#ifndef _COMMON_H
#define _COMMON_H

#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
#include <string.h>  
#include <assert.h>
#include <stdbool.h>
#include <math.h>
#include <SDL2/SDL.h>

#define PROGRAM_NAME "Symulator pól elektromagnetycznych"

#define con_printf printf // TODO?

#define max2(a, b) ((a) > (b) ? (a) : (b))
#define max3(a, b, c) (max2(max2(a, b), c))
#define min2(a, b) ((a) < (b) ? (a) : (b))
#define min3(a, b, c) (min2(min2(a, b), c))
#define sq(x) ((x)*(x))

char *va(const char *fmt, ...);
int64_t get_time(void);

typedef float vec_t;
typedef vec_t vec2_t[2];   
typedef vec_t vec3_t[3];    
typedef vec_t vec4_t[4];
typedef vec_t mst2_t[4];
/* mst2_t is a 3x3 scale&translate matrix (only 4 components are needed):
 * [ dw  0   dx ]
 * [ 0   dh  dy ]
 * [ 0   0   1  ]
 */

static inline void v2_copy(vec_t *R, vec_t *A)
{
	R[0] = A[0];
	R[1] = A[1];
}

static inline void v3_copy(vec_t *R, vec_t *A)
{
	R[0] = A[0];
	R[1] = A[1];
	R[2] = A[2];
}

static inline void v4_copy(vec_t *R, vec_t *A)
{
	R[0] = A[0];
	R[1] = A[1];
	R[2] = A[2];
	R[3] = A[3];
}

static inline void v2_set(vec_t *R, vec_t a, vec_t b)
{
	R[0] = a;
	R[1] = b;
}

static inline void v3_set(vec_t *R, vec_t a, vec_t b, vec_t c)
{
	R[0] = a;
	R[1] = b;
	R[2] = c;
}

static inline void v2_add(vec_t *R, vec_t *A, vec_t *B)
{
	R[0] = A[0] + B[0];
	R[1] = A[1] + B[1];
}

static inline void v2_sub(vec_t *R, vec_t *A, vec_t *B)
{
	R[0] = A[0] - B[0];
	R[1] = A[1] - B[1];
}

static inline void v2_mul(vec_t *R, vec_t *A, vec_t b)
{
	R[0] = A[0] * b;
	R[1] = A[1] * b;
}

static inline void v3_add(vec_t *R, vec_t *A, vec_t *B)
{
	R[0] = A[0] + B[0];
	R[1] = A[1] + B[1];
	R[2] = A[2] + B[2];
}

static inline void v3_acc(vec_t *R, vec_t *A)
{
	R[0] += A[0];
	R[1] += A[1];
	R[2] += A[2];
}

static inline void v3_sub(vec_t *R, vec_t *A, vec_t *B)
{
	R[0] = A[0] - B[0];
	R[1] = A[1] - B[1];
	R[2] = A[2] - B[2];
}

static inline void v3_mul(vec_t *R, vec_t *A, vec_t b)
{
	R[0] = A[0] * b;
	R[1] = A[1] * b;
	R[2] = A[2] * b;
}

static inline void mst2_set_identity(mst2_t R)
{
	R[0] = 0;
	R[1] = 0;
	R[2] = 1;
	R[3] = 1;
}

static inline void mst2_set(mst2_t R, vec_t dx, vec_t dy, vec_t dw, vec_t dh)
{
	R[0] = dx;
	R[1] = dy;
	R[2] = dw;
	R[3] = dh;
}

static inline void mst2_inv(mst2_t R, mst2_t A)
{
	mst2_t copy = {A[0], A[1], A[2], A[3]};

	R[0] = -copy[0] / copy[2];
	R[1] = -copy[1] / copy[3];
	R[2] = 1 / copy[2];
	R[3] = 1 / copy[3];
}

static inline void v2_mul_mst2(vec_t *R, vec_t *A, mst2_t M)
{
	R[0] = M[0] + A[0] * M[2];
	R[1] = M[1] + A[1] * M[3];
}

static inline void v2_div_mst2(vec_t *R, vec_t *A, mst2_t M)
{
	mst2_t inv;

	mst2_inv(inv, M);
	v2_mul_mst2(R, A, inv);
}

// v2_mul_mst2 but without translation
static inline void v2_mul_mst2_nt(vec_t *R, vec_t *A, mst2_t M)
{
	R[0] = A[0] * M[2];
	R[1] = A[1] * M[3];
}

// v2_div_mst2 but without translation
static inline void v2_div_mst2_nt(vec_t *R, vec_t *A, mst2_t M)
{
	mst2_t inv;

	mst2_inv(inv, M);
	v2_mul_mst2_nt(R, A, inv);
}

static inline void mst2_dump(mst2_t M)
{
	printf("[%f\t%f\t%f]\n", M[2], 0.0, M[0]);
	printf("[%f\t%f\t%f]\n", 0.0, M[3], M[1]);
	printf("[%f\t%f\t%f]\n", 0.0, 0.0, 1.0);
}

static inline float remap(float x, float a0, float b0, float a1, float b1)
{
	return (x - a0) * (b1 - a1) / (b0 - a0) + a1;
}

#define DEG2RAD(x) ((x) / (180.0f / M_PI))

#endif // _COMMON_H