(C++ question) I need to be able make a compiled code (like a .dll?) which other programmers can use on linux, win,, mac, etc.
The compiled code would simply do calculations and spit out an answer in memory.
I need it to have certain functions that they can easily call and understand (without actually seeing the source).
I am starting a turn based battle (similar to pokemon) app. How could i make this and make it cross platform. Also is it possible to make it access gps and allow other devices with the same app communicate with each other?
I have done things on the command line but i never made anything with images so i dont even know where to start for this app.
I'm working on a project which uses gtk+ and gtkmm. We use them in preference to MFC because the program needs to be cross-platform. For quite a long time, customers on OS-X and Linux have sometimes complained that the program would crash during shutdown but the Windows version (which I work on) never seemed to suffer. However, I'm now transferring my build environment to a new PC and I'm noticing the same shutdown crashes. It's a bit complicated so let me start with a small example:-
Code:
namespace Whatever {
class B {
public:
virtual ~B();
private:
int bb;
[Code] ....
Suppose I run the above program. When it stops at breakpoint #1 I make a note of the value of pA. Eventually the program reaches breakpoints #2 and #3. At each point my this pointer is exactly the same number. If the value of pA was 0x03604fb0, my this pointer is identical at both stages.
Now let's consider the real example:-
Code:
namespace Gtk {
class Widget {
public:
virtual ~Widget() {}
[Code] .....
Suppose I run the real example. At breakpoint #1 the value of pW is 0x03604fb0. But by the time I reach breakpoint #2 my this point is slightly different:- 0x03604fcc. It doesn't seem right to me and I'm wondering if it might be contributing to our shutdown crashes.
I discussed a topic about how to write cross-platform file IO code with a member named Disch for about a year ago. Since I am a beginner I am not sure if the "rules" for doing this has changed or not within C++.
He taught me that differenct CPU:s use different endianness when reading and writing to files. However, why can't the C++ standard file IO functions detect what endianness should be used on the current machine that is running the program? Why didn't the developers who created the standard library develop file IO functions that are cross-platform from the beginning? Have the rules changed since last year?
What I learn is that if you need to store data in files that will be read and written to on different machines, you have to define in the program what endianness should be used. For example, if I needed to store 4 bytes, I had to do this manually with my own functions and define in those which endianness is used.
System();is bad, I get that. Is there another way, that works across platforms I can use to execute an external program. If not, is there a windows specific way.
View 2 Replies View RelatedI am planning to develop a GUI that will run on Windows, Linux, Android & iOS. If am right, VC++ apps don't work on Linux, Android & iOS. Is that correct?
Is there an alternative to that? Which other tool works for GUI development on above mentioned 4 platforms?
In my game, I want to display dialogues for exceptions, and I don't really want to use something heavy like Qt, but then I also don't want to write and maintain my own platform-specific code to do it. Is there any library that can display simple message dialogues, just a few lines of text and an OK button, without being complete overkill like a full-blown GUI library?
View 13 Replies View RelatedSuppose:
cin >> number;
pointer = new type[number + (rand()%number);
So, I wont know the memory allocated for pointer. How can I check it in all OS?
I am overriding OnSaveDocument in my MFC document class to strip out the carriage returns when saving my app's document to a UNIX file system but not when the user is saving a file to a Windows file system.
Is there a way to determine if the lpszPathName in OnSaveDocument(LPCTSTR lpszPathName) is a UNIX or Windows file system?
Note, I want to avoid hard coding server names and I want to avoid overriding the FileSave dialog and forcing the user to select Windows or UNIX.
I have a C++ code that reads the database password from the registry and decrypts it using CryptUnprotectData. We have to deploy this application on a Windows 7 machine.
When I compile my code on Windows XP and run it on the test Windows 7 machine, it works absolutely fine. When I compile the same code on my laptop having Windows 7 and run it on the test Windows 7 machine, CryptUnprotectData fails with GetLastError() return '87'. If I run this application on my own laptop with Windows 7 on it, it again works fine probably because my laptop has a lot of things installed including Visual Studio and all the service packs etc.
I believe I have missed out installing some dependency on the test Windows 7 machine but I am unable to figure out what is that. What is it that's making the Windows XP compiled code running fine on the test machine and not the code that's compiled on Windows 7.
Here is the call to CryptUnprotectData in the code:
if (CryptUnprotectData(
&cipherText,
NULL,
NULL, // Optional entropy
NULL, // Reserved
NULL, // Optional PromptStruct
CRYPTPROTECT_UI_FORBIDDEN,
&plainText))
[code]....
How to make a source code into a functional program that a user can open and use without coming across the source code and building or running it.
View 1 Replies View RelatedI am not a C programmer (or a programmer at all). I am just a hobbyist who writes random code (i.e.: ignorant).C is not my area, and I my experience with it is quite LIMITED!Today, I found out that if I need to get "square root" in C I will be in trouble if I depend solely on the compiler..Is it possible to make the compiler to generate smarter code for this (quite trivial code):
Code:
void intprime_c(unsigned long* fprimes, unsigned long count)
{
unsigned long divc = 3;
unsigned long num = 2;
unsigned long sqr;
unsigned long pfound = 0;
}
[code]...
By "without ugly hacks" I mean using already existing code that came with GCC. Because the others did not need ugly hacks to perform better (it is all about being fair).To compute the "square root" in x86 one just need 3 instructions:
fild
fsqrt
fistp
But the compiler is generating a call to a "fsqrt" function and wasting a lot of time by doing this. If not, then why is it taking so long? Is it something wrong in my code (at least the output was verified to be the correct)?
Time taken to get the first 2500000 primes (x86_64):
Assembly = 72.400s (human written, unoptimized, coder level: newbie (i.e.: ignorant))
pascal = 75.200s (written by the same person)
C (fsqrt) = 83.600s (written by the same person)
C (sqrt) = 85.900s (written by the same person)
If it matters, I compiled the C code with this command: gcc -O2 -fno-omit-frame-pointer -fPIC -c ./prime.
This code compiles in release mode but I get this compile error in debug mode:
Error1error C2664: 'GetPrivateProfileStringA' : cannot convert parameter 4 from 'wchar_t [255]' to 'LPSTR'g:easywebstoreuploaderini.cpp45
Code:
CString CIniFile::getKeyValue(CString strKey, CString strSection) {
wchar_t ac_Result[255];
// Get the info from the .ini file
m_lRetValue = GetPrivateProfileString(strSection, strKey, _T(""), ac_Result, 255, m_strFileName);
CString strResult(ac_Result);
return strResult;
}
I need to have Ufasoft Miner source code modified so it's rendered undetectable to antivirus software. The source code is located here: [URL]
It's programmed in C++.
We have other unrelated projects after this, that you might apply to.
I have a c file which can be compiled in Linux via GCC , but when I compile it in NetBeans via Cygwin or MinGW , it doesn't work and keeps throwing a segmentation fault.
View 14 Replies View RelatedToday I am given an assignment to find the zeroes of a function using Newton-Raphson method. Till now, the input I gave to a program was data. But now the function (whose zeroes are to be calculated) is also an input.
Is there a way where I can compile and build a function into a file and during execution of my program open the file and run the machine-language code in it and get the return value?
I am using visual studio 2012 on windows 7. but, when I have compiled my programs and run them on an older pc to test out its functions, I receive an error saying that the program is not a "valid win32 application." I have even tested this with a very simple hello world console application, but the problem still remains. Where is the error coming from? is the application corrupted during transport? (upload to internet) or are programs compiled on win 7 incompatible with win xp
View 6 Replies View RelatedI have a weird problem, my computer restarts imidiately after program writen in dev-cpp is compiled AND run. When I run any program, it lasts about 1 second, then program closes, and computer reboots. It doesn't matter whether program is writen now or earlier, my dev-cpp version is 4.9.9.2. Source code can be as simple as this:
#include <iostream>
#include <conio.h>
using namespace std;
int main() {
getch();
return 0;
}
and it restarts anyway...
I am looking at reducing the size of a compiled executable for easier distribution.
What factors affect the size of an output executable?
Would literally having defined and implemented less functions, would make the exec. smaller? Meaning that instead of have a DLL ( yes im on windows ), I would download the source code of a library and comment out the functions ( and code ) that I am not using -- Would this process decrease the size of my exec.?
I am an experience C programmer but never implement GUI.
I need to make a demo implementation that will be run on Linux and will implement GUI.
I searched the WEB and found lot of information, among is implementing the GUI in HTML and run the API through web browser.
How can I make such implementation in C?
I am working on a script compiler that must output compiled script into binary file. Compiling etc is not a problem. The problem is detecting some specific cases. Nothing seems to work. If it works, then it breaks as soon as i modify the script.
Here is example "script1":
Code:
1VAR1 c1 = 44
2VAR2 c2 = 66
3beginscript
4if(c1=44)
5do_nothing
[Code] ....
Second example "script2", when there can be also some command between ENDIF and ENDIF. In this case: do_nothing command.
Code:
1VAR1 c1 = 44
2VAR2 c2 = 66
3beginscript
4if(c1=44)
5do_nothing
[Code] ....
The INDEXES before each line are not in actual script. They are just to point YOU to specific lines. Although the INDEXes are in compiled script!! This is very important. As you see there can be simple IF_ENDIF and nested (more complex) IF_ENDIF.
i.e IF_ENDIF inside another IF_ENDIF.
There are also IF_ELSE_ENDIF and some other ones, but im trying to make simple IF_ENDIF work first.
ENDIF is "SPECIAL" command, the IF, DO_NOTHING are "usual" commands.
"Usual" commands must always jump over(!) the ENDIF. ALWAYS!!
They must "ignore" them!
One strong RULE is like this for usual commands: always jump over any ENDIF, not matter what. If there is one, two or more ENDIF's in a row, then just jump over them to the closest NEXT usual block command. If there is some "usual" block command between multiple ENDIFs, then jump to this command and this command must therefore check whats next command right after it. And do the same: check if next command is ENDIF, if yes, jump over it, until "usual" block command is found.
This is the place im stuck. When i some time ago thinked about some ideas, i saw some patterns. One of them was that: Seems like if its nested IF_ENDIF, then every usual block command jumps out of it, i.e. right after the final ENDIF of this current nested IF_ENDIF.
But as soon as i added do_nothing between the two ENDIFs the so called "pattern" broke. In script2 above you see index 11 is do_nothing. Ok its in nested IF_ENDIF it should jump out to command index 17. But no, because there is do_nothing between index 13 and 16. If we jump out at index 11, the command 14 would never execute. This is a BIG NO. One idea i was thinking and trying was to use STL::FIND, STL::FIND_IF to find next "usual" command after specific index. But my code seems to crash sometimes and not work always.
Code:
bool NextNonENDIF(int i) {
return (i!=98);
}
int findNextBlockCmd(vector<int>&vec, int curidx)
[Code] ....
Here i pass him the vector that contains all the command TYPES in current script. Each command has its own TYPE or better called unique ID in which way compiler knows what is what. So in this case im trying to find a command thats NOT "ENDIF", in other words im trying to find next usual command after specific type of command. Lets just say the TYPE or unique ID of do_nothing is 555, im trying to find it.
How i should continue with this? What to use maybe stl::stack, some custom command indexing, some sort of labelling for usual commands in nested IF_ENDIFs or what?
In general, look script2, and i ask: There is index 11, this guy should look if there is any usual block command left for him before the final ENDIF at index 16. If there is, jump to it. If there is none, jump out of this nested IF_ENDIF to index 17.
Question: how to do it? What algorithms to use? I can use STL, BOOST, whatever. And i can use C++11.
I am trying to compute the cross product of an 1x6 column vector "D" with a 6xN matrix "S".
vector< vector<float> > D(1, vector<float>(6));
vector< vector<float> > S(6, vector<float>(10)); // Example where N = 10
float cProduct = D*S; // ?
The last line fails, so I'm wondering how you would get the cross product?
I have Mq4 platform calling functions from DLL some how it doesnt make any differents when I make the call....
// DLL Code
#define WIN32_LEAN_AND_MEAN
#define MT4_EXPFUNC __declspec(dllexport)
using namespace std;
std::string My_String;
#define stringify(mymonths ) # mymonths
[Code] ....
I call this function
bool counts = StartRulls(bars);
Print("counts =",counts );
2013.02.09 23:03:242010.03.31 16:37 My_Mq4.mq4 EURCAD,M5: counts = 1
My result always stays 1
Consider the situation where you're writing a cross-platform library that has functions for creating and manipulating windows. To create a window suitable for OpenGL rendering on Windows you need to call a bunch of different functions such as GetModuleHandle, RegisterClass, CreateWindow, SetPixelFormat, GetDC, wglCreateContextGetDC and so on. All of these functions can potentially fail in one way or another and the Windows documentation doesn't even attempt to list all the different error codes that these functions return.
Let's say your function for creating a window is called create_window(). What kind of error message should you return if any of these platform specific functions fail? It could be something as simple as MultiByteToWideChar failing for some reason when you convert the UTF-8 string your API uses internally to the UTF-16 string that the Windows API expects. I've read that you're not supposed to leak implementation details from your API but what are you suppose to return when an encoding conversion fails that is supposed to be completely transparent to the user of your library?
I've decided to simply return an error code indicating a platform specific error in those cases because there's no way I can anticipate all the different errors that the Windows API might return. The problem with that is that almost all the errors end up being platform errors and without a way to actually tell what the error is then you're basically saying that some unknown error happened. That's not very useful. You could have a function called get_platform_error() that you call to obtain the exact platform error that occurred, but I'm not a fan of such a design and I've had enough trouble with GetLastError() style error handling as it is.
An alternative to that is to create a struct that represents errors and have a field in it where you can store platform specific errors. I believe this is what Apple do with their NSError error object but I'm not sure how I feel about that approach.
Assuming you implement a way to return the platform specific error code then the next part is obtaining a string that describes the error. Your library can obviously not implement error strings for every single error code that Windows might return so you're forced to use FormatMessage. The problem with that function is that you can't force it to return error messages in a specific language and it's not even guaranteed that you can get an English translation of the error string. I don't want to display error messages that mixes English with the current language the operating system uses so how do I solve this problem?
Are there any good open source libraries I could study? The ones I've looked at so far have subpar error handling at best. Many of them don't even check the return values from platform specific functions.
I'm creating a small command line game in C. I have never done anything cross platforms, but this is small enough (so far) that it might not be too bad.
When I am done, I'm not sure how it will be distributed: Either I will just send people the C files and say "compile on your system with these options", or I will just have executables for various systems. Probably Windows 7/8, Ubuntu, CentOS, and whatever I can find to test on.
I right now I'm testing/developing on Windows 7 using MinGW. So my questions are: while I'm developing, how should I be compiling/testing it?
I have cross sections in the form of rectangles in the XY plane formed from two point (top left, bottom right) as well as their Z position. I'd like finding some sort of API that can extrude a basic linear-average-approximated 3D shape (preferably eventually into STL format) from these points. I've tried googling but to no avail. The aim is to build a 3D shape from 2D wireframes.
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