Thread: Angle of Trajectory?

  1. #1 napkin111's Avatar
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    Apr 2002

    Angle of Trajectory?

    I'm trying to create a bullet class that stores the bullets current position (x,y,z) and its trajectory. Traditionally I've used 3 variables called xtraject, ytraject, and ztraject where each loop xtraject was added to x and same for y/z. So in order to get the bullet travelling upper right at a 45 degree angle xtraject and ytraject would be 1. I'm want to have bullets that can fire at arbitrary angles, perhaps just have an angle variable (maybe I would need 2?) to control which way it goes and then a speed to say how fast its moving.

    Do I use polar coordinates to do this? What about quaternions?


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  2. #2
    and the hat of int overfl Salem's Avatar
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  3. #3
    C++ Developer XSquared's Avatar
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    You really need to learn how to use the search button, buddy.
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  4. #4
    Super Moderator VirtualAce's Avatar
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    Aug 2001
    Although that post is really not about the same thing. There is another post here about bullets that covers it better.


    #define PI 3.14159
    #define DEGTORAD(angle) ((double)angle*PI/180.0)
    struct point2D
      double x;
      double y;
    struct Bullet
       point2D Pos;
       point2D Vel;
       double speed;
       int active;
    void FireBullet(point2D Start,int angle,double speed,Bullet *newbullet)
    //Assuming we have an array of Bullet objects called Bullets
    void UpdateBullets
      for (int i=0;i<NumBullets;i++)
         if (Bullets[i].active)
    This is only for 2D, for 3D you must do a little more.

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