If you want to move without changing the pan,
so you DON`T need:

vec_set();
vec_sub();
vec_to_angle();

This 3 things are only to change the pan. To move the entity you have to use c_move(); if you want the collision. If you set player.x directly, there is no collision.

Use only the following line:
c_move (player, vector(10 * time_step, 0, 0), nullvector, IGNORE_PASSABLE | GLIDE);

Hope that helps....