Writing a Picture Puzzle Game - Android NDK Game Development - page 267

How to do it...

The idea behind the rendering is quite simple. We let the individual quads move in a way that
their corners slide along four guiding curves. The following igure shows the same quad in a
series of positions:

The four curves show the paths of the quad's corners.

1. We start with the helper Curve class, which implements the linear interpolation on

the set of control points. A curve is represented in a parametric form.
A parametric equation of a curve is a representation of this curve
through equations expressing the coordinates of the points of the
curve as functions of a variable called a parameter.

Courtesy: http://en.wikipedia.org/wiki/Parametric_equation

class Curve
{
public:
Curve() {}

2. The AddControlPoint() method adds a new control point to the curve. The curve

is lazy-evaluated, and now we just store the speciied values:
void AddControlPoint( float t, const vec3& Pos )
{
T.push_back( t );
P.push_back( Pos );
}