pixels | 🦀 | Graphics library

I'm trying to test a Text that on my component I can print it in different colors, so on my test I'm verifying it gets the expected color. I was looking for a method to return the color but I did not find any.

From now I'm asserting that the text is correct and the visibility is correct, but when trying to find the method to get the colour I get too deep and I'm looking for a simpler solution.

I don't know if this is possible, but I am trying to take the image of a custom outdoor football field layout and have the players' GPS coordinates correspond to the image xand y position. This way, it can be viewed via the app to show the players' current location on the field as a sort of live tracking.

I have also looked into this Convert GPS coordinates to coordinate plane. The problem is that I don't know if this would work and wanted to confirm beforehand. The image provided in the post was for indoor location, and it was from 11 years ago.

I used Location and Google Maps packages for flutter. The player's latitude and longitude correspond to the actual latitude and longitude that the simulator in the android studio shows when tested.

The layout in question and a close comparison to the result I am looking for.

Any help on this matter would be appreciated highly, and thanks in advance for all the help.

Edit:

After looking more at the matter I tried the answer of this post GPS Conversion - pixel coords to GPS coords, but it wasn't working as intended. I took some points on the image and the correspond coordinates, and followed the same logic that the answer used, but reversed it to give me the actual image X, Ypositions.

The formula that was given in the post above:

(Solution has been found, please avoid reading on.)

I am creating a pixel art editor for Android, and as for all pixel art editors, a paint bucket (fill tool) is a must need.

To do this, I did some research on flood fill algorithms online.

I stumbled across the following video which explained how to implement an iterative flood fill algorithm in your code. The code used in the video was JavaScript, but I was easily able to convert the code from the video to Kotlin:

https://www.youtube.com/watch?v=5Bochyn8MMI&t=72s&ab_channel=crayoncode

Here is an excerpt of the JavaScript code from the video:

Converted code:

I'm trying to learn Python/Pygame and I made a simple Pong game. However I cannot get the square to bounce off the sides at the perfect pixel as the drawing of the square is updating let's say 3 pixels every frame.

I have a code to decide when the square is hitting the edges and bounce in a reverse direction like this:

I have created a working CNN model in Keras/Tensorflow, and have successfully used the CIFAR-10 & MNIST datasets to test this model. The functioning code as seen below:

I’m writing a pretty complex app in React/Redux/Redux Toolkit, and I came across a situation which I’m not really sure how to handle. I found a way to do it, but I’m wondering if it can cause issues or if there is a better way. The short version is that I want the reducer to communicate to the caller without modifying the state, and the only way I’ve found is to mutate the action.

Description:

To simplify, let’s say that I want to implement a horizontal scrollbar (but in reality it’s significantly more complicated). The state contains the current position, a number capped between some min and max values, and the UI draws a rectangle that has that position and that can be clicked and dragged horizontally.

Main property: If the user clicks and drags further than the min/max value, then the rectangle does not move further, but if the user then moves in the other direction, the rectangle should wait until the mouse is back at its original position before starting to move back (exactly like scrollbars behave on most/all operating system).

Keep in mind that my real use case is significantly more complex, I have a dozen of similar situations, sometimes capping between min and max, sometimes snapping every 100 pixels, sometimes more complicated constraints that depend on various parts of the state, etc. I’d like a solution that works in all such cases and that preserves the separation between the UI and the logic.

Constraints:

• I do not want the UI/component/custom hook to have the responsibility to compute when we reach the min/max, because in my use case it can be pretty complex and depend on various parts of the state. So the reducer is the only place that knows whether we did reach the min/max.
• On the other hand, in order to implement the Main property above, I do need to somehow remember where we clicked on the rectangle, or how many pixels of a given "drag" action was handled, in order to know when to start moving back. But I don’t want to store that in the state as it’s really a UI detail that doesn’t belong there (and also because I have quite a few different situations where I need to do that and my state would become significantly more complex, and unnecessary state changes will be performance heavy).

Problem:

So the reducer is the only part that knows if we reached the min/max, and the only way a reducer usually communicates to the rest of the app is through the state, but I don’t want to communicate that information through the state.

Solution?

I actually managed to find a way to solve it, which seems to work just fine but feels somewhat wrong: mutating the action object in the reducer.

The reducer takes the action "dragged by 10 pixels", realizes that it can only drag by 3 pixels, creates a new state where it has been dragged by 3 pixels, and adds an action.response = 3 field to the action.

Then after my custom hook dispatched the "dragged by 10 pixels" action, it looks at the action.response field of the return value of dispatch to know how much was actually handled, and it remembers the difference with the expected value (in this case it remembers that we are 7 pixels away from the original position). In this way, if at the next mousemove we drag by -9 pixels, my custom hook can add that number to the 7 pixels it remembers, and tell the reducer that we only moved by -2 pixels.

It seems to me that this solution preserves separation of UI/logic perfectly:

• The reducer only needs to know by how many pixels we moved and then return the new state and how many pixels were actually handled (through mutating the action)
• The custom hook can remember how far off we are from the original position (without having to know why), and then it will simply correct event.movementX to compensate with how much the reducer didn’t handle in previous actions, and then send the correct delta to the reducer.

It also works just fine with things like snapping at every 100 pixels or such.

The only weird thing is that the reducer mutates the action, which I would assume is not supposed to happen as it should be a pure function, but I couldn’t find any issue with it so far. The app just works, Redux Toolkit doesn’t complain, and the devtools work just fine as well.

Is there any issue with this solution?

Is there another way it could be done?

I am looking for an easy way to count the number of the green pixels in the image below, where the original image is the same but the green pixels are black.

I tried it with numpy.diff(), but then I am counting some pixels twice. I thought about numpy.gradient() – but here I am not sure if it is the right tool.

I know there have to be many solutions to this problem, but I don't know how to google for it. I am looking for a solution in python.

To make it clearer, I have only one image (only black and white pixels). The image with the green pixel is just for illustration.

I am trying to linearly scale an image so the whole greyscale range is used. This is to improve the lighting of the shot. When plotting the histogram however I don't know how to get the scaled histogram so that its smoother so it's a curve as aspired to discrete bins. Any tips or points would be much appreciated.

Unhandled promise rejection: Error: No native splash screen registered for given view controller. Call 'SplashScreen.show' for given view controller first.

I get the following warning only on my ios emulator when I first launch the app. Not on my ios physical device or android emulator. I am using expo-splash-screen for my splash screen. Is this something I can just ignore or do I need to resolve it because I can't figure out how to resolve it. The splash screen seems to load fine. Is it an error with expo-splash-screen? I followed expo's tutorial on setting it up.

warning: