I'm using the C-based screenshot concept from JHolta's answer in Take a screenshot via a python script. [Linux] in order to generate screenshots I'd like to display in PyGame. With some minor tweaks (prepending extern "C" to the functions and importing Xutil instead of Xlib) the provided code works amazingly well. In short, it uses Image.frombuffer on a byte array returned by the C library. With show(), the image and anything about it I manipulate is displayed by ImageMagick.
However, if I convert it to Python 3's PyGame as per PIL and pygame.image, I only get a black surface. It's not a straightforward issue, though: If I draw onto the image before converting it into a PyGame image (like in the OP of the latter link), that does show on a black background when blitting the result. Furthermore, printing the byte objects from PILImage.tobytes and pygame.image.tostring shows they both contain data and their len is identical.
What am I doing wrong here? I'll gladly provide code if necessary, but I think it's more of a conceptual issue and I didn't really change the snippets from these answers a lot.
(Similar issue in Python 2, by the way, but there PyGame uses str instead of byte for tostring / fromstring and printing the tostring appears to yield an empty string.)
It turns out that a buggy trigger caused the screenshoot to be taken again while the fullscreen window displaying it was opening. I suppose there are a few milliseconds of blackness or of an undefined state (in the context of the screenshot function) at that moment, and the library is fast enough to catch that.
I'm not sure if this should stay up because it's basically a reminder to check for things that a human can't perceive. Feel free to delete if it's not appropriate.
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Below, you can see two barplots I've superimposed in order to better see the contrast. Both barplots were generated using identical code (different data, but this is unimportant) in two simultaneously opened Jupyter Notebooks. The code for both calls 'C3' as the color, but as you can clearly see, this displays differently in both notebooks. This is the case with both the inline and the plt.savefig versions of the images. I have also tried other colors such as 'C0' and get similar slight differences.
Any ideas what might be causing this and how I might remedy it? Thanking you all in advance.
Per the color documentation the CN syntax is used to index into the current color cycler. Since RGB codes work and CN doesn't, it leads me to the conclusion that somehow the different notebooks are using different color cycles. Try the following snippet in each notebook and see if it gives you a different answer:
import matplotlib as mpl
print(mpl.rcParams["axes.prop_cycle"])
I think it's likely that somewhere in one of the notebooks there's been a call to set_prop_cycle() that has somehow changed the cycler that is being used. Also check out this post for more info on selecting the colors via the cycler.
The short answer would be to avoid the 'CN' notation.
I am trying to capture a part of my screen with PIL.ImageGrab and then converting it to an numpy.array as you can see below.
np.array(ImageGrab.grab(bbox=(0, 0, 720, 480)))
What I can't figure out is, how to get this data into a Kivy window or a widget?
All my Widgets are in separate classes so I would like to have one Screen class with all the code necessary for this part of my Window.
I have already tried methods like this one, but I don't know how to implement it since Kivy confuses me a lot sometimes.
If my idea just isn't realizable, I guess you could save each captured frame as .jpg format and then load it into Kivy. But I imagine this is not the most efficient way.
Thanks a lot in advance! Dominik
I am making a game, and I want it to be fullscreen. However, the pygame fullscreen is strange, creating a screen too large. So I referred to this: Pygame FULLSCREEN Display Flag Creates A Game Screen That Is Too Large For The Screen. However, when I followed these instructions
import ctypes
ctypes.windll.user32.SetProcessDPIAware()
true_res = (ctypes.windll.user32.GetSystemMetrics(0), ctypes.windll.user32.GetSystemMetrics(1))
pygame.display.set_mode(true_res,pygame.FULLSCREEN)
from an answer (but instead using pywin32 instead of ctypes, like this: win32api.GetSystemMetric(0)).
I used this, and while it does create a fullscreen, it also creates a black border around my screen and enlarges everything a slight bit, including my cursor. How can I get rid of this black border and get all shapes to normal size? Or is there a better way to create a good fullscreen?
If it helps, I use Windows 10.
Thanks in advance!
I think the problem of enlarging everything arose with the use of ctypes module as because the ctypes module makes use of a function named as GetSystemMetrics() whose work is to get the size of the screen of your system.
And might be the import pygame is loading some dll that is not compatible with a dll that windll needs.
So I suggest either you update the ctype library or pygame library or update both libraries or you can enlarge screen size by providing custom width and height values according to the resolution supported by your system.
Hope this helps !!
I'm trying to load a bitmap in Direct2D that already contains an alpha channel, but Direct 2D seems to always ignore the alpha channel surrounding the desired image, replacing it with opaque black. Has anyone had success with this, and could show me their code? has anyone loaded a PNG file, and convert it to a bitmap? (MSDN says it's possible, but i can't find any cases where people have had success) or is this a mask thing?
In any case, could you show me a example code snippet explaining how to do one of these things? i'm trying to make a game, i have everything else working, and this is the literal final step. if someone could show me exactly how this is done, that would make my day! just transparency in an image. that's all i need.
This may be a naive question, but I was wondering if there's a better way than using text() to adding text to a plot. Note, I'm also using layout() as well. Specifically, I have a section of a plot where I would like to add some text with headings followed by regular text.
text() is fine it seems for simple annotations, but to get the spacing right for several lines of text seems to require a lot of manual manipulation of the x and y and cex parameters. Any suggestions?
Here are some alternative options to consider:
- the gplots package has a textplot function to add some text output in a base graphics plot.
- plotrix has a function addtable2plot
- for grid graphics grid.text() is available and in gridExtra there is a function grid.table() (see, e.g., R-Wiki)
If you're using base graphics, then text() is probably your best bet, and fiddling with coordinates etc is part of the game. If you want to learn a new framework, the lattice package is a reworking of the basic approach to plotting in R. It be installed by default so help(package='lattice') will get you started.
Here's a pretty good guide (pdf) to graphics in general in R, with a substantial section on lattice:
download