Getting points equidstant from each other in openGL on a circle - opengl

Question

I'm trying to write code for a weaving pattern in OpenGL.
Weaving Pattern
Pic
Now, I am trying to write code for a similar pattern using a circle.
I draw a circle using points, each point is drawn using cos and sin functions.
I understand this is not as efiicient as SeigeLord's method as it makes higher use of resources.
I am able to get the circle, I want to get points on it's circumference.
My code :
#include<GL/glut.h>
#include<stdio.h>
#include<math.h>
int n, r;
void display()
{
int i, j;
glClearColor(0.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(-50, 50, -50, 50);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
for (i = 0;i <= 360;i += 1)
{
glBegin(GL_POINTS);
glVertex2f(r*cos(i), r*sin(i));
glEnd();
}
/*for (i = 0;i < 360;i += 10)
{
glBegin(GL_LINES);
glVertex2f(r*cos(i), r*sin(i));
glVertex2f(r*cos(i + 300), r*sin(i + 300));
glEnd();
}*/
glFlush();
}
int main(int argc, char **argv)
{
r = 30;
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
glutInitWindowPosition(300, 50);
glutInitWindowSize(800, 800);
glutCreateWindow("Cylinder");
glutDisplayFunc(display);
glutMainLoop();
}
I tried using the commented code for getting lines between points 300 degrees apart, do this every at point 10 degrees apart.(It looks good at 3 degrees apart).
Now, this obviously doesn't work as we use trigonometric functions, which won't space out the points equally.
I hope you understand my question, how can I get points on the circle equally apart?
One solution, I think might work is, while plotting the points itself, if I use an array to save every nth point, I may get equidistant points. Am I right? Is there any other way of getting the points?
Please do correct me if I am wrong anywhere above, I am just newbie here.

Answer 1

Note that sin and cos take their input in radians(i.e. 0 to 2* pi), not degrees(0 to 360). So your code should probably be
for (i = 0;i <= 360;i += 1)
{
glBegin(GL_POINTS);
glVertex2f(r*cos(i * (M_PI / 180.)), r*sin(i* (M_PI / 180.)));
glEnd();
}
edit:
To get N equidistant point we have to put them (1/N) part of the circle away from each other:
for (i = 0;i < N;i += 1)
{
double angle = i * (2.0 * M_PI / N);
glBegin(GL_POINTS);
glVertex2f(r*cos(angle), r*sin(angle));
glEnd();
}