Add sqr function to CinderMath.h

[IntellectualKitty]

[paulhoux]

What's the use case for this?

[IntellectualKitty]

Using a squaring function makes for shorter, easier code. It also more closely resembles the mathematical equation the code is performing.

For example, this seems shorter, simpler, and easier to read:

float distance = cinder::math<float>::sqrt( cinder::math<float>::sqr( x2 - x1 ) + cinder::math<float>::sqr( y2 - y1 ) );

than this:

float deltaX = x2 - x1;
float deltaXSqr = deltaX  * deltaX;
float deltaY = y2 - y1;
float deltaYSqr = deltaY  * deltaY;
float distance = cinder::math<float>::sqrt( deltaXSqr + deltaYSqr );

[andrewfb]

I am up for this change if there are no objections

[totalgee]

Just a minor point: what about calling it sq() or squared(), so there is no ambiguity about the sqr being "square root"? Or alternatively (better?), there is already a length2() in GLM (GLX) that does this -- squaring a scalar and doing dot(v,v) on vectors (which returns the squared length).

[paulhoux]

As a side note:

float deltaX = x2 - x1;
float deltaXSqr = deltaX  * deltaX;
float deltaY = y2 - y1;
float deltaYSqr = deltaY  * deltaY;
float distance = cinder::math<float>::sqrt( deltaXSqr + deltaYSqr );

can be simplified to:

auto delta = vec2( x2 - x1, y2 - y1 );
auto distance = glm::length( delta );

or:

auto distanceSquared = glm::dot( delta, delta );