Cleanup: Move geometry component implementations to separate files

Currently the implementations specific to each geometry type are in
the same file. This makes it difficult to tell which code is generic
for all component types and which is specific to a certain type.
The two files, `attribute_access.cc`, and `geometry_set.cc` are
also getting quite long.

This commit splits up the implementation for every geometry component,
and adds an internal header file for the common parts of the attribute
access code. This was discussed with Jacques Lucke.

1 files changed, 207 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/geometry_component_pointcloud.cc b/source/blender/blenkernel/intern/geometry_component_pointcloud.cc
new file mode 100644
index 00000000000..d7f0bf55bc9
--- /dev/null
+++ b/source/blender/blenkernel/intern/geometry_component_pointcloud.cc
@@ -0,0 +1,207 @@
+/*
+ * 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 "DNA_pointcloud_types.h"
+
+#include "BKE_attribute_access.hh"
+#include "BKE_geometry_set.hh"
+#include "BKE_lib_id.h"
+#include "BKE_pointcloud.h"
+
+#include "attribute_access_intern.hh"
+
+/* -------------------------------------------------------------------- */
+/** \name Geometry Component Implementation
+ * \{ */
+
+PointCloudComponent::PointCloudComponent() : GeometryComponent(GeometryComponentType::PointCloud)
+{
+}
+
+PointCloudComponent::~PointCloudComponent()
+{
+  this->clear();
+}
+
+GeometryComponent *PointCloudComponent::copy() const
+{
+  PointCloudComponent *new_component = new PointCloudComponent();
+  if (pointcloud_ != nullptr) {
+    new_component->pointcloud_ = BKE_pointcloud_copy_for_eval(pointcloud_, false);
+    new_component->ownership_ = GeometryOwnershipType::Owned;
+  }
+  return new_component;
+}
+
+void PointCloudComponent::clear()
+{
+  BLI_assert(this->is_mutable());
+  if (pointcloud_ != nullptr) {
+    if (ownership_ == GeometryOwnershipType::Owned) {
+      BKE_id_free(nullptr, pointcloud_);
+    }
+    pointcloud_ = nullptr;
+  }
+}
+
+bool PointCloudComponent::has_pointcloud() const
+{
+  return pointcloud_ != nullptr;
+}
+
+/* Clear the component and replace it with the new point cloud. */
+void PointCloudComponent::replace(PointCloud *pointcloud, GeometryOwnershipType ownership)
+{
+  BLI_assert(this->is_mutable());
+  this->clear();
+  pointcloud_ = pointcloud;
+  ownership_ = ownership;
+}
+
+/* Return the point cloud and clear the component. The caller takes over responsibility for freeing
+ * the point cloud (if the component was responsible before). */
+PointCloud *PointCloudComponent::release()
+{
+  BLI_assert(this->is_mutable());
+  PointCloud *pointcloud = pointcloud_;
+  pointcloud_ = nullptr;
+  return pointcloud;
+}
+
+/* Get the point cloud from this component. This method can be used by multiple threads at the same
+ * time. Therefore, the returned point cloud should not be modified. No ownership is transferred.
+ */
+const PointCloud *PointCloudComponent::get_for_read() const
+{
+  return pointcloud_;
+}
+
+/* Get the point cloud from this component. This method can only be used when the component is
+ * mutable, i.e. it is not shared. The returned point cloud can be modified. No ownership is
+ * transferred. */
+PointCloud *PointCloudComponent::get_for_write()
+{
+  BLI_assert(this->is_mutable());
+  if (ownership_ == GeometryOwnershipType::ReadOnly) {
+    pointcloud_ = BKE_pointcloud_copy_for_eval(pointcloud_, false);
+    ownership_ = GeometryOwnershipType::Owned;
+  }
+  return pointcloud_;
+}
+
+bool PointCloudComponent::is_empty() const
+{
+  return pointcloud_ == nullptr;
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Attribute Access
+ * \{ */
+
+int PointCloudComponent::attribute_domain_size(const AttributeDomain domain) const
+{
+  BLI_assert(domain == ATTR_DOMAIN_POINT);
+  UNUSED_VARS_NDEBUG(domain);
+  if (pointcloud_ == nullptr) {
+    return 0;
+  }
+  return pointcloud_->totpoint;
+}
+
+namespace blender::bke {
+
+template<typename T, AttributeDomain Domain>
+static ReadAttributePtr make_array_read_attribute(const void *data, const int domain_size)
+{
+  return std::make_unique<ArrayReadAttribute<T>>(Domain, Span<T>((const T *)data, domain_size));
+}
+
+template<typename T, AttributeDomain Domain>
+static WriteAttributePtr make_array_write_attribute(void *data, const int domain_size)
+{
+  return std::make_unique<ArrayWriteAttribute<T>>(Domain, MutableSpan<T>((T *)data, domain_size));
+}
+
+/**
+ * In this function all the attribute providers for a point cloud component are created. Most data
+ * in this function is statically allocated, because it does not change over time.
+ */
+static ComponentAttributeProviders create_attribute_providers_for_point_cloud()
+{
+  static auto update_custom_data_pointers = [](GeometryComponent &component) {
+    PointCloudComponent &pointcloud_component = static_cast<PointCloudComponent &>(component);
+    PointCloud *pointcloud = pointcloud_component.get_for_write();
+    if (pointcloud != nullptr) {
+      BKE_pointcloud_update_customdata_pointers(pointcloud);
+    }
+  };
+  static CustomDataAccessInfo point_access = {
+      [](GeometryComponent &component) -> CustomData * {
+        PointCloudComponent &pointcloud_component = static_cast<PointCloudComponent &>(component);
+        PointCloud *pointcloud = pointcloud_component.get_for_write();
+        return pointcloud ? &pointcloud->pdata : nullptr;
+      },
+      [](const GeometryComponent &component) -> const CustomData * {
+        const PointCloudComponent &pointcloud_component = static_cast<const PointCloudComponent &>(
+            component);
+        const PointCloud *pointcloud = pointcloud_component.get_for_read();
+        return pointcloud ? &pointcloud->pdata : nullptr;
+      },
+      update_custom_data_pointers};
+
+  static BuiltinCustomDataLayerProvider position(
+      "position",
+      ATTR_DOMAIN_POINT,
+      CD_PROP_FLOAT3,
+      CD_PROP_FLOAT3,
+      BuiltinAttributeProvider::NonCreatable,
+      BuiltinAttributeProvider::Writable,
+      BuiltinAttributeProvider::NonDeletable,
+      point_access,
+      make_array_read_attribute<float3, ATTR_DOMAIN_POINT>,
+      make_array_write_attribute<float3, ATTR_DOMAIN_POINT>,
+      nullptr,
+      nullptr);
+  static BuiltinCustomDataLayerProvider radius(
+      "radius",
+      ATTR_DOMAIN_POINT,
+      CD_PROP_FLOAT,
+      CD_PROP_FLOAT,
+      BuiltinAttributeProvider::Creatable,
+      BuiltinAttributeProvider::Writable,
+      BuiltinAttributeProvider::Deletable,
+      point_access,
+      make_array_read_attribute<float, ATTR_DOMAIN_POINT>,
+      make_array_write_attribute<float, ATTR_DOMAIN_POINT>,
+      nullptr,
+      nullptr);
+  static CustomDataAttributeProvider point_custom_data(ATTR_DOMAIN_POINT, point_access);
+  return ComponentAttributeProviders({&position, &radius}, {&point_custom_data});
+}
+
+}  // namespace blender::bke
+
+const blender::bke::ComponentAttributeProviders *PointCloudComponent::get_attribute_providers()
+    const
+{
+  static blender::bke::ComponentAttributeProviders providers =
+      blender::bke::create_attribute_providers_for_point_cloud();
+  return &providers;
+}
+
+/** \} */