How to get the Projection ProjectionMatrixFromCameraIntrinsics

ProjectionMatrixForCameraIntrinsics(float width, float height, float fx, float fy,float cx, float cy,  float near, float far) {
const float xscale = near / fx;
const float yscale = near / fy;

const float xoffset = (cx - (width / 2.0)) * xscale;

const float yoffset = -(cy - (height / 2.0)) * yscale;

return glm::frustum(xscale * -width / 2.0f - xoffset,
xscale * width / 2.0f - xoffset,
yscale * -height / 2.0f - yoffset,
yscale * height / 2.0f - yoffset, near, far);
}