raytracing/raytracer_challenge
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[FEAT] Matrix: Add cofactor

Browse Source
This commit is contained in:
NADAL Jean-Baptiste
2024-02-02 18:17:27 +01:00
parent f2a7ce738e
commit 47400a4d14
3 changed files with 38 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
raytracing/src/matrix.cpp
View File

@@ -208,16 +208,16 @@ double Matrix::determinant(void)
/* ------------------------------------------------------------------------- */
Matrix Matrix::sub_matrix(uint8_t a_rows, uint8_t a_cols)
Matrix Matrix::sub_matrix(uint8_t a_row, uint8_t a_col)
{
Matrix the_sub = *this;
the_sub.m_data.erase(the_sub.m_data.begin() + a_rows);
the_sub.m_data.erase(the_sub.m_data.begin() + a_row);
the_sub.m_rows--;
for (int the_row = 0; the_row < the_sub.m_rows; the_row++)
{
the_sub.m_data[the_row].erase(the_sub.m_data[the_row].begin() + a_cols);
the_sub.m_data[the_row].erase(the_sub.m_data[the_row].begin() + a_col);
}
the_sub.m_cols--;
@@ -226,9 +226,23 @@ Matrix Matrix::sub_matrix(uint8_t a_rows, uint8_t a_cols)
/* ------------------------------------------------------------------------- */
double Matrix::minor(uint8_t a_rows, uint8_t a_cols)
double Matrix::minor(uint8_t a_row, uint8_t a_col)
{
return sub_matrix(a_rows, a_cols).determinant();
return sub_matrix(a_row, a_col).determinant();
}
/* ------------------------------------------------------------------------- */
double Matrix::cofactor(uint8_t a_row, uint8_t a_col)
{
int8_t an_inverter = 1;
if ((a_row + a_col) % 2 != 0)
{
an_inverter = -1;
}
return an_inverter * minor(a_row, a_col);
}
/* ------------------------------------------------------------------------- */

5
raytracing/src/matrix.h
View File

@@ -61,8 +61,9 @@ namespace Raytracer
bool transpose(void);
double determinant(void);
Matrix sub_matrix(uint8_t a_rows, uint8_t a_cols);
double minor(uint8_t a_rows, uint8_t a_cols);
Matrix sub_matrix(uint8_t a_row, uint8_t a_col);
double minor(uint8_t a_row, uint8_t a_col);
double cofactor(uint8_t a_row, uint8_t a_col);
static Matrix identity(void);

16
tests/03_matrix.cpp
View File

@@ -294,3 +294,19 @@ TEST_CASE("[Matrix] Calculating a minor of a 3x3 matrix", "[Matrix]")
REQUIRE(a.minor(1, 0) == 25);
}
/* ------------------------------------------------------------------------- */
TEST_CASE("[Matrix] Calculating a cofactor of a 3x3 matrix", "[Matrix]")
{
Matrix a = {
{3, 5, 0},
{2, -1, -7},
{6, -1, 5}
};
REQUIRE(a.minor(0, 0) == -12.0);
REQUIRE(a.cofactor(0, 0) == -12.0);
REQUIRE(a.minor(1, 0) == 25.0);
REQUIRE(a.cofactor(1, 0) == -25.0);
}