#ifndef _BGC_MATRIX2X2_H_
#define _BGC_MATRIX2X2_H_

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

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

inline void bgc_fp32_matrix2x2_reset(BGC_FP32_Matrix2x2* matrix)
{
    matrix->r1c1 = 0.0f;
    matrix->r1c2 = 0.0f;
    matrix->r2c1 = 0.0f;
    matrix->r2c2 = 0.0f;
}

inline void bgc_fp64_matrix2x2_reset(BGC_FP64_Matrix2x2* matrix)
{
    matrix->r1c1 = 0.0;
    matrix->r1c2 = 0.0;
    matrix->r2c1 = 0.0;
    matrix->r2c2 = 0.0;
}

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

inline void bgc_fp32_matrix2x2_make_identity(BGC_FP32_Matrix2x2* matrix)
{
    matrix->r1c1 = 1.0f;
    matrix->r1c2 = 0.0f;
    matrix->r2c1 = 0.0f;
    matrix->r2c2 = 1.0f;
}

inline void bgc_fp64_matrix2x2_make_identity(BGC_FP64_Matrix2x2* matrix)
{
    matrix->r1c1 = 1.0;
    matrix->r1c2 = 0.0;
    matrix->r2c1 = 0.0;
    matrix->r2c2 = 1.0;
}

// ================ Set Diagonal ================ //

inline void bgc_fp32_matrix2x2_make_diagonal(const float d1, const float d2, BGC_FP32_Matrix2x2* matrix)
{
    matrix->r1c1 = d1;
    matrix->r1c2 = 0.0f;
    matrix->r2c1 = 0.0f;
    matrix->r2c2 = d2;
}

inline void bgc_fp64_matrix2x2_make_diagonal(const double d1, const double d2, BGC_FP64_Matrix2x2* matrix)
{
    matrix->r1c1 = d1;
    matrix->r1c2 = 0.0;
    matrix->r2c1 = 0.0;
    matrix->r2c2 = d2;
}

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

inline void bgc_fp32_matrix2x2_make_for_turn(const float angle, const int angle_unit, BGC_FP32_Matrix2x2* matrix)
{
    const float radians = bgc_fp32_angle_to_radians(angle, angle_unit);
    const float cosine = cosf(radians);
    const float sine = sinf(radians);

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

inline void bgc_fp64_matrix2x2_make_for_turn(const double angle, const int angle_unit, BGC_FP64_Matrix2x2* matrix)
{
    const double radians = bgc_fp64_angle_to_radians(angle, angle_unit);
    const double cosine = cos(radians);
    const double sine = sin(radians);

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

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

inline float bgc_fp32_matrix2x2_get_determinant(const BGC_FP32_Matrix2x2* matrix)
{
    return matrix->r1c1 * matrix->r2c2 - matrix->r1c2 * matrix->r2c1;
}

inline double bgc_fp64_matrix2x2_get_determinant(const BGC_FP64_Matrix2x2* matrix)
{
    return matrix->r1c1 * matrix->r2c2 - matrix->r1c2 * matrix->r2c1;
}

// ================ Is Identity ================= //

inline int bgc_fp32_matrix2x2_is_identity(const BGC_FP32_Matrix2x2* matrix)
{
    return bgc_fp32_is_unit(matrix->r1c1) && bgc_fp32_is_zero(matrix->r1c2)
        && bgc_fp32_is_zero(matrix->r2c1) && bgc_fp32_is_unit(matrix->r2c2);
}

inline int bgc_fp64_matrix2x2_is_identity(const BGC_FP64_Matrix2x2* matrix)
{
    return bgc_fp64_is_unit(matrix->r1c1) && bgc_fp64_is_zero(matrix->r1c2)
        && bgc_fp64_is_zero(matrix->r2c1) && bgc_fp64_is_unit(matrix->r2c2);
}

// ================ Is Singular ================= //

inline int bgc_fp32_matrix2x2_is_singular(const BGC_FP32_Matrix2x2* matrix)
{
    return bgc_fp32_is_zero(bgc_fp32_matrix2x2_get_determinant(matrix));
}

inline int bgc_fp64_matrix2x2_is_singular(const BGC_FP64_Matrix2x2* matrix)
{
    return bgc_fp64_is_zero(bgc_fp64_matrix2x2_get_determinant(matrix));
}

// ================ Is Rotation ================= //

inline int bgc_fp32_matrix2x2_is_rotation(const BGC_FP32_Matrix2x2* matrix)
{
    BGC_FP32_Matrix2x2 product;

    product.r1c1 = matrix->r1c1 * matrix->r1c1 + matrix->r1c2 * matrix->r2c1;
    product.r1c2 = matrix->r1c1 * matrix->r1c2 + matrix->r1c2 * matrix->r2c2;

    product.r2c1 = matrix->r2c1 * matrix->r1c1 + matrix->r2c2 * matrix->r2c1;
    product.r2c2 = matrix->r2c1 * matrix->r1c2 + matrix->r2c2 * matrix->r2c2;

    return bgc_fp32_matrix2x2_is_identity(&product);
}

inline int bgc_fp64_matrix2x2_is_rotation(const BGC_FP64_Matrix2x2* matrix)
{
    BGC_FP64_Matrix2x2 product;

    product.r1c1 = matrix->r1c1 * matrix->r1c1 + matrix->r1c2 * matrix->r2c1;
    product.r1c2 = matrix->r1c1 * matrix->r1c2 + matrix->r1c2 * matrix->r2c2;

    product.r2c1 = matrix->r2c1 * matrix->r1c1 + matrix->r2c2 * matrix->r2c1;
    product.r2c2 = matrix->r2c1 * matrix->r1c2 + matrix->r2c2 * matrix->r2c2;

    return bgc_fp64_matrix2x2_is_identity(&product);
}

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

inline void bgc_fp32_matrix2x2_copy(const BGC_FP32_Matrix2x2* source, BGC_FP32_Matrix2x2* destination)
{
    destination->r1c1 = source->r1c1;
    destination->r1c2 = source->r1c2;

    destination->r2c1 = source->r2c1;
    destination->r2c2 = source->r2c2;
}

inline void bgc_fp64_matrix2x2_copy(const BGC_FP64_Matrix2x2* source, BGC_FP64_Matrix2x2* destination)
{
    destination->r1c1 = source->r1c1;
    destination->r1c2 = source->r1c2;

    destination->r2c1 = source->r2c1;
    destination->r2c2 = source->r2c2;
}

// ==================== Swap ==================== //

inline void bgc_fp32_matrix2x2_swap(BGC_FP32_Matrix2x2* matrix1, BGC_FP32_Matrix2x2* matrix2)
{
    const float r1c1 = matrix2->r1c1;
    const float r1c2 = matrix2->r1c2;

    const float r2c1 = matrix2->r2c1;
    const float r2c2 = matrix2->r2c2;

    matrix2->r1c1 = matrix1->r1c1;
    matrix2->r1c2 = matrix1->r1c2;

    matrix2->r2c1 = matrix1->r2c1;
    matrix2->r2c2 = matrix1->r2c2;

    matrix1->r1c1 = r1c1;
    matrix1->r1c2 = r1c2;

    matrix1->r2c1 = r2c1;
    matrix1->r2c2 = r2c2;
}

inline void bgc_fp64_matrix2x2_swap(BGC_FP64_Matrix2x2* matrix1, BGC_FP64_Matrix2x2* matrix2)
{
    const double r1c1 = matrix2->r1c1;
    const double r1c2 = matrix2->r1c2;

    const double r2c1 = matrix2->r2c1;
    const double r2c2 = matrix2->r2c2;

    matrix2->r1c1 = matrix1->r1c1;
    matrix2->r1c2 = matrix1->r1c2;

    matrix2->r2c1 = matrix1->r2c1;
    matrix2->r2c2 = matrix1->r2c2;

    matrix1->r1c1 = r1c1;
    matrix1->r1c2 = r1c2;

    matrix1->r2c1 = r2c1;
    matrix1->r2c2 = r2c2;
}

// ================== Convert =================== //

inline void bgc_fp64_matrix2x2_convert_to_fp32(const BGC_FP64_Matrix2x2* source, BGC_FP32_Matrix2x2* destination)
{
    destination->r1c1 = (float)source->r1c1;
    destination->r1c2 = (float)source->r1c2;

    destination->r2c1 = (float)source->r2c1;
    destination->r2c2 = (float)source->r2c2;
}

inline void bgc_fp32_matrix2x2_convert_to_fp64(const BGC_FP32_Matrix2x2* source, BGC_FP64_Matrix2x2* destination)
{
    destination->r1c1 = source->r1c1;
    destination->r1c2 = source->r1c2;

    destination->r2c1 = source->r2c1;
    destination->r2c2 = source->r2c2;
}

// ================ Get Inverse ================= //

inline int bgc_fp32_matrix2x2_get_inverse(const BGC_FP32_Matrix2x2* matrix, BGC_FP32_Matrix2x2* inverse)
{
    const float determinant = bgc_fp32_matrix2x2_get_determinant(matrix);

    if (bgc_fp32_is_zero(determinant)) {
        return 0;
    }

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

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

    const float multiplier = 1.0f / determinant;

    inverse->r1c1 = r1c1 * multiplier;
    inverse->r1c2 = r1c2 * multiplier;

    inverse->r2c1 = r2c1 * multiplier;
    inverse->r2c2 = r2c2 * multiplier;

    return 1;
}

inline int bgc_fp64_matrix2x2_get_inverse(const BGC_FP64_Matrix2x2* matrix, BGC_FP64_Matrix2x2* inverse)
{
    const double determinant = bgc_fp64_matrix2x2_get_determinant(matrix);

    if (bgc_fp64_is_zero(determinant)) {
        return 0;
    }

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

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

    const double multiplier = 1.0 / determinant;

    inverse->r1c1 = r1c1 * multiplier;
    inverse->r1c2 = r1c2 * multiplier;

    inverse->r2c1 = r2c1 * multiplier;
    inverse->r2c2 = r2c2 * multiplier;

    return 1;
}

// =================== Invert =================== //

inline int bgc_fp32_matrix2x2_invert(BGC_FP32_Matrix2x2* matrix)
{
    return bgc_fp32_matrix2x2_get_inverse(matrix, matrix);
}

inline int bgc_fp64_matrix2x2_invert(BGC_FP64_Matrix2x2* matrix)
{
    return bgc_fp64_matrix2x2_get_inverse(matrix, matrix);
}

// ================= Transpose ================== //

inline void bgc_fp32_matrix2x2_transpose(BGC_FP32_Matrix2x2* matrix)
{
    const float r1c2 = matrix->r1c2;
    matrix->r1c2 = matrix->r2c1;
    matrix->r2c1 = r1c2;
}

inline void bgc_fp64_matrix2x2_transpose(BGC_FP64_Matrix2x2* matrix)
{
    const double r1c2 = matrix->r1c2;
    matrix->r1c2 = matrix->r2c1;
    matrix->r2c1 = r1c2;
}

// =============== Get Transpose ================ //

inline void bgc_fp32_matrix2x2_get_transposed(const BGC_FP32_Matrix2x2* matrix, BGC_FP32_Matrix2x2* transposed)
{
    const float r1c2 = matrix->r1c2;

    transposed->r1c1 = matrix->r1c1;
    transposed->r1c2 = matrix->r2c1;

    transposed->r2c1 = r1c2;
    transposed->r2c2 = matrix->r2c2;
}

inline void bgc_fp64_matrix2x2_get_transposed(const BGC_FP64_Matrix2x2* matrix, BGC_FP64_Matrix2x2* transposed)
{
    const double r1c2 = matrix->r1c2;

    transposed->r1c1 = matrix->r1c1;
    transposed->r1c2 = matrix->r2c1;

    transposed->r2c1 = r1c2;
    transposed->r2c2 = matrix->r2c2;
}

// ================== Get Row =================== //

inline void bgc_fp32_matrix2x2_get_row(const int number, const BGC_FP32_Matrix2x2* matrix, BGC_FP32_Vector2* row)
{
    if (number == 1) {
        row->x1 = matrix->r1c1;
        row->x2 = matrix->r1c2;
        return;
    }

    if (number == 2) {
        row->x1 = matrix->r2c1;
        row->x2 = matrix->r2c2;
        return;
    }

    row->x1 = 0.0f;
    row->x2 = 0.0f;
}

inline void bgc_fp64_matrix2x2_get_row(const int number, const BGC_FP64_Matrix2x2* matrix, BGC_FP64_Vector2* row)
{
    if (number == 1) {
        row->x1 = matrix->r1c1;
        row->x2 = matrix->r1c2;
        return;
    }

    if (number == 2) {
        row->x1 = matrix->r2c1;
        row->x2 = matrix->r2c2;
        return;
    }

    row->x1 = 0.0;
    row->x2 = 0.0;
}

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

inline void bgc_fp32_matrix2x2_set_row(const int number, const BGC_FP32_Vector2* row, BGC_FP32_Matrix2x2* matrix)
{
    if (number == 1) {
        matrix->r1c1 = row->x1;
        matrix->r1c2 = row->x2;
        return;
    }

    if (number == 2) {
        matrix->r2c1 = row->x1;
        matrix->r2c2 = row->x2;
    }
}

inline void bgc_fp64_matrix2x2_set_row(const int number, const BGC_FP64_Vector2* row, BGC_FP64_Matrix2x2* matrix)
{
    if (number == 1) {
        matrix->r1c1 = row->x1;
        matrix->r1c2 = row->x2;
        return;
    }

    if (number == 2) {
        matrix->r2c1 = row->x1;
        matrix->r2c2 = row->x2;
    }
}

// ================= Get Column ================= //

inline void bgc_fp32_matrix2x2_get_column(const int number, const BGC_FP32_Matrix2x2* matrix, BGC_FP32_Vector2* column)
{
    if (number == 1) {
        column->x1 = matrix->r1c1;
        column->x2 = matrix->r2c1;
        return;
    }

    if (number == 2) {
        column->x1 = matrix->r1c2;
        column->x2 = matrix->r2c2;
        return;
    }

    column->x1 = 0.0f;
    column->x2 = 0.0f;
}

inline void bgc_fp64_matrix2x2_get_column(const int number, const BGC_FP64_Matrix2x2* matrix, BGC_FP64_Vector2* column)
{
    if (number == 1) {
        column->x1 = matrix->r1c1;
        column->x2 = matrix->r2c1;
        return;
    }

    if (number == 2) {
        column->x1 = matrix->r1c2;
        column->x2 = matrix->r2c2;
        return;
    }

    column->x1 = 0.0;
    column->x2 = 0.0;
}

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

inline void bgc_fp32_matrix2x2_set_column(const int number, const BGC_FP32_Vector2* column, BGC_FP32_Matrix2x2* matrix)
{
    if (number == 1) {
        matrix->r1c1 = column->x1;
        matrix->r2c1 = column->x2;
        return;
    }

    if (number == 2) {
        matrix->r1c2 = column->x1;
        matrix->r2c2 = column->x2;
    }
}

inline void bgc_fp64_matrix2x2_set_column(const int number, const BGC_FP64_Vector2* column, BGC_FP64_Matrix2x2* matrix)
{
    if (number == 1) {
        matrix->r1c1 = column->x1;
        matrix->r2c1 = column->x2;
        return;
    }

    if (number == 2) {
        matrix->r1c2 = column->x1;
        matrix->r2c2 = column->x2;
    }
}

// ==================== Add ===================== //

inline void bgc_fp32_matrix2x2_add(const BGC_FP32_Matrix2x2* matrix1, const BGC_FP32_Matrix2x2* matrix2, BGC_FP32_Matrix2x2* 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;
}

inline void bgc_fp64_matrix2x2_add(const BGC_FP64_Matrix2x2* matrix1, const BGC_FP64_Matrix2x2* matrix2, BGC_FP64_Matrix2x2* 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;
}

// ================= Add scaled ================= //

inline void bgc_fp32_matrix2x2_add_scaled(const BGC_FP32_Matrix2x2* basic_matrix, const BGC_FP32_Matrix2x2* scalable_matrix, const float scale, BGC_FP32_Matrix2x2* sum)
{
    sum->r1c1 = basic_matrix->r1c1 + scalable_matrix->r1c1 * scale;
    sum->r1c2 = basic_matrix->r1c2 + scalable_matrix->r1c2 * scale;

    sum->r2c1 = basic_matrix->r2c1 + scalable_matrix->r2c1 * scale;
    sum->r2c2 = basic_matrix->r2c2 + scalable_matrix->r2c2 * scale;
}

inline void bgc_fp64_matrix2x2_add_scaled(const BGC_FP64_Matrix2x2* basic_matrix, const BGC_FP64_Matrix2x2* scalable_matrix, const double scale, BGC_FP64_Matrix2x2* sum)
{
    sum->r1c1 = basic_matrix->r1c1 + scalable_matrix->r1c1 * scale;
    sum->r1c2 = basic_matrix->r1c2 + scalable_matrix->r1c2 * scale;

    sum->r2c1 = basic_matrix->r2c1 + scalable_matrix->r2c1 * scale;
    sum->r2c2 = basic_matrix->r2c2 + scalable_matrix->r2c2 * scale;
}

// ================== Subtract ================== //

inline void bgc_fp32_matrix2x2_subtract(const BGC_FP32_Matrix2x2* minuend, const BGC_FP32_Matrix2x2* subtrahend, BGC_FP32_Matrix2x2* 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;
}

inline void bgc_fp64_matrix2x2_subtract(const BGC_FP64_Matrix2x2* minuend, const BGC_FP64_Matrix2x2* subtrahend, BGC_FP64_Matrix2x2* 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;
}

// ================== Multiply ================== //

inline void bgc_fp32_matrix2x2_multiply(const BGC_FP32_Matrix2x2* multiplicand, const float multiplier, BGC_FP32_Matrix2x2* product)
{
    product->r1c1 = multiplicand->r1c1 * multiplier;
    product->r1c2 = multiplicand->r1c2 * multiplier;

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

inline void bgc_fp64_matrix2x2_multiply(const BGC_FP64_Matrix2x2* multiplicand, const double multiplier, BGC_FP64_Matrix2x2* product)
{
    product->r1c1 = multiplicand->r1c1 * multiplier;
    product->r1c2 = multiplicand->r1c2 * multiplier;

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

// =================== Divide =================== //

inline void bgc_fp32_matrix2x2_divide(const BGC_FP32_Matrix2x2* dividend, const float divisor, BGC_FP32_Matrix2x2* quotient)
{
    bgc_fp32_matrix2x2_multiply(dividend, 1.0f / divisor, quotient);
}

inline void bgc_fp64_matrix2x2_divide(const BGC_FP64_Matrix2x2* dividend, const double divisor, BGC_FP64_Matrix2x2* quotient)
{
    bgc_fp64_matrix2x2_multiply(dividend, 1.0 / divisor, quotient);
}

// ================ Interpolate ================= //

inline void bgc_fp32_matrix2x2_interpolate(const BGC_FP32_Matrix2x2* first, const BGC_FP32_Matrix2x2* second, const float phase, BGC_FP32_Matrix2x2* interpolation)
{
    const float counter_phase = 1.0f - phase;

    interpolation->r1c1 = first->r1c1 * counter_phase + second->r1c1 * phase;
    interpolation->r1c2 = first->r1c2 * counter_phase + second->r1c2 * phase;

    interpolation->r2c1 = first->r2c1 * counter_phase + second->r2c1 * phase;
    interpolation->r2c2 = first->r2c2 * counter_phase + second->r2c2 * phase;
}

inline void bgc_fp64_matrix2x2_interpolate(const BGC_FP64_Matrix2x2* first, const BGC_FP64_Matrix2x2* second, const double phase, BGC_FP64_Matrix2x2* interpolation)
{
    const double counter_phase = 1.0 - phase;

    interpolation->r1c1 = first->r1c1 * counter_phase + second->r1c1 * phase;
    interpolation->r1c2 = first->r1c2 * counter_phase + second->r1c2 * phase;

    interpolation->r2c1 = first->r2c1 * counter_phase + second->r2c1 * phase;
    interpolation->r2c2 = first->r2c2 * counter_phase + second->r2c2 * phase;
}

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

inline void bgc_fp32_multiply_matrix2x2_by_vector2(const BGC_FP32_Matrix2x2* matrix, const BGC_FP32_Vector2* vector, BGC_FP32_Vector2* product)
{
    const float x1 = matrix->r1c1 * vector->x1 + matrix->r1c2 * vector->x2;
    const float x2 = matrix->r2c1 * vector->x1 + matrix->r2c2 * vector->x2;

    product->x1 = x1;
    product->x2 = x2;
}

inline void bgc_fp64_multiply_matrix2x2_by_vector2(const BGC_FP64_Matrix2x2* matrix, const BGC_FP64_Vector2* vector, BGC_FP64_Vector2* product)
{
    const double x1 = matrix->r1c1 * vector->x1 + matrix->r1c2 * vector->x2;
    const double x2 = matrix->r2c1 * vector->x1 + matrix->r2c2 * vector->x2;

    product->x1 = x1;
    product->x2 = x2;
}

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

inline void bgc_fp32_multiply_vector2_by_matrix2x2(const BGC_FP32_Vector2* vector, const BGC_FP32_Matrix2x2* matrix, BGC_FP32_Vector2* product)
{
    const float x1 = vector->x1 * matrix->r1c1 + vector->x2 * matrix->r2c1;
    const float x2 = vector->x1 * matrix->r1c2 + vector->x2 * matrix->r2c2;

    product->x1 = x1;
    product->x2 = x2;
}

inline void bgc_fp64_multiply_vector2_by_matrix2x2(const BGC_FP64_Vector2* vector, const BGC_FP64_Matrix2x2* matrix, BGC_FP64_Vector2* product)
{
    const double x1 = vector->x1 * matrix->r1c1 + vector->x2 * matrix->r2c1;
    const double x2 = vector->x1 * matrix->r1c2 + vector->x2 * matrix->r2c2;

    product->x1 = x1;
    product->x2 = x2;
}

#endif