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- /*
- * DoRayMe - a quick and dirty Raytracer
- * Matrix implementation
- *
- * Created by Manoël Trapier
- * Copyright (c) 2020 986-Studio.
- *
- */
- #include <stdio.h>
- #include <matrix.h>
- #include <tuple.h>
- #include <math_helper.h>
- Matrix::Matrix(int width)
- {
- int i;
- this->size = width;
- for(i = 0; i < width*width; i++)
- {
- this->data[i] = 0;
- }
- };
- Matrix::Matrix(double values[], int width)
- {
- int x, y;
- this->size = width;
- for(y = 0; y < this->size; y++)
- {
- for (x = 0 ; x < this->size ; x++)
- {
- this->data[this->size * x + y] = values[this->size * x + y];
- }
- }
- };
- bool Matrix::operator==(const Matrix &b) const
- {
- int i;
- if (this->size != b.size)
- {
- /* If they are not the same size don't even bother */
- return false;
- }
- for(i = 0; i < this->size*this->size; i++)
- {
- if (!double_equal(this->data[i], b.data[i]))
- {
- return false;
- }
- }
- return true;
- }
- bool Matrix::operator!=(const Matrix &b) const
- {
- int i;
- if (this->size != b.size)
- {
- /* If they are not the same size don't even bother */
- return true;
- }
- for(i = 0; i < this->size*this->size; i++)
- {
- if (!double_equal(this->data[i], b.data[i]))
- {
- return true;
- }
- }
- return false;
- }
- Matrix Matrix::operator*(const Matrix &b) const
- {
- int x, y, k;
- Matrix ret = Matrix(this->size);
- if (this->size == b.size)
- {
- for (y = 0 ; y < this->size ; y++)
- {
- for (x = 0 ; x < this->size ; x++)
- {
- double v = 0;
- for (k = 0 ; k < this->size ; k++)
- {
- v += this->get(x, k) * b.get(k, y);
- }
- ret.set(x, y, v);
- }
- }
- }
- return ret;
- }
- /* TODO: Check if we can optimise this function. It is called a lot */
- Tuple Matrix::operator*(const Tuple &b) const
- {
- return Tuple(b.x * this->get(0, 0) + b.y * this->get(0, 1) + b.z * this->get(0, 2) + b.w * this->get(0, 3),
- b.x * this->get(1, 0) + b.y * this->get(1, 1) + b.z * this->get(1, 2) + b.w * this->get(1, 3),
- b.x * this->get(2, 0) + b.y * this->get(2, 1) + b.z * this->get(2, 2) + b.w * this->get(2, 3),
- b.x * this->get(3, 0) + b.y * this->get(3, 1) + b.z * this->get(3, 2) + b.w * this->get(3, 3));
- }
- Matrix Matrix::identity()
- {
- int i;
- for(i = 0; i < this->size; i++)
- {
- this->set(i, i, 1);
- }
- return *this;
- }
- Matrix Matrix::transpose()
- {
- int x, y;
- Matrix ret = Matrix(this->size);
- for (y = 0 ; y < this->size ; y++)
- {
- for (x = 0 ; x < this->size ; x++)
- {
- ret.set(y, x, this->get(x, y));
- }
- }
- return ret;
- }
- Matrix Matrix::submatrix(int row, int column)
- {
- int i, j;
- int x = 0, y = 0;
- Matrix ret = Matrix(this->size - 1);
- for (i = 0 ; i < this->size ; i++)
- {
- if (i == row)
- {
- /* Skip that row */
- continue;
- }
- y = 0;
- for (j = 0 ; j < this->size ; j++)
- {
- if (j == column)
- {
- /* skip that column */
- continue;
- }
- ret.set(x, y, this->get(i, j));
- y++;
- }
- x++;
- }
- return ret;
- }
- double Matrix::determinant()
- {
- double det = 0;
- if (this->size == 2)
- {
- det = this->data[0] * this->data[3] - this->data[1] * this->data[2];
- }
- else
- {
- int col;
- for(col = 0; col < this->size; col++)
- {
- det = det + this->get(0, col) * this->cofactor(0, col);
- }
- }
- return det;
- }
- Matrix Matrix::inverse()
- {
- Matrix ret = Matrix(this->size);
- if (this->isInvertible())
- {
- int row, col;
- double c;
- for (row = 0; row < this->size; row++)
- {
- for (col = 0; col < this->size; col++)
- {
- c = this->cofactor(row, col);
- ret.set(col, row, c / this->determinant());
- }
- }
- }
- return ret;
- }
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