88 Solved Topics
Remove Filter  | Hi. I am familiar with the following C graphics libraries: Cairo, SDL, SDL2, and OpenGL. The problem I have found with these is that they either require shared libraries (Cairo/SDL/SDL2) or are difficult to make cross-platform (OpenGL). I am wondering if there are any graphics libraries for C that do …  |
| | Hello, I posted on this forum two times before about a particular pair of non-printing characters being inserted into my code. You can find the threads [here](https://www.daniweb.com/software-development/threads/441611/stray-non-printing-characters-in-my-programs) and [here](https://www.daniweb.com/software-development/cpp/threads/450296/arbitrarily-appearing-non-printing-character). Two great posters tried their best to solve this problem (mike_2000_17 and deceptikon) to no avail. Finally, using the hints that … |
| | Hello, I have a bug in my program somewhere and I cannot understand why. The program merely prints data from a binary file. Here is the code: #include <iostream> #include <fstream> #include <vector> #include <cstdint> using namespace std; int main(int argc, char *argv[]) { if (argc!=2) { cout<<"Invalid argument count, … |
| | Hello, I recently took a course on assembler/compiler construction. In it we covered parsing algorithms such as LL(n), LR(n), LALR(n), and SLR(n). I understand how these parsing algorithms can be used to determine **if** an input string follows a context free grammar (CFG). At some point I also understood how … |
| | Hello, I was recently looking through some of my code and found what I believe to be a memory leak. It is in a function that appends two strings and I am not sure how to resolve it. Here is the function: const char *strapp(const char *str,const char *s) { …  |
| | Hello, I feel like this is probably something silly, but for some reason if I declare a variable at a certain point in my code, then never use it... it crashes. This is literally what happens: //... code here int isBuf=0;//one of my variables int zeroAddr=0;//<-- another variable I want, … |
| | Hello, Looking at the standard streams provided by the stl libraries, it seems as though it is impossible to have 1 stream to use for both standard console IO and file/string IO. However, before I give up I would like to ask, is this possible: generic_stream stream; stream=cin; //now I … |
| | Hello, I have a `HWND` for a window. I have double checked that it is a 100% valid window by using `SetActiveWindow()`, `SetFocus()`, and `SetForegroundWindow()` on it, successfully bringing it to the frontmost window. However whenever I try to use `GetPixel` on it it returns -1 (0xFFFFFFFF). What am I …  |
| | Hello, I have a file which I need to read which contains some unusual characters (EG: '╠') and I need to be able to read it and convert those characters to numbers. As an example of what I am looking for would be code that reads a file and prints … |
| | Hello, I wrote a library for arbitrary precision arithmetic recently and spent a long time implementing efficient multiplication algorithms. Now I am looking to see if it is possible for me to optimize anywhere else. One place that I thought should be more optimizeable is my division algorithm. Right now … |
| | Hello, I have a particular set up of cast operators and constructors which is leading to a compile-time ambiguity error. I am wondering if somebody can explain why this is happening and what can be done to fix it. For example, here we have 2 classes: class A { int … |
| | Hello, I have a quick question about c/c++ syntax. Basically I am wondering when it is allowable to have numbers in identifiers. My compiler happens to allow numbers in: * Function names * Class names * Variable names * Pre-processor names As long as they do not begin with numbers. … |
| | I need to know which of these three copies of code is considered best. I also need to which one is more efficient memory wise and which is more efficient time wise. Thanks: enums [CODE]enum MyEnum{EnumTypeOne=1,EnumTypeTwo=2,EnumTypeThree=4,EnumTypeFour=8};[/CODE] macros [CODE]#define EnumTypeOne 1 #define EnumTypeTwo 2 #define EnumTypeThree 4 #define EnumTypeFour 8 typedef …  |
| | Hello, I can get OpenGL to render 3D scenes to the screen, but I want to render them to a pixel array. Basically I want some magical code to fill in the blanks for this code segment: int width=500; int height=500; uint32_t *colours=new uint32_t[width*height]; //Magic code! glBegin(GL_TRIANGLES); //other drawing stuff, … |
| | Hello, I am working on an event driven library and am having one minor problem. Basically I have two ways to get what I want done. Method 1: Smart pointers and factory functions #include <iostream> #include <vector> #include <memory> using namespace std; class Object { public: virtual int getInt(){return 0;} … |
| | Hello, I am wondering how libraries create graphics contexts in a cross-platform manner. Somehow libraries like SDL create graphical windows seemingly without using the system headers. I know how to set up a window for graphics using Win32API, and how to get input from it using the same. How do … |
| | Hello, I noticed that in c++ everything that can be done using a static function in a class could be done by using a public function in the same namespace. Assuming that you bind your classes in a namespace these functions do not take up names in the global namespace. … |
| | Hello, I have recently decided to learn TeX for note taking purposes (both my parents are doctors, I inherited my handwriting from them, my class notes up until now look somewhat like the voynich manuscript) since MS Word takes far too long to type equations into. Overall it is going … |
| | Hello, I have a chain of inherited classes like this: class A { protected: int a; public: int getA(){return a;} }; class B:public A { protected: int b; public: int getB(){return b;} }; Based on that you can see that the public can only read the values in those classes, … |
| | Hello, I was just noticing that the 'const'ness of references often causes me to rewrite a large chunk of my code with pointers. For example if I have a class that needs access to a large amount of data from another class I would love to use a reference. However … |
| | Hello, First of all some background. My friend and I are having a bit of a competition over theoretically infinite number storage. We have agreed that the first person with a working arbitrary precision integer library with the theoretical ability to store an infinitely large number (IE: if the hard … |
| | Hello, As may be apparent from my previous posts, I am in a "If its worth doing, its worth overdoing" sort of competition with a friend of mine. Our goal is arbitrary precision integer arithmetic. I think I am close to getting the data storage working, but now I want … |
| | I have a program using old data for a game I play to indicate which pixels correspond to the health bar in my game. (my program just loops until a button is clicked and presses a key if the health bar drops too low). Unfortunately the health bar has moved … |
| | Hello, I made an arbitrary precision integer library a few weeks ago. It works well, but is bounded by `256^(8*sizeof(size_t))` because it uses a simple dynamically allocated array to do its work. I want some way to have theoretically unbounded storage. I think that file io is probably best, but … |
| | I quickly threw together a drawing program in SDL and I am having a couple of issues with lag. The program lags really hard when the size is larger than about 700x700 pixels, and I cannot find anything other than a couple of SDL_BlitSurface calls to the 'image' surface in … |
| | Hello. I am wondering how EOFs are indicated to either the cstdio functions or the fstream functions. Mainly I am wondering how it differentiates it from data. For example, if EOF is a 2-byte code wouldn't this break the system by inserting a 'false' eof flag: for (int i=0; i<256; … |
| | I notice that daniweb does not have a forum for logical circuitry :(. Does anybody know a good site that does? Is it possible for logical circuitry to be added to daniweb? I often like to design custom circuits from transistor or gate level and up, and I have never …  |
| | Hello. As a Software Engineer I admit a slight lack of knowledge with hardware. I am usually quite good with any hardware that is contained within the case, my issues lie in networking. Usually I fix my own computer problems, but now I have a couple networking problems that I … |
| | Hello. I was reading http://xkcd.com/287/ while bored and thus decided to write a program that would solve such np complete problems. Here is what I got: #include <iostream> #include <vector> using namespace std; template <typename T> T NPMenuProblem(T desired, vector<T> options, vector<T> &ret) { vector<T> save=ret; T remainder; T min=desired; … |
| | Hello, I am making a program that deals with bitmap files and I want to try to load bitmap data manually. The issue is that I cannot find a good resource for exactly what bitmap files can contain. [Wikipedia](http://en.wikipedia.org/wiki/BMP_file_format) has a decent article, but it is missing some important information. … |
| | Hello, I am working on an arbitrary precision arithmetic library. I already created a version that just stored numbers as "before decimal point [unsigned array]" and "after decimal point [unsigned array]". The issue is that it is both inefficient and incomplete. I would like to incorporate complex numbers into the …  |
| | I want to be able to make a program that emulates what a human at a computer can do. IE: I want to be able to read the visual information of a window (a 2d array of colour would be perfect) and be able to send virtual key syms and … |
| | Hi, I am wondering if there is a somewhat simple way to output extended ascii values in c. Basically I am thinking actually about unicode characters, stored in ints. Is there an easy way to do this, or would it require a custom gui console? |
| | I used to use a tutorial for windows console API, but the website was taken down :(. So now I need to ask how to do these things (which ALL were included on the website) in the console with windows API: * Mouse events (clicks and unclicks) * Cursor seeking … |
| | I have a C++ console project in Code::Blocks and I have set breakpoints to test an error. I have set the build for the project to produce debugging symbols for the debug build. I built it, then when I hit debug it just ignored my breakpoints and skipped to the … |
| | I need to calculate chi squared cdf from x->infinity with n=255 degrees of freedom. I cannot seem to get it to work. You can find formulae for chi squared distributions using google. Here is my non-functional approximation code: double riemannsum(double(*fnc)(double),double dx, double xmin, double xmax) { double ret=0; double x=xmin; … |
| | I am using code::blocks and have written a dll. I am currently testing it but am getting tired of having to compile it, copy the DLL, DEF, H and A files into a test project, and then compiling the test project every time I need to fix something. Is there … |
| | I never knew that near and far were reserved until I made a struct for bounding boxes like this: struct boundingBox { float near, far; float left,right; float top,bottom; }; Does anybody know what near and far do, because I got the error that the declaration does not declare anything. … |
| | I recently looked at [URL="http://www.songho.ca/opengl/gl_vbo.html"]this[/URL] description of VBOs and a sample implementation of them. When I ran the executable, it was significantly faster with no VBOs than with them. I don't understand why it should be slower with the VBOs than without. Can anybody explain why? |
| | I am trying to find a bug in my new and (theoretically) improved syntax highlighter program. I have made 3 versions now and have been able to debug them all with ease. Unfortunately my debugger does not do well with std containers as it shows ALL the information they contain … |
| | I understand that data on computers can be compressed (I see it all the time with zip files and jpegs) but I was wondering just how compression works. Thinking it through, if you data is represented by 1s and 0s then it can be corresponded 1 to 1 with a … |
| | A few friends and I made a bet to see who could single-handedly (we defined that as a team of up to 10 people, all of whom must be personal friends) make the best video game over the course of two years. I am planning on making a first-person horror … |
| | I have a program that dynamically allocates an array and uses it. The thing is that under certain situations this array will get infinitely long. As such I would like to know if/when the array has gotten too long and then start saving it to a file (where length will … |
| | Hello, I have been working with opengl and other graphics libraries and they all require the bits per pixel of the screen on initialization of a window. My question is, is there any way to get the system's preffered bits per pixel? or that of the monitor? |
| | A friend of mine recently asked me to help debug some code. I looked through it and it was riddled all over with goto statements. I know why he uses them (he used to program mainly in assembly and batch) and I tried to explain why he should try to … |
| | I am getting ready to write a programming competition on Tuesday (the Canadian Computing Competition) and I remember that last year it said that only standard libraries can be used. I was having trouble deciding which libraries are standard. I ended up using windows.h and when I suddenly realized that … |
| | To what extent does the system endianness effect a program. I know that doing pointer assignment will be affected, and unions are too, but what about bitshift operators? Do they apply to the value, merely emulating real bitshifts, or do they apply to the bits themselves? Are there any other … |
| | I was wondering if there is any way using the mingw g++ compiler to make code that acts like this: [CODE]#define myLanguageBlock(X) doMyLanguageBlock(#X) void doMyLanguageBlock(const char* code){/*this executes the code as if it were in another language, I have already written this function*/} int main() { myLanguageBlock( this is all … |
| | I was just wondering how exit worked? Does it use some lower-level language feature in its implementation? Is it compiler-specific? What is it? (I am talking about the function in stdlib.h btw) |
| | I have an alpha beta interface and have implemented a tic tac toe class from it. For some reason my AI tends to occasionally make stupid moves (such as making a fork rather than blocking a 2 in a row) I was wondering if anybody can see where I went … |
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