mousemoverel

Moves the mouse cursor by a relative offset from its current position. Uses SendInput with relative mode (no MOUSEEVENTF_ABSOLUTE flag):

INPUT input = {};
input.type = INPUT_MOUSE;
input.mi.dwFlags = MOUSEEVENTF_MOVE;  // relative mode
input.mi.dx = x;  // pixel delta
input.mi.dy = y;
SendInput(1, &input, sizeof(INPUT));

In relative mode, dx/dy are pixel deltas. Positive x = right, positive y = down. Ideal for Roblox camera rotation where you need delta (mouse look) movement. The OS handles acceleration/pointer speed curves before moving the cursor.