void
draw_bezier_curve(int num_segments, control_point p[], int num_points)
{
float x = p[0].x;
float y = p[0].y;
glBegin(GL_LINE_STRIP);
glVertex2f(x, y);
for(int i = 1; i < num_segments; i++){
evaluate_bezier_curve(&x, &y, p, num_points, i / (float)num_segments);
glVertex2f(x, y);
}
glVertex2f(p[num_points - 1].x, p[num_points - 1].y);
glEnd();
}
void draw_bezier_curve(int num_segments, control_point p[], int num_points)
{
float x, y;
glBegin(GL_LINE_STRIP);
// start line
glVertex2f(p[0].x, p[0].y);
// calculate and draw points in the middle
for (int i = 1; i < num_segments; i++) {
evaluate_bezier_curve(&x, &y, p, num_points, i / (float) num_segments);
glVertex2f(x, y);
}
// end line
glVertex2f(p[num_points - 1].x, p[num_points - 1].y);
glEnd();
}
/*
* get x_value for certain u
*/
float get_x_value(float *x_u, float *y_u, control_point p[], float u)
{
evaluate_bezier_curve(x_u, y_u, p, 4, u);
return *x_u;
}