#ifndef _GEOMETRY_MATRIX2X2_H_
#define _GEOMETRY_MATRIX2X2_H_

#include "angle.h"
#include "vector2.h"
#include "matrixes.h"

// =================== Reset ==================== //

static inline void bg_fp32_matrix2x2_reset(BgFP32Matrix2x2* matrix)
{
    matrix->r1c1 = 0.0f;
    matrix->r1c2 = 0.0f;
    matrix->r2c1 = 0.0f;
    matrix->r2c2 = 0.0f;
}

static inline void bg_fp64_matrix2x2_reset(BgFP64Matrix2x2* matrix)
{
    matrix->r1c1 = 0.0;
    matrix->r1c2 = 0.0;
    matrix->r2c1 = 0.0;
    matrix->r2c2 = 0.0;
}

// ================== Identity ================== //

static inline void bg_fp32_matrix2x2_set_to_identity(BgFP32Matrix2x2* matrix)
{
    matrix->r1c1 = 1.0f;
    matrix->r1c2 = 0.0f;
    matrix->r2c1 = 0.0f;
    matrix->r2c2 = 1.0f;
}

static inline void bg_fp64_matrix2x2_set_to_identity(BgFP64Matrix2x2* matrix)
{
    matrix->r1c1 = 1.0;
    matrix->r1c2 = 0.0;
    matrix->r2c1 = 0.0;
    matrix->r2c2 = 1.0;
}

// ================ Make Diagonal =============== //

static inline void bg_fp32_matrix2x2_set_to_diagonal(const float d1, const float d2, BgFP32Matrix2x2* matrix)
{
    matrix->r1c1 = d1;
    matrix->r1c2 = 0.0f;
    matrix->r2c1 = 0.0f;
    matrix->r2c2 = d2;
}

static inline void bg_fp64_matrix2x2_set_to_diagonal(const double d1, const double d2, BgFP64Matrix2x2* matrix)
{
    matrix->r1c1 = d1;
    matrix->r1c2 = 0.0;
    matrix->r2c1 = 0.0;
    matrix->r2c2 = d2;
}

// ============== Rotation Matrix =============== //

static inline void bg_fp32_matrix2x2_make_turn(const float angle, const angle_unit_t unit, BgFP32Matrix2x2* matrix)
{
    const float radians = bg_fp32_angle_to_radians(angle, unit);
    const float cosine = cosf(radians);
    const float sine = sinf(radians);

    matrix->r1c1 = cosine;
    matrix->r1c2 = -sine;
    matrix->r2c1 = sine;
    matrix->r2c2 = cosine;
}

static inline void bg_fp64_matrix2x2_make_turn(const double angle, const angle_unit_t unit, BgFP64Matrix2x2* matrix)
{
    const double radians = bg_fp64_angle_to_radians(angle, unit);
    const double cosine = cos(radians);
    const double sine = sin(radians);

    matrix->r1c1 = cosine;
    matrix->r1c2 = -sine;
    matrix->r2c1 = sine;
    matrix->r2c2 = cosine;
}

// ==================== Copy ==================== //

static inline void bg_fp32_matrix2x2_copy(const BgFP32Matrix2x2* from, BgFP32Matrix2x2* to)
{
    to->r1c1 = from->r1c1;
    to->r1c2 = from->r1c2;

    to->r2c1 = from->r2c1;
    to->r2c2 = from->r2c2;
}

static inline void bg_fp64_matrix2x2_copy(const BgFP64Matrix2x2* from, BgFP64Matrix2x2* to)
{
    to->r1c1 = from->r1c1;
    to->r1c2 = from->r1c2;

    to->r2c1 = from->r2c1;
    to->r2c2 = from->r2c2;
}

// ============= Copy to twin type ============== //

static inline void bg_fp32_matrix2x2_set_from_fp64(const BgFP64Matrix2x2* from, BgFP32Matrix2x2* to)
{
    to->r1c1 = (float)from->r1c1;
    to->r1c2 = (float)from->r1c2;

    to->r2c1 = (float)from->r2c1;
    to->r2c2 = (float)from->r2c2;
}

static inline void bg_fp64_matrix2x2_set_from_fp32(const BgFP32Matrix2x2* from, BgFP64Matrix2x2* to)
{
    to->r1c1 = from->r1c1;
    to->r1c2 = from->r1c2;

    to->r2c1 = from->r2c1;
    to->r2c2 = from->r2c2;
}

// ================ Determinant ================= //

static inline float bg_fp32_matrix2x2_get_determinant(const BgFP32Matrix2x2* matrix)
{
    return matrix->r1c1 * matrix->r2c2 - matrix->r1c2 * matrix->r2c1;
}

static inline double bg_fp64_matrix2x2_get_determinant(const BgFP64Matrix2x2* matrix)
{
    return matrix->r1c1 * matrix->r2c2 - matrix->r1c2 * matrix->r2c1;
}

// ================== Singular ================== //

static inline int bg_fp32_matrix2x2_is_singular(const BgFP32Matrix2x2* matrix)
{
    const float determinant = bg_fp32_matrix2x2_get_determinant(matrix);

    return -BG_FP32_EPSYLON <= determinant && determinant <= BG_FP32_EPSYLON;
}

static inline int bg_fp64_matrix2x2_is_singular(const BgFP64Matrix2x2* matrix)
{
    const double determinant = bg_fp64_matrix2x2_get_determinant(matrix);

    return -BG_FP64_EPSYLON <= determinant && determinant <= BG_FP64_EPSYLON;
}

// =============== Transposition ================ //

static inline void bg_fp32_matrix2x2_transpose(BgFP32Matrix2x2* matrix)
{
    const float tmp = matrix->r1c2;
    matrix->r1c2 = matrix->r2c1;
    matrix->r2c1 = tmp;
}

static inline void bg_fp64_matrix2x2_transpose(BgFP64Matrix2x2* matrix)
{
    const double tmp = matrix->r1c2;
    matrix->r1c2 = matrix->r2c1;
    matrix->r2c1 = tmp;
}

// ================= Inversion ================== //

static inline int bg_fp32_matrix2x2_invert(BgFP32Matrix2x2* matrix)
{
    const float determinant = bg_fp32_matrix2x2_get_determinant(matrix);

    if (-BG_FP32_EPSYLON <= determinant && determinant <= BG_FP32_EPSYLON) {
        return 0;
    }

    const float r1c1 =  matrix->r2c2;
    const float r1c2 = -matrix->r1c2;

    const float r2c1 = -matrix->r2c1;
    const float r2c2 =  matrix->r1c1;

    matrix->r1c1 = r1c1 / determinant;
    matrix->r1c2 = r1c2 / determinant;

    matrix->r2c1 = r2c1 / determinant;
    matrix->r2c2 = r2c2 / determinant;

    return 1;
}

static inline int bg_fp64_matrix2x2_invert(BgFP64Matrix2x2* matrix)
{
    const double determinant = bg_fp64_matrix2x2_get_determinant(matrix);

    if (-BG_FP64_EPSYLON <= determinant && determinant <= BG_FP64_EPSYLON) {
        return 0;
    }

    const double r1c1 =  matrix->r2c2;
    const double r1c2 = -matrix->r1c2;

    const double r2c1 = -matrix->r2c1;
    const double r2c2 =  matrix->r1c1;

    matrix->r1c1 = r1c1 / determinant;
    matrix->r1c2 = r1c2 / determinant;

    matrix->r2c1 = r2c1 / determinant;
    matrix->r2c2 = r2c2 / determinant;

    return 1;
}

// =============== Set Transposed =============== //

static inline void bg_fp32_matrix2x2_set_transposed(const BgFP32Matrix2x2* from, BgFP32Matrix2x2* to)
{
    float tmp = from->r1c2;

    to->r1c1 = from->r1c1;
    to->r1c2 = from->r2c1;

    to->r2c1 = tmp;
    to->r2c2 = from->r2c2;
}

static inline void bg_fp64_matrix2x2_set_transposed(const BgFP64Matrix2x2* from, BgFP64Matrix2x2* to)
{
    double tmp = from->r1c2;

    to->r1c1 = from->r1c1;
    to->r1c2 = from->r2c1;

    to->r2c1 = tmp;
    to->r2c2 = from->r2c2;
}

// ================ Set Inverted ================ //

static inline int bg_fp32_matrix2x2_set_inverted(const BgFP32Matrix2x2* from, BgFP32Matrix2x2* to)
{
    const float determinant = bg_fp32_matrix2x2_get_determinant(from);

    if (-BG_FP32_EPSYLON <= determinant && determinant <= BG_FP32_EPSYLON) {
        return 0;
    }

    const float r1c1 =  from->r2c2;
    const float r1c2 = -from->r1c2;

    const float r2c1 = -from->r2c1;
    const float r2c2 =  from->r1c1;

    to->r1c1 = r1c1 / determinant;
    to->r1c2 = r1c2 / determinant;

    to->r2c1 = r2c1 / determinant;
    to->r2c2 = r2c2 / determinant;

    return 1;
}

static inline int bg_fp64_matrix2x2_set_inverted(const BgFP64Matrix2x2* from, BgFP64Matrix2x2* to)
{
    const double determinant = bg_fp64_matrix2x2_get_determinant(from);

    if (-BG_FP64_EPSYLON <= determinant && determinant <= BG_FP64_EPSYLON) {
        return 0;
    }

    const double r1c1 =  from->r2c2;
    const double r1c2 = -from->r1c2;

    const double r2c1 = -from->r2c1;
    const double r2c2 =  from->r1c1;

    to->r1c1 = r1c1 / determinant;
    to->r1c2 = r1c2 / determinant;

    to->r2c1 = r2c1 / determinant;
    to->r2c2 = r2c2 / determinant;

    return 1;
}

// ================= Set Row 1 ================== //

static inline void bg_fp32_matrix2x2_set_row1(const float c1, const float c2, BgFP32Matrix2x2* matrix)
{
    matrix->r1c1 = c1;
    matrix->r1c2 = c2;
}

static inline void bg_fp64_matrix2x2_set_row1(const double c1, const double c2, BgFP64Matrix2x2* matrix)
{
    matrix->r1c1 = c1;
    matrix->r1c2 = c2;
}

// ================= Set Row 2 ================== //

static inline void bg_fp32_matrix2x2_set_row2(const float c1, const float c2, BgFP32Matrix2x2* matrix)
{
    matrix->r2c1 = c1;
    matrix->r2c2 = c2;
}

static inline void bg_fp64_matrix2x2_set_row2(const double c1, const double c2, BgFP64Matrix2x2* matrix)
{
    matrix->r2c1 = c1;
    matrix->r2c2 = c2;
}

// ================ Set Column 1 ================ //

static inline void bg_fp32_matrix2x2_set_column1(const float r1, const float r2, BgFP32Matrix2x2* matrix)
{
    matrix->r1c1 = r1;
    matrix->r2c1 = r2;
}

static inline void bg_fp64_matrix2x2_set_column1(const double r1, const double r2, BgFP64Matrix2x2* matrix)
{
    matrix->r1c1 = r1;
    matrix->r2c1 = r2;
}

// ================ Set Column 2 ================ //

static inline void bg_fp32_matrix2x2_set_column2(const float r1, const float r2, BgFP32Matrix2x2* matrix)
{
    matrix->r1c2 = r1;
    matrix->r2c2 = r2;
}

static inline void bg_fp64_matrix2x2_set_column2(const double r1, const double r2, BgFP64Matrix2x2* matrix)
{
    matrix->r1c2 = r1;
    matrix->r2c2 = r2;
}

// ================ Append scaled =============== //

static inline void bg_fp32_matrix2x2_append_scaled(BgFP32Matrix2x2* basic_vector, const BgFP32Matrix2x2* scalable_vector, const float scale)
{
    basic_vector->r1c1 += scalable_vector->r1c1 * scale;
    basic_vector->r1c2 += scalable_vector->r1c2 * scale;

    basic_vector->r2c1 += scalable_vector->r2c1 * scale;
    basic_vector->r2c2 += scalable_vector->r2c2 * scale;
}

static inline void bg_fp64_matrix2x2_append_scaled(BgFP64Matrix2x2* basic_vector, const BgFP64Matrix2x2* scalable_vector, const double scale)
{
    basic_vector->r1c1 += scalable_vector->r1c1 * scale;
    basic_vector->r1c2 += scalable_vector->r1c2 * scale;

    basic_vector->r2c1 += scalable_vector->r2c1 * scale;
    basic_vector->r2c2 += scalable_vector->r2c2 * scale;
}

// ================== Addition ================== //

static inline void bg_fp32_matrix2x2_add(const BgFP32Matrix2x2* matrix1, const BgFP32Matrix2x2* matrix2, BgFP32Matrix2x2* sum)
{
    sum->r1c1 = matrix1->r1c1 + matrix2->r1c1;
    sum->r1c2 = matrix1->r1c2 + matrix2->r1c2;

    sum->r2c1 = matrix1->r2c1 + matrix2->r2c1;
    sum->r2c2 = matrix1->r2c2 + matrix2->r2c2;
}

static inline void bg_fp64_matrix2x2_add(const BgFP64Matrix2x2* matrix1, const BgFP64Matrix2x2* matrix2, BgFP64Matrix2x2* sum)
{
    sum->r1c1 = matrix1->r1c1 + matrix2->r1c1;
    sum->r1c2 = matrix1->r1c2 + matrix2->r1c2;

    sum->r2c1 = matrix1->r2c1 + matrix2->r2c1;
    sum->r2c2 = matrix1->r2c2 + matrix2->r2c2;
}

// ================ Subtraction ================= //

static inline void bg_fp32_matrix2x2_subtract(const BgFP32Matrix2x2* minuend, const BgFP32Matrix2x2* subtrahend, BgFP32Matrix2x2* difference)
{
    difference->r1c1 = minuend->r1c1 - subtrahend->r1c1;
    difference->r1c2 = minuend->r1c2 - subtrahend->r1c2;

    difference->r2c1 = minuend->r2c1 - subtrahend->r2c1;
    difference->r2c2 = minuend->r2c2 - subtrahend->r2c2;
}

static inline void bg_fp64_matrix2x2_subtract(const BgFP64Matrix2x2* minuend, const BgFP64Matrix2x2* subtrahend, BgFP64Matrix2x2* difference)
{
    difference->r1c1 = minuend->r1c1 - subtrahend->r1c1;
    difference->r1c2 = minuend->r1c2 - subtrahend->r1c2;

    difference->r2c1 = minuend->r2c1 - subtrahend->r2c1;
    difference->r2c2 = minuend->r2c2 - subtrahend->r2c2;
}

// =============== Multiplication =============== //

static inline void bg_fp32_matrix2x2_multiply(const BgFP32Matrix2x2* multiplicand, const float multiplier, BgFP32Matrix2x2* product)
{
    product->r1c1 = multiplicand->r1c1 * multiplier;
    product->r1c2 = multiplicand->r1c2 * multiplier;

    product->r2c1 = multiplicand->r2c1 * multiplier;
    product->r2c2 = multiplicand->r2c2 * multiplier;
}

static inline void bg_fp64_matrix2x2_multiply(const BgFP64Matrix2x2* multiplicand, const double multiplier, BgFP64Matrix2x2* product)
{
    product->r1c1 = multiplicand->r1c1 * multiplier;
    product->r1c2 = multiplicand->r1c2 * multiplier;

    product->r2c1 = multiplicand->r2c1 * multiplier;
    product->r2c2 = multiplicand->r2c2 * multiplier;
}

// ================== Division ================== //

static inline void bg_fp32_matrix2x2_divide(const BgFP32Matrix2x2* dividend, const float divisor, BgFP32Matrix2x2* quotient)
{
    quotient->r1c1 = dividend->r1c1 / divisor;
    quotient->r1c2 = dividend->r1c2 / divisor;

    quotient->r2c1 = dividend->r2c1 / divisor;
    quotient->r2c2 = dividend->r2c2 / divisor;
}

static inline void bg_fp64_matrix2x2_divide(const BgFP64Matrix2x2* dividend, const double divisor, BgFP64Matrix2x2* quotient)
{
    quotient->r1c1 = dividend->r1c1 / divisor;
    quotient->r1c2 = dividend->r1c2 / divisor;

    quotient->r2c1 = dividend->r2c1 / divisor;
    quotient->r2c2 = dividend->r2c2 / divisor;
}

// ============ Left Vector Product ============= //

static inline void bg_fp32_matrix2x2_left_product(const BgFP32Vector2* vector, const BgFP32Matrix2x2* matrix, BgFP32Vector2* result)
{
    bg_fp32_vector2_set_values(
        vector->x1 * matrix->r1c1 + vector->x2 * matrix->r2c1,
        vector->x1 * matrix->r1c2 + vector->x2 * matrix->r2c2,
        result
    );
}

static inline void bg_fp64_matrix2x2_left_product(const BgFP64Vector2* vector, const BgFP64Matrix2x2* matrix, BgFP64Vector2* result)
{
    bg_fp64_vector2_set_values(
        vector->x1 * matrix->r1c1 + vector->x2 * matrix->r2c1,
        vector->x1 * matrix->r1c2 + vector->x2 * matrix->r2c2,
        result
    );
}

// ============ Right Vector Product ============ //

static inline void bg_fp32_matrix2x2_right_product(const BgFP32Matrix2x2* matrix, const BgFP32Vector2* vector, BgFP32Vector2* result)
{
    bg_fp32_vector2_set_values(
        matrix->r1c1 * vector->x1 + matrix->r1c2 * vector->x2,
        matrix->r2c1 * vector->x1 + matrix->r2c2 * vector->x2,
        result
    );
}

static inline void bg_fp64_matrix2x2_right_product(const BgFP64Matrix2x2* matrix, const BgFP64Vector2* vector, BgFP64Vector2* result)
{
    bg_fp64_vector2_set_values(
        matrix->r1c1 * vector->x1 + matrix->r1c2 * vector->x2,
        matrix->r2c1 * vector->x1 + matrix->r2c2 * vector->x2,
        result
    );
}

#endif