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  • ping to web server from iphone

    - by Sreelal
    Hi , I am developing an aplication which needs to download some data from webserver.So i need to first ping to the web server to check whether the service is available after checking the internet connectivity .I used the following code to check server availability ` BOOL success = NO; const char *host_name = [@"http://192.168.1.7:8080/TestWeb/webresources/" cStringUsingEncoding:NSASCIIStringEncoding]; SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL, host_name); SCNetworkReachabilityFlags flags; success = SCNetworkReachabilityGetFlags(reachability, &flags); BOOL isAvailable = success && (flags & kSCNetworkFlagsReachable) && !(flags & kSCNetworkFlagsConnectionRequired); return isAvailable; ` where my server is uploaded locally.But this code always return an invalid result,but it works correctly if i gave some exixting sites like google.com.Please let me know whats i am doing wrong..

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  • Why does this code fail in D2010, but not D7?

    - by Tom1952
    Why does this code get an access error on the Result := Buffer line in D2010, but not D7? Something, I'd guess, involving UniCode, but the compiler doesn't generate any warnings. Any suggestions on an elegant workaround? function GetTempPathAndFileName( const aExtension: string): string; var Buffer: array[0..MAX_PATH] of Char; begin repeat GetTempPath(SizeOf(Buffer) - 1, Buffer); GetTempFileName(Buffer, '~', 0, Buffer); Result := Buffer; // <--- crashes on this line, Result := ChangeFileExt(Result, aExtension); until not FileExists(Result); end; { GetTempPathAndFileName }

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  • how to serialize / deserialize classes defined in .proto (protobuf)

    - by make
    Hi, Could someone please help me with serialization/deserialization classes defined in .proto (protobuf). here is an exp that I am trying to build: file.proto message Data{ required string x1 = 1; required uint32 x2 = 2; required float x3 = 3; } message DataExge { repeated Data data = 1; } client.cpp ... void serialize(const DataExge &data_snd){ try { ofstream ofs("DataExge"); data_snd.SerializeToOstream(&ofs); } catch(exception &e) { cerr << "serialize/exception: " << e.what() << endl; exit(1); } } void deserialize(DataExge &data_rec){ try { ifstream ifs("DataExge"); data_rec.ParseFromIstream(&ifs); } catch(exception& e) { cerr << "deserialize/exception: " << e.what() << endl; exit(1); } } int main(){ ... DataExge dataexge; Data *dat = dataexge.add_data(); char *y1 = "operation1"; uint32_t y2 = 123 ; float y3 = 3.14; // assigning data to send() dat->set_set_x1(y1); dat->set_set_x2(y2); dat->set_set_x3(y3); //sending data to the client serialize(dataexge); if (send(socket, &dataexge, sizeof(dataexge), 0) < 0) { cerr << "send() failed" ; exit(1); } //receiving data from the server deserialize(dataexge); if (recv(socket, &dataexge, sizeof(dataexge), 0) < 0) { cerr << "recv() failed"; exit(1); } //printing received data cout << dat->x1() << "\n"; cout << dat->x2() << "\n"; cout << dat->x3() << "\n"; ... } server.cpp ... void serialize(const DataExge &data_snd){ try { ofstream ofs("DataExge"); data_snd.SerializeToOstream(&ofs); } catch(exception &e) { cerr << "serialize/exception: " << e.what() << endl; exit(1); } } void deserialize(DataExge &data_rec){ try { ifstream ifs("DataExge"); data_rec.ParseFromIstream(&ifs); } catch(exception& e) { cerr << "deserialize/exception: " << e.what() << endl; exit(1); } } int main(){ ... DataExge dataexge; Data *dat = dataexge.add_data(); //receiving data from the client deserialize(dataexge); if (recv(socket, &dataexge, sizeof(dataexge), 0) < 0) { cerr << "recv() failed"; exit(1); } //printing received data cout << dat->x1() << "\n"; cout << dat->x2() << "\n"; cout << dat->x3() << "\n"; // assigning data to send() dat->set_set_x1("operation2"); dat->set_set_x2(dat->x2() + 1); dat->set_set_x3(dat->x3() + 1.1); //sending data to the client serialize(dataexge); //error// I am getting error at this line ... if (send(socket, &dataexge, sizeof(dataexge), 0) < 0) { cerr << "send() failed" ; exit(1); } ... } Thanks for your help and replies -

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  • C: sprintf and recursion

    - by Shinka
    In C, is it possible to use recursion within the sprintf function ? For some reason I get a segmentation fault when I do it: inline char *TreeNode_toString(const TreeNode *node) { char *out; if(TreeNode_isExternal(node)) // If the node has no children... { sprintf(out, "%s:%.2f", node->name, node->distance); } else // The node is strictly binary, so it will have two non-null children { char *l = TreeNode_toString(node->l); // l = left child char *r = TreeNode_toString(node->r); // r = right child sprintf(out, "(%s,%s):%.2f", l, r, node->distance); } return out; }

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  • How fast can you make linear search?

    - by Mark Probst
    I'm looking to optimize this linear search: static int linear (const int *arr, int n, int key) { int i = 0; while (i < n) { if (arr [i] >= key) break; ++i; } return i; } The array is sorted and the function is supposed to return the index of the first element that is greater or equal to the key. They array is not large (below 200 elements) and will be prepared once for a large number of searches. Array elements after the n-th can if necessary be initialized to something appropriate, if that speeds up the search. No, binary search is not allowed, only linear search.

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  • pthread_create from non-static member function

    - by Stanislav Palatnik
    This is somewhat similiar to this : http://stackoverflow.com/questions/1151582/pthread-function-from-a-class But the function that's getting called in the end is referencing the this pointer, so it cannot be made static. void * Server::processRequest() { std::string tmp_request, outRequest; tmp_request = this->readData(); outRequest = this->parse(tmp_request); this->writeReply(outRequest); } void * LaunchMemberFunction(void * obj) { return ((Server *)obj)->processRequest(); } and then the pthread_create pthread_create(&handler[tcount], &attr, (void*)LaunchMemberFunction,(void*)&SServer); errors: SS_Twitter.cpp:819: error: invalid conversion from void* to void* ()(void) SS_Twitter.cpp:819: error: initializing argument 3 of int pthread_create(pthread_t*, const pthread_attr_t*, void* ()(void), void*)

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  • qtableview (libqt) how do I correctly create a QModelIndex

    - by Chris Camacho
    I'm trying to enter edit mode on a specific cell like this void MainWindow::on_addButton_released(void) { tm->addRow(); tableView->scrollToBottom(); int ec=tm->firstWritableColumn(); int r=tm->rowCount(QModelIndex()); QModelIndex id = tm->index(r, ec, QModelIndex()); tableView->setCurrentIndex(id); tableView->edit(id); qDebug() << "row:" << r << " col:" << ec << "index:" << id; } my model creates an index like this QModelIndex TableModel::index(int row,int column,QModelIndex parent) const { Q_UNUSED(parent); return createIndex(row,column,0); } the debug output looks like this row: 9 col: 1 index: QModelIndex(9,1,0x0,TableModel(0xbf3f50) ) I'm fairly sure that the index is somehow invalid as setCurrentIndex doesn't seem to be working

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  • How can I refactor this to use an inline function or template instead of a macro?

    - by BillyONeal
    Hello, everyone :) I have a useful macro here: #define PATH_PREFIX_RESOLVE(path, prefix, environment) \ if (boost::algorithm::istarts_with(path, prefix)) { \ ExpandEnvironmentStringsW(environment, buffer, MAX_PATH); \ path.replace(0, (sizeof(prefix)/sizeof(wchar_t)) - 1, buffer); \ if (Exists(path)) return path; \ } It's used about 6 times within the scope of a single function (that's it), but macros seem to have "bad karma" :P Anyway, the problem here is the sizeof(prefix) part of the macro. If I just replace this with a function taking a const wchar_t[], then the sizeof() will fail to deliver expected results. Simply adding a size member doesn't really solve the problem either. Making the user supply the size of the constant literal also results in a mess of duplicated constants at the call site. Any ideas on this one?

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  • How do I copy object in Qt?

    - by Martin
    I'm using Qt and have some real basic problems. I have created my own widget MyTest that have a variable obj. I need to set this variable obj from an object outside of the widget so that the variable is copied not just a pointer to another object. I get an error message and can't figure out how to do this basic stuff. This is the code I'm using: MyTest.h: class MyTest : public QWidget { Q_OBJECT public: void setObj(QObject &inobj); QObject obj; .... } MyTest.cpp: void MyTest::setObj(QObject &inobj) { obj = inobj; //HERE I get the error message: "illegal access from 'QObject' to protected/private member 'QObject::operator=(const QObject &)'" } main.cpp: int main(int argc, char *argv[]) { QApplication a(argc, argv); QObject *ob = new QObject(); MyTest w; w.setObj(*ob); } Thanks for your help!

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  • C++ Project compiles as static lib, fails (linker error) as dynamic lib. why??

    - by Roey
    Hi All. I've a VS2008 native C++ project, that I wish to compile as a DLL. It only references one external library (log4cplus.lib), and uses its functions. (also uses log4cplus's .h files , naturally). When I try to compile my project as a static library, it succeeeds. When I try as DLL, it fails : 1>MessageWriter.obj : error LNK2019: unresolved external symbol "public: static class log4cplus::Logger __cdecl log4cplus::Logger::getInstance(class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> > const &)" (?getInstance@Logger@log4cplus@@SA?AV12@ABV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@Z) referenced in function "class log4cplus::Logger __cdecl Log(void)" (?Log@@YA?AVLogger@log4cplus@@XZ) There are 4 more errors just like this related to functions within log4cplus.lib. It seems like something really stupid.. please help me :) Thanks!

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  • CFSocketConnectToAddress and unrecognized selector sent to instance

    - by madmik3
    Hello, I am somewhat new to iPhone dev and I have been getting unrecognized selector when I call CFSocketConnectToAddress in this code. I think it might be something basic that I am doing wrong. Any idea? this is the complete error I get. NSInvalidArgumentException unrecognized selector sent to instance 0x3922170 0x3922170 is the calling class. - (BOOL)connect { CFSocketRef mySocket = CFSocketCreate(kCFAllocatorDefault, PF_INET, SOCK_DGRAM,IPPROTO_UDP, 0, socketCallback, NULL); @try { CFDataRef data = (CFDataRef)[_netService addresses]; CFSocketConnectToAddress(mySocket, data, 500); } @catch (NSException * e) { NSLog([e name]); NSLog([e reason]); } //char joke[] = "Why did the chicken cross the road?"; //CFSocketError err = CFSocketSendData(mySocket, joke, (strlen(joke)+1), 10); return true; } void socketCallback ( CFSocketRef s, CFSocketCallBackType callbackType, CFDataRef address, const void *data, void *info) { }

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  • Reading PowerPoint Effects with VBA

    - by OneNerd
    I have been working with VBA inside PowerPoint, and have a grasp on most things. What I am struggling with is reading the effect/animation settings for each object. I seem to be able to get a lot of what I need through the Powerpoint.ActivePresentation.Slides(slide_id).TimeLine.MainSequence(seq_num) What confuses me is how to convert the numeric value of Powerpoint.ActivePresentation.Slides(slide_id).TimeLine.MainSequence(seq_num).EffectType to an effect (so looking for a table of values to effects or perhaps a CONST table). Also, how to read in all the different level of effects (like entrance, or emphasis, etc) is really confusing. not to mention I cannot wrap my head around the timeline (which seems like it is not really a timeline). Can anyone point me to any good articles or documentation that discusses how to read the effects and animations properly and fully? Thanks.

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  • dynamic array pointer to binary file

    - by Yijinsei
    Hi guys, Know this might be rather basic, but I been trying to figure out how to one after create a dynamic array such as double* data = new double[size]; be used as a source of data to be kept in to a binary file such as ofstream fs("data.bin",ios:binary"); fs.write(reinterpret_cast<const char *> (data),size*sizeof(double)); When I finish writing, I attempt to read the file through double* data = new double[size]; ifstream fs("data.bin",ios:binary"); fs.read(reinterpret_cast<char*> (data),size*sizeof(double)); However I seem to encounter a run time error when reading the data. Do you guys have any advice how i should attempt to write a dynamic array using pointers passed from other methods to be stored in binary files?

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  • Design pattern for cost calculator app?

    - by Anders Svensson
    Hi, I have a problem that I’ve tried to get help for before, but I wasn’t able to solve it then, so I’m trying to simplify the problem now to see if I can get some more concrete help with this because it is driving me crazy… Basically, I have a working (more complex) version of this application, which is a project cost calculator. But because I am at the same time trying to learn to design my applications better, I would like some input on how I could improve this design. Basically the main thing I want is input on the conditionals that (here) appear repeated in two places. The suggestions I got before was to use the strategy pattern or factory pattern. I also know about the Martin Fowler book with the suggestion to Refactor conditional with polymorphism. I understand that principle in his simpler example. But how can I do either of these things here (if any would be suitable)? The way I see it, the calculation is dependent on a couple of conditions: 1. What kind of service is it, writing or analysis? 2. Is the project small, medium or large? (Please note that there may be other parameters as well, equally different, such as “are the products new or previously existing?” So such parameters should be possible to add, but I tried to keep the example simple with only two parameters to be able to get concrete help) So refactoring with polymorphism would imply creating a number of subclasses, which I already have for the first condition (type of service), and should I really create more subclasses for the second condition as well (size)? What would that become, AnalysisSmall, AnalysisMedium, AnalysisLarge, WritingSmall, etc…??? No, I know that’s not good, I just don’t see how to work with that pattern anyway else? I see the same problem basically for the suggestions of using the strategy pattern (and the factory pattern as I see it would just be a helper to achieve the polymorphism above). So please, if anyone has concrete suggestions as to how to design these classes the best way I would be really grateful! Please also consider whether I have chosen the objects correctly too, or if they need to be redesigned. (Responses like "you should consider the factory pattern" will obviously not be helpful... I've already been down that road and I'm stumped at precisely how in this case) Regards, Anders The code (very simplified, don’t mind the fact that I’m using strings instead of enums, not using a config file for data etc, that will be done as necessary in the real application once I get the hang of these design problems): public abstract class Service { protected Dictionary<string, int> _hours; protected const int SMALL = 2; protected const int MEDIUM = 8; public int NumberOfProducts { get; set; } public abstract int GetHours(); } public class Writing : Service { public Writing(int numberOfProducts) { NumberOfProducts = numberOfProducts; _hours = new Dictionary<string, int> { { "small", 125 }, { "medium", 100 }, { "large", 60 } }; } public override int GetHours() { if (NumberOfProducts <= SMALL) return _hours["small"] * NumberOfProducts; if (NumberOfProducts <= MEDIUM) return (_hours["small"] * SMALL) + (_hours["medium"] * (NumberOfProducts - SMALL)); return (_hours["small"] * SMALL) + (_hours["medium"] * (MEDIUM - SMALL)) + (_hours["large"] * (NumberOfProducts - MEDIUM)); } } public class Analysis : Service { public Analysis(int numberOfProducts) { NumberOfProducts = numberOfProducts; _hours = new Dictionary<string, int> { { "small", 56 }, { "medium", 104 }, { "large", 200 } }; } public override int GetHours() { if (NumberOfProducts <= SMALL) return _hours["small"]; if (NumberOfProducts <= MEDIUM) return _hours["medium"]; return _hours["large"]; } } public partial class Form1 : Form { public Form1() { InitializeComponent(); List<int> quantities = new List<int>(); for (int i = 0; i < 100; i++) { quantities.Add(i); } comboBoxNumberOfProducts.DataSource = quantities; } private void comboBoxNumberOfProducts_SelectedIndexChanged(object sender, EventArgs e) { Service writing = new Writing((int) comboBoxNumberOfProducts.SelectedItem); Service analysis = new Analysis((int) comboBoxNumberOfProducts.SelectedItem); labelWriterHours.Text = writing.GetHours().ToString(); labelAnalysisHours.Text = analysis.GetHours().ToString(); } }

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  • JNI unsigned char to byte array

    - by Jeff Storey
    I'm working with a C++ library that stores image byte data in an array of unsigned characters. My jni function returns a jByteArray (which then gets converted to a BufferedImage on the java side), but I'm not sure how to fill the jByteArray from the unsigned character array (if it is possible). Can anyone provide a snippet for this last part to basically do this: // size is the size of the unsigned char array const int size = 100; unsigned char* buf = new unsigned char[size]; // buf gets passed to another library here to be populated jbyteArray bArray = env->NewByteArray(size); // now how do I get the data from buf to bArray? Thanks, Jeff

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  • OpenGL/GLSL checking if shader compiled fine on intel cards

    - by clamp
    hello, i am using this code to check if my glsl shader compiled fine. glGetObjectParameterivARB(obj, GL_OBJECT_INFO_LOG_LENGTH_ARB, &infologLength); if (infologLength > 1) { int charsWritten = 0; char * const infoLog = new char[infologLength]; glGetInfoLogARB(obj, infologLength, &charsWritten, infoLog); tError(infoLog, false); delete infoLog; } } the length of the returned string is empty on nvidia and ATI cards, but on intel cards this one returns the string "no errors." now what is the best way to find out, if there are really no errors? should i just check for this string? or is there a convention what this function glGetInfoLogARB should return?

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  • Help understanding some OpenGL stuff

    - by shinjuo
    I am working with some code to create a triangle that moves with arrow keys. I want to create a second object that moves independently. This is where I am having trouble, I have created the second actor, but cannot get it to move. There is too much code to post it all so I will just post a little and see if anyone can help at all. ogl_test.cpp #include "platform.h" #include "srt/scheduler.h" #include "model.h" #include "controller.h" #include "model_module.h" #include "graphics_module.h" class blob : public actor { public: blob(float x, float y) : actor(math::vector2f(x, y)) { } void render() { transform(); glBegin(GL_TRIANGLES); glVertex3f(0.25f, 0.0f, -5.0f); glVertex3f(-.5f, 0.25f, -5.0f); glVertex3f(-.5f, -0.25f, -5.0f); glEnd(); end_transform(); } void update(controller& c, float dt) { if (c.left_key) { rho += pi / 9.0f * dt; c.left_key = false; } if (c.right_key) { rho -= pi / 9.0f * dt; c.right_key = false; } if (c.up_key) { v += .1f * dt; c.up_key = false; } if (c.down_key) { v -= .1f * dt; if (v < 0.0) { v = 0.0; } c.down_key = false; } actor::update(c, dt); } }; class enemyOne : public actor { public: enemyOne(float x, float y) : actor(math::vector2f(x, y)) { } void render() { transform(); glBegin(GL_TRIANGLES); glVertex3f(0.25f, 0.0f, -5.0f); glVertex3f(-.5f, 0.25f, -5.0f); glVertex3f(-.5f, -0.25f, -5.0f); glEnd(); end_transform(); } void update(controller& c, float dt) { if (c.left_key) { rho += pi / 9.0f * dt; c.left_key = false; } if (c.right_key) { rho -= pi / 9.0f * dt; c.right_key = false; } if (c.up_key) { v += .1f * dt; c.up_key = false; } if (c.down_key) { v -= .1f * dt; if (v < 0.0) { v = 0.0; } c.down_key = false; } actor::update(c, dt); } }; int APIENTRY WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, char* lpCmdLine, int nCmdShow ) { model m; controller control(m); srt::scheduler scheduler(33); srt::frame* model_frame = new srt::frame(scheduler.timer(), 0, 1, 2); srt::frame* render_frame = new srt::frame(scheduler.timer(), 1, 1, 2); model_frame->add(new model_module(m, control)); render_frame->add(new graphics_module(m)); scheduler.add(model_frame); scheduler.add(render_frame); blob* prime = new blob(0.0f, 0.0f); m.add(prime); m.set_prime(prime); enemyOne* primeTwo = new enemyOne(2.0f, 0.0f); m.add(primeTwo); m.set_prime(primeTwo); scheduler.start(); control.start(); return 0; } model.h #include <vector> #include "vec.h" const double pi = 3.14159265358979323; class controller; using math::vector2f; class actor { public: vector2f P; float theta; float v; float rho; actor(const vector2f& init_location) : P(init_location), rho(0.0), v(0.0), theta(0.0) { } virtual void render() = 0; virtual void update(controller&, float dt) { float v1 = v; float theta1 = theta + rho * dt; vector2f P1 = P + v1 * vector2f(cos(theta1), sin(theta1)); if (P1.x < -4.5f || P1.x > 4.5f) { P1.x = -P1.x; } if (P1.y < -4.5f || P1.y > 4.5f) { P1.y = -P1.y; } v = v1; theta = theta1; P = P1; } protected: void transform() { glPushMatrix(); glTranslatef(P.x, P.y, 0.0f); glRotatef(theta * 180.0f / pi, 0.0f, 0.0f, 1.0f); //Rotate about the z-axis } void end_transform() { glPopMatrix(); } }; class model { private: typedef std::vector<actor*> actor_vector; actor_vector actors; public: actor* _prime; model() { } void add(actor* a) { actors.push_back(a); } void set_prime(actor* a) { _prime = a; } void update(controller& control, float dt) { for (actor_vector::iterator i = actors.begin(); i != actors.end(); ++i) { (*i)->update(control, dt); } } void render() { for (actor_vector::iterator i = actors.begin(); i != actors.end(); ++i) { (*i)->render(); } } };

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  • Does copy_from_user modify the user pointer?

    - by Michael
    Does the copy_from_user function, declared in uaccess.h, modify the (void __user *)from pointer? The pointer isn't declared as const in the function declaration, only the contents it points to. The reason I ask is that I want to use copy_from_user twice, with the second copy_from_user copying from the place where the first one finished. I was planning on doing something like this, is it guaranteed to work? //buf is a user pointer that is already defined copy_from_user(my_first_alloced_region, buf, some_size); //do stuff copy_from_user(my_second_alloced_region, buf + some_size, some_other_size); Thanks in advance.

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  • Why protected superclass member cannot be accessed in a subclass function when passed as an argument

    - by KNoodles
    I get a compile error, which I'm slightly confused about. This is on VS2003. error C2248: 'A::y' : cannot access protected member declared in class 'A' class A { public: A() : x(0), y(0) {} protected: int x; int y; }; class B : public A { public: B() : A(), z(0) {} B(const A& item) : A(), z(1) { x = item.y;} private: int z; }; The problem is with x = item.y; The access is specified as protected. Why doesn't the constructor of class B have access to A::y?

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  • error C2065: undeclared identifier

    - by karikari
    Currently, I have this function inside my other cpp file: UINT32 functionHtml(const wchar_t *url) { WinHttpClient client(url); client.SendHttpRequest(); wstring httpResponseHeader = client.GetHttpResponseHeader(); wstring httpResponse = client.GetHttpResponse(); writeToLog(httpResponse.c_str()); return 0; } I have another cpp file, and I would like to execute the stuff inside the above file. Here is the code for the other file: HRESULT CButtonDemoBHO::onDocumentComplete(IDispatch *pDisp, VARIANT *vUrl){ ATLTRACE("CButtonDemoBHO::onDocumentComplete %S\n", vUrl->bstrVal); // <---- i would like to call funtionHTML here or .. if (isMainFrame(pDisp)){ m_normalPageLoad=false; // <---- here.. MessageBox(m_hWnd, L"Main Document has completed loading", L"Document Complete", MB_OK); return S_OK; } return S_OK; } I got the error C2065: 'url' : undeclared identifier. Need help.

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  • explicit copy constructor or implicit parameter by value

    - by R Samuel Klatchko
    I recently read (and unfortunately forgot where), that the best way to write operator= is like this: foo &operator=(foo other) { swap(*this, other); return *this; } instead of this: foo &operator=(const foo &other) { foo copy(other); swap(*this, copy); return *this; } The idea is that if operator= is called with an rvalue, the first version can optimize away construction of a copy. So when called with a rvalue, the first version is faster and when called with an lvalue the two are equivalent. I'm curious as to what other people think about this? Would people avoid the first version because of lack of explicitness? Am I correct that the first version can be better and can never be worse?

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  • Passing big multi-dimensional array to function in C

    - by kirbuchi
    Hi, I'm having trouble passing a big array to a function in C. I declare: int image[height][width][3]={}; where height and width can be as big as 1500. And when I call: foo((void *)image,height,width); which is declared as follows: int *foo(const int *inputImage, int h, int w); I get segmentation fault error. What's strange is that if my values are: height=1200; width=290; theres no problem, but when they're: height=1200; width=291; i get the mentioned error. At 4 bytes per integer with both height and width of 1500 (absolute worst case) the array size would be of 27MB which imo isn't that big and shouldn't really matter because I'm only passing a pointer to the first element of the array. Any advice?

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  • Qt drag & drop button; drop not detecting

    - by Thomas Verbeke
    I'm creating a 2D game in QT and i'm trying to implement a drag & drop into my program. For some reason the drop is not registered: qDebug should print a message on dropping but this doesn't happen. #include "dialog.h" #include "ui_dialog.h" #include "world.h" #include <vector> Dialog::Dialog(QWidget *parent) : QDialog(parent), ui(new Ui::Dialog) { ui->setupUi(this); scene = new QGraphicsScene(this); ui->graphicsView->setScene(scene); MySquare *item; QGraphicsRectItem *enemyItem; World *myWorld = new World(); std::vector<Tile*> tiles = myWorld->createWorld(":/texture.jpg"); int count = 0; foreach (Tile *tile, tiles){ count++; item = new MySquare(tile->getXPos()*4,tile->getYPos()*4,4,4); item->setBrush(QColor(tile->getValue()*255,tile->getValue()*255,tile->getValue()*255)); item->setAcceptDrops(true); scene->addItem(item); } player = new MySquare(10,20,10,10); player->setAcceptDrops(true); scene->addItem(player); //drag & drop part QPushButton *pushButton = new QPushButton("Click Me",this); connect(pushButton,SIGNAL(pressed()),this,SLOT(makeDrag())); setAcceptDrops(true); } void Dialog::makeDrag() { QDrag *dr = new QDrag(this); // The data to be transferred by the drag and drop operation is contained in a QMimeData object QMimeData *data = new QMimeData; data->setText("This is a test"); // Assign ownership of the QMimeData object to the QDrag object. dr->setMimeData(data); // Start the drag and drop operation dr->start(); } mysquare.cpp #include "mysquare.h" MySquare::MySquare(int _x,int _y, int _w, int _h) { isPlayer=false; Pressed=false; setFlag(ItemIsMovable); setFlag(ItemIsFocusable); setAcceptDrops(true); color=Qt::red; color_pressed = Qt::green; x = _x; y = _y; w = _w; h = _h; } QRectF MySquare::boundingRect() const { return QRectF(x,y,w,h); } void MySquare::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { QRectF rec = boundingRect(); QBrush brush(color); if (Pressed){ brush.setColor(color); } else { brush.setColor(color_pressed); } painter->fillRect(rec,brush); painter->drawRect(rec); } void MySquare::mousePressEvent(QGraphicsSceneMouseEvent *event) { Pressed=true; update(); QGraphicsItem::mousePressEvent(event); qDebug() << "mouse Pressed"; } void MySquare::mouseReleaseEvent(QGraphicsSceneMouseEvent *event) { Pressed=false; update(); QGraphicsItem::mousePressEvent(event); qDebug() << "mouse Released"; } void MySquare::keyPressEvent(QKeyEvent *event){ int x = pos().x(); int y = pos().y(); //key handling QGraphicsItem::keyPressEvent(event); } void MySquare::dropEvent(QDropEvent *event) { qDebug("dropEvent - square"); // Unpack dropped data and handle it the way you want qDebug("Contents: %s", event->mimeData()->text().toLatin1().data()); } void MySquare::dragMoveEvent(QDragMoveEvent *event){ qDebug("dragMoveEvent - square "); event->accept(); } void MySquare::dragEnterEvent(QDragEnterEvent *event){ event->setAccepted(true); qDebug("dragEnterEvent - square"); event->acceptProposedAction(); } void MySquare::setBrush(QColor _color){ color = _color; color_pressed = _color; update(); //repaint } edit; there is no problem with qDebug() i'm just using it to test them i'm inside the drag events..which i'm not

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  • How do I use texture-mapping in a simple ray tracer?

    - by fastrack20
    I am attempting to add features to a ray tracer in C++. Namely, I am trying to add texture mapping to the spheres. For simplicity, I am using an array to store the texture data. I obtained the texture data by using a hex editor and copying the correct byte values into an array in my code. This was just for my testing purposes. When the values of this array correspond to an image that is simply red, it appears to work close to what is expected except there is no shading. The bottom right of the image shows what a correct sphere should look like. This sphere's colour using one set colour, not a texture map. Another problem is that when the texture map is of something other than just one colour pixels, it turns white. My test image is a picture of water, and when it maps, it shows only one ring of bluish pixels surrounding the white colour. When this is done, it simply appears as this: Here are a few code snippets: Color getColor(const Object *object,const Ray *ray, float *t) { if (object->materialType == TEXTDIF || object->materialType == TEXTMATTE) { float distance = *t; Point pnt = ray->origin + ray->direction * distance; Point oc = object->center; Vector ve = Point(oc.x,oc.y,oc.z+1) - oc; Normalize(&ve); Vector vn = Point(oc.x,oc.y+1,oc.z) - oc; Normalize(&vn); Vector vp = pnt - oc; Normalize(&vp); double phi = acos(-vn.dot(vp)); float v = phi / M_PI; float u; float num1 = (float)acos(vp.dot(ve)); float num = (num1 /(float) sin(phi)); float theta = num /(float) (2 * M_PI); if (theta < 0 || theta == NAN) {theta = 0;} if (vn.cross(ve).dot(vp) > 0) { u = theta; } else { u = 1 - theta; } int x = (u * IMAGE_WIDTH) -1; int y = (v * IMAGE_WIDTH) -1; int p = (y * IMAGE_WIDTH + x)*3; return Color(TEXT_DATA[p+2],TEXT_DATA[p+1],TEXT_DATA[p]); } else { return object->color; } }; I call the colour code here in Trace: if (object->materialType == MATTE) return getColor(object, ray, &t); Ray shadowRay; int isInShadow = 0; shadowRay.origin.x = pHit.x + nHit.x * bias; shadowRay.origin.y = pHit.y + nHit.y * bias; shadowRay.origin.z = pHit.z + nHit.z * bias; shadowRay.direction = light->object->center - pHit; float len = shadowRay.direction.length(); Normalize(&shadowRay.direction); float LdotN = shadowRay.direction.dot(nHit); if (LdotN < 0) return 0; Color lightColor = light->object->color; for (int k = 0; k < numObjects; k++) { if (Intersect(objects[k], &shadowRay, &t) && !objects[k]->isLight) { if (objects[k]->materialType == GLASS) lightColor *= getColor(objects[k], &shadowRay, &t); // attenuate light color by glass color else isInShadow = 1; break; } } lightColor *= 1.f/(len*len); return (isInShadow) ? 0 : getColor(object, &shadowRay, &t) * lightColor * LdotN; } I left out the rest of the code as to not bog down the post, but it can be seen here. Any help is greatly appreciated. The only portion not included in the code, is where I define the texture data, which as I said, is simply taken straight from a bitmap file of the above image. Thanks.

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  • Calculix Data Visualiser using QT

    - by Ann
    I am doing a project on CalculiX data visualizor,using Qt.I 've to draw the structure and after giving force the displacement should be shawn as variation in color.I chose HSV coloring,but while executing I got an error message:"QColor::from Hsv:HSV parameters out of range".The code is: DataViz1::DataViz1(QWidget *parent) : QWidget(parent), ui(new Ui::DataViz1) { DArea = new QGLScreen(this); DArea-setGeometry(QRect(10,10,700,600)); //TODO This values are feeded by user dfile="/home/41407/color.txt";//input file with displacement mfile="/home/41407/mesh21.txt";//input file nodeId="*NODE"; elId="*ELEMENT"; DataId="displ"; parseMfile(); parseDfile(); DArea->Nodes=Nodes; DArea->Elements=Elements; DArea->Data=Data; DArea->fillColorArray(); //printf("Colr is %d",DArea->pickColor(-11.02,0));fflush(stdout); ui->setupUi(this); } DataViz1::~DataViz1() { delete ui; } void DataViz1::parseMfile() { QFile file(mfile); if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) return; int node_end=0; QTextStream in(&file); in.skipWhiteSpace(); while (!in.atEnd()) { QString line = in.readLine(); if(line.startsWith(nodeId))//Node block in Mfile { while(1) { line = in.readLine(); if(line.startsWith(elId)) { break; } Nodes< while(1) { line = in.readLine(); Elements<<line; //printf("Element is %s\n",line.toLocal8Bit().constData());fflush(stdout); if(in.atEnd()) break; } } } } void DataViz1::parseDfile() { QFile file(dfile); if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) return; int node_end=0; QTextStream in(&file); in.skipWhiteSpace(); while (!in.atEnd()) { QString line = in.readLine(); if(line.startsWith(DataId)) { continue; } line = in.readLine(); Data< } /......................................................................../ include "qglscreen.h" include GLfloat LightAmbient[]= { 0.5f, 0.5f, 0.5f, 1.0f }; GLfloat LightDiffuse[]= { 1.0f, 1.0f, 1.0f, 1.0f }; GLfloat LightPosition[]= { 0.0f, 0.0f, 2.0f, 1.0f }; QGLScreen::QGLScreen(QWidget *parent):QGLWidget(QGLFormat(QGL::SampleBuffers), parent) { clearColor = Qt::black; xRot = 0; yRot = 0; zRot = 0; ifdef QT_OPENGL_ES_2 program = 0; endif //TODO user input ElType="HE8"; DType="SolidFrame"; axis="X"; } QGLScreen::~QGLScreen() { } QSize QGLScreen::minimumSizeHint() const { return QSize(50, 50); } QSize QGLScreen::sizeHint() const { return QSize(200, 200); } void QGLScreen::setClearColor(const QColor &color) { clearColor = color; updateGL(); } void QGLScreen::initializeGL() { xRot=0; yRot=0; zRot=0; scaling = 1.0; /* select clearing (background) color */ glClearColor (0.0, 0.0, 0.0, 0.0); glMatrixMode(GL_PROJECTION); glLoadIdentity(); // glViewport(0,0,10,10); glOrtho(-10.0, +10.0, -10.0, +10.0, -10.0,+10.0); glEnable (GL_LINE_SMOOTH); glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE); } void QGLScreen::wheel1() { scaling1 += .0025; count2++; update(); } void QGLScreen::wheel2() { if(count2-14) { scaling1 -= .0025; count2--; update(); } } void QGLScreen::drawModel(int x1,int y1,int x2,int y2) { makeCurrent(); QStringList Cnode,Celement; for (int i = 0; i < Elements.size(); ++i) { Celement=Elements.at(i).split(","); // printf("Element is %s",Celement.at(0).toLocal8Bit().constData());fflush(stdout); //printf("Node at el is %s\n",(findNode(Celement.at(1).toInt())).at(1).toLocal8Bit().constData()); fflush(stdout); if(ElType=="HE8") { //First four nodes float ENX1=(findNode(Celement.at(1).toInt())).at(1).toDouble(); float ENX2=(findNode(Celement.at(2).toInt())).at(1).toDouble(); float ENX3=(findNode(Celement.at(3).toInt())).at(1).toDouble(); float ENX4=(findNode(Celement.at(4).toInt())).at(1).toDouble(); float ENY1=(findNode(Celement.at(1).toInt())).at(2).toDouble(); float ENY2=(findNode(Celement.at(2).toInt())).at(2).toDouble(); float ENY3=(findNode(Celement.at(3).toInt())).at(2).toDouble(); float ENY4=(findNode(Celement.at(4).toInt())).at(2).toDouble(); float ENZ1=(findNode(Celement.at(1).toInt())).at(3).toDouble(); float ENZ2=(findNode(Celement.at(2).toInt())).at(3).toDouble(); float ENZ3=(findNode(Celement.at(3).toInt())).at(3).toDouble(); float ENZ4=(findNode(Celement.at(4).toInt())).at(3).toDouble(); //Second four Nodes float ENX5=(findNode(Celement.at(5).toInt())).at(1).toDouble(); float ENX6=(findNode(Celement.at(6).toInt())).at(1).toDouble(); float ENX7=(findNode(Celement.at(7).toInt())).at(1).toDouble(); float ENX8=(findNode(Celement.at(8).toInt())).at(1).toDouble(); float ENY5=(findNode(Celement.at(5).toInt())).at(2).toDouble(); float ENY6=(findNode(Celement.at(6).toInt())).at(2).toDouble(); float ENY7=(findNode(Celement.at(7).toInt())).at(2).toDouble(); float ENY8=(findNode(Celement.at(8).toInt())).at(2).toDouble(); float ENZ5=(findNode(Celement.at(5).toInt())).at(3).toDouble(); float ENZ6=(findNode(Celement.at(6).toInt())).at(3).toDouble(); float ENZ7=(findNode(Celement.at(7).toInt())).at(3).toDouble(); float ENZ8=(findNode(Celement.at(8).toInt())).at(3).toDouble(); //Identify Colors GLfloat ENC[8][3]; for(int k=1;k<8;k++) { int hsv=pickColor(findData(Celement.at(k).toInt()).toDouble(),0); //printf("hsv is %d=",hsv);fflush(stdout); getRGB(hsv); //printf("%d*%d*%d\n",red,green,blue); //ENC[k]={red,green,blue}; ENC[k][0]=red; ENC[k][1]=green; ENC[k][2]=blue; } //Plot the first four direct loop if(DType=="WireFrame"){ glBegin(GL_LINE_LOOP); glColor3f(255,0,0); glVertex3f(ENX1,ENY1,ENZ1); glColor3f(255,0,0); glVertex3f(ENX2,ENY2,ENZ2); glColor3f(255,0,0); glVertex3f(ENX3,ENY3,ENZ3); glColor3f(255,0,0); glVertex3f(ENX4,ENY4,ENZ4); glEnd(); //Plot the second four direct loop glBegin(GL_LINE_LOOP); glColor3f(0,0,255); glVertex3f(ENX5,ENY5,ENZ5); glColor3f(0,0,255); glVertex3f(ENX6,ENY6,ENZ6); glColor3f(0,0,255); glVertex3f(ENX7,ENY7,ENZ7); glColor3f(0,0,255); glVertex3f(ENX8,ENY8,ENZ8); glEnd(); //Plot the interconnections glBegin(GL_LINE); glColor3f(150,150,150); glVertex3f(ENX1,ENY1,ENZ1); glVertex3f(ENX5,ENY5,ENZ5); glEnd(); glBegin(GL_LINE); glColor3f(150,150,150); glVertex3f(ENX2,ENY2,ENZ2); glVertex3f(ENX6,ENY6,ENZ6); glEnd(); glBegin(GL_LINE); glColor3f(150,150,150); glVertex3f(ENX3,ENY3,ENZ3); glVertex3f(ENX7,ENY7,ENZ7); glEnd(); glBegin(GL_LINE); glColor3f(150,150,150); glVertex3f(ENX4,ENY4,ENZ4); glVertex3f(ENX8,ENY8,ENZ8); glEnd(); } if(DType=="SolidFrame") { glBegin(GL_QUADS); glColor3fv(ENC[1]); glVertex3f(ENX1,ENY1,ENZ1); glColor3fv(ENC[2]); glVertex3f(ENX2,ENY2,ENZ2); glColor3fv(ENC[3]); glVertex3f(ENX3,ENY3,ENZ3); glColor3fv(ENC[4]); glVertex3f(ENX4,ENY4,ENZ4); glEnd(); //break; glBegin(GL_QUADS); glColor3fv(ENC[5]); glVertex3f(ENX5,ENY5,ENZ5); glColor3fv(ENC[6]); glVertex3f(ENX6,ENY6,ENZ6); glColor3fv(ENC[7]); glVertex3f(ENX7,ENY7,ENZ7); glColor3fv(ENC[8]); glVertex3f(ENX8,ENY8,ENZ8); glEnd(); glBegin(GL_QUAD_STRIP); glColor3fv(ENC[1]); glVertex3f(ENX1,ENY1,ENZ1); glColor3fv(ENC[5]); glVertex3f(ENX5,ENY5,ENZ5); glColor3fv(ENC[2]); glVertex3f(ENX2,ENY2,ENZ2); glColor3fv(ENC[6]); glVertex3f(ENX6,ENY6,ENZ6); glEnd(); glBegin(GL_QUAD_STRIP); glColor3fv(ENC[3]); glVertex3f(ENX3,ENY3,ENZ3); glColor3fv(ENC[7]); glVertex3f(ENX7,ENY7,ENZ7); glColor3fv(ENC[4]); glVertex3f(ENX4,ENY4,ENZ4); glColor3fv(ENC[8]); glVertex3f(ENX8,ENY8,ENZ8); glEnd(); glBegin(GL_QUAD_STRIP); glColor3fv(ENC[2]); glVertex3f(ENX2,ENY2,ENZ2); glColor3fv(ENC[6]); glVertex3f(ENX6,ENY6,ENZ6); glColor3fv(ENC[3]); glVertex3f(ENX3,ENY3,ENZ3); glColor3fv(ENC[7]); glVertex3f(ENX7,ENY7,ENZ7); glEnd(); glBegin(GL_QUAD_STRIP); glColor3fv(ENC[1]); glVertex3f(ENX1,ENY1,ENZ1); glColor3fv(ENC[5]); glVertex3f(ENX5,ENY5,ENZ5); glColor3fv(ENC[4]); glVertex3f(ENX4,ENY4,ENZ4); glColor3fv(ENC[8]); glVertex3f(ENX8,ENY8,ENZ8); glEnd(); } } } } QStringList QGLScreen::findNode(int element) { QStringList Temp; for (int i = 0; i < Nodes.size(); ++i) { Temp=Nodes.at(i).split(","); if(Temp.at(0).toInt()==element) { break; } } return Temp; } QString QGLScreen::findData(int Node) { QString Temp; QRegExp sep("\s+"); for (int i = 0; i < Data.size(); ++i) { if((Data.at(i).split("\t")).at(0).section(sep,1,1).toInt()==Node) { if(axis=="X") { Temp=Data.at(i).split("\t").at(0).section(sep,2,2); } if(axis=="Y") { Temp=Data.at(i).split("\t").at(0).section(sep,3,3); } if(axis=="Z") { Temp=Data.at(i).split("\t").at(0).section(sep,4,4); } break; } } return Temp; } void QGLScreen::fillColorArray() { QString Temp1,Temp2,Temp3; double d1s=0,d2s=0,d3s=0,d1l=0,d2l=0,d3l=0,diff=0; QRegExp sep("\\s+"); for (int i = 0; i < Data.size(); ++i) { Temp1=(Data.at(i).split("\t")).at(0).section(sep,2,2); if(d1s>Temp1.toDouble()) { d1s=Temp1.toDouble(); } if(d1l<Temp1.toDouble()) { d1l=Temp1.toDouble(); } Temp2=(Data.at(i).split("\t")).at(0).section(sep,3,3); if(d2s>Temp2.toDouble()) { d2s=Temp2.toDouble(); } if(d2l<Temp2.toDouble()) { d2l=Temp2.toDouble(); } Temp3=(Data.at(i).split("\t")).at(0).section(sep,4,4); if(d3s>Temp3.toDouble()) { d3s=Temp3.toDouble(); } if(d3l<Temp3.toDouble()) { d3l=Temp3.toDouble(); } // printf("data is %s",Temp.toLocal8Bit().constData());fflush(stdout); } color[0][0]=d1l; for(int i=1;i<360;i++) { //printf("Large is%f small is %f",d1l,d1s); diff=d1l-d1s; if(d1l==0&&d1s<0) color[0][i]=color[0][i-1]-diff/360; else if(d1l>0&&d1s==0) color[0][i]=color[0][i-1]+diff/360; else if(d1l>0&&d1s<0) color[0][i]=color[0][i-1]-diff/360; diff=d2l-d2s; if(d2l==0&&d2s<0) color[1][i]=color[1][i-1]-diff/360; else if(d2l>0&&d2s==0) color[1][i]=color[1][i-1]+diff/360; else if(d2l>0&&d2s<0) color[1][i]=color[1][i-1]-diff/360; diff=d3l-d3s; if(d3l==0&&d3s<0) color[2][i]=color[2][i-1]-diff/360; else if(d3l>0&&d3s==0) color[2][i]=color[2][i-1]+diff/360; else if(d3l>0&&d3s<0) color[2][i]=color[2][i-1]-diff/360; } //for(int i=0;i<360;i++) printf("%d %f %f %f\n",i,color[0][i],color[1][i],color[2][i]); } int QGLScreen::pickColor(double data,int Did) { int i,pos; if(axis=="X")Did=0; if(axis=="Y")Did=1; if(axis=="Z")Did=2; //printf("%f data is",data);fflush(stdout); for(int i=0;i<360;i++) { if(color[Did][i]<data && data>color[Did][i+1]) { //printf("Orginal dat is %f Data found is %f and pos %d\n",data,color[Did][i],i);fflush(stdout); pos=i; break; } } return pos; } void QGLScreen::getRGB(int hsv) { QColor c; c.setHsv(hsv,255,255,255); QColor r=QColor::fromHsv(hsv,255,255); red=r.red(); green=r.green(); blue=r.blue(); } void QGLScreen::paintGL() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushAttrib(GL_ALL_ATTRIB_BITS); glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity(); GLfloat x = 3.0 * GLfloat(width()) / height(); glOrtho(-x, +x, -3.0, +3.0, 4.0, 15.0); glMatrixMode(GL_MODELVIEW); glPushMatrix(); glLoadIdentity(); glTranslatef(0.0, 0.0, -10.0); glScalef(scaling, scaling, scaling); glRotatef(xRot, 1.0, 0.0, 0.0); glRotatef(yRot, 0.0, 1.0, 0.0); glRotatef(zRot, 0.0, 0.0, 1.0); drawModel(0,0,1,1); /* don't wait! * start processing buffered OpenGL routines */ glFlush (); } /void QGLScreen::zoom1() { scaling+=.05; update(); }/ void QGLScreen::resizeGL(int width, int height) { int side = qMin(width, height); glViewport((width - side) / 2, (height - side) / 2, side, side); #if !defined(QT_OPENGL_ES_2) glMatrixMode(GL_PROJECTION); glLoadIdentity(); #ifndef QT_OPENGL_ES glOrtho(-0.5, +0.5, +0.5, -0.5, 4.0, 15.0); #else glOrthof(-0.5, +0.5, +0.5, -0.5, 4.0, 15.0); #endif glMatrixMode(GL_MODELVIEW); #endif } void QGLScreen::mousePressEvent(QMouseEvent *event) { lastPos = event-pos(); } void QGLScreen::mouseMoveEvent(QMouseEvent *event) { GLfloat dx = GLfloat(event->x() - lastPos.x()) / width(); GLfloat dy = GLfloat(event->y() - lastPos.y()) / height(); if (event->buttons() & Qt::LeftButton) { xRot+= 180 * dy; yRot += 180 * dx; update(); } else if (event->buttons() & Qt::RightButton) { xRot += 180 * dy; yRot += 180 * dx; update(); } lastPos = event->pos(); } void QGLScreen::mouseReleaseEvent(QMouseEvent * /* event */) { emit clicked(); }

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