Alright I need some help with moving the ball around the screen. I want the ball to move in a random direction at the start of each level/game. If you can please show me how to do this. I am thinking of a way by using a seed, but I am sure I am making this way to hard and not really sure how I would implement this. Also what kind of structure would I have for moving the ball. I got 2 variables, these hold the posistion where to ball is at. g_ball_position_x //currently set at 400 g_ball_position_y //currently set at 350 I am using C and I am unsure how to get this going. thank you for your time.

Use a random number generator to get your initial positions in the range that is desired (screen height and screen width I assume), but you also need something to store the random velocity of the object. If you want the ball to start at some constant speed, generate a random angle [0, 2pi] or [0, 360], cast it into radians if its not already, and then set vx equal to vi*cost and vy equal to vi*sint where vi is that initial speed you want. If you want random speed, you could repeat the same process where the vi is in some range [low, high], because otherwise you might get a ball that move really slowly.

Brendan

I havent had any trig or higher math classes but I am reading up on some formulas etc, but in to get a better understanding of what your saying could you give me code so I can learn from it please. It gives me a better understanding how to put the math into code.

[edited by - Dalik on December 9, 2002 3:54:58 AM]

just look up vectors in the articles section of gamedev. or on google.

You really need to advance your math when you get into graphics... but I will give you a few hints.

it''d probably be easiest to make a ball object, using a struct...
i.e.
_________________________
struct ball
{
int x; //stores x position
int y; //stores y position
int vx; //stores horizontal movement per fram
int vy; //stores vertical movement per frame
}
_______________________

for the random point of it, just set up a random structure... using c++, you could use the time from windows to see srand, then use the rand function and set that up for your x and y.
With this setup, to adjust when the ball hits a side, u just say vx=-vx or vy=-vy...
anyway... this is all elementary... and if you didn''t have this much figured out, i honestly suggest you sit down with a few good books and read them before getting into high level programming

If barbie is so popular, why do you have to buy her friends?

This is what I have so far, and the ball moves straight up. Thats the good news. Bad news I dont think its all correct here is the movment code, also the ball should move in different directions not just up.




g_ball_position_y is the position of the ball, its global

ball.direction_x/y are values in the ball struct
same as vx and vy

ball.angle is in the ball struct also and is given a random value from rand()

If you have any ideas let me know, I will be working on it still

this is the code I have to bouce the ball off the wall



This isnt working either one of the 2 are not working
also



doesnt work either
any ideas would be great thnx.