Pygame - first person shooter "look" with mouse

Question

I am not writing a game but a scientific renderer using Pygame. I'd like the controls to work just like in a first-person shooter, so that a user can navigate using a familiar set of controls.

I have tried to write the code to have the same properties as the 'look' feature in e.g. Skyrim or Half-Life but the mouse doesn't move the cursor - it lets you look around and around, in infinite circles. Clicking should have no effect.

The first attempt for the controls:

(code inside a game loop)

delta_y, delta_x = pygame.mouse.get_rel()
rotation_direction.x = float(delta_x)
rotation_direction.y = float(delta_y)

(don't ask me why, but y and x need to be reversed like this to get the expected look directions; must be something to do with the camera transform implementation, which isn't mine.)

This, however, leads to a cursor sitting on top of the window, and when the cursor gets to the edge of the screen the window stops rotating; i.e. the code is reporting the actual position on the screen.

I tried to 'reset' the mouse position every game loop (and, incidentally, hide the mouse):

pygame.mouse.set_pos([150, 150])
pygame.mouse.set_visible(False)

But this generates a symmetrical 'move back to start' delta in the next loop, meaning that you couldn't 'look' anywhere.

To summarize, I want to:

detect actual mouse motion reported from the device
not move/show any OS cursor
not clip at the 'edge of a screen'

What is the best way to do this, using Pygame or other Python hacks?

score 6 · Accepted Answer · edited Sep 24 '12 at 07:08

6

http://www.pygame.org/docs/ref/mouse.html :

If the mouse cursor is hidden, and input is grabbed to the current display the mouse will enter a virtual input mode, where the relative movements of the mouse will never be stopped by the borders of the screen. See the functions pygame.mouse.set_visible - hide or show the mouse cursor and pygame.event.set_grab (docs) - control the sharing of input devices with other applications to get this configured.

edited Sep 24 '12 at 07:08

tehwalrus

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answered Sep 23 '12 at 22:41

Ofir

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In other words, also call pygame.event.set_grab(True) – Ofir Sep 23 '12 at 22:44
Aha, I looked in the docs for a mouse capture function but couldn't find it, hence the suggestion in my answer. – Kylotan Sep 23 '12 at 22:53
On my computer the order mattered, grabbing then hiding the mouse still got caught on the edges, whereas grabbing then hiding works fine. – cuppajoeman Aug 04 '23 at 02:47

score 1 · Answer 2 · answered Sep 23 '12 at 22:40

1

Try calling pygame.mouse.get_rel() once more immediately after the set_pos call to 'throw away' whatever relative movement the set_pos call has performed.

answered Sep 23 '12 at 22:40

Kylotan

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I did think about this after I'd posted the question, but @Ofir's answer is much simpler. Thanks! – tehwalrus Sep 24 '12 at 07:13
His answer is also the 'proper' way. :) – Kylotan Sep 24 '12 at 12:42
I stopped short of saying that, as it sounded a bit mean! but yes, I suppose it is :) – tehwalrus Sep 24 '12 at 13:03

score 0 · Answer 3 · edited May 23 '17 at 10:29

0

Since you are using pyOpenGL, try gluLookAt() example: How do I use gluLookAt properly?

edited May 23 '17 at 10:29

Community

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answered Sep 24 '12 at 01:28

ninMonkey

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While this doesn't strictly answer the question (which is about mouse events capture,) `gluLookAt` is something I hadn't seen before, and looks very relevant to anyone trying to solve this problem - in my case, it would allow me to avoid using some python code (much slower) to do the same thing by hand. Thanks for the heads up! :) – tehwalrus Sep 24 '12 at 07:17

Pygame - first person shooter "look" with mouse

3 Answers3