SendInput for mouse movement on Windows

[s1hofmann]

Short overview
The current implementation uses SetCursorPos for mouse movment.
We might consider using SendInput like we do for scrolling and keyboard input.

Use case
Automating multimedia applications like e.g. games

Detailed description
As reported in nut-tree/nut.js#168 it is currently not possible to cause in-game mouse movement with nut.js, although desktop mouse movement works fine.
A possible reason for this could be the usage of SetCursorPos instead of SendInput.
Following the above mentioned docs it seems like SetCursorPos is more desktop centered, whereas SendInput actually inserts events into the keyboard and mouse inputstream.

[Reiss-Cashmore]

I have done a crude test to see if I could get SendInput working

This works for relative movements only

void moveMouseRelative(MMPoint point)
{
	// SetCursorPos ((int)point.x, (int)point.y);

        INPUT mouseInput;

	mouseInput.type = INPUT_MOUSE;
	mouseInput.mi.dx = (int)point.x;
	mouseInput.mi.dy = (int)point.y;
	mouseInput.mi.mouseData = 0;     
	mouseInput.mi.time = 0;
        mouseInput.mi.dwFlags = MOUSEEVENTF_MOVE;
        mouseInput.mi.dwExtraInfo = 0;
	SendInput(1, &mouseInput, sizeof(mouseInput));
}

I explored how that snippet could be adapted to work for absolute positioning on the display

int CalculateAbsoluteCoordinateX(int x)
{
	MMSize displaySize = getMainDisplaySize();
        return (x * 65536) / displaySize.width;
}

int CalculateAbsoluteCoordinateY(int y)
{
	MMSize displaySize = getMainDisplaySize();
        return (y * 65536) / displaySize.height;
}

void moveMouseAbsolute(MMPoint point)
{
	// SetCursorPos ((int)point.x, (int)point.y);

        INPUT mouseInput;

	mouseInput.type = INPUT_MOUSE;
	mouseInput.mi.dx = (int) CalculateAbsoluteCoordinateX(point.x);
	mouseInput.mi.dy = (int) CalculateAbsoluteCoordinateY(point.y);
	mouseInput.mi.mouseData = 0;     
	mouseInput.mi.time = 0;
        mouseInput.mi.dwFlags = MouseEventFlags.MOUSEEVENTF_MOVE | MouseEventFlags.MOUSEEVENTF_ABSOLUTE;
        mouseInput.mi.dwExtraInfo = 0;
	SendInput(1, &mouseInput, sizeof(mouseInput));
}

I don't know if you would want to create some more methods within mouse.c or modify the existing moveMouse method and maybe add some flags on the params.

I have not thoroughly tested platform support but it works well on Windows 10 for me locally.

This script has some great examples in it
https://github.com/npocmaka/batch.scripts/blob/master/hybrids/.net/c/mouse.bat

I don't mind raising a PR but this is only prototype code and not very production friendly. I can work on it more if you want

[s1hofmann]

Hi @Reiss-Cashmore 👋

Just modify the moveMouse implementation using SendInput and dwFlags set to MOUSEEVENTF_ABSOLUTE

Thanks for your support!