2d Rotate arround a center

[JeffM2501]

Vector2 p = { 100,200 };   // the point in world space
Matrix  rotMatrix = MatrixRotateZ(45 * DEG2RAD);   // the rotation
Matrix translate = MatrixTranslate(90, 180, 0);   // the center in world space

Matrix tForm = MatrixInvert(translate);   // translate to be local by the center
tForm = MatrixMultiply(tForm, rotMatrix);    // rotate
tForm = MatrixMultiply(tForm, translate);   // translate back to world space

p = Vector2Transform(p, tForm);   // p transformed by the rotation around the center