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  • Debugging Minimum Translation Vector

    - by SyntheCypher
    I implemented the minimum translation vector from codezealot's tutorial on SAT (Separating Axis Theorem) but I'm having an issue I can't quite figure out. Here's the example I have: As you can see in top and bottom left images regardless of the side the of the green car which red car is penetrating the MTV for the red car still remains as a negative number also here is the same example when the front of the red car is facing the opposite direction the number will always be positive. When the red car is past the half way through the green car it should switch polarity. I thought I'd compensated for this in my code, but apparently not either that or it's a bug I can find. Here is my function for finding and returning the MTV, any help would be much appreciated: Code

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  • What is a normalized Vector?

    - by draiden
    Can someone explain the following code? I need to learn what each part means so I can turn it into enemy movement in a space shoot-em-up Vec2d playerPos; Vec2d direction; // always normalized float velocity; I get the above is naming two 2d Vector objects, and creating a variable called velocity. I'm not sure what the normalized comment is about, though. update() { direction = normalize(playerPos - enemyPos); playerPos = playerPos + direction * velocity; }

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  • Orienting ship movement in asteroids [closed]

    - by BadSniper
    Possible Duplicate: Move sprite in the direction it is facing? I'm programming asteroids game. I'm trying to give velocity in the direction of ship face. I've tried using velocity.x = velocity.x * cos r, velocity.y = velocity.y * sin r where velocity is a vector and r is the angle rotated. but it's not moving in right direction. Could someone help with this problem? It is supposed to return the vector in which ship is facing. I don't understand the problem.

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  • Do classes which have a vector has a member have memory issues

    - by user263766
    I am just starting out C++, so sorry if this is a dumb question. I have a class Braid whose members are vectors. I have not written an assignment operator. When I do a lot of assignments to an object of the type Braid, I run into memory issues :- 0 0xb7daff89 in _int_malloc () from /lib/libc.so.6 #1 0xb7db2583 in malloc () from /lib/libc.so.6 #2 0xb7f8ac59 in operator new(unsigned int) () from /usr/lib/libstdc++.so.6 #3 0x0804d05e in __gnu_cxx::new_allocator<int>::allocate (this=0xbf800204, __n=1) at /usr/lib/gcc/i686-pc-linux-gnu/4.4.3/../../../../include/c++/4.4.3/ext/new_allocator.h:89 #4 0x0804cb0e in std::_Vector_base<int, std::allocator<int> >::_M_allocate (this=0xbf800204, __n=1) at /usr/lib/gcc/i686-pc-linux-gnu/4.4.3/../../../../include/c++/4.4.3/bits/stl_vector.h:140 #5 0x0804c086 in _Vector_base (this=0xbf800204, __n=1, __a=...) at /usr/lib/gcc/i686-pc-linux-gnu/4.4.3/../../../../include/c++/4.4.3/bits/stl_vector.h:113 #6 0x0804b4b7 in vector (this=0xbf800204, __x=...) at /usr/lib/gcc/i686-pc-linux-gnu/4.4.3/../../../../include/c++/4.4.3/bits/stl_vector.h:242 #7 0x0804b234 in Braid (this=0xbf800204) at braid.h:13 #8 0x080495ed in Braid::cycleBraid (this=0xbf8001b4) at braid.cpp:191 #9 0x080497c6 in Braid::score (this=0xbf800298, b=...) at braid.cpp:251 #10 0x08049c46 in Braid::evaluateMove (this=0xbf800468, move=1, pos=0, depth=2, b=...) I suspect that these memory issues are because the vectors are getting resized. What I want to know is whether objects of type Braid automatically expand when its members expand? he code I am writing is really long so I will post the section which is causing the problems. Here is the relevant section of the code :- class Braid { private : vector<int> braid; //Stores the braid. int strands; vector < vector<bool> > history; vector < vector<bool> > CM; public : Braid () : strands(0) {} Braid operator * (Braid); Braid* inputBraid(int,vector<int>); int printBraid(); int printBraid(vector<vector<int>::iterator>); vector<int>::size_type size() const; ..... ..... } Here is the function which causes the issue :- int Braid::evaluateMove(int move,int pos,int depth,Braid b) { int netscore = 0; Braid curr(*this); curr = curr.move(move,pos); netscore += curr.score(b); while(depth > 1) { netscore += curr.evaluateMove(1,0,depth,b); netscore += curr.evaluateMove(2,0,depth,b); for(int i = 0; i < braid.size();++i) { netscore += curr.evaluateMove(3,i,depth,b); netscore += curr.evaluateMove(4,i,depth,b); netscore += curr.evaluateMove(5,i,depth,b); curr = curr.cycleBraid(); netscore += curr.evaluateMove(6,0,depth,b); } --depth; } return netscore; }

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  • Why Does My Vector<PEVENTLOGRECORD> Mysteriously Get Cleared?

    - by Eric
    Hello everyone, I am making a program that reads and stores data from Windows EventLog files (.evt) in C++. I am using the calls OpenBackupEventLog(ServerName, FileName) and ReadEventLog(...). Also using this: PEVENTLOGRECORD Anyway, without supplying all of the code, here is the basic idea: 1. I get a handle to the .evt file using OpenBackupEventLog() and passing in a file name. 2. I then use ReadEventLog() to fill up a buffer with an unknown number of EventLog messages. 3. I traverse through the buffer and add each message to a vector 4. I keep filling up buffers (repeat steps 2 and 3) until I reach the end of the file. Here is my code for filling the vector: vector<PEVENTLOGRECORD> allRecords; while(_status == ERROR_SUCCESS) { if(!ReadEventLog(...)) CheckStatus(); else FillVectorFromBuffer(allRecords) } // Function FillVectorFromBuffer FillVectorFromBuffer(vector(PEVENTLOGRECORD) &allRecords) { int bytesExamined = 0; PBYTE pRecord = (PBYTE)_lpBuffer; // This is one of the params in ReadEventLog() while(bytesExamined < _pnBytesRead) // Another param from ReadEventLog { PEVENTLOGRECORD currentRecord = (PEVENTLOGRECORD)(pRecord); allRecords.push_back(currentRecord); pRecord += currentRecord->Length; bytesExamined += currentRecord->Length; } } Anyway, whenever I run this, it will get all the EventLogs in the file, and the vector will have everything I want it to. But as soon as this line: if(!ReadEventLog()) gets called and returns true (aka ReadEventLog() returns false), then every field in my vector gets set to zero. The vector will still contain the correct number of elements, it's just that all of the fields in the PEVENTLOGRECORD struct are now zero. Anyone with better debugging experience have any ideas? Thanks.

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  • returning reference to a vector from a method and using its public members

    - by memC
    dear experts, I have a vector t_vec that stores references to instances of class Too. The code is shown below. In the main , I have a vector t_vec_2 which has the same memory address as B::t_vec. But when I try to access t_vec_2[0].val1 it gives error val1 not declared. Could you please point out what is wrong? Also, if you know of a better way to return a vector from a method, please let me know! Thanks in advance. class Too { public: Too(); ~Too(){}; int val1; }; Too::Too(){ val1 = 10; }; class B { public: vector<Too*> t_vec; Too* t1; vector<Too*>& get_tvec(); B(){t1 = new Too();}; ~B(){delete t1;}; }; vector<Too*>& B::get_tvec(){ t_vec.push_back(t1); return t_vec; } int main(){ B b; b = B(); vector<Too*>& t_vec_2 = b.get_tvec(); // Getting error std::cout << "\n val1 = " << t_vec_2[0].val1; return 0; }

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  • Empty vector of type <stuff*>

    - by bo23
    I have a vector populated with objects: std::vector<Stuff*> stuffVector; and am trying to delete all elements of it using a cleanup function void CleanUp() { for (std::vector<Stuff*>::size_type i = 0 ; i < stuffVector.size() ; i++) { stuffVector.erase(stuffVector.begin()+i); } cout << stuffVector.size() << endl; if (stuffVector.size() == 0) cout << "Vector Emptied" << endl; } This always reports back with a size of however many objects are in the vector, and doesn't actually seem to delete anything at all. It's odd as a similar function works elsewhere to delete a specific object from the vector: void DestroyStuff() { if (stuffVector.size() > 1) { for (std::vector<Stuff*>::size_type i = 0 ; i < stuffVector.size() ; i++ ) { if(stuffVector[i]->CanDestroy()) { stuffVector.erase (stuffVector.begin()+i); } } } } The above works fine, but CleanUp() does not. Why might this be happening?

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  • std::vector optimisation required

    - by marcp
    I've written a routine that uses std::vector<double> rather heavily. It runs rather slowly and AQTime seems to imply that I am constructing mountains of vectors but I'm not sure why I would be. For some context, my sample run iterates 10 times. Each iteration copies 3 c arrays of ~400 points into vectors and creates 3 new same sized vectors for output. Each output point might be the result of summing up to 20 points from 2 of the input vectors, which works out to a worst case of 10*400*3*2*20 = 480,000 dereferences. Incredibly the profiler indicates that some of the std:: methods are being called 46 MILLION times. I suspect I'm doing something wrong! Some code: vector<double>gdbChannel::GetVector() { if (fHaveDoubleData & (fLength > 0)) { double * pD = getDoublePointer(); vector<double>v(pD, pD + fLength); return v; } else { throw(Exception("attempt to retrieve vector on empty line")); ; } } void gdbChannel::SaveVector(GX_HANDLE _hLine, const vector<double> & V) { if (hLine != _hLine) { GetLine(_hLine, V.size(), true); } GX_DOUBLE * pData = getDoublePointer(); memcpy(pData, &V[0], V.size()*sizeof(V[0])); ReplaceData(); } ///This routine gets called 10 times bool SpecRatio::DoWork(GX_HANDLE_PTR pLine) { if (!(hKin.GetLine(*pLine, true) && hUin.GetLine(*pLine, true) && hTHin.GetLine(*pLine, true))) { return true; } vector<double>vK = hKin.GetVector(); vector<double>vU = hUin.GetVector(); vector<double>vTh = hTHin.GetVector(); if ((vK.size() == 0) || (vU.size() == 0) || (vTh.size() == 0)) { return true; } ///TODO: confirm all vectors the same lenghth len = vK.size(); vUK.clear(); // these 3 vectors are declared as private class members vUTh.clear(); vThK.clear(); vUK.reserve(len); vUTh.reserve(len); vThK.reserve(len); // TODO: ensure everything is same fidincr, fidstart and length for (int i = 0; i < len; i++) { if (vK.at(i) < MinK) { vUK.push_back(rDUMMY); vUTh.push_back(rDUMMY); vThK.push_back(rDUMMY); } else { vUK.push_back(RatioPoint(vU, vK, i, UMin, KMin)); vUTh.push_back(RatioPoint(vU, vTh, i, UMin, ThMin)); vThK.push_back(RatioPoint(vTh, vK, i, ThMin, KMin)); } } hUKout.setFidParams(hKin); hUKout.SaveVector(*pLine, vUK); hUTHout.setFidParams(hKin); hUTHout.SaveVector(*pLine, vUTh); hTHKout.setFidParams(hKin); hTHKout.SaveVector(*pLine, vThK); return TestError(); } double SpecRatio::VValue(vector<double>V, int Index) { double result; if ((Index < 0) || (Index >= len)) { result = 0; } else { try { result = V.at(Index); if (OasisUtils::isDummy(result)) { result = 0; } } catch (out_of_range) { result = 0; } } return result; } double SpecRatio::RatioPoint(vector<double>Num, vector<double>Denom, int Index, double NumMin, double DenomMin) { double num = VValue(Num, Index); double denom = VValue(Denom, Index); int s = 0; // Search equalled 10 in this case while (((num < NumMin) || (denom < DenomMin)) && (s < Search)) { num += VValue(Num, Index - s) + VValue(Num, Index + s); denom += VValue(Denom, Index - s) + VValue(Denom, Index + s); s++; } if ((num < NumMin) || (denom < DenomMin)) { return rDUMMY; } else { return num / denom; } } The top AQTime offenders are: std::_Uninit_copy , double *, std::allocator 3.65 secs and 115731 Hits std::_Construct 1.69 secs and 46450637 Hits std::_Vector_const_iterator ::operator !=1.66 secs and 46566395 Hits and so on... std::allocator<double>::construct, operator new, std::_Vector_const_iterator<double, std::allocator<double> >::operator ++, std::_Vector_const_iterator<double, std::allocator<double> >::operator * std::_Vector_const_iterator<double, std::allocator<double> >::operator == each get called over 46 million times. I'm obviously doing something wrong to cause all these objects to be created. Can anyone see my error(s)?

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  • Pointing class property to another class with vectors

    - by jmclem
    I've got a simple class, and another class that has a property that points to the first class: #include <iostream> #include <vector> using namespace std; class first{ public: int var1; }; class second{ public: first* classvar; }; Then, i've got a void that's supposed to point "classvar" to the intended iteration of the class "first". void fill(vector<second>& sec, vector<first>& fir){ sec[0].classvar = &fir[0]; } Finally the main(). Create and fill a vector of class "first", create "second" vector, and run the fill function. int main(){ vector<first> a(1); a[0].var1 = 1000; vector<second> b(1); fill(b, a); cout << b[0].classvar.var1 << '\n'; system("PAUSE"); return 0; } This gives me the following error: 1>c:\...\main.cpp(29) : error C2228: left of '.var1' must have class/struct/union 1> type is 'first *' And I can't figure out why it reads the "classvar" as the whole vector instead of just the single instance. Should I do this cout << b[0].classvar[0].var1 << '\n'; it reads perfectly. Can anyone figure out the problem? Thanks in advance

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  • For normal mapping, why can we not simply add the tangent normal to the surface normal?

    - by sebf
    I am looking at implementing bump mapping (which in all implementations I have seen is really normal mapping), and so far all I have read says that to do this, we create a matrix to convert from world-space to tangent-space, in order to transform the lights and eye direction vectors into tangent space, so that the vectors from the normal map may be used directly in place of those passed through from the vertex shader. What I do not understand though, is why we cannot just use the normalised sum of the sampled-normal vector, and the surface-normal? (assuming we already transform and pass through the surface normal for the existing lighting functions) Take the diagram below; the normal is simply the deviation from the 'reference normal' for any given coordinate system, correct? And transforming the surface normal of a mapped surface from world space to tangent space makes it equivalent to the tangent space 'reference normal', no? If so, why do we transform all lighting vectors into tangent space, instead of simply transforming the sampled tangent once in the pixel shader?

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  • VS2010 vector's iterator incompatible

    - by Ernesto Rojo Jr
    I just updated to VS2010 from 2008. Now i'm getting an exception from vector iterators. Here's a code snippet that shows the issue. std::vector<CButton*> m_objButtons; for (std::vector<CButton*>::iterator i = m_objButtons.begin(); i != m_objButtons.end(); ++i) {} I get the debug message "vector iterators incompatible". Anyone run into this too?

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  • ArrayCollection versus Vector Objects in FLEX

    - by Vetsin
    Can anyone tell me the applicable differences between an ArrayCollection and a Vector in flex? I'm unsure if I should be using one over the other. I saw that Vector is type safe and that makes me feel better, but are there disadvantages? public var ac:ArrayCollection = new ArrayCollection(); versus public var vec:Vector.<String> = new Vector.<String>(); Thanks.

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  • Clamping a vector to a minimum and maximum?

    - by user146780
    I came accross this: t = Clamp(t/d, 0, 1) but I'm not sure how to perform this operation on a vector. What are the steps to clamp a vector if one was writing their own vector implementation? Thanks clamp clamping a vector to a minimum and a maximum ex: pc = # the point you are coloring now p0 = # start point p1 = # end point v = p1 - p0 d = Length(v) v = Normalize(v) # or Scale(v, 1/d) v0 = pc - p0 t = Dot(v0, v) t = Clamp(t/d, 0, 1) color = (start_color * t) + (end_color * (1 - t))

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  • vector does not erase content correctly (infite amount run of copy asignment operator untill crash [BEX])?

    - by Gam Erix
    Well my problem is that after I want to "unload" loaded DLL's the copy assignmnent operator is called an unlimited amount of times until crash. The code from which I remove the vector data looks like this: void UnloadPlugins() { dbg(("[DBG]UnloadPlugins()")); for(std::vector<DLLInfo>::iterator it = plugins.begin(); it != plugins.end(); ++it) { plugins.erase(it); } dbg(("[DBG]UnloadPlugins()::Done")); } however "[DBG]UnloadPlugins()::Done" gets never printed. this is my copy assignmnent operator: // 2. copy assignment operator DLLInfo& operator=(const DLLInfo& that) { dbg(("[DBG]Start-DLLInfo& operator=(const DLLInfo& that)")); Instance = that.Instance;//hinstance dbg(("[DBG]DLLInfo 1")); //Identifier.assign(that.Identifier);//string dbg(("[DBG]DLLInfo 2")); IsAMX = that.IsAMX;//integer dbg(("[DBG]DLLInfo 3")); dwSupportFlags = that.dwSupportFlags;//integer dbg(("[DBG]DLLInfo 4")); Load = that.Load;//integer dbg(("[DBG]DLLInfo 5")); Unload = that.Unload;//integer dbg(("[DBG]DLLInfo 6")); Supports = that.Supports;//integer dbg(("[DBG]DLLInfo 7")); ProcessTick = that.ProcessTick;//integer dbg(("[DBG]DLLInfo 8")); AmxLoad = that.AmxLoad;//integer dbg(("[DBG]DLLInfo 9")); AmxUnload = that.AmxUnload;//integer dbg(("[DBG]DLLInfo 10")); UseDestructor = that.UseDestructor;//bool dbg(("[DBG]DLLInfo 11")); KeyboardHit = that.KeyboardHit;//integer dbg(("[DBG]End-DLLInfo& operator=(const DLLInfo& that)")); return *this; } So the log looks like: [17:50:50] [DBG]UnloadPlugins() [17:50:50] [DBG]~DLLInfo [17:50:50] [DBG]~DLLInfo::if(this->UseDestructor) passed [17:50:50] [DBG]~DLLInfo::if(this->UseDestructor)::if(this->Unload != NULL && this->IsAMX) passed [17:50:50] [DBG]~DLLInfo::end [17:50:50] [DBG]Start-DLLInfo& operator=(const DLLInfo& that) [17:50:50] [DBG]DLLInfo 1 [17:50:50] [DBG]DLLInfo 2 [17:50:50] [DBG]DLLInfo 3 [17:50:50] [DBG]DLLInfo 4 [17:50:50] [DBG]DLLInfo 5 [17:50:50] [DBG]DLLInfo 6 [17:50:50] [DBG]DLLInfo 7 [17:50:50] [DBG]DLLInfo 8 [17:50:50] [DBG]DLLInfo 9 [17:50:50] [DBG]DLLInfo 10 [17:50:50] [DBG]DLLInfo 11 [17:50:50] [DBG]End-DLLInfo& operator=(const DLLInfo& that) [17:50:50] [DBG]Start-DLLInfo& operator=(const DLLInfo& that) ... [17:50:50] [DBG]End-DLLInfo& operator=(const DLLInfo& that) ...repeat until crash What could the problem be?

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  • what does AngleVectors method in quake 3 source code does

    - by kypronite
    I just downloaded quake 3 for learning purposes. I know some of some linear algebra(basic vector math ie: dot,cross product). However I can't decipher what below method does, I know what is yaw,pitch and roll. But I can't connect these with vector. Worse, I'm not sure this fall under what math 'category', so I don't really know how to google. Hence the question here. Anyone? void AngleVectors( const vec3_t angles, vec3_t forward, vec3_t right, vec3_t up) { float angle; static float sr, sp, sy, cr, cp, cy; // static to help MS compiler fp bugs angle = angles[YAW] * (M_PI*2 / 360); sy = sin(angle); cy = cos(angle); angle = angles[PITCH] * (M_PI*2 / 360); sp = sin(angle); cp = cos(angle); angle = angles[ROLL] * (M_PI*2 / 360); sr = sin(angle); cr = cos(angle); if (forward) { forward[0] = cp*cy; forward[1] = cp*sy; forward[2] = -sp; } if (right) { right[0] = (-1*sr*sp*cy+-1*cr*-sy); right[1] = (-1*sr*sp*sy+-1*cr*cy); right[2] = -1*sr*cp; } if (up) { up[0] = (cr*sp*cy+-sr*-sy); up[1] = (cr*sp*sy+-sr*cy); up[2] = cr*cp; } } ddddd

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  • Flattening PDF transparency

    - by Jan
    I have a PDF, made with Inkscape, that uses transparent colors. This image shall be used in a LaTeX document. While preserving the transparency is nice for editing, it can be a problem for printing. Printing usually involves PDF to PS conversion. Since Postscript does not support transparency, this requires either flatting, i.e. creating a vector graphic that works without transparency or rastering, i.e. rendering a bitmap image. When a PDF document containing such a figure is printed (or converted to PS) using Evince (or Cairo or Ghostscript), the whole page gets rendered as a bitmap, rendering fonts ugly (different from other pages). (Adobe Acrobat handles such PDFs well.) Unfortunately, converting the PDF figures to EPS (before including them with LaTeX) doesn't help much, because both pdftops and pdf2ps (again, Cairo or Ghostscript) rasterize the image, i.e. render a bitmap (saved as EPS). (This is slightly better, because it doesn't affect the whole page, but I'd still prefer a vector graphics.) How can I flatten transparency with Inkscape or other software on Linux?

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  • Detecting walls or floors in pygame

    - by Serial
    I am trying to make bullets bounce of walls, but I can't figure out how to correctly do the collision detection. What I am currently doing is iterating through all the solid blocks and if the bullet hits the bottom, top or sides, its vector is adjusted accordingly. However, sometimes when I shoot, the bullet doesn't bounce, I think it's when I shoot at a border between two blocks. Here is the update method for my Bullet class: def update(self, dt): if self.can_bounce: #if the bullet hasnt bounced find its vector using the mousclick pos and player pos speed = -10. range = 200 distance = [self.mouse_x - self.player[0], self.mouse_y - self.player[1]] norm = math.sqrt(distance[0] ** 2 + distance[1] ** 2) direction = [distance[0] / norm, distance[1 ] / norm] bullet_vector = [direction[0] * speed, direction[1] * speed] self.dx = bullet_vector[0] self.dy = bullet_vector[1] #check each block for collision for block in self.game.solid_blocks: last = self.rect.copy() if self.rect.colliderect(block): topcheck = self.rect.top < block.rect.bottom and self.rect.top > block.rect.top bottomcheck = self.rect.bottom > block.rect.top and self.rect.bottom < block.rect.bottom rightcheck = self.rect.right > block.rect.left and self.rect.right < block.rect.right leftcheck = self.rect.left < block.rect.right and self.rect.left > block.rect.left each test tests if it hit the top bottom left or right side of the block its colliding with if self.can_bounce: if topcheck: self.rect = last self.dy *= -1 self.can_bounce = False print "top" if bottomcheck: self.rect = last self.dy *= -1 #Bottom check self.can_bounce = False print "bottom" if rightcheck: self.rect = last self.dx *= -1 #right check self.can_bounce = False print "right" if leftcheck: self.rect = last self.dx *= -1 #left check self.can_bounce = False print "left" else: # if it has already bounced and colliding again kill it self.kill() for enemy in self.game.enemies_list: if self.rect.colliderect(enemy): self.kill() #update position self.rect.x -= self.dx self.rect.y -= self.dy This definitely isn't the best way to do it but I can't think of another way. If anyone has done this or can help that would be awesome!

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  • Sorting for 2D Drawing

    - by Nexian
    okie, looked through quite a few similar questions but still feel the need to ask mine specifically (I know, crazy). Anyhoo: I am drawing a game in 2D (isometric) My objects have their own arrays. (i.e. Tiles[], Objects[], Particles[], etc) I want to have a draw[] array to hold anything that will be drawn. Because it is 2D, I assume I must prioritise depth over any other sorting or things will look weird. My game is turn based so Tiles and Objects won't be changing position every frame. However, Particles probably will. So I am thinking I can populate the draw[] array (probably a vector?) with what is on-screen and have it add/remove object, tile & particle references when I pan the screen or when a tile or object is specifically moved. No idea how often I'm going to have to update for particles right now. I want to do this because my game may have many thousands of objects and I want to iterate through as few as possible when drawing. I plan to give each element a depth value to sort by. So, my questions: Does the above method sound like a good way to deal with the actual drawing? What is the most efficient way to sort a vector? Most of the time it wont require efficiency. But for panning the screen it will. And I imagine if I have many particles on screen moving across multiple tiles, it may happen quite often. For reference, my screen will be drawing about 2,800 objects at any one time. When panning, it will be adding/removing about ~200 elements every second, and each new element will need adding in the correct location based on depth.

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  • Make an object slide around an obstacle

    - by Isaiah
    I have path areas set up in a game I'm making for canvas/html5 and have got it working to keep the player within these areas. I have a function isOut(boundary, x, y) that returns true if the point is outside the boundary. What I do is check only the new position x/y separately with the corresponding old position x/y. Then if each one is out I assign them the past value from the frame before. The old positions are kept in a variable from a closure I made. like this: opos = [x,y];//old position npos = [x,y];//new position if(isOut(bound, npos[0], opos[1])){ npos[0] = opos[0]; //assign it the old x position } if(isOut(bound, opos[0], npos[1])){ npos[1] = opos[1]; //assign it the old y position } It looks nice and works good at certain angles, but if your boundary has diagonal regions it results in jittery motion. What's happening is the y pos exits the area while x doesn't and continues pushing the player to the side, once it has moved the player to the side a bit the player can move forward and then the y exits again and the whole process repeats. Anyone know how I may be able to achieve a smoother slide? I have access to the player's velocity vector, the angle, and the speed(when used with the angle). I can move the play with either angle/speed or x/yvelocities as I've built in backups to translate one to the other if either have been altered manually.

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  • passing multiple vectors to function by reference (using structure)

    - by madman
    Hi StackOverflow, Can someone tell me the correct way of passing multiple vectors to a function that can take only a single argument? (specifically for pthread_create (..) function) I tried the following but it does not seem to work :-( First, I created the following structure struct ip2 { void* obj; int dim; int n_s; vector<vector<vector<double> > > *wlist; vector<int> *nrsv; struct model *pModel; }; The threads that I have created actually needs all these parameters. Since im using pthreads_create I put all this in a structure and then passed the pointer to the structure as an argument to pthread_create (as shown). some_fxn() { //some code struct ip2 ip; ip.obj=(void*) this; ip.n_s=n_s; ip.wlist=&wlist; ip.nrsv=&nrsv; ip.pModel=pModel; ip.dim=dim; pthread_create(&callThd1[lcntr], &attr1, &Cls::Entry, (void*) &ip); } The Entry method looks something like this. void* Cls::Entry(void *ip) { struct ip2 *x; x = (struct ip2 *)ip; (reinterpret_cast<Cls1 *>(x->obj))->Run(x->dim,x->n_s, x->wlist, x->nrsv, x->pModel); } The Run method looks something like this. void Run(int dim, int n_c, vector<vector<vector<double> > > *wlist, vector<int> *nrsv, struct model* pModel ) { //some code for(int k = 0; k < n_c; ++k) { //some code end = index + nrsv[k]; //some code } I get the following error when I try to compile the program. error: no match for ‘operator+’ in ‘index + *(((std::vector<int, std::allocator<int> >*)(((unsigned int)k) * 12u)) + nrsv)’ Can someone tell me how to do it the right way. Madhavan

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