Curves: Rename "Hair" types, variables, and functions to "Curves"

Based on discussions from T95355 and T94193, the plan is to use
the name "Curves" to describe the data-block container for multiple
curves. Eventually this will replace the existing "Curve" data-block.
However, it will be a while before the curve data-block can be replaced
so in order to distinguish the two curve types in the UI, "Hair Curves"
will be used, but eventually changed back to "Curves".

This patch renames "hair-related" files, functions, types, and variable
names to this convention. A deep rename is preferred to keep code
consistent and to avoid any "hair" terminology from leaking, since the
new data-block is meant for all curve types, not just hair use cases.

The downside of this naming is that the difference between "Curve"
and "Curves" has become important. That was considered during
design discussons and deemed acceptable, especially given the
non-permanent nature of the somewhat common conflict.

Some points of interest:
- All DNA compatibility is lost, just like rBf59767ff9729.
- I renamed `ID_HA` to `ID_CV` so there is no complete mismatch.
- `hair_curves` is used where necessary to distinguish from the
  existing "curves" plural.
- I didn't rename any of the cycles/rendering code function names,
  since that is also used by the old hair particle system.

Differential Revision: https://developer.blender.org/D14007

1 files changed, 473 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/curves.cc b/source/blender/blenkernel/intern/curves.cc
new file mode 100644
index 00000000000..f5672e9b288
--- /dev/null
+++ b/source/blender/blenkernel/intern/curves.cc
@@ -0,0 +1,473 @@
+/*
+ * 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 bke
+ */
+
+#include <cmath>
+#include <cstring>
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_curves_types.h"
+#include "DNA_defaults.h"
+#include "DNA_material_types.h"
+#include "DNA_object_types.h"
+
+#include "BLI_index_range.hh"
+#include "BLI_listbase.h"
+#include "BLI_math_base.h"
+#include "BLI_math_vec_types.hh"
+#include "BLI_rand.hh"
+#include "BLI_string.h"
+#include "BLI_utildefines.h"
+
+#include "BKE_anim_data.h"
+#include "BKE_curves.h"
+#include "BKE_customdata.h"
+#include "BKE_global.h"
+#include "BKE_idtype.h"
+#include "BKE_lib_id.h"
+#include "BKE_lib_query.h"
+#include "BKE_lib_remap.h"
+#include "BKE_main.h"
+#include "BKE_modifier.h"
+#include "BKE_object.h"
+
+#include "BLT_translation.h"
+
+#include "DEG_depsgraph_query.h"
+
+#include "BLO_read_write.h"
+
+using blender::float3;
+using blender::IndexRange;
+using blender::MutableSpan;
+using blender::RandomNumberGenerator;
+
+static const char *ATTR_POSITION = "position";
+static const char *ATTR_RADIUS = "radius";
+
+static void curves_random(Curves *curves);
+
+static void curves_init_data(ID *id)
+{
+  Curves *curves = (Curves *)id;
+  BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(curves, id));
+
+  MEMCPY_STRUCT_AFTER(curves, DNA_struct_default_get(Curves), id);
+
+  CustomData_reset(&curves->geometry.point_data);
+  CustomData_reset(&curves->geometry.curve_data);
+
+  CustomData_add_layer_named(&curves->geometry.point_data,
+                             CD_PROP_FLOAT3,
+                             CD_CALLOC,
+                             nullptr,
+                             curves->geometry.point_size,
+                             ATTR_POSITION);
+  CustomData_add_layer_named(&curves->geometry.point_data,
+                             CD_PROP_FLOAT,
+                             CD_CALLOC,
+                             nullptr,
+                             curves->geometry.point_size,
+                             ATTR_RADIUS);
+
+  BKE_curves_update_customdata_pointers(curves);
+
+  curves_random(curves);
+}
+
+static void curves_copy_data(Main *UNUSED(bmain), ID *id_dst, const ID *id_src, const int flag)
+{
+  Curves *curves_dst = (Curves *)id_dst;
+  const Curves *curves_src = (const Curves *)id_src;
+  curves_dst->mat = static_cast<Material **>(MEM_dupallocN(curves_src->mat));
+
+  curves_dst->geometry.point_size = curves_src->geometry.point_size;
+  curves_dst->geometry.curve_size = curves_src->geometry.curve_size;
+
+  const eCDAllocType alloc_type = (flag & LIB_ID_COPY_CD_REFERENCE) ? CD_REFERENCE : CD_DUPLICATE;
+  CustomData_copy(&curves_src->geometry.point_data,
+                  &curves_dst->geometry.point_data,
+                  CD_MASK_ALL,
+                  alloc_type,
+                  curves_dst->geometry.point_size);
+  CustomData_copy(&curves_src->geometry.curve_data,
+                  &curves_dst->geometry.curve_data,
+                  CD_MASK_ALL,
+                  alloc_type,
+                  curves_dst->geometry.curve_size);
+  BKE_curves_update_customdata_pointers(curves_dst);
+
+  curves_dst->geometry.offsets = static_cast<int *>(MEM_dupallocN(curves_src->geometry.offsets));
+
+  curves_dst->batch_cache = nullptr;
+}
+
+static void curves_free_data(ID *id)
+{
+  Curves *curves = (Curves *)id;
+  BKE_animdata_free(&curves->id, false);
+
+  BKE_curves_batch_cache_free(curves);
+
+  CustomData_free(&curves->geometry.point_data, curves->geometry.point_size);
+  CustomData_free(&curves->geometry.curve_data, curves->geometry.curve_size);
+
+  MEM_SAFE_FREE(curves->geometry.offsets);
+
+  MEM_SAFE_FREE(curves->mat);
+}
+
+static void curves_foreach_id(ID *id, LibraryForeachIDData *data)
+{
+  Curves *curves = (Curves *)id;
+  for (int i = 0; i < curves->totcol; i++) {
+    BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, curves->mat[i], IDWALK_CB_USER);
+  }
+}
+
+static void curves_blend_write(BlendWriter *writer, ID *id, const void *id_address)
+{
+  Curves *curves = (Curves *)id;
+
+  CustomDataLayer *players = nullptr, players_buff[CD_TEMP_CHUNK_SIZE];
+  CustomDataLayer *clayers = nullptr, clayers_buff[CD_TEMP_CHUNK_SIZE];
+  CustomData_blend_write_prepare(
+      &curves->geometry.point_data, &players, players_buff, ARRAY_SIZE(players_buff));
+  CustomData_blend_write_prepare(
+      &curves->geometry.curve_data, &clayers, clayers_buff, ARRAY_SIZE(clayers_buff));
+
+  /* Write LibData */
+  BLO_write_id_struct(writer, Curves, id_address, &curves->id);
+  BKE_id_blend_write(writer, &curves->id);
+
+  /* Direct data */
+  CustomData_blend_write(writer,
+                         &curves->geometry.point_data,
+                         players,
+                         curves->geometry.point_size,
+                         CD_MASK_ALL,
+                         &curves->id);
+  CustomData_blend_write(writer,
+                         &curves->geometry.curve_data,
+                         clayers,
+                         curves->geometry.curve_size,
+                         CD_MASK_ALL,
+                         &curves->id);
+
+  BLO_write_int32_array(writer, curves->geometry.curve_size + 1, curves->geometry.offsets);
+
+  BLO_write_pointer_array(writer, curves->totcol, curves->mat);
+  if (curves->adt) {
+    BKE_animdata_blend_write(writer, curves->adt);
+  }
+
+  /* Remove temporary data. */
+  if (players && players != players_buff) {
+    MEM_freeN(players);
+  }
+  if (clayers && clayers != clayers_buff) {
+    MEM_freeN(clayers);
+  }
+}
+
+static void curves_blend_read_data(BlendDataReader *reader, ID *id)
+{
+  Curves *curves = (Curves *)id;
+  BLO_read_data_address(reader, &curves->adt);
+  BKE_animdata_blend_read_data(reader, curves->adt);
+
+  /* Geometry */
+  CustomData_blend_read(reader, &curves->geometry.point_data, curves->geometry.point_size);
+  CustomData_blend_read(reader, &curves->geometry.curve_data, curves->geometry.point_size);
+  BKE_curves_update_customdata_pointers(curves);
+
+  BLO_read_int32_array(reader, curves->geometry.curve_size + 1, &curves->geometry.offsets);
+
+  /* Materials */
+  BLO_read_pointer_array(reader, (void **)&curves->mat);
+}
+
+static void curves_blend_read_lib(BlendLibReader *reader, ID *id)
+{
+  Curves *curves = (Curves *)id;
+  for (int a = 0; a < curves->totcol; a++) {
+    BLO_read_id_address(reader, curves->id.lib, &curves->mat[a]);
+  }
+}
+
+static void curves_blend_read_expand(BlendExpander *expander, ID *id)
+{
+  Curves *curves = (Curves *)id;
+  for (int a = 0; a < curves->totcol; a++) {
+    BLO_expand(expander, curves->mat[a]);
+  }
+}
+
+IDTypeInfo IDType_ID_CV = {
+    /*id_code */ ID_CV,
+    /*id_filter */ FILTER_ID_CV,
+    /*main_listbase_index */ INDEX_ID_CV,
+    /*struct_size */ sizeof(Curves),
+    /*name */ "Hair Curves",
+    /*name_plural */ "Hair Curves",
+    /*translation_context */ BLT_I18NCONTEXT_ID_CURVES,
+    /*flags */ IDTYPE_FLAGS_APPEND_IS_REUSABLE,
+    /*asset_type_info */ nullptr,
+
+    /*init_data */ curves_init_data,
+    /*copy_data */ curves_copy_data,
+    /*free_data */ curves_free_data,
+    /*make_local */ nullptr,
+    /*foreach_id */ curves_foreach_id,
+    /*foreach_cache */ nullptr,
+    /*foreach_path */ nullptr,
+    /*owner_get */ nullptr,
+
+    /*blend_write */ curves_blend_write,
+    /*blend_read_data */ curves_blend_read_data,
+    /*blend_read_lib */ curves_blend_read_lib,
+    /*blend_read_expand */ curves_blend_read_expand,
+
+    /*blend_read_undo_preserve */ nullptr,
+
+    /*lib_override_apply_post */ nullptr,
+};
+
+static void curves_random(Curves *curves)
+{
+  CurvesGeometry &geometry = curves->geometry;
+  const int numpoints = 8;
+
+  geometry.curve_size = 500;
+
+  geometry.curve_size = 500;
+  geometry.point_size = geometry.curve_size * numpoints;
+
+  curves->geometry.offsets = (int *)MEM_calloc_arrayN(
+      curves->geometry.curve_size + 1, sizeof(int), __func__);
+  CustomData_realloc(&geometry.point_data, geometry.point_size);
+  CustomData_realloc(&geometry.curve_data, geometry.curve_size);
+  BKE_curves_update_customdata_pointers(curves);
+
+  MutableSpan<int> offsets{geometry.offsets, geometry.curve_size + 1};
+  MutableSpan<float3> positions{(float3 *)geometry.position, geometry.point_size};
+  MutableSpan<float> radii{geometry.radius, geometry.point_size};
+
+  for (const int i : offsets.index_range()) {
+    geometry.offsets[i] = numpoints * i;
+  }
+
+  RandomNumberGenerator rng;
+
+  for (int i = 0; i < geometry.curve_size; i++) {
+    const IndexRange curve_range(offsets[i], offsets[i + 1] - offsets[i]);
+    MutableSpan<float3> curve_positions = positions.slice(curve_range);
+    MutableSpan<float> curve_radii = radii.slice(curve_range);
+
+    const float theta = 2.0f * M_PI * rng.get_float();
+    const float phi = saacosf(2.0f * rng.get_float() - 1.0f);
+
+    float3 no = {std::sin(theta) * std::sin(phi), std::cos(theta) * std::sin(phi), std::cos(phi)};
+    no = blender::math::normalize(no);
+
+    float3 co = no;
+    for (int key = 0; key < numpoints; key++) {
+      float t = key / (float)(numpoints - 1);
+      curve_positions[key] = co;
+      curve_radii[key] = 0.02f * (1.0f - t);
+
+      float3 offset = float3(rng.get_float(), rng.get_float(), rng.get_float()) * 2.0f - 1.0f;
+      co += (offset + no) / numpoints;
+    }
+  }
+}
+
+void *BKE_curves_add(Main *bmain, const char *name)
+{
+  Curves *curves = static_cast<Curves *>(BKE_id_new(bmain, ID_CV, name));
+
+  return curves;
+}
+
+BoundBox *BKE_curves_boundbox_get(Object *ob)
+{
+  BLI_assert(ob->type == OB_CURVES);
+  Curves *curves = static_cast<Curves *>(ob->data);
+
+  if (ob->runtime.bb != nullptr && (ob->runtime.bb->flag & BOUNDBOX_DIRTY) == 0) {
+    return ob->runtime.bb;
+  }
+
+  if (ob->runtime.bb == nullptr) {
+    ob->runtime.bb = MEM_cnew<BoundBox>(__func__);
+
+    float min[3], max[3];
+    INIT_MINMAX(min, max);
+
+    float(*curves_co)[3] = curves->geometry.position;
+    float *curves_radius = curves->geometry.radius;
+    for (int a = 0; a < curves->geometry.point_size; a++) {
+      float *co = curves_co[a];
+      float radius = (curves_radius) ? curves_radius[a] : 0.0f;
+      const float co_min[3] = {co[0] - radius, co[1] - radius, co[2] - radius};
+      const float co_max[3] = {co[0] + radius, co[1] + radius, co[2] + radius};
+      DO_MIN(co_min, min);
+      DO_MAX(co_max, max);
+    }
+
+    BKE_boundbox_init_from_minmax(ob->runtime.bb, min, max);
+  }
+
+  return ob->runtime.bb;
+}
+
+void BKE_curves_update_customdata_pointers(Curves *curves)
+{
+  curves->geometry.position = (float(*)[3])CustomData_get_layer_named(
+      &curves->geometry.point_data, CD_PROP_FLOAT3, ATTR_POSITION);
+  curves->geometry.radius = (float *)CustomData_get_layer_named(
+      &curves->geometry.point_data, CD_PROP_FLOAT, ATTR_RADIUS);
+}
+
+bool BKE_curves_customdata_required(Curves *UNUSED(curves), CustomDataLayer *layer)
+{
+  return layer->type == CD_PROP_FLOAT3 && STREQ(layer->name, ATTR_POSITION);
+}
+
+/* Dependency Graph */
+
+Curves *BKE_curves_new_for_eval(const Curves *curves_src, int totpoint, int totcurve)
+{
+  Curves *curves_dst = static_cast<Curves *>(BKE_id_new_nomain(ID_CV, nullptr));
+
+  STRNCPY(curves_dst->id.name, curves_src->id.name);
+  curves_dst->mat = static_cast<Material **>(MEM_dupallocN(curves_src->mat));
+  curves_dst->totcol = curves_src->totcol;
+
+  curves_dst->geometry.point_size = totpoint;
+  curves_dst->geometry.curve_size = totcurve;
+  CustomData_copy(&curves_src->geometry.point_data,
+                  &curves_dst->geometry.point_data,
+                  CD_MASK_ALL,
+                  CD_CALLOC,
+                  totpoint);
+  CustomData_copy(&curves_src->geometry.curve_data,
+                  &curves_dst->geometry.curve_data,
+                  CD_MASK_ALL,
+                  CD_CALLOC,
+                  totcurve);
+  BKE_curves_update_customdata_pointers(curves_dst);
+
+  return curves_dst;
+}
+
+Curves *BKE_curves_copy_for_eval(Curves *curves_src, bool reference)
+{
+  int flags = LIB_ID_COPY_LOCALIZE;
+
+  if (reference) {
+    flags |= LIB_ID_COPY_CD_REFERENCE;
+  }
+
+  Curves *result = (Curves *)BKE_id_copy_ex(nullptr, &curves_src->id, nullptr, flags);
+  return result;
+}
+
+static Curves *curves_evaluate_modifiers(struct Depsgraph *depsgraph,
+                                         struct Scene *scene,
+                                         Object *object,
+                                         Curves *curves_input)
+{
+  Curves *curves = curves_input;
+
+  /* Modifier evaluation modes. */
+  const bool use_render = (DEG_get_mode(depsgraph) == DAG_EVAL_RENDER);
+  const int required_mode = use_render ? eModifierMode_Render : eModifierMode_Realtime;
+  ModifierApplyFlag apply_flag = use_render ? MOD_APPLY_RENDER : MOD_APPLY_USECACHE;
+  const ModifierEvalContext mectx = {depsgraph, object, apply_flag};
+
+  /* Get effective list of modifiers to execute. Some effects like shape keys
+   * are added as virtual modifiers before the user created modifiers. */
+  VirtualModifierData virtualModifierData;
+  ModifierData *md = BKE_modifiers_get_virtual_modifierlist(object, &virtualModifierData);
+
+  /* Evaluate modifiers. */
+  for (; md; md = md->next) {
+    const ModifierTypeInfo *mti = BKE_modifier_get_info(static_cast<ModifierType>(md->type));
+
+    if (!BKE_modifier_is_enabled(scene, md, required_mode)) {
+      continue;
+    }
+
+    if ((mti->type == eModifierTypeType_OnlyDeform) &&
+        (mti->flags & eModifierTypeFlag_AcceptsVertexCosOnly)) {
+      /* Ensure we are not modifying the input. */
+      if (curves == curves_input) {
+        curves = BKE_curves_copy_for_eval(curves, true);
+      }
+
+      /* Ensure we are not overwriting referenced data. */
+      CustomData_duplicate_referenced_layer_named(&curves->geometry.point_data,
+                                                  CD_PROP_FLOAT3,
+                                                  ATTR_POSITION,
+                                                  curves->geometry.point_size);
+      BKE_curves_update_customdata_pointers(curves);
+
+      /* Created deformed coordinates array on demand. */
+      mti->deformVerts(
+          md, &mectx, nullptr, curves->geometry.position, curves->geometry.point_size);
+    }
+  }
+
+  return curves;
+}
+
+void BKE_curves_data_update(struct Depsgraph *depsgraph, struct Scene *scene, Object *object)
+{
+  /* Free any evaluated data and restore original data. */
+  BKE_object_free_derived_caches(object);
+
+  /* Evaluate modifiers. */
+  Curves *curves = static_cast<Curves *>(object->data);
+  Curves *curves_eval = curves_evaluate_modifiers(depsgraph, scene, object, curves);
+
+  /* Assign evaluated object. */
+  const bool is_owned = (curves != curves_eval);
+  BKE_object_eval_assign_data(object, &curves_eval->id, is_owned);
+}
+
+/* Draw Cache */
+
+void (*BKE_curves_batch_cache_dirty_tag_cb)(Curves *curves, int mode) = nullptr;
+void (*BKE_curves_batch_cache_free_cb)(Curves *curves) = nullptr;
+
+void BKE_curves_batch_cache_dirty_tag(Curves *curves, int mode)
+{
+  if (curves->batch_cache) {
+    BKE_curves_batch_cache_dirty_tag_cb(curves, mode);
+  }
+}
+
+void BKE_curves_batch_cache_free(Curves *curves)
+{
+  if (curves->batch_cache) {
+    BKE_curves_batch_cache_free_cb(curves);
+  }
+}