ccore/include/core/Generic.h

#ifndef CORE_GENERIC_H
#define CORE_GENERIC_H

#include "core/Matrix.h"

// clang-format off
#define GENERIC_PAIR(type, name) type: name, const type : name
// clang-format on

#define GENERIC_FLOAT_VECTOR(a, name)     \
    _Generic(                             \
        (a),                              \
        GENERIC_PAIR(Vector2*, name##V2), \
        GENERIC_PAIR(Vector3*, name##V3), \
        GENERIC_PAIR(Vector4*, name##V4))

#define GENERIC_VECTOR(a, name)               \
    _Generic(                                 \
        (a),                                  \
        GENERIC_PAIR(Vector2*, name##V2),     \
        GENERIC_PAIR(Vector3*, name##V3),     \
        GENERIC_PAIR(Vector4*, name##V4),     \
        GENERIC_PAIR(IntVector2*, name##IV2), \
        GENERIC_PAIR(IntVector3*, name##IV3), \
        GENERIC_PAIR(IntVector4*, name##IV4))

#define ZERO_VECTOR(a)                               \
    _Generic(                                        \
        (a),                                         \
        GENERIC_PAIR(Matrix*, &(Vector3){0}),        \
        GENERIC_PAIR(Vector2*, &(Vector2){0}),       \
        GENERIC_PAIR(Vector3*, &(Vector3){0}),       \
        GENERIC_PAIR(Vector4*, &(Vector4){0}),       \
        GENERIC_PAIR(IntVector2*, &(IntVector2){0}), \
        GENERIC_PAIR(IntVector3*, &(IntVector3){0}), \
        GENERIC_PAIR(IntVector4*, &(IntVector4){0}))

#define GENERIC_FACTOR(b, type, base, factor)                \
    type:                                                    \
    _Generic((b), GENERIC_PAIR(type, base), default: factor)

#define SELECT_OP(_1, _2, _3, name, ...) name

#define addSet(a, b) GENERIC_VECTOR(a, addSet)(a, b)
#define add3(a, b, c) GENERIC_VECTOR(a, add)(a, b, c)
#define add2(a, b) add3(ZERO_VECTOR(a), a, b)
#define add(...) SELECT_OP(__VA_ARGS__, add3, add2, 0)(__VA_ARGS__)

#define subSet(a, b) GENERIC_VECTOR(a, subSet)(a, b)
#define sub3(a, b, c) GENERIC_VECTOR(a, sub)(a, b, c)
#define sub2(a, b) sub3(ZERO_VECTOR(a), a, b)
#define sub(...) SELECT_OP(__VA_ARGS__, sub3, sub2, 0)(__VA_ARGS__)

#define mulSet(a, b)                                                 \
    _Generic(                                                        \
        (a),                                                         \
        Matrix *: mulSetMatrix,                                      \
        Quaternion *: mulSetQ,                                       \
        GENERIC_FACTOR(b, Vector2*, mulSetV2, mulSetV2F),            \
        GENERIC_FACTOR(b, Vector3*, mulSetV3, mulSetV3F),            \
        GENERIC_FACTOR(b, Vector4*, mulSetV4, mulSetV4F),            \
        GENERIC_FACTOR(b, IntVector2*, mulSetIV2, mulSetIV2F),       \
        GENERIC_FACTOR(b, IntVector3*, mulSetIV3, mulSetIV3F),       \
        GENERIC_FACTOR(b, IntVector4*, mulSetIV4, mulSetIV4F))(a, b)

#define mul3(a, b, c)                                             \
    _Generic(                                                     \
        (a),                                                      \
        Matrix *: mulMatrix,                                      \
        Quaternion *: mulQ,                                       \
        GENERIC_FACTOR(c, Vector2*, mulV2, mulV2F),               \
        Vector3 *: _Generic(                                      \
                     (c),                                         \
                Vector3 *: _Generic(                              \
                             (b),                                 \
                        GENERIC_PAIR(Quaternion*, mulQV3),        \
                        GENERIC_PAIR(Matrix*, mulMatrixV3),       \
                        default: mulV3),                          \
                default: mulV3F),                                 \
        GENERIC_FACTOR(c, Vector4*, mulV4, mulV4F),               \
        GENERIC_FACTOR(c, IntVector2*, mulIV2, mulIV2F),          \
        GENERIC_FACTOR(c, IntVector3*, mulIV3, mulIV3F),          \
        GENERIC_FACTOR(c, IntVector4*, mulIV4, mulIV4F))(a, b, c)
#define mul2(a, b) mul3(ZERO_VECTOR(a), a, b)
#define mul(...) SELECT_OP(__VA_ARGS__, mul3, mul2, 0)(__VA_ARGS__)

#define divSet(a, b)                                                 \
    _Generic(                                                        \
        (a),                                                         \
        GENERIC_FACTOR(b, Vector2*, divSetV2, divSetV2F),            \
        GENERIC_FACTOR(b, Vector3*, divSetV3, divSetV3F),            \
        GENERIC_FACTOR(b, Vector4*, divSetV4, divSetV4F),            \
        GENERIC_FACTOR(b, IntVector2*, divSetIV2, divSetIV2F),       \
        GENERIC_FACTOR(b, IntVector3*, divSetIV3, divSetIV3F),       \
        GENERIC_FACTOR(b, IntVector4*, divSetIV4, divSetIV4F))(a, b)

#define div3(a, b, c)                                             \
    _Generic(                                                     \
        (a),                                                      \
        GENERIC_FACTOR(c, Vector2*, divV2, divV2F),               \
        GENERIC_FACTOR(c, Vector3*, divV3, divV3F),               \
        GENERIC_FACTOR(c, Vector4*, divV4, divV4F),               \
        GENERIC_FACTOR(c, IntVector2*, divIV2, divIV2F),          \
        GENERIC_FACTOR(c, IntVector3*, divIV3, divIV3F),          \
        GENERIC_FACTOR(c, IntVector4*, divIV4, divIV4F))(a, b, c)
#define div2(a, b) div3(ZERO_VECTOR(a), a, b)
#define div(...) SELECT_OP(__VA_ARGS__, div3, div2, 0)(__VA_ARGS__)

#define invertSet(a) GENERIC_VECTOR(a, invertSet)(a)
#define invert2(a, b) GENERIC_VECTOR(a, invert)(a, b)
#define invert1(a) invert2(ZERO_VECTOR(a), a)
#define invert(...) SELECT_OP(0, __VA_ARGS__, invert2, invert1, 0)(__VA_ARGS__)
#define dot(a, b) GENERIC_FLOAT_VECTOR(a, dot)(a, b)
#define squareLength(a) GENERIC_FLOAT_VECTOR(a, squareLength)(a)
#define length(a) GENERIC_FLOAT_VECTOR(a, length)(a)
#define normalize(a) GENERIC_FLOAT_VECTOR(a, normalize)(a)

#undef cross
#define SELECT_OP(_1, _2, _3, name, ...) name
#define cross3(a, b, c) cross(a, b, c)
#define cross2(a, b) cross(&(Vector3){0}, a, b)
#define cross(...) SELECT_OP(__VA_ARGS__, cross3, cross2, 0)(__VA_ARGS__)

#define convert(a, b)                  \
    _Generic(                          \
        (a),                           \
        Vector2 *: convertIV2,         \
        Vector3 *: convertIV3,         \
        Vector4 *: convertIV4,         \
        IntVector2 *: convertV2,       \
        IntVector3 *: convertV3,       \
        IntVector4 *: convertV4)(a, b)

#endif