#include "vector4f.h"
#include <SDL2/SDL.h>

vec4_t vec4_create(GLfloat x, GLfloat y, GLfloat z, GLfloat w)
{
    vec4_t a = {x, y, z, w};
    return a;
}

vec4_t vec4_add(const vec4_t* a, const vec4_t* b)
{
    vec4_t c;
    c.x = a->x + b->x;
    c.y = a->y + b->y;
    c.z = a->z + b->z;
    c.w = a->w + b->w;
    return c;
}

vec4_t vec4_sub(const vec4_t* a, const vec4_t* b)
{
    vec4_t c;
    c.x = a->x - b->x;
    c.y = a->y - b->y;
    c.z = a->z - b->z;
    c.w = a->w - b->w;
    return c;
}

vec4_t vec4_scalar_mul(const vec4_t* a, GLfloat scalar)
{
    vec4_t c;
    c.x = a->x * scalar;
    c.y = a->y * scalar;
    c.z = a->z * scalar;
    c.w = a->w * scalar;
    return c;
}

GLfloat vec4_dot_mul(const vec4_t* a, const vec4_t* b)
{
    return ( (a->x * b->x) + (a->y * b->y) + (a->z * b->z) + (a->w * b->w) );
}


vec4_t vec4_cross_mul(const vec4_t* a, const vec4_t* b)
{
    vec4_t c;
    c.x = (a->y * b->z) - (a->z * b->y);
    c.y = (a->z * b->x) - (a->x * b->z);
    c.z = (a->x * b->y) - (a->y * b->x);
    c.w = 1.0f;
    return c;
}

GLfloat vec4_length(vec4_t* a)
{
    return SDL_sqrtf(SDL_pow(a->x, 2.0f) + SDL_pow(a->y, 2.0f) + SDL_pow(a->z, 2.0f) + SDL_pow(a->w, 2.0f) );
}

vec4_t vec4_normalize(vec4_t* a)
{
    vec4_t b;
    GLfloat length = vec4_length(a);
    b.x = a->x / length;
    b.y = a->y / length;
    b.z = a->z / length;
    b.w = a->w / length;
    return b;
}