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Activity for aura-lsprog-86
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #293459 |
Post edited: Minor grammar correction. |
— | 4 days ago |
| Edit | Post #293459 | Initial revision | — | 4 days ago |
| Question | — |
Iterating over pixels in QImage (Qt): which method adapts better for any image size? I asked this in SE years ago. I'm aware of two methods in order to access all the pixels in a `QImage` called `img`. Method 1 for (int y = 0; y < img.height(); y++) { QRgb line = (QRgb ) img.scanline(y); for (int x = 0; x < img.width(); x++) { // line[x... (more) |
— | 4 days ago |
| Edit | Post #293458 | Initial revision | — | 4 days ago |
| Answer | — |
A: How to correctly model the delay timer for a CHIP8 emulator written in C? I received this answer in SE. Sadly, the user who wrote the answer is no longer in the site. Don't use threads and synchronization primitives (semaphores, shared memory, etc) for this. In fact, I'd go as far as to say: don't use threads for anything unless you explicitly need multi-processor c... (more) |
— | 4 days ago |
| Edit | Post #293457 | Initial revision | — | 4 days ago |
| Question | — |
How to correctly model the delay timer for a CHIP8 emulator written in C? I asked this question in SE a while back. TL;DR I need to emulate a timer in C that allows concurrent writes and reads, whilst preserving constant decrements at 60 Hz (not exactly, but approximately accurate). It will be part of a Linux CHIP8 emulator. Using a thread-based approach with shared... (more) |
— | 4 days ago |
| Edit | Post #293436 |
Post edited: Change ownership of reviewed script |
— | 5 days ago |
| Edit | Post #293449 | Initial revision | — | 6 days ago |
| Answer | — |
A: Why is a for loop getting stuck when using a uint64_t counter, whereas a while loop isn't? SE user DU Jiaen provided the following answer, edited by Martin Zabel and found here. The expression `i >= 0` is always true if `i` is of an unsigned integer type. The alternative and simple way is to change it into: uint64t i; for (i = 15; i != -1; i--) { ... } This works no m... (more) |
— | 6 days ago |
| Edit | Post #293447 | Initial revision | — | 6 days ago |
| Answer | — |
A: Why is a for loop getting stuck when using a uint64_t counter, whereas a while loop isn't? SE user M Oehm provided with the following answer, as it can be found here. The condition `i >= 0` is always true if `i` is an unsigned type. Decrementing an unsigned zero will not produce a negative value, but the counter will wrap to the maximum representable number for the given type. C ... (more) |
— | 6 days ago |
| Edit | Post #293446 | Initial revision | — | 6 days ago |
| Question | — |
Why is a for loop getting stuck when using a uint64_t counter, whereas a while loop isn't? I asked this question a while ago over SE. When I use a `for` loop with a `uint64t` as a counter, it gets stuck forever, even though the condition seems to be well defined. Offending MCVE #include #include int main() { uint64t i; for (i = 15; i >= 0; i... (more) |
— | 6 days ago |
| Edit | Post #293444 |
Post edited: Remove commented unsigned int typedef used in the correction. |
— | 6 days ago |
| Edit | Post #293444 | Initial revision | — | 6 days ago |
| Answer | — |
A: Line-drawing algorithm prints nonsensical intermediate Y values. Where is the problem? I answered myself as it can be found here. Silly me! The root of the entire problem was the type used in both `point.x` and `point.y`: typedef unsigned int uint; typedef struct { uint x; uint y; } point; As both are unsigned integers, they "wrap up" once... (more) |
— | 6 days ago |
| Edit | Post #293443 | Initial revision | — | 6 days ago |
| Question | — |
Line-drawing algorithm prints nonsensical intermediate Y values. Where is the problem? This question was originally asked in SE. I have a program that draws lines using line drawing algorithms. I use `gcc 5.2.1` on Xubuntu 15.10 to compile it. Executing it throws a "Segment violation" fault. Further investigation let me isolate the problem in this MCVE: #include ... (more) |
— | 6 days ago |
| Edit | Post #293437 |
Post edited: Reformat code blocks inside bullet points. |
— | 6 days ago |
| Edit | Post #293436 |
Post edited: Add Fedora dependency install command |
— | 6 days ago |
| Edit | Post #293438 | Initial revision | — | 6 days ago |
| Answer | — |
A: Serial copying from disk images to folder in Bash The following answer was given by SE user Edward. The original source can be found here. The other answer gave some really good advice; this is intended as a complementary answer with still more things to think about. Put default arguments at the top of the script If someone wanted to ch... (more) |
— | 6 days ago |
| Edit | Post #293437 | Initial revision | — | 6 days ago |
| Answer | — |
A: Serial copying from disk images to folder in Bash The following answer was given by SE user Oh My Goodness. The original source can be found here. Instead of `cat "$x" | command` or `echo "$x" | command`, use `command /dev/null || exit 1 done } # Code here... require jq udisksctl Read `CONF` just once,... (more) |
— | 6 days ago |
| Edit | Post #293436 | Initial revision | — | 6 days ago |
| Question | — |
Serial copying from disk images to folder in Bash (Brought over from SE.) This is a Bash script that copies files stored inside disk images to a directory, using a defined structure provided via a JSON file. I've included the external programs it requires and the test I used so that you can test it too. Any comments regarding programming s... (more) |
— | 6 days ago |
| Edit | Post #293432 |
Post edited: Amend lack of MathJax in answer |
— | 7 days ago |
| Edit | Post #293432 | Initial revision | — | 7 days ago |
| Answer | — |
A: A simple implementation of a mutable String in C (User JS1 answered as follows; source.) Unsafe loop This loop in `stringfind()` is unsafe since it could read past the end of your buffer: > while (str->data[pos] != c) ++pos; You should add an additional check like this: while (pos length && str->data[pos] != c) ++pos; ... (more) |
— | 7 days ago |
| Edit | Post #293431 | Initial revision | — | 7 days ago |
| Question | — |
A simple implementation of a mutable String in C (Brought over from SE.) The following code implements a simple interface to operate on mutable `String`s in C. It is composed of two files: one for the structure definition and the available operations, and the other with the actual implementation. = This can be inexact, as only adding cha... (more) |
— | 7 days ago |
| Comment | Post #293416 |
Thanks for your insight! I understand the reasoning: if a private field is such, then there is no need to alter it from the outside. (Maybe if the field is part of a compiled library, but I suspect there are better patterns such as composition to deal with this.) (more) |
— | 7 days ago |
| Edit | Post #293429 |
Post edited: Add linux in title and tags |
— | 7 days ago |
| Edit | Post #293430 | Initial revision | — | 7 days ago |
| Answer | — |
A: Scanner fails when executing Java with admin rights (sudo) in Eclipse in Linux I've finally managed to get it working without using a wrapper for `java`. It has to do with filesystem capabilities in Linux. To let `java` list and select network interfaces, as well as analyse and capture packets, go to the directory where the executable the IDE uses is (for example, `/usr/lib/... (more) |
— | 7 days ago |
| Edit | Post #293429 | Initial revision | — | 7 days ago |
| Question | — |
Scanner fails when executing Java with admin rights (sudo) in Eclipse in Linux (Brought over from SE.) The problem I have followed this procedure in order to run Java applications as root when needed from Eclipse (as I use Xubuntu, for instance, when using `jnetpcap` to capture and analyse packets). The problem I have is that any `Scanner` statement reading from `Syst... (more) |
— | 7 days ago |
| Edit | Post #293416 |
Post edited: |
— | 8 days ago |
| Edit | Post #293416 | Initial revision | — | 8 days ago |
| Answer | — |
A: How can I set a private class instance variable to the File object used by an unmarshaller? I've found a way to set the private field without exposing it or giving it a setter: Reflection. Using external event listeners, I can get ahold of the `File` object. Then, inside the `beforeUnmarshal` method, and after checking that I got the correct object, I use reflection to get the private fi... (more) |
— | 8 days ago |
| Edit | Post #293414 | Initial revision | — | 8 days ago |
| Question | — |
How can I set a private class instance variable to the File object used by an unmarshaller? (Brought over from SE) The problem I'm coding a Java Swing application dealing with XML files, so I'm using JAXB in order to marshal classes into documents and unmarshal the other way around. I want to include a private field in the class that gets marshalled, which will store the backin... (more) |
— | 8 days ago |