/*
    See license.txt in the root of this project.
*/

# ifndef LUAVECTORLIB_H
# define LUAVECTORLIB_H

/* 

    We could use unsigned for rows and columns but it is more work and although it might be a bit 
    more efficient for now we stick to int. We assume sane vectors so the next maxima are actually
    already over the top. 

*/

# define max_vector_rows     24000000 /* we can have many rows if we use vectors for graphic but still ... */
# define max_vector_columns  24000000 /* normally there are only a few columns involved so ... */
# define max_vector         240000000 /* so we stay way below |max_vector_rows * max_vector_columns| */

# define max_point_rows    1000000000
# define max_point_columns 1000000000 /* normally 1 */
# define max_point         1000000000

typedef enum vector_classification {
    generic_type,
    zero_type,
    identity_type,     // definer product
    translation_type,  // definer product inverse determinant
    scaling_type,      // definer product inverse determinant
    rotation_type,     // definer product inverse determinant
    affine_type,       // definer product inverse determinant
    points_type,
    point_type,
} vector_classification;

typedef struct vectordata {
    int    rows;
    int    columns;
    int    type;
    int    stacking;
    int    index;
    int    size;
    double data[1];
} vectordata;

typedef vectordata *vector;

# define max_mesh 4 * 1024 * 1024

// average is kind of optional so maybe ...

typedef enum mesh_classification {
    no_mesh_type         = 0x00,
    dot_mesh_type        = 0x01,
    line_mesh_type       = 0x02,
    triangle_mesh_type   = 0x03,
    quad_mesh_type       = 0x04,
    /* these are virtual that is: point indices calculated on demand */
    triangle_5_mesh_type = 0x05,  /* [ 1 2 3 ] [ 4 5 6 ] */
    triangle_6_mesh_type = 0x06,  /* [ u / v ]  */
    triangle_7_mesh_type = 0x07,  /* [ 1 2 3 ] [ 1 3 4 ] */
} mesh_classification;

# define is_virtual_mesh_type(t) (t >= triangle_5_mesh_type && t <= triangle_7_mesh_type)

typedef struct meshdata {
    int       size;
    int       type;
    /* used for virtual meshes */
    int       rows;
    int       columns;
    /* */
    int       index;
    int       dimension;
    /* */
    unsigned *points;
    double   *average;
    /* */
    size_t    pointsbytes;
    size_t    averagebytes;
} meshdata;

typedef meshdata *mesh;

/* this has to be redone: 2 3 6 */

# define pointx(n)  (c[n+0])
# define pointy(n)  (c[n+1])
# define pointz(n)  (c[n+2])
# define pointnx(n) (c[n+3])
# define pointny(n) (c[n+4])
# define pointnz(n) (c[n+5])

typedef struct pointdata {
    union {
        double c[6];
        struct {
            double x;
            double y;
            double z;
            double nx;
            double ny;
            double nz;
        };
    };
} pointdata;

typedef enum pointtypes {
    point_type_default, /* x y z nx ny nz */
    point_type_xyz,     /* x y z          */
    point_type_xy,      /* x y            */
} pointtypes;

# define points_have_normals(p) (p->type == point_type_default)

typedef pointdata *point;

typedef struct pointsdata {
    int    rows;
    int    columns;
    int    type;
    int    stacking;
    int    index;
    int    size;
    int    pool;
    int    step;
    point  data;
    size_t bytes;
} pointsdata;

typedef pointsdata *points;

typedef struct normaldata {
    double x;
    double y;
    double z;
} normaldata;

typedef normaldata *normal;

typedef struct normalsdata {
    int    size;
    int    index;
    normal data;
    size_t bytes;
} normalsdata;

typedef normalsdata *normals;

/*tex

    In |lmtzbufferlib| we depend on this library so we have to provide a minimal set of helpers for
    that one. The memory helpers are somewhat inefficient but we need it because zbuffers take a
    lot memory. We can always comment the calls.

*/

extern vector   vectorlib_get                      (lua_State *L, int index); /* also use aux here */

extern mesh     vectorlib_mesh_aux_get             (lua_State *L, int index);
extern int      vectorlib_contour_aux_makemesh     (lua_State *L, int columns, int rows, int type);
extern points   vectorlib_points_aux_get           (lua_State *L, int index);
extern points   vectorlib_points_aux_push          (lua_State *L, int r, int c, int type, int wipe, int step);
extern int      vectorlib_points_aux_grow          (lua_State *L, points p, int step);
extern int      vectorlib_points_aux_prune         (lua_State *L, points p, int step);

extern normals  vectorlib_normals_aux_get          (lua_State *L, int index);
extern normals  vectorlib_normals_aux_push         (lua_State *L, int s, int wipe);

extern int      vectorlib_mesh_aux_get_points_okay (const mesh triangles, const points vertices, int index, int t[3]);
extern void     vectorlib_mesh_aux_get_points      (const mesh triangles, int index, int t[3]);

extern void   * vectorlib_memory_malloc            (size_t n);
extern void   * vectorlib_memory_realloc           (void *p, size_t n, size_t m);
extern void   * vectorlib_memory_calloc            (size_t n, size_t m);
extern void     vectorlib_memory_free              (void * p, size_t n);

# endif