SceneDuplicator.hpp

#pragma once
#include <halp/controls.hpp>
#include <halp/meta.hpp>
 
#include <ossia/dataflow/geometry_port.hpp>
 
#include <cstdint>
#include <memory>
#include <string>
 
namespace Threedim
{
 
// Scene-graph-level duplicator: given a prototype scene_spec, emits N cloned
// root nodes placed by a procedural pattern. Complementary to Instancer, which
// does GPU-primitive instancing -- one mesh, N instances, one draw call, up to
// a million particles from a single-mesh prototype. This one clones a rich
// prototype with hierarchy, multiple meshes and lights into N CPU clones, each
// with its own TRS, scaling to dozens or a few hundred.
//
// Materials, animations, skeletons and environment pass through from the
// prototype unchanged and are shared across clones; only the root-level node
// tree is cloned, so downstream path-based tooling addresses each clone
// independently.
//
// Patterns: Grid lays `count` clones on an XZ grid with `spacing` at Y=0; Ring
// puts them on a circle of `radius` in the XZ plane facing outward; Line runs
// them along +X with `spacing` separation.
//
// Each clone's root node is named `<proto_name>_<idx>`, 0-indexed, so
// SceneDuplicator(prototype=ChairScene, mode=Ring, count=8) yields /Chair_0 to
// /Chair_7 and ConfigurePrimitive(paths=["/Chair_*"]) addresses them all.
class SceneDuplicator
{
public:
  halp_meta(name, "Scene Duplicator")
  halp_meta(category, "Visuals/3D/Scene")
  halp_meta(c_name, "scene_duplicator")
  halp_meta(description, "Clone a scene hierarchy into a grid, ring or line of independently transformed copies.")
  halp_meta(authors, "ossia team")
  halp_meta(
      manual_url,
      "https://ossia.io/score-docs/processes/scene-duplicator.html")
  halp_meta(uuid, "9e7a4b3d-5f2c-4a8b-9d1e-6c3f8b5d2a7e")
 
  enum Pattern
  {
    Grid,
    Ring,
    Line
  };
 
  struct ins
  {
    struct
    {
      halp_meta(name, "Scene In");
      ossia::scene_spec scene;
      uint8_t dirty{0};
    } scene_in;
 
    // Port-driven rebuild: controls trigger rebuild(); upstream
    // scene_in changes detected in operator()().
    struct : halp::combobox_t<"Pattern", Pattern>
    {
      struct range
      {
        std::string_view values[3]{"Grid", "Ring", "Line"};
        int init{0};
      };
      void update(SceneDuplicator& n) { n.rebuild(); }
    } pattern;
 
    struct : halp::spinbox_i32<"Count", halp::irange{1, 4096, 4}>
    { void update(SceneDuplicator& n) { n.rebuild(); } } count;
    struct : halp::hslider_f32<"Spacing", halp::range{0.01, 1000., 2.}>
    { void update(SceneDuplicator& n) { n.rebuild(); } } spacing;
    struct : halp::hslider_f32<"Radius", halp::range{0.01, 1000., 5.}>
    { void update(SceneDuplicator& n) { n.rebuild(); } } radius;
    // Grid mode: grid is `cols × rows` with cols ≈ round(sqrt(count)).
    // Exposed as a control so the user can force a specific aspect.
    // 0 = auto (square-ish).
    struct : halp::spinbox_i32<"Grid cols", halp::irange{0, 256, 0}>
    { void update(SceneDuplicator& n) { n.rebuild(); } } grid_cols;
  } inputs;
 
  struct outs
  {
    struct
    {
      halp_meta(name, "Scene Out");
      ossia::scene_spec scene;
      uint8_t dirty{0};
    } scene_out;
  } outputs;
 
  void rebuild();
  void operator()();
 
  // Stable shared_ptr cached while inputs are unchanged — keeps
  // ScenePreprocessor's fingerprint fast-path warm.
  std::shared_ptr<const ossia::scene_state> m_cached_out;
  uint8_t m_pending_dirty{0xFF};
  const ossia::scene_state* m_cached_in_state{};
  int64_t m_cached_in_version{-1};
  int64_t m_version_counter{0};
};
 
}