I have been trying to make a vector class to handle particles in a particle system I am making. The problem I have is when I try to change the dir it does not do what it is supposed to. If I keep pressing up it will just bounce back from between two directions same with down. But if I go up down repeatedly it changes a little bit but not much. I cannot figure out why this is happening.
This is my class

struct sPosition{float x,y;};

class cVector{
    float Mag;
    sPosition Pos;
    sPosition Dir;

    cVector(float PosX = 0.0f,float PosY = 0.0f, float Magn = 0.0f, float Degrees = 0.0f){
        Pos.x = PosX;
        Pos.y = PosY;
        Mag = Magn;
    float GetPosX(){return Pos.x;}
    float GetPosY(){return Pos.y;}
    float GetDirX(){return Dir.x;}
    float GetDirY(){return Dir.y;}
    float GetDirR(){return float (atan2(Dir.x,Dir.y * -1.0f));}
    float GetMag(){return Mag;}

    void SetPos(float PosX,float PosY){Pos.x = PosX; Pos.y = PosY;}
    void SetDir(float DirX,float DirY){Dir.x = DirX; Dir.y = DirY;}
    void SetDirR(float Rads){
        Dir.x = float (cos(Rads));
        Dir.y = float (sin(Rads) * -1.0);
    void SetDirD(float Degs){
        Dir.x = float (cos(DegToRad<float>(Degs)));
        Dir.y = float (sin(DegToRad<float>(Degs)) * -1.0);
    void SetMag(float Magn){Mag = Magn;}


this is my main.cpp just in case it is useful. I am using sfml graphics library btw.

#include <SFML/Graphics.hpp>
#include "Vectors.h"
sf::RenderWindow App(sf::VideoMode(800, 600, 32), "SFML Graphics");

int main(){
    cVector VectA(200.0f,300.0f,100.0f,45.0f);
    // Create the main rendering window

    // Start game loop
    while (App.IsOpened())
        sf::Event Event;
        while (App.GetEvent(Event)){
            // Close window : exit
            if (Event.Type == sf::Event::Closed)
            if ((Event.Type == sf::Event::KeyPressed) && (Event.Key.Code == sf::Key::Up))
                VectA.SetDirR(VectA.GetDirR() + 0.1f);
            if ((Event.Type == sf::Event::KeyPressed) && (Event.Key.Code == sf::Key::Down))
                VectA.SetDirR(VectA.GetDirR() - 0.1f);


        // Clear the screen (fill it with black color)
                                 VectA.GetPosX() + (VectA.GetDirX() * VectA.GetMag()),
                                 VectA.GetPosY() + (VectA.GetDirY() * VectA.GetMag()),


    return EXIT_SUCCESS;

Your order of arguments for atan2 is wrong. It should be (y, x), not (x, y).

ooh thank you, didn't know that I was wrestling with this for a while lol

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