diff --git a/src/vec.c b/src/vec.c
index 79a5348..b77c17a 100644
--- a/src/vec.c
+++ b/src/vec.c
@@ -3,41 +3,52 @@
 #include "vec.h"
 
 void vec_cpy(Vec *destination, Vec source) {
+	/* memcpy for vectors */
 	destination->x = source.x;
 	destination->y = source.y;
 }
 
 void vec_add(Vec *vector, Vec force) {
+	/* addition */
 	vector->x += force.x;
 	vector->y += force.y;
 }
 
 void vec_sub(Vec *vector, Vec force) {
+	/* substraction */
 	vector->x -= force.x;
 	vector->y -= force.y;
 }
 
 void vec_mul(Vec *vector, int scale) {
+	/* multiplication */
 	vector->x *= scale;
 	vector->y *= scale;
 }
 
 void vec_mulf(Vec *vector, float scale) {
+	/* floating point multiplication */
 	vector->x *= scale;
 	vector->y *= scale;
 }
 
 void vec_div(Vec *vector, int scale) {
+	/* division */
 	vector->x /= scale;
 	vector->y /= scale;
 }
 
 void vec_divf(Vec *vector, float scale) {
+	/* floating point division */
 	vector->x /= scale;
 	vector->y /= scale;
 }
 
 void vec_lerp(Vec *from, Vec to, float scale) {
+	/* A linear interpolation function, can be used for camera and
+	 * animations. 'scale' is the transformation speed, 1 being
+	 * instant.
+	 */
 	/* from * (1 - scale) + temp * scale */
 	Vec temp;
 	vec_cpy(&temp, to);
@@ -50,6 +61,7 @@ void vec_lerp(Vec *from, Vec to, float scale) {
 }
 
 void vec_clamp(Vec *to_limit, Vec min, Vec max) {
+	/* clamp a vector between two points */
 	if (to_limit->x < min.x) to_limit->x = min.x;
 	if (to_limit->y < min.y) to_limit->y = min.y;
 	if (to_limit->x > max.x) to_limit->x = max.x;
@@ -57,5 +69,8 @@ void vec_clamp(Vec *to_limit, Vec min, Vec max) {
 }
 
 void vec_drect(Vec top_left, Vec bottom_right, int color) {
+	/* Draw a rectangle corresponding to two vectors position with
+	 * given 'color'.
+	 */
 	drect(top_left.x, top_left.y, bottom_right.x, bottom_right.y, color);
 }