lg_scene_graph.h

/*
 *      LibGame - Copyright (C) Emmanuel Thomas-Maurin 2011-2025
 *      All rights reserved
 */
 
/*
 * LG_NODE_NTOS AND LG_SCENE ARE USED MAINLY IN LG_SCENE.C
 * (THIS MAY CREATE A BIT OF CONFUSION)
 */
 
#ifndef LG_SCENE_GRAPH_H
#define LG_SCENE_GRAPH_H
 
#define SCENENODE_NAME_MAX_LEN                  (64 - 1)
#define SCENENODE_CHILD_MAX_NUM                 256
#define SCENE_GRAPH_MAX_DEPTH                   32
#define SCENEGRAPH_PRINTOUT_MAX_DEPTH           8
 
#define NODE_NTOS_MAX_NUM                       1024
 
#define SCENE_SERIAL_DATA_SIZE                  offsetof(LG_Scene, cam1)
 
typedef enum {
        ROOT,
        FIRST_OBJ,
        MESH,                   /* Mesh = OBJ or VBO (= VBO/IBO/INFO) */
        LINES3D,
        GRID,                   /* Means lines3d_vb is dynamic */
        LANDSCAPE_ROOT,
        QT_NODE,
        SKYBOX,
        LIGHT,
        SHADER_ONLY,
        UNDEFINED
} lg_scenenode_type;
 
typedef struct LG_SceneNode LG_SceneNode;
 
/*
 * NODE'S LOCAL_MATRIX = NODE'S TRANSFORMATION RELATIVE TO ITS PARENT
 * NODE'S WORLD_MATRIX = NODE'S TRANSFORMATION RELATIVE TO THE ROOT NODE (WORLD)
 */
struct LG_SceneNode {
        int32_t                 id;                                     /* User-defined - SHOULD BE UNIQUE */
        char                    name[SCENENODE_NAME_MAX_LEN + 1];       /* User-defined - may be NOT unique */
        lg_scenenode_type       type;
        LG_SceneNode            *parent;
        LG_SceneNode            *child[SCENENODE_CHILD_MAX_NUM];
        unsigned int            n_child;
        LG_Mesh                 *mesh;
        Lines3D_VB              lines3d_vb;                             /* Line set vertex buffer and num of vertices */
        mat4_t                  local_matrix0;                          /* 'Private' member - how to 'hide' this stuff */
        mat4_t                  world_matrix0;                          /* 'Private' member - how to 'hide' this stuff */
        mat4_t                  *local_matrix;                          /* Adjust (TRS) the mesh/lines3d_vb in its local space */
        mat4_t                  *world_matrix;                          /* Put (TRS) the mesh/lines3d_vb in world space */
        LG_ShaderProg           shader_prog;
        LG_ShaderULocs          shader_u_loc;                           /* Shader uniforms locations */
        LG_VAO                  vao;                                    /* Vertex Array Object */
        LG_Texture              *tex_1;                                 /* For textures other than thoses from mesh mtl file */
};
 
/*
 * === Scene node serializable data ===
 * NTOS stands for (mesh file) Name and (scene node) TOS (Transl/Orientation/Scaling)
 * (could/should be ITNTOS for Ids/Type/Name/Transl/Orientation/Scaling for more accuracy)
 * Use float for LG_EulerAng
 */
typedef union {
        struct {
                /* Ids and Type */
                int32_t         id;                                     /* User-defined - SHOULD BE UNIQUE -> always > 0, 0 = top node */
                int32_t         parent_id;                              /* Set to < 0 if node = top node */
                int32_t         type;                                   /* Actually lg_scenenode_type (int), may be other that MESH */
                /* Name */
                char            name[LG_MESH_NAME_MAX_LEN + 1];         /* OBJ/FBX basename if type == MESH */
                /* Transl. */
                float           x_t;
                float           y_t;
                float           z_t;
                /* Orientation as Euler ang (as 3 floats) - TO BE USED IN GAME LOOP UI */
                float           x_oe;
                float           y_oe;
                float           z_oe;
                /* Scaling */
                float           x_s;
                float           y_s;
                float           z_s;
                /* Orientation as a quat (as 4 doubles) - TO BE USED WHEN SAVING/LOADING */
                double          x_oq;
                double          y_oq;
                double          z_oq;
                double          w_oq;
        };
        struct {
                int32_t         id2;
                int32_t         parent_id2;
                int32_t         type2;
                char            name2[LG_MESH_NAME_MAX_LEN + 1];
                float           v[17];
        };
} LG_Node_NTOS;
 
/* New nodes/nodes ids added to the scene should start at or above first_obj_node/SCENE_FIRST_OBJ_NODE_ID (id = 3) */
enum {
        SCENE_ROOT_NODE_ID = 0,
        SCENE_GRID_NODE_ID,
        SCENE_XYZ_ARROWS_NODE_ID,
        SCENE_FIRST_OBJ_NODE_ID         /* Actually first user obj - 1 */
};
 
typedef struct {
        /* All serializable data */
        int32_t         id;             /* Set to -1 on error */
        LG_Light        light1;
        Rec2Df          landscape_rec;
        LG_Node_NTOS    nodes_ntos[NODE_NTOS_MAX_NUM];
        int32_t         n_node_ntos;
        char            euler_ang_rot_order[4];
        /* Not serializable data */
        LG_Camera       *cam1;
        LG_SceneNode    *root;
        LG_SceneNode    *grid;
        LG_SceneNode    *xyz_arrows;
        LG_SceneNode    *first_obj_node;
} LG_Scene;
 
LG_SceneNode    *lg_scenenode_new(int, const char *, lg_scenenode_type);
 
void            lg_scenenode_add_child(LG_SceneNode *, LG_SceneNode *);
 
void            lg_scenenode_remove_child(LG_SceneNode *, LG_SceneNode *);
 
void            lg_scenenode_free(LG_SceneNode *);
 
/* Any good ? */
#define         lg_scenenode_free2(s_node) {lg_scenenode_free(s_node); s_node = NULL;}
 
LG_SceneNode    *lg_scenenode_get_root(LG_SceneNode *);
 
int             lg_scenenode_remove_and_free_leaf(LG_SceneNode *);
 
void            lg_scenenode_remove_and_free_all(LG_SceneNode *);
 
void            lg_traverse_scene_graph(LG_SceneNode *, int (*)(LG_SceneNode *));
 
void            lg_traverse_scene_graph_2(LG_SceneNode *, int (*)(LG_SceneNode *, LG_Scene *), LG_Scene *);
 
LG_SceneNode    *lg_scenenode_find_by_id(LG_SceneNode *, int);
 
LG_SceneNode    *lg_scenenode_find_by_name(LG_SceneNode *, const char *);
 
void            lg_scenenode_reset_local_matrix(LG_SceneNode *);
 
void            lg_scenenode_set_local_matrix(LG_SceneNode *, vec3_t, LG_Quat, vec3_t);
 
void            lg_scenenode_update_local_matrix(LG_SceneNode *, vec3_t, LG_Quat, vec3_t);
 
void            lg_scenenode_update_world_matrix_tree(LG_SceneNode *, mat4_t *);
 
void            lg_scenenode_set_world_matrix(LG_SceneNode *, vec3_t, LG_Quat, vec3_t);
 
void            lg_scenenode_attach_to_camera(LG_SceneNode *, const LG_Camera *, vec3_t, vec3_t);
 
int             lg_scenenode_clone_worldm_l3dvb(LG_SceneNode *, LG_SceneNode *);
 
void            lg_traverse_printout_scene_graph(LG_SceneNode *, zboolean);
 
void            lg_scenenode_info(LG_SceneNode *);
 
int             lg_scenenode_info2(LG_SceneNode *);
 
const char      *lg_scenenode_type_string(int);
 
#endif /* LG_SCENE_GRAPH_H */