Add: allow using SDL2 in "relative mouse mode" #8360
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This mode doesn't wrap the mouse constantly, but requests SDL / OS to lock the mouse pointer. This solves mouse problems on a few OSes, like GUI Linux via WSL2, where the X11-server is not allowed to change the mouse position in Windows (as it isn't capturing it). This also is needed for other OSes that by design can never capture the mouse, like with Emscripten, as it runs in a browser. You can enable this moude via "-vsdl:relative_mode".
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What's the difference between normal mouse mode and relative mouse mode? Why not use this mode all the time? |
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https://wiki.libsdl.org/SDL_SetRelativeMouseMode
(I also wrote this in the PR description btw .. not sure what more information you expect here :D) I am not sure if always using it is a good idea, that is to say: I need relative mouse mode for Emscripten to work properly, and I can imagine that other targets have the opposite problem. This patch makes it non-intrusive for current users, making sure there is no regression. We could experiment if relative mouse mode works for other targets too, but if it ain't broken, don't fix it, I say. If we want to go down the road of: either one or the other, this PR is never going to land, as it would be an endless back and forth between people :P We simply don't have enough expertise atm to strike a balance there :) Does this answer satisfy you? :D |
| this->delta.x = delta_x; | ||
| this->delta.y = delta_y; | ||
| } else { | ||
| int last_position_x = this->pos.x; |
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Isn't this supposed to be "this->last_position.x"?
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@frosch123 did some testing on a real Linux system, and found out that Relative Mode has some nasty effects there: you cannot escape your window :) This is absolutely the way it is intended to work, but that makes is nearly useless for any target except one that is prepared for this, like Emscripten. So I suggest we don't do the PR like this, but merge it into the Emscripten PR, where we |
This mode doesn't wrap the mouse constantly, but requests SDL / OS
to lock the mouse pointer. This solves mouse problems on a few
OSes, like GUI Linux via WSL2, where the X11-server is not allowed
to change the mouse position in Windows (as it isn't capturing it).
This also is needed for other OSes that by design can never
capture the mouse, like with Emscripten, as it runs in a browser.
You can enable this moude via "-vsdl:relative_mode".