How to clip rendering in OpenGL (C++)
How to clip rendering in OpenGL (simple rectangle area)? Please post a C++ example. ...
c++
2d HUD not drawing properly over QGLWidget (using QPainter)
Hi I am trying to display HUD over my 3D game. For starters, I am just trying to display "Hello World", but I haven't had any success yet! The scene freezes / flickers once I am done. I am using Qt/C++ and QGLWdiget / QPainter to get this done. I have used overpainting example as my reference to get started. Here is what I do: overri...
C++ boost function overloaded template
I cannot figure out why this segment gives unresolved overloaded function error (gcc version 4.3.4 (Debian 4.3.4-6)): #include <algorithm> #include <boost/function.hpp> // this does not work int main1() { typedef boost::function<const int&(const int&, const int&)> max; max m(&std::max<int>); } // this does not work int main2()...
boost.asio's socket's recieve/send functions are bad?
Data may be read from or written to a connected TCP socket using the receive(), async_receive(), send() or async_send() member functions. However, as these could result in short writes or reads, an application will typically use the following operations instead: read(), async_read(), write() and async_write(). I ...
Help with infrequent segmentation fault in accessing boost::unordered_multimap or struct
I'm having trouble debugging a segmentation fault. I'd appreciate tips on how to go about narrowing in on the problem. The error appears when an iterator tries to access an element of a struct Infection, defined as: struct Infection { public: explicit Infection( double it, double rt ) : infT( it ), recT( rt ) {} double infT; // in...
Is it good practice to separate code into blocks?
If I have a method that does multiple, related things, is it good practice to stick each "thing" that the method does into a seperate block? Ex. { int var //Code } { int var //More Code } It would help reduce the number of local variables, and make the code more readable, but I'm not sure if it's a good idea. ...
Can the template parameters of a constructor be explicitly specified?
A constructor of a class can be a template function. At the point where such a constructor is called, the compiler usually looks at the arguments given to the constructor and determines the used template parameters from them. Is there also some syntax to specify the template parameters explicitly? A contrived example: struct A { tem...
Can I Always debug multiple instances of a same object that is of type thread with GDB?
program runs fine. When I put a breakpoint a segmentation fault is generated. Is it me or GDB? At run time this never happens and if I instantiate only one object then no problems. Im using QtCreator on ubuntu x86_64 karmic koala. UPDATE1: I have made a small program containing a simplified version of that class. You can download ...
A question on vectors, pointers and iterators
Guys, I have a midterm examination tomorrow, and I was looking over the sample paper, and I'm not sure about this question. Any help would be appreciated. Let v be a vector<Thingie*>, so that each element v[i] contains a pointer to a Thingie. If p is a vector<Thingie*>::iterator, answer the following questions: what type is p? what ty...
Idiomatic use of auto_ptr to transfer ownership to a container
I'm refreshing my C++ knowledge after not having used it in anger for a number of years. In writing some code to implement some data structure for practice, I wanted to make sure that my code was exception safe. So I've tried to use std::auto_ptrs in what I think is an appropriate way. Simplifying somewhat, this is what I have: class...
STL member variable initalization issue with windows API
I am creating a windows app that uses a vector of stings as a member variable. For some reason, I can compile but when it tries to get at any of the vectors members is crashes. the error is 0xC0000005: Access violation reading location 0xcdcdcdd9. in the member function of the vector class. this is the size() function where it breaks...
Casting problem cant convert from void to float C++
as i said i get this horrible error i dont really know what to do anymore float n= xAxis[i].Normalize(); thats where i get the error and i get it cuz normalize is a void function this is it void CVector::normalize() { float len=Magnitude(); this->x /= len; this->y /= len; } i need normalize to stay as void tho i tried norma...
Returning a C++ reference in a const member functions
A have a class hierarchy that looks somethign like this: class AbstractDataType { public: virtual int getInfo() = 0; }; class DataType: public AbstractDataType { public: virtual int getInfo() { }; }; class Accessor { DataType data; public: const AbstractDataType& getData() const { return(data); } ...
Help with POCO library (Shared memory)
I was advised to use the POCO library for inter-process communication (IPC). Looks like a powerful library and there is some documentation in the code, but I would prefer a working example , since I am not very familiar with the IPC stuff. I 've been searching for some time now and I'm out of luck. If anyone has used POCO Shared Memor...
Storing header and data sections in a CSV file
This should be relatively easy to do, but after several hours straight programming my mind seems a bit frazzled and could do with some help. I have a C++ class which I am currently using to store read/write data to file. I was initially using binary data, but have decided to store the data as CSV in order to let programs written in othe...
override the operator overloading in C++ ?
helo guys i have class call Complex I did operator overloading like such Complex c = a + b; // where a and b are object of Complex class which basically is operator+(Complex& that); but I dont know how to say for example double c = a + 10; //where a is object of Complex class but 10 is integer / double I did define type...
SDL side-scroller scrolls inconsistantly
So I'm working on an upgrade from my previous project (that I posted here for code review) this time implementing a repeating background (like what is used on cartoons) so that SDL doesn't have to load really big images for a level. There's a strange inconsistency in the program, however: the first time the user scrolls all the way to th...
SWIG-Lua question on class returning another class
I am concreting a question I had earlier. I have two classes in C++ and I use SWIG to wrap them. A method in one class can return a pointer to the other class. How can I get Lua to see it as more than just a userdata? More concretely: I have class fruit { int numberofseeds; //some other stuff about fruit constructors etc... ...
Implementing eval and load functions inside a scripting engine with Flex and Bison.
Hy guys, i'm developing a scripting engine with flex and bison and now i'm implementing the eval and load functions for this language. Just to give you an example, the syntax is like : import std.*; load( "some_script.hy" ); eval( "foo = 123;" ); println( foo ); So, in my lexer i've implemented the function : void hyb_parse_string...
Binding a member signal to a function
This line of code compiles correctly without a problem: boost::bind(boost::ref(connected_), boost::dynamic_pointer_cast<session<version> >(shared_from_this()), boost::asio::placeholders::error); However when assigning it to a boost::function or as a callback like this: socket_->async_connect(connection_->r...