opengl array of pool balls - c++

Question

i am drawing an array of pool balls in opengl using c++
the problem i am facing is the array draws in a straight line.
when i use gltranslate the balls still only translate along the line when i edit the z and y axis
what i want to do is set the balls up in a triangle shape like the breaking of a pool match
how do i use the array code to set the balls up like this?
any help would be much appreciated
balls[7];
for (int x = ball-start; x<ball-end;x++)
{
glTranslatef(0,0,0.5);
glColor3f(1,0,0);
ball[x].drawball();
}

Answer 1

assuming:
struct Ball {
double x,y,z;
void drawball(void);
/* ... */
} ball[7];
try:
for(int i=0; i<7 ;i++)
{
glPushMatrix();
glTranslated(ball[i].x,ball[i].y,ball[i].z);
glColor3f(1,0,0);
ball[i].drawball();
glPopMatrix();
}
details probably vary, but hopefully you get the idea.

Answer 2

Do something like this:
// first of all, include the x,y position (assuming 2D, since pool) in the Ball object:
class Ball
{
//...
private:
float xpos, ypos;
//...
};
Then when you construct the array of balls, rather than just making 8 balls, you're going to want to allocate the memory on the heap so that it will last throughout your entire game. So do this:
Ball *ball= new Ball*[8];
ball[0] = new Ball(x0,y0);
ball[1] = new Ball(x1,y1);
ball[2] = new Ball(x2,y2);
ball[3] = new Ball(x3,y3);
// ...
Make sure that when your game is over, you clean up after yourself.
for (int i = 0; i < 8; i++)
delete ball[i];
delete [] ball;
Then in your Ball::draw() do something like this:
Ball::draw()
{
glColor3f(/*yellow*/); // Set the color to yellow
glTranslatef(-xpos, -ypos, 0); // Move to the position of the ball
// Draw the ball
glTranslatef(xpos, ypos, 0); // Move back to the default position
}
All you have to do is come up with the correct (x0,y0),(x1,y1),(x2,y2)... to form a triangle! Does this make sense/answer your question?