prosperon/source/engine/gameobject.h

#ifndef GAMEOBJECT_H
#define GAMEOBJECT_H

#include "quickjs/quickjs.h"
#include "HandmadeMath.h"
#include "transform.h"
#include "script.h"
#include "warp.h"

#define dag_rm(p,c) do{\
 for (int i = arrlen(p->children)-1; i--; i >=0) {\
  if (p->children[i] == c) { \
  arrdelswap(p->children,i);\
  c->parent=NULL;\
  break;\
}}}while(0)

#define dag_set(p,c) do{\
  arrpush(p->children,c);\
  if(c->parent) dag_rm(c->parent,c);\
  c->parent=p;\
}while(0)

#define dag_clip(p) do{\
  if (p->parent)\
    dag_rm(p->parent,p);\
}while(0)

struct gameobject {
  cpBodyType phys;
  cpBody *body; /* NULL if this object is dead; has 2d position and rotation, relative to global 0 */  
  HMM_Vec3 scale; /* local */  
  int next;
  float mass;
  float friction;
  float elasticity;
  float damping;
  float timescale;
  float maxvelocity;
  float maxangularvelocity;
  unsigned int layer;
  cpBitmask categories;
  cpBitmask mask;
  unsigned int warp_mask;
  JSValue ref;
  HMM_Mat4 world;
  float drawlayer; 
};

/*
  Friction uses coulomb model. When shapes collide, their friction is multiplied. Some example values:
  Steel on steel: 0.0005
  Wood on steel: 0.0012
  Wood on wood: 0.0015
  => steel = 0.025
  => wood = 0.04
  => hardrubber = 0.31
  => concrete = 0.05
  => rubber = 0.5
  Hardrubber on steel: 0.0077
  Hardrubber on concrete: 0.015
  Rubber on concrete: 0.025
*/

typedef struct gameobject gameobject;

gameobject *MakeGameobject();
void gameobject_apply(gameobject *go);
void gameobject_free(gameobject *go);

transform2d go2t(gameobject *go);
transform3d go2t3(gameobject *go);

HMM_Vec2 go2world(gameobject *go, HMM_Vec2 pos);
HMM_Vec2 world2go(gameobject *go, HMM_Vec2 pos);

HMM_Mat3 t_go2world(gameobject *go);
HMM_Mat3 t_world2go(gameobject *go);
HMM_Mat4 t3d_go2world(gameobject *go);
HMM_Mat4 t3d_world2go(gameobject *go);

HMM_Vec2 go_pos(gameobject *go);
void gameobject_setpos(gameobject *go, cpVect vec);
float go_angle(gameobject *go);
void gameobject_setangle(gameobject *go, float angle);

gameobject *body2go(cpBody *body);
gameobject *shape2go(cpShape *shape);

void go_shape_apply(cpBody *body, cpShape *shape, gameobject *go);

/* Tries a few methods to select a gameobject; if none is selected returns -1 */

void gameobject_draw_debug(gameobject *go);
#endif