njin_anim3d.h

#pragma once
#include "_types.h"
#include "njin_3d.h"
#include <functional>
 
namespace njin {
struct context;


struct spring3d_chain {
  i32 bone = -1;          
  f32 stiffness = 1.0f;
  f32 drag = 0.4f;
  f32 gravity = 0.0f;                     
  vec3 gravity_dir{0.0f, -1.0f, 0.0f};    
  f32 radius = 0.02f;                     
};

struct spring3d_collider {
  i32 bone = -1;          
  vec3 offset{};          
  vec3 tail{};            
  f32 radius = 0.1f;      
};

struct spring3d_desc {
  model_handle model{};                          
  const spring3d_chain *chains = nullptr;        
  u32 chain_count = 0;                           
  const spring3d_collider *colliders = nullptr;  
  u32 collider_count = 0;                        
};

spring3d_handle spring3d_create(context &ctx, const spring3d_desc &desc);

i32 spring3d_update(context &ctx, spring3d_handle handle, const model_pose &pose, const transform3d &transform, f32 dt,
                    bone_pose3d *out, i32 count);

void spring3d_reset(context &ctx, spring3d_handle handle);

void spring3d_destroy(context &ctx, spring3d_handle handle);

const char *bone_humanoid_name(const char *name);

struct retarget3d_desc {
  model_handle source{};  
  model_handle target{};  
  const char *const *pairs = nullptr;
  u32 pair_count = 0;     
  bool humanoid = true;
};

retarget3d_handle retarget3d_create(context &ctx, const retarget3d_desc &desc);

i32 retarget3d_pose(const context &ctx, retarget3d_handle handle, const model_pose &pose, bone_pose3d *out,
                    i32 count);

i32 retarget3d_source_bone(const context &ctx, retarget3d_handle handle, i32 bone);

void retarget3d_destroy(context &ctx, retarget3d_handle handle);

struct foot3d_leg {
  i32 upper = -1; 
  i32 lower = -1; 
  i32 foot = -1;  
};

struct foot3d_desc {
  model_handle model{}; 
  const foot3d_leg *legs = nullptr;
  u32 leg_count = 0; 
  f32 max_step = 0.5f;
  f32 max_tilt = 35.0f;
  f32 smoothing = 15.0f;
  vec3 knee_forward{0.0f, 0.0f, 1.0f};
};

foot3d_handle foot3d_create(context &ctx, const foot3d_desc &desc);

using foot3d_ground = std::function<bool(vec3 from, f32 distance, vec3 &point, vec3 &normal)>;

i32 foot3d_update(context &ctx, foot3d_handle handle, const model_pose &pose, const transform3d &transform, f32 dt,
                  bone_pose3d *out, i32 count, f32 weight = 1.0f);

i32 foot3d_update(context &ctx, foot3d_handle handle, const model_pose &pose, const transform3d &transform, f32 dt,
                  bone_pose3d *out, i32 count, const foot3d_ground &ground, f32 weight = 1.0f);

f32 foot3d_hip_offset(const context &ctx, foot3d_handle handle);

void foot3d_reset(context &ctx, foot3d_handle handle);

void foot3d_destroy(context &ctx, foot3d_handle handle);
} // namespace njin