Answer and Explanation:
#take input from user
n = int(input("Enter any number: "))
#sum variable to store sum
sum=0
#condition to exit from loop
while n!=-999:
#adding entered number in sum variable
sum=sum+n
#take input from user
n = int(input("Enter any number : "))
#print the sum
print("sum =",sum)
output:
Enter any number: 10
Enter any number : 100
Enter any number : -999
sum = 110
You could learn C++ and use the Open GL library. Open GL is a library designed to make 2D and 3D applications. And use another library called <span>Simple and Fast Multimedia Library</span> to create the window itself.
There are multiple tutorials that teach C++ and OpenGL. There are other graphics libraries, but Open GL is the most popular.