c++ How to wait for multiple mouse clicks - c++

Question

I want to draw a Triangle in CImg library. However, I do not know how to write the code that will allow me to draw the triangle using three mouse clicks.
The code in the documentation is this:
while (!main_disp.is_closed() && !draw_disp.is_closed())
{
main_disp.wait();
if (main_disp.button() && main_disp.mouse_y()>=0)
http://cimg.sourceforge.net/reference/group__cimg__tutorial.html
But it is for one mouse click, which I implemented successfully to draw a circle on the mouse click. But to do for three mouse clicks or two has proven to be difficult for me.
I also have the problem of inputting the color I want. I wrote red for example as:
const unsigned char red[] = {250, 0, 0};
Then I want the user to choose which color, enter his choice(assume it's red) and then pass this definition of red into the image.
Anyone can help with this ?!

Answer 1

If you know how to detect when the mouse button is clicked, you can store information about that click for later. For example, you can store previous mouse clicks in a deque.
struct point
{
int x,y;
};
...
std::deque<point> clicks;
while (!main_disp.is_closed() && !draw_disp.is_closed())
{
main_disp.wait();
if (main_disp.button())
{
clicks.push_front({mouse_disp.mouse_x(), mouse_disp.mouse_y()});
if (clicks.size() >= 3)
{
// draw a triangle using clicks[0], clicks[1] and clicks[2]
}
}
}