_comps.h

#pragma once
 
#include "_math.h"
#include "_types.h"
#include <entt/entity/entity.hpp>
namespace njin {

struct transform {
  vec2 pos{};       
  f32 rot = 0.0f;   
  f32 scale = 1.0f; 
};

struct camera_2d {
  vec2 offset{};
  f32 zoom = 1.0f;
};

struct camera_on {};

struct sprite {
  texture_handle texture{}; 
  rect source{};
  vec2 origin{0.5f, 0.5f};
  rgba tint{1.0f, 1.0f, 1.0f, 1.0f}; 
  i32 layer = 0;       
  f32 sort_offset = 0.0f;
  bool flip_x = false; 
  bool flip_y = false; 
  bool visible = true; 
  texture_handle normal{};
  texture_handle material{};
  texture_handle emissive{};
  f32 emissive_power = 1.0f; 
};

struct sprite_anim {
  vec2 frame_size{};    
  i32 first = 0;        
  i32 count = 1;        
  f32 fps = 10.0f;      
  bool loop = true;     
  bool playing = true;  
  f32 time = 0.0f;      
  i32 frame = 0;        
  bool finished = false; 
};

inline void anim_play(sprite_anim &anim, i32 first, i32 count, f32 fps,
                      bool loop = true) {
  if (anim.first == first && anim.count == count && anim.playing &&
      !anim.finished)
    return;
  anim.first = first;
  anim.count = count;
  anim.fps = fps;
  anim.loop = loop;
  anim.playing = true;
  anim.time = 0.0f;
  anim.frame = 0;
  anim.finished = false;
}

struct scene_owned {
  scene_handle scene{}; 
};

struct child_of {
  entt::entity parent = entt::null; 
  transform local{}; 
  bool destroy_with_parent = true; 
};

inline transform transform_combine(const transform &parent,
                                   const transform &local) {
  return transform{.pos = parent.pos + rotate(local.pos * parent.scale, parent.rot),
                   .rot = parent.rot + local.rot,
                   .scale = parent.scale * local.scale};
}

inline transform transform_relative(const transform &parent,
                                    const transform &world) {
  const f32 scale = parent.scale != 0.0f ? parent.scale : 1.0f;
  return transform{.pos = rotate(world.pos - parent.pos, -parent.rot) / scale,
                   .rot = world.rot - parent.rot,
                   .scale = world.scale / scale};
}

} // namespace njin