsgraph);
}

void FRS_end_stroke_rendering(Render * /*re*/)
{
  // clear canvas
  controller->Clear();
}

void FRS_free_view_map_cache(void)
{
  // free cache
  controller->DeleteViewMap(true);
#if 0
  if (G.debug & G_DEBUG_FREESTYLE) {
    printf("View map cache freed\n");
  }
#endif
}

//=======================================================
//   Freestyle Panel Configuration
//=======================================================

void FRS_copy_active_lineset(FreestyleConfig *config)
{
  FreestyleLineSet *lineset = BKE_freestyle_lineset_get_active(config);

  if (lineset) {
    lineset_buffer.linestyle = lineset->linestyle;
    lineset_buffer.flags = lineset->flags;
    lineset_buffer.selection = lineset->selection;
    lineset_buffer.qi = lineset->qi;
    lineset_buffer.qi_start = lineset->qi_start;
    lineset_buffer.qi_end = lineset->qi_end;
    lineset_buffer.edge_types = lineset->edge_types;
    lineset_buffer.exclude_edge_types = lineset->exclude_edge_types;
    lineset_buffer.group = lineset->group;
    strcpy(lineset_buffer.name, lineset->name);
    lineset_copied = true;
  }
}

void FRS_paste_active_lineset(FreestyleConfig *config)
{
  if (!lineset_copied) {
    return;
  }

  FreestyleLineSet *lineset = BKE_freestyle_lineset_get_active(config);

  if (lineset) {
    if (lineset->linestyle) {
      id_us_min(&lineset->linestyle->id);
    }
    lineset->linestyle = lineset_buffer.linestyle;
    if (lineset->linestyle) {
      id_us_plus(&lineset->linestyle->id);
    }
    lineset->flags = lineset_buffer.flags;
    lineset->selection = lineset_buffer.selection;
    lineset->qi = lineset_buffer.qi;
    lineset->qi_start = lineset_buffer.qi_start;
    lineset->qi_end = lineset_buffer.qi_end;
    lineset->edge_types = lineset_buffer.edge_types;
    lineset->exclude_edge_types = lineset_buffer.exclude_edge_types;
    if (lineset->group) {
      id_us_min(&lineset->group->id);
      lineset->group = nullptr;
    }
    if (lineset_buffer.group) {
      lineset->group = lineset_buffer.group;
      id_us_plus(&lineset->group->id);
    }
    strcpy(lineset->name, lineset_buffer.name);
    BKE_freestyle_lineset_unique_name(config, lineset);
    lineset->flags |= FREESTYLE_LINESET_CURRENT;
  }
}

void FRS_delete_active_lineset(FreestyleConfig *config)
{
  FreestyleLineSet *lineset = BKE_freestyle_lineset_get_active(config);

  if (lineset) {
    BKE_freestyle_lineset_delete(config, lineset);
  }
}

/**
 * Reinsert the active lineset at an offset \a direction from current position.
 * \return if position of active lineset has changed.
 */
bool FRS_move_active_lineset(FreestyleConfig *config, int direction)
{
  FreestyleLineSet *lineset = BKE_freestyle_lineset_get_active(config);
  return (lineset != nullptr) && BLI_listbase_link_move(&config->linesets, lineset, direction);
}

// Testing

Material *FRS_create_stroke_material(Main *bmain, struct FreestyleLineStyle *linestyle)
{
  bNodeTree *nt = (linestyle->use_nodes) ? linestyle->nodetree : nullptr;
  Material *ma = BlenderStrokeRenderer::GetStrokeShader(bmain, nt, true);
  ma->id.us = 0;
  return ma;
}

}  // extern "C"