void updateTransforms()
{
w2dx = viewScale * dpiX / 25.4f;
w2dy = viewScale * dpiY / 25.4f;
float wdy = ydown ? -w2dy : w2dy;
float xc = cxWnd * 0.5f;
float yc = cyWnd * 0.5f;
matD2W.set(1.f / w2dx, 0, 0, 1.f / wdy,
centerW.x - xc / w2dx, centerW.y - yc / wdy);
matW2D.set(w2dx, 0, 0, wdy,
xc - w2dx * centerW.x, yc - wdy * centerW.y);
matD2M = matD2W * matW2M;
matM2D = matM2W * matW2D;
}
