Scaling relative to a fixed point

Actually, we can control the location of a scaled object by choosing a positin , called the fixed point (xf, yf), that is to remain unchanged after the scaling transformation.

Scaling relative to a fixed point (xf, yf) :

x'= x*xScale +xf*(1-xScale)

y'= y*yScale+yf*(1-yScale)

Scaling relative to the fixed point (2,2), with xScale=2 and yScale=2

Let's consider the point (3,2), scaling relative to a fixed point (2, 2) :

x'= 3*2 +2*(1-2) = 4

y'= 2*2+2*(1-2) = 2

Let's consider the point (1,3), scaling relative to a fixed point (2, 2) :

x'= 1*2 +2*(1-2) = 0

y'= 3*2+2*(1-2) = 4

Let's try !