x1 = 0 (slider from -10 to 10, step 1)
y1 = -2 (slider from -10 to 10, step 1)
x2 = 1 (slider from -10 to 10, step 1)
y2 = 1 (slider from -10 to 10, step 1)
A: (x1, y1)
B: (x2, y2)