/* SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup DNA
 */

#pragma once

#include "DNA_ID.h"
#include "DNA_customdata_types.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifdef __cplusplus
namespace blender::bke {
class CurvesGeometryRuntime;
}  // namespace blender::bke
using CurvesGeometryRuntimeHandle = blender::bke::CurvesGeometryRuntime;
#else
typedef struct CurvesGeometryRuntimeHandle CurvesGeometryRuntimeHandle;
#endif

typedef enum CurveType {
  CURVE_TYPE_CATMULL_ROM = 0,
  CURVE_TYPE_POLY = 1,
  CURVE_TYPE_BEZIER = 2,
  CURVE_TYPE_NURBS = 3,
} CurveType;

typedef enum HandleType {
  /** The handle can be moved anywhere, and doesn't influence the point's other handle. */
  BEZIER_HANDLE_FREE = 0,
  /** The location is automatically calculated to be smooth. */
  BEZIER_HANDLE_AUTO = 1,
  /** The location is calculated to point to the next/previous control point. */
  BEZIER_HANDLE_VECTOR = 2,
  /** The location is constrained to point in the opposite direction as the other handle. */
  BEZIER_HANDLE_ALIGN = 3,
} HandleType;

/**
 * A reusable data structure for geometry consisting of many curves. All control point data is
 * stored contiguously for better efficiency. Data for each curve is stored as a slice of the
 * main #point_data array.
 *
 * The data structure is meant to be embedded in other data-blocks to allow reusing
 * curve-processing algorithms for multiple Blender data-block types.
 */
typedef struct CurvesGeometry {
  /**
   * A runtime pointer to the "position" attribute data.
   * \note This data is owned by #point_data.
   */
  float (*position)[3];
  /**
   * A runtime pointer to the "radius" attribute data.
   * \note This data is owned by #point_data.
   */
  float *radius;

  /**
   * The type of each curve. #CurveType.
   * \note This data is owned by #curve_data.
   */
  int8_t *curve_type;

  /**
   * The start index of each curve in the point data. The size of each curve can be calculated by
   * subtracting the offset from the next offset. That is valid even for the last curve because
   * this array is allocated with a length one larger than the number of splines.
   *
   * \note This is *not* stored in #CustomData because its size is one larger than #curve_data.
   */
  int *curve_offsets;

  /**
   * All attributes stored on control points (#ATTR_DOMAIN_POINT).
   */
  CustomData point_data;

  /**
   * All attributes stored on curves (#ATTR_DOMAIN_CURVE).
   */
  CustomData curve_data;

  /**
   * The total number of control points in all curves.
   */
  int point_size;
  /**
   * The number of curves in the data-block.
   */
  int curve_size;

  /**
   * Runtime data for curves, stored as a pointer to allow defining this as a C++ class.
   */
  CurvesGeometryRuntimeHandle *runtime;
} CurvesGeometry;

typedef struct Curves {
  ID id;
  /* Animation data (must be immediately after id). */
  struct AnimData *adt;

  CurvesGeometry geometry;

  int flag;
  int attributes_active_index;

  /* Materials. */
  struct Material **mat;
  short totcol;
  short _pad2[3];

  /**
   * Used as base mesh when curves represent e.g. hair or fur. This surface is used in edit modes.
   * When set, the curves will have attributes that indicate a position on this surface. This is
   * used for deforming the curves when the surface is deformed dynamically.
   *
   * This is expected to be a mesh object.
   */
  struct Object *surface;

  /* Draw Cache. */
  void *batch_cache;
} Curves;

/* Curves.flag */
enum {
  HA_DS_EXPAND = (1 << 0),
};

/* Only one material supported currently. */
#define CURVES_MATERIAL_NR 1

#ifdef __cplusplus
}
#endif