From bc909e185ffdbecc494f22f5c3926339d1d2bd09 Mon Sep 17 00:00:00 2001
From: Luca Conte <main@lugico.de>
Date: Thu, 16 May 2024 16:26:45 +0200
Subject: [PATCH] add some comments

---
 u08-2/matrixMath.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/u08-2/matrixMath.c b/u08-2/matrixMath.c
index d01b39c..f9acc51 100644
--- a/u08-2/matrixMath.c
+++ b/u08-2/matrixMath.c
@@ -111,7 +111,7 @@ void rotationX(mat4* out, GLfloat angle) {
 	out->m22 = cos(angle);
 }
 
-// MULTIPLY ANY TO MATRICES
+// MULTIPLY ANY TWO MATRICES
 void multiplyAny(GLfloat* out, GLfloat* A, GLfloat* B, int wA, int hA, int wB) {
 	int sizeOut = hA * wB;
 	GLfloat* result = (GLfloat*) malloc(sizeOut * sizeof(GLfloat));
@@ -145,25 +145,26 @@ void scale(mat4* out, mat4* in, vec3* v) {
 	multiply(out, &scalingMatrix, in);
 }
 
-// MULTIPLY in WITH ROTATION MATRIX OF a AROUND Z AXIS
+// MULTIPLY in WITH ROTATION MATRIX OF angle AROUND Z AXIS
 void rotateZ(mat4* out, mat4* in, GLfloat angle) {
 	mat4 rotationMatrix;
 	rotationZ(&rotationMatrix, angle);
 	multiply(out, &rotationMatrix, in);
 }
-// MULTIPLY in WITH ROTATION MATRIX OF a AROUND Y AXIS
+// MULTIPLY in WITH ROTATION MATRIX OF angle AROUND Y AXIS
 void rotateY(mat4* out, mat4* in, GLfloat angle) {
 	mat4 rotationMatrix;
 	rotationY(&rotationMatrix, angle);
 	multiply(out, &rotationMatrix, in);
 }
-// MULTIPLY in WITH ROTATION MATRIX OF a AROUND X AXIS
+// MULTIPLY in WITH ROTATION MATRIX OF angle AROUND X AXIS
 void rotateX(mat4* out, mat4* in, GLfloat angle) {
 	mat4 rotationMatrix;
 	rotationX(&rotationMatrix, angle);
 	multiply(out, &rotationMatrix, in);
 }
 
+// TRANSPOSE MATRIX OF ANY SIZE
 void transposeAny(GLfloat* out, GLfloat* in, int w, int h) {
 	int size = w * h;
 	GLfloat* result = (GLfloat*) malloc(size * sizeof(GLfloat));
@@ -178,10 +179,12 @@ void transposeAny(GLfloat* out, GLfloat* in, int w, int h) {
 }
 
 
+// TRANSPOSE 4x4 MATRIX
 void transpose(mat4* out, mat4* in) {
 	transposeAny((GLfloat*)out, (GLfloat*)in, 4, 4);
 }
 
+// PRINT MATRIX OF ANY SIZE
 void printAny(GLfloat* M, int w, int h) {
 	GLfloat* transposed = (GLfloat*) malloc(w * h * sizeof(GLfloat));
 	transposeAny(transposed, M, w, h);
@@ -208,12 +211,14 @@ void mat3Print(mat3* m) {
 	printAny((GLfloat*)m, 3, 3);
 }
 
+// TURN mat4 INTO mat3 BY CUTTING LAST COLUMN AND ROW
 void mat3From4(mat3* out, mat4* in) {
 	memcpy(&out->m00, &in->m00, sizeof(vec3));
 	memcpy(&out->m01, &in->m01, sizeof(vec3));
 	memcpy(&out->m02, &in->m02, sizeof(vec3));
 }
 
+// TRANSPOSE 3x3 MATRIX
 void mat3Transpose(mat3* out, mat3* in) {
 	transposeAny((GLfloat*)out, (GLfloat*)in, 3, 3);
 }
@@ -223,6 +228,7 @@ void mat3Transpose(mat3* out, mat3* in) {
  *  d - m10   e - m11   f - m12
  *  g - m20   h - m21   i - m22
  */
+// GET THE MINOR MATRIX OF A 3x3 MATRIX
 void mat3Minor(mat3* out, mat3* in) {
 	mat3 result;
 
@@ -241,6 +247,7 @@ void mat3Minor(mat3* out, mat3* in) {
 	memcpy(out, &result, sizeof(mat3));
 }
 
+// GET THE COFACTOR MATRIX OF A 3x3 MATRIX
 void mat3Cofactor(mat3* out, mat3* in) {
 	mat3 result;
 	mat3Minor(out, in);
@@ -251,17 +258,20 @@ void mat3Cofactor(mat3* out, mat3* in) {
 	out->m12 *= -1;
 }
 
+// GET ADJOING MATRRIX OF 3x3 MATRIX
 void mat3Adjoint(mat3* out, mat3* in) {
 	mat3Cofactor(out, in);
 	mat3Transpose(out, out);
 }
 
+// MULTIPLY A 3x3 MATRIX WITH A SCALAR x (componentwise)
 void mat3MultiplyScalar(mat3* out, mat3* in, GLfloat x) {
 	for (int i = 0; i < 9; i++) {
 		((GLfloat*)out)[i] = ((GLfloat*)in)[i] * x;
 	}
 }
 
+// CALCULATE DETERMINANT OF 3x3 MATRIX
 GLfloat mat3Determinant(mat3* M) {
 	return
 		  M->m00 * M->m11 * M->m22
@@ -274,6 +284,7 @@ GLfloat mat3Determinant(mat3* M) {
 	;
 }
 
+// GET INVERSE OF 3x3 MATRIX
 void mat3Inverse(mat3* out, mat3* in) {
 	mat3 result;
 	mat3Adjoint(&result, in);
@@ -282,6 +293,7 @@ void mat3Inverse(mat3* out, mat3* in) {
 	memcpy(out, &result, sizeof(mat3));
 }
 
+// GET THE SUM OF DIFFERENCES BETWEEON TWO MATRICES
 GLfloat sumDiffAny(GLfloat* A, GLfloat* B, int w, int h) {
 	GLfloat result = 0;
 	for (int i = 0; i < w * h; i++) {
@@ -290,10 +302,12 @@ GLfloat sumDiffAny(GLfloat* A, GLfloat* B, int w, int h) {
 	return result;
 }
 
+// GET THE SUM OF DIFFERENCES BETWEEN TWO 3x3 MATRICES
 GLfloat mat3SumDiff(mat3* A, mat3* B) {
 	return sumDiffAny((GLfloat*)A, (GLfloat*)B, 3, 3);
 }
 
+// COMPONENTWISE SUBTRACT vec2 b FROM vec2 a
 void vec2Subtract(vec2* out, vec2* a, vec2* b) {
 	out->x = a->x - b->x;
 	out->y = a->y - b->y;