Floor casting algorithm just doing weird things - c

Question

I'm actually using the algorithme of Toto Briac from Raycaster, searching for more effective floor/ceiling raycast
When using it, the floor casting is working well for east and west side, but for north and south it just does weird things (just look image).
double pixelsToBottom;
double pixelsToMid;
double directDistFloor;
double realDistance;
double y;
t_point f_p;
pixelsToBottom = (double)data->s_height - wall[1].y;
pixelsToMid = (double)data->s_height / 2 - pixelsToBottom;
for (int i = pixelsToMid; i < data->s_height / 2; i += 1)
{
directDistFloor = (data->dist_proj * (double)(data->s_height / 2)) / i;
realDistance = directDistFloor / fabs(cos(angle));
f_p.x = data->player.pos.x + cos(angle) * (realDistance) / (data->dist_proj / (64.0));
f_p.y = data->player.pos.y + sin(angle) * (realDistance) / (data->dist_proj / (64.0));
y = (wall->x + (i + data->s_height / 2) * data->s_width) / data->s_width;
pixel_put(&data->obj, wall->x, y, f_pixel(data, f_p));
}
But i'm facing an issu, when i'm facing north and south side it's all ok, but when the ray is going into east or west side, the texture just do a weird thing like that :
I know that it refer to : realDistance = directDistFloor / fabs(cos(angle));
if i replace the cos(angle) by sin(angle) in this line, it just invert things. I didn't find a way to change the calcule in right moment. I you have any idea I will take it ! Thank you !!

Answer 1

It's okay I found the answer, for the people who are interest, in the line realDistance = directDistFloor / fabs(cos(angle)); I was using the angle of the ray in the world, I changed it by the angle relative to my player dir (so 0° if it's the player dir ray) and it work properly ! Thank's #ZwergofPhoenix for the time you took !