feat(matrix3): Initialize few basic functions

include/math/matrix3.h

@@ -0,0 +1,19 @@
+#ifndef MATRIX_H
+#define MATRIX_H
+
+typedef struct {
+    float m[9];
+} Mat3;
+
+Mat3 mat3(float arr[9]);
+Mat3 mat3Zro();
+Mat3 mat3Ity();
+
+Mat3 mat3Add(Mat3 m1, Mat3 m2);
+Mat3 mat3Sub(Mat3 m1, Mat3 m2);
+Mat3 mat3Scl(Mat3 m, float scalar);
+Mat3 mat3Mul(Mat3 m1, Mat3 m2);
+Mat3 mat3Tpo(Mat3 m);
+float mat3Det(Mat3 m);
+
+#endif // MATRIX_H

src/main.c

@@ -1,5 +1,3 @@
-#include <stdlib.h>
-
 int main() {
-    return EXIT_FAILURE;
+    return 0;
 }

src/math/matrix3.c

@@ -0,0 +1,90 @@
+#include "math/matrix3.h"
+#include <string.h>
+#include <math.h>
+
+Mat3 mat3(float arr[9]) {
+    Mat3 mat;
+    memcpy(mat.m, arr, 9*sizeof(float));
+    return mat;
+}
+
+Mat3 mat3Zro() {
+    return (Mat3){0};
+}
+
+Mat3 mat3Ity() {
+    return (Mat3) {{
+        1, 0, 0,
+        0, 1, 0,
+        0, 0, 1
+    }};
+}
+
+Mat3 mat3Add(Mat3 m1, Mat3 m2) {
+    Mat3 mat;
+    
+    for(int i = 0; i<9; i++) {
+        mat.m[i] = m1.m[i] + m2.m[i];
+    }
+
+    return mat;
+}
+
+Mat3 mat3Sub(Mat3 m1, Mat3 m2) {
+    Mat3 mat;
+
+    for(int i = 0; i<9; i++) {
+        mat.m[i] = m1.m[i] - m2.m[i];
+    }
+
+    return mat;
+}
+
+Mat3 mat3Scl(Mat3 m, float scalar) {
+    Mat3 mat;
+
+    for(int i = 0; i<9; i++) {
+        mat.m[i] = m.m[i] * scalar;
+    }
+
+    return mat;
+}
+
+Mat3 mat3Mul(Mat3 m1, Mat3 m2) {
+    Mat3 mat; 
+
+    for(int i = 0; i<3; i++) {
+        int i3 = i * 3;
+        for (int j = 0; j < 3; j++) {
+            float sum = 0;
+            
+            for (int k = 0; k < 3; k++) {
+                sum += m1.m[i3 + k] * m2.m[k*3 + j];    
+            }
+
+            mat.m[i3 + j] = sum;
+        }
+    }
+
+    return mat;
+}
+
+Mat3 mat3Tpo(Mat3 m) {
+    Mat3 mat;
+
+    for(int i = 0; i<3; i++) {
+        int i3 = i * 3;
+        
+        for (int j = 0; j < 3; j++) {
+            mat.m[i3 + j] = m.m[j*3 + i];
+        }
+    }
+
+    return mat;
+}
+
+float mat3Det(Mat3 m) {
+    return m.m[0] * (m.m[4] * m.m[8] - m.m[5] * m.m[7]) -
+           m.m[1] * (m.m[3] * m.m[8] - m.m[5] * m.m[6]) +
+           m.m[2] * (m.m[3] * m.m[7] - m.m[4] * m.m[6]);
+}