Function ProcessMouse_SDL

engine/Poseidon/Input/InputProcessingSdl.cpp:217–248

void SDLInput_BufferMouseWheel(float dy)
{
    GInput.mouse.BufferWheel(dy);
}

void ProcessMouse_SDL(DWORD timeDelta)
{
    if (!GWorld->IsUserInputEnabled())
    {
        GInput.mouse.DiscardBuffered();
        return;
    }

    // Compute cursor clamp from aspect settings
    MouseState::CursorClamp clamp;
    const MouseState::CursorClamp* clampPtr = nullptr;
    if (::Poseidon::GEngine)
    {
        AspectSettings as;
        ::Poseidon::GEngine->GetAspectSettings(as);
        float screenTopX = as.uiTopLeftX / (as.uiTopLeftX - as.uiBottomRightX);
        float screenTopY = as.uiTopLeftY / (as.uiTopLeftY - as.uiBottomRightY);
        float screenBotX = (1 - as.uiTopLeftX) / (as.uiBottomRightX - as.uiTopLeftX);
        float screenBotY = (1 - as.uiTopLeftY) / (as.uiBottomRightY - as.uiTopLeftY);
        clamp.minX = screenTopX * 2 - 1;
        clamp.maxX = screenBotX * 2 - 1;
        clamp.minY = screenTopY * 2 - 1;
        clamp.maxY = screenBotY * 2 - 1;
        clampPtr = &clamp;
    }

    // Aiming spans the full window, so it uses the window aspect ratio
    // (Width/Height).  The cursor's coordinates are relative to the HUD region,
    // so it uses that region's aspect ratio (Width2D/Height2D) — this keeps its
    // speed consistent and unaffected by the HUD width limit.  Both fall back to
    // the 4:3 reference when the engine size is unavailable.