grease_pencil_io_intern.hh

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/* SPDX-FileCopyrightText: 2024 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include "BLI_bounds_types.hh"
#include "BLI_color_types.hh"
#include "BLI_function_ref.hh"
#include "BLI_math_matrix_types.hh"
#include "BLI_string_ref.hh"
#include "BLI_vector.hh"
 
#include "grease_pencil_io.hh"
 
#include <cstdint>
#include <optional>
 
#pragma once

 
struct Scene;
struct Object;
struct Material;
struct RegionView3D;
namespace blender::bke::greasepencil {
class Layer;
class Drawing;
}  // namespace blender::bke::greasepencil
 
namespace blender::io::grease_pencil {
 
class GreasePencilImporter {
 protected:
  const IOContext context_;
  const ImportParams params_;
 
  Object *object_ = nullptr;
 
 public:
  GreasePencilImporter(const IOContext &context, const ImportParams &params);
 
  Object *create_object(StringRefNull name);
  int32_t create_material(StringRefNull name, bool stroke, bool fill);
};
 
class GreasePencilExporter {
 public:
  struct ObjectInfo {
    Object *object;
    float depth;
  };
 
 protected:
  const IOContext context_;
  const ExportParams params_;
 
  /* Camera projection matrix, only available with an active camera. */
  std::optional<float4x4> camera_persmat_;
  blender::Bounds<float2> camera_rect_;
  float2 camera_fac_;
  blender::Bounds<float2> screen_rect_;
 
 public:
  GreasePencilExporter(const IOContext &context, const ExportParams &params);
 
  void prepare_render_params(Scene &scene, int frame_number);
 
  static ColorGeometry4f compute_average_stroke_color(const Material &material,
                                                      const Span<ColorGeometry4f> vertex_colors);
  static float compute_average_stroke_opacity(const Span<float> opacities);
 
  /* Returns a value if point sizes are all equal. */
  static std::optional<float> try_get_uniform_point_width(const RegionView3D &rv3d,
                                                          const Span<float3> world_positions,
                                                          const Span<float> radii);
 
  Vector<ObjectInfo> retrieve_objects() const;
 
  using WriteStrokeFn = FunctionRef<void(const Span<float3> positions,
                                         const Span<float3> positions_left,
                                         const Span<float3> positions_right,
                                         bool cyclic,
                                         int8_t type,
                                         const ColorGeometry4f &color,
                                         float opacity,
                                         std::optional<float> width,
                                         bool round_cap,
                                         bool is_outline)>;
 
  void foreach_stroke_in_layer(const Object &object,
                               const bke::greasepencil::Layer &layer,
                               const bke::greasepencil::Drawing &drawing,
                               WriteStrokeFn stroke_fn);
 
  float2 project_to_screen(const float4x4 &transform, const float3 &position) const;
 
  bool is_selected_frame(const GreasePencil &grease_pencil, int frame_number) const;
 
  std::string coord_to_svg_string(const float2 &screen_co) const;
 
 private:
  std::optional<Bounds<float2>> compute_screen_space_drawing_bounds(
      const RegionView3D &rv3d,
      Object &object,
      int layer_index,
      const bke::greasepencil::Drawing &drawing);
  std::optional<Bounds<float2>> compute_objects_bounds(
      const RegionView3D &rv3d,
      const Depsgraph &depsgraph,
      Span<GreasePencilExporter::ObjectInfo> objects,
      int frame_number);
};
 
}  // namespace blender::io::grease_pencil