Stack Overflow
Stack Overflow

Questions tagged [bitmask]

Bitmask is a technique used to isolate specific bits in a byte in order to work only on the desired ones. They are used in IP addresses to separate the network prefix and the host number for example.

738 questions
0
votes
1 answer

How to decode hexadecimal bitmask with php?

I have a database with a field containing a bit mask, and I have a hex bit mask list which looks like this: 2^8 256 = Type 1 2^9 512 = Type 2 2^0 001 = Type 3 2^4 016 = Type 4 2^1 002 = Type 5 2^5 032 = Type 6 I'm trying to "decode" (not sure of…
Tony
  • 121
  • 2
  • 13
0
votes
1 answer

Code only working on iOS 7

Hi I've been making a game with the SpriteKit framework and I set a collision bit mask when 2 objects collide. One of those objects, let's say the object A, can have 2 states: black or normal so when the two objects collide and the A object is on…
Facundo Schiavoni
  • 451
  • 7
  • 17
0
votes
1 answer

Bit math and masks correlation to numbers

Good evening, I am trying to correlate the required values to the values that needs to be sent to an I2C device, and I am having issues with the bit math and masking. My range goes from -15 to 15, so does the range of the device. Example of required…
Deskwizard
  • 5
  • 1
0
votes
1 answer

Swift collision not working. I think something is wrong with my code in didBeginContact

I've been working on a game that has to perform a test every time my test node contacts with my check node. As these two nodes are the only nodes that will be checking for collision in the game, I decided to use this method to initiate my test. The…
John Imyeob Kim
  • 3
  • 1
0
votes
0 answers

Check that a bitmask flag is zero

I'm getting data from a server. The first bit indicates whether a message was read or not read: 1 for "read" and 0 for "not read". The second bit says whether the message was edited or not. So I'm trying to read the statuses: typedef…
Maria
  • 755
  • 1
  • 11
  • 29
0
votes
1 answer

Converting a struct of integers into a bitmask

Is it possible (if so, how) to convert a struct of integers into a bitmask. One bit for each integer (0 if the int is 0, otherwise 1). For example struct Int_List_t { uint64_t int1; uint64_t int2; uint64_t int3; uint64_t int4; }…
Nigel Armstrong
  • 3
  • 2
0
votes
2 answers

Merging 13 bits array into an array of unsigned char

I'm writing an algorithm that compresses data (LZSS) and it requires me to have two 13-bit values which I'll have to later merge together. In some cases, however, I don't need 13 bits; 8 are enough. For this purpose I have a structure like…
Nikooo777
  • 1
0
votes
2 answers

How to create BufferedImage with BITMASK Transparency?

The BufferedImage class implements Transparency, which has three values: OPAQUE means no transparency. TRANSLUCENT means every pixel has an Alpha value between 0 and 1. BITMASK means every pixel is either opaque or completely transparent. I can…
Leif Sabellek
  • 173
  • 1
  • 9
0
votes
2 answers

Bitmask as member enum with default parameter

I can't figure out how to implement a bitmask parameter for my class. Specifically my CreateMenuDlg function I've searched google quite a bit, finding all sorts of forum questions that ask about bitmasks, bitfields, etc. and everyone posts minimal…
Numerials
  • 3
  • 2
0
votes
1 answer

how to store exclusive OR boolean as bitmask

I am working with a interface where most flags are implicitly false when not set, but some parameters have an explicit 'x-not-set' flag, so that either flag can be passed in but never both and in some cases, neither should be passed in. I think the…
Anthony
  • 36,459
  • 25
  • 97
  • 163
0
votes
2 answers

Bitwise AND operation on UInt8 enum

Having the following enumeration enum ColliderType: UInt8 { case Hero = 0b1 case GoblinOrBoss = 0b10 case Projectile = 0b100 case Wall = 0b1000 case Cave = 0b10000 } I'm trying to do something very simple: let combined =…
Shai
  • 25,159
  • 9
  • 44
  • 67
0
votes
0 answers

Checking for collision in SWIFT

I have two objects that I want to collide: ball and centerBlock. I created physics bodies for each and wrote the following: ball.physicsBody!.categoryBitMask = BodyType.ballCategory.toRaw() ball.physicsBody = SKPhysicsBody(circleOfRadius:…
Tommy
  • 140
  • 8
0
votes
0 answers

How to use bitmask operations in SQL

I'm already quite familiar with the concept of bitmasks, and also with the bitwise operators used to modify them. However, I have one specific problem that I can't solve. Here's the problem: I have a large number of relatively large bitmasks…
Arshia001
  • 1,854
  • 14
  • 19
0
votes
1 answer

C++ Bitmask 72bit variable and cut off leading and trailing zero's - Help please

I have a 72 bit unsigned variable and I am only interested in 24 bits. The variable is split into the 34 bits / 24 bits / 14 bits. The bit mask works fine but I would like to dump the 34 zero's at the front and the 14 zero's at the back and store…
Hearny
  • 17
  • 3
0
votes
1 answer

Bitmask understanding in C program

I have a program that my professor gave me for a HW, and I want to see if any of y'all can explain me how bits work. Note: I don't want you guys to give me the answer; I want to learn so if you guys can explain me how this work would be awesome so I…
user3977404
1 2 3
…
49 50