#include "matrix2x2.h"

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

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;

    const float multiplier = 1.0f / determinant;

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

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

    return 1;
}

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;

    const double multiplier = 1.0 / determinant;

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

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

    return 1;
}

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

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;

    const float multiplier = 1.0f / determinant;

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

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

    return 1;
}

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;

    const double multiplier = 1.0 / determinant;

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

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

    return 1;
}