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  • Error inserting data in binary tree

    - by chepe263
    I copied this code (in spanish) http://www.elrincondelc.com/nuevorincon/index.php?pag=codigos&id=4 and wrote a new one. This is my code: #include <cstdlib> #include <conio.h> #include <iostream> using namespace std; struct nodoarbol { int dato; struct nodoarbol *izq; struct nodoarbol *der; }; typedef nodoarbol Nodo; typedef Nodo *Arbol; void insertar(Arbol *, int); void inorden(Arbol); void postorden(Arbol); void preorden(Arbol); void insertar(Arbol *raiz, int nuevo){ if (*raiz==NULL){ *raiz = (Nodo *)malloc(sizeof(Nodo)); if (*raiz != NULL){ (*raiz)->dato=nuevo; (*raiz)->der=NULL; (*raiz)->izq=NULL; } else{ cout<<"No hay memoria suficiente u ocurrio un error"; } } else{ if (nuevo < (*raiz)->dato) insertar( &((*raiz)->izq), nuevo ); else if (nuevo > (*raiz)->dato) insertar(&((*raiz)->der), nuevo); } }//inseertar void inorden(Arbol raiz){ if (raiz != NULL){ inorden(raiz->izq); cout << raiz->dato << " "; inorden(raiz->der); } } void preorden(Arbol raiz){ if (raiz != NULL){ cout<< raiz->dato << " "; preorden(raiz->izq); preorden(raiz->der); } } void postorden(Arbol raiz){ if (raiz!=NULL){ postorden(raiz->izq); postorden(raiz->der); cout<<raiz->dato<<" "; } } int main() { int i; i=0; int val; Arbol raiz = NULL; for (i=0; i<10; i++){ cout<<"Inserte un numero"; cin>>val; insertar( (raiz), val); } cout<<"\nPreorden\n"; preorden(raiz); cout<<"\nIneorden\n"; inorden(raiz); cout<<"\nPostorden\n"; postorden(raiz); return 0; } I'm using netbeans 7.1.1, mingw32 compiler This is the output: make[2]: Leaving directory `/q/netbeans c++/NetBeansProjects/treek' make[1]: Leaving directory `/q/netbeans c++/NetBeansProjects/treek' main.cpp: In function 'int main()': main.cpp:110:30: error: cannot convert 'Arbol {aka nodoarbol*}' to 'Nodo** {aka nodoarbol**}' for argument '1' to 'void insertar(Nodo**, int)' make[2]: *** [build/Release/MinGW-Windows/main.o] Error 1 make[1]: *** [.build-conf] Error 2 make: *** [.build-impl] Error 2 BUILD FAILED (exit value 2, total time: 11s) I don't understand what's wrong since i just copied the code (and rewrite it to my own code). I'm really good in php, asp.net (vb) and other languages but c is a headche for me. I've been struggling with this problem for about an hour. Could somebody tell me what could it be?

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  • Reordering Variadic Parameters

    - by void-pointer
    I have come across the need to reorder a variadic list of parameters that is supplied to the constructor of a struct. After being reordered based on their types, the parameters will be stored as a tuple. My question is how this can be done so that a modern C++ compiler (e.g. g++-4.7) will not generate unnecessary load or store instructions. That is, when the constructor is invoked with a list of parameters of variable size, it efficiently pushes each parameter into place based on an ordering over the parameters' types. Here is a concrete example. Assume that the base type of every parameter (without references, rvalue references, pointers, or qualifiers) is either char, int, or float. How can I make it so that all the parameters of base type char appear first, followed by all of those of base type int (which leaves the parameters of base type float last). The relative order in which the parameters were given should not be violated within sublists of homogeneous base type. Example: foo::foo() is called with arguments float a, char&& b, const float& c, int&& d, char e. The tuple tupe is std::tuple<char, char, int, float, float>, and it is constructed like so: tuple_type{std::move(b), e, std::move(d), a, c}. Consider the struct defined below, and assume that the metafunction deduce_reordered_tuple_type is already implemented. How would you write the constructor so that it works as intended? If you think that the code for deduce_reodered_tuple_type, would be useful to you, I can provide it; it's a little long. template <class... Args> struct foo { // Assume that the metafunction deduce_reordered_tuple_type is defined. typedef typename deduce_reordered_tuple_type<Args...>::type tuple_type; tuple_type t_; foo(Args&&... args) : t_{reorder_and_forward_parameters<Args>(args)...} {} }; Edit 1 The technique I describe above does have applications in mathematical frameworks that make heavy use of expression templates, variadic templates, and metaprogramming in order to perform aggressive inlining. Suppose that you wish to define an operator that takes the product of several expressions, each of which may be passed by reference, reference to const, or rvalue reference. (In my case, the expressions are conditional probability tables and the operation is the factor product, but something like matrix multiplication works suitably as well.) You need access to the data provided by each expression in order to evaluate the product. Consequently, you must move the expressions passed as rvalue references, copy the expressions passed by reference to const, and take the addresses of expressions passed by reference. Using the technique I describe above now poses several benefits. Other expressions can use uniform syntax to access data elements from this expression, since all of the heavy-lifting metaprogramming work is done beforehand, within the class. We can save stack space by grouping the pointers together and storing the larger expressions towards the end of the tuple. Implementing certain types of queries becomes much easier (e.g. check whether any of the pointers stored in the tuple aliases a given pointer). Thank you very much for your help!

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  • Can anyone help me find why this C program work on VS2005 but not on DEV-C++

    - by user333771
    Hello to everybody..and greetings from Greece I have a C program for an exercise and it has a strange issue The program runs just fine on VS 2005 but it crashes on DEV-C++ and the problem that the problem is that the exercise is always evaluated against DEV-C++ The program is about inserting nodes to a BST and this is where the problem lies... Well i would really appreciate some help. enter code here #include <stdio.h> #include <stdlib.h> #include <malloc.h> typedef struct tree_node { int value; int weight; struct tree_node *left; struct tree_node *right; } TREE_NODE; /* The Following function creates a Binary Search Treed */ TREE_NODE *create_tree(int list[], int size); TREE_NODE *search_pos_to_insert(TREE_NODE *root, int value, int *left_or_right); /* this is the problematic function */ void inorder(TREE_NODE *root); /* Inorder Traversing */ TREE_NODE *temp; int main() { TREE_NODE *root; /* Pointer to the root of the BST */ int values[] = {10, 5, 3, 4, 1, 9, 6, 7, 8, 2}; /* Values for BST */ int size = 10, tree_weight; root = create_tree(values, 10); printf("\n"); inorder(root); /* Inorder BST*/ system("PAUSE"); } TREE_NODE *search_pos_to_insert(TREE_NODE *root, int value, int *left_or_right) { if(root !=NULL) { temp = root; if(value >root->value) { *left_or_right=1; *search_pos_to_insert(root->right, value, left_or_right); } else { *left_or_right=0; *search_pos_to_insert(root->left, value, left_or_right); } } else return temp;/* THIS IS THE PROBLEM (1) */ } TREE_NODE *create_tree(int list[], int size) { TREE_NODE *new_node_pntr, *insert_point, *root = NULL; int i, left_or_right; /* First Value of the Array is the root of the BST */ new_node_pntr = (TREE_NODE *) malloc(sizeof(TREE_NODE)); new_node_pntr->value = list[0]; /* ¸íèåóå ôçí ðñþôç ôéìÞ ôïõ ðßíáêá. */ new_node_pntr->weight = 0; new_node_pntr->left = NULL; new_node_pntr->right = NULL; root = new_node_pntr; /* Now the rest of the arrat. */ for (i = 1; i < size; i++) { insert_point = search_pos_to_insert(root, list[i], &left_or_right); /* THIS IS THE PROBLEM (2) */ /* insert_point just won't get the return from temp */ new_node_pntr = (TREE_NODE *) malloc(sizeof(TREE_NODE)); new_node_pntr->value = list[i]; new_node_pntr->weight = 0; new_node_pntr->left = NULL; new_node_pntr->right = NULL; if (left_or_right == 0) insert_point->left = new_node_pntr; else insert_point->right = new_node_pntr; } return(root); } void inorder(TREE_NODE *root) { if (root == NULL) return; inorder(root->left); printf("Value: %d, Weight: %d.\n", root->value, root->weight); inorder(root->right); }

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  • Basic C question, concerning memory allocation and value assignment

    - by VHristov
    Hi there, I have recently started working on my master thesis in C that I haven't used in quite a long time. Being used to Java, I'm now facing all kinds of problems all the time. I hope someone can help me with the following one, since I've been struggling with it for the past two days. So I have a really basic model of a database: tables, tuples, attributes and I'm trying to load some data into this structure. Following are the definitions: typedef struct attribute { int type; char * name; void * value; } attribute; typedef struct tuple { int tuple_id; int attribute_count; attribute * attributes; } tuple; typedef struct table { char * name; int row_count; tuple * tuples; } table; Data is coming from a file with inserts (generated for the Wisconsin benchmark), which I'm parsing. I have only integer or string values. A sample row would look like: insert into table values (9205, 541, 1, 1, 5, 5, 5, 5, 0, 1, 9205, 10, 11, 'HHHHHHH', 'HHHHHHH', 'HHHHHHH'); I've "managed" to load and parse the data and also to assign it. However, the assignment bit is buggy, since all values point to the same memory location, i.e. all rows look identical after I've loaded the data. Here is what I do: char value[10]; // assuming no value is longer than 10 chars int i, j, k; table * data = (table*) malloc(sizeof(data)); data->name = "table"; data->row_count = number_of_lines; data->tuples = (tuple*) malloc(number_of_lines*sizeof(tuple)); tuple* current_tuple; for(i=0; i<number_of_lines; i++) { current_tuple = &data->tuples[i]; current_tuple->tuple_id = i; current_tuple->attribute_count = 16; // static in our system current_tuple->attributes = (attribute*) malloc(16*sizeof(attribute)); for(k = 0; k < 16; k++) { current_tuple->attributes[k].name = attribute_names[k]; // for int values: current_tuple->attributes[k].type = DB_ATT_TYPE_INT; // write data into value-field int v = atoi(value); current_tuple->attributes[k].value = &v; // for string values: current_tuple->attributes[k].type = DB_ATT_TYPE_STRING; current_tuple->attributes[k].value = value; } // ... } While I am perfectly aware, why this is not working, I can't figure out how to get it working. I've tried following things, none of which worked: memcpy(current_tuple->attributes[k].value, &v, sizeof(int)); This results in a bad access error. Same for the following code (since I'm not quite sure which one would be the correct usage): memcpy(current_tuple->attributes[k].value, &v, 1); Not even sure if memcpy is what I need here... Also I've tried allocating memory, by doing something like: current_tuple->attributes[k].value = (int *) malloc(sizeof(int)); only to get "malloc: * error for object 0x100108e98: incorrect checksum for freed object - object was probably modified after being freed." As far as I understand this error, memory has already been allocated for this object, but I don't see where this happened. Doesn't the malloc(sizeof(attribute)) only allocate the memory needed to store an integer and two pointers (i.e. not the memory those pointers point to)? Any help would be greatly appreciated! Regards, Vassil

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  • C++ Unions bit fields task

    - by learningtolive
    Can somebody clear me out why would I use union and with what purpose the same address for the cin'ed variable and bit field (task from the Schildts C++ book)? In other words why would I use union for : char ch; struct byte bit; // Display the ASCII code in binary for characters. #include <iostream> #include <conio.h> using namespace std; // a bit field that will be decoded struct byte { unsigned a : 1; unsigned b : 1; unsigned c : 1; unsigned d : 1; unsigned e : 1; unsigned f : 1; unsigned g : 1; unsigned h : 1; }; union bits { char ch; struct byte bit; } ascii ; void disp_bits(bits b); int main() { do { cin >> ascii.ch; cout << ": "; disp_bits(ascii); } while(ascii.ch!='q'); // quit if q typed return 0; } // Display the bit pattern for each character. void disp_bits(bits b) { if(b.bit.h) cout << "1 "; else cout << "0 "; if(b.bit.g) cout << "1 "; else cout << "0 "; if(b.bit.f) cout << "1 "; else cout << "0 "; if(b.bit.e) cout << "1 "; else cout << "0 "; if(b.bit.d) cout << "1 "; else cout << "0 "; if(b.bit.c) cout << "1 "; else cout << "0 "; if(b.bit.b) cout << "1 "; else cout << "0 "; if(b.bit.a) cout << "1 "; else cout << "0 "; cout << "\n"; }

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  • Referencing variables in a structure / C++

    - by user1628622
    Below, I provided a minimal example of code I created. I managed to get this code working, but I'm not sure if the practice being employed is sound. In essence, what I am trying to do is have the 'Parameter' class reference select elements in the 'States' class, so variables in States can be changed via Parameters. Questions I have: is the approach taken OK? If not, is there a better way to achieve what I am aiming for? Example code: struct VAR_TYPE{ public: bool is_fixed; // If is_fixed = true, then variable is a parameter double value; // Numerical value std::string name; // Description of variable (to identify it by name) }; struct NODE{ public: VAR_TYPE X, Y, Z; /* VAR_TYPE is a structure of primitive types */ }; class States{ private: std::vector <NODE_ptr> node; // shared ptr to struct NODE std::vector <PROP_DICTIONARY_ptr> property; // CAN NOT be part of Parameter std::vector <ELEMENT_ptr> element; // CAN NOT be part of Parameter public: /* ect */ void set_X_reference ( Parameter &T , int i ) { T.push_var( &node[i]->X ); } void set_Y_reference ( Parameter &T , int i ) { T.push_var( &node[i]->Y ); } void set_Z_reference ( Parameter &T , int i ) { T.push_var( &node[i]->Z ); } bool get_node_bool_X( int i ) { return node[i]->X.is_fixed; } // repeat for Y and Z }; class Parameter{ private: std::vector <VAR_TYPE*> var; public: /* ect */ }; int main(){ States S; Parameter P; /* Here I initialize and set S, and do other stuff */ // Now I assign components in States to Parameters for(int n=0 ; n<S.size_of_nodes() ; n++ ){ if ( S.get_node_bool_X(n)==true ){ S.set_X_reference ( P , n ); }; // repeat if statement for Y and Z }; /* Now P points selected to data in S, and I can * modify the contents of S through P */ return 0; }; Update The reason this issue cropped up is I am working with Fortran legacy code. To sum up this Fotran code - it's a numerical simulation of a flight vehicle. This code has a fairly rigid procedural framework one must work within, which comes with a pre-defined list of allowable Fortran types. The Fortran glue code can create an instance of a C++ object (in actuality, a reference from the perspective of Fortran), but is not aware what is contained in it (other means are used to extract C++ data into Fortran). The problem that I encountered is when a C++ module is dynamically linked to the Fortran glue code, C++ objects have to be initialized each instance the C++ code is called. This happens by virtue of how the Fortran template is defined. To avoid this cycle of re-initializing objects, I plan to use 'State' as a container class. The Fortran code allows a 'State' object, which has an arbitrary definition; but I plan to use it to harness all relevant information about the model. The idea is to use the Parameters class (which is exposed and updated by the Fortran code) to update variables in States.

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  • SharpDX: best practice for multiple RenderForms?

    - by Rob Jellinghaus
    I have an XNA app, but I really need to add multiple render windows, which XNA doesn't do. I'm looking at SharpDX (both for multi-window support and for DX11 / Metro / many other reasons). I decided to hack up the SharpDX DX11 MultiCubeTexture sample to see if I could make it work. My changes are pretty trivial. The original sample had: [STAThread] private static void Main() { var form = new RenderForm("SharpDX - MiniCubeTexture Direct3D11 Sample"); ... I changed this to: struct RenderFormWithActions { internal readonly RenderForm Form; // should just be Action but it's not in System namespace?! internal readonly Action RenderAction; internal readonly Action DisposeAction; internal RenderFormWithActions(RenderForm form, Action renderAction, Action disposeAction) { Form = form; RenderAction = renderAction; DisposeAction = disposeAction; } } [STAThread] private static void Main() { // hackity hack new Thread(new ThreadStart(() = { RenderFormWithActions form1 = CreateRenderForm(); RenderLoop.Run(form1.Form, () = form1.RenderAction(0)); form1.DisposeAction(0); })).Start(); new Thread(new ThreadStart(() = { RenderFormWithActions form2 = CreateRenderForm(); RenderLoop.Run(form2.Form, () = form2.RenderAction(0)); form2.DisposeAction(0); })).Start(); } private static RenderFormWithActions CreateRenderForm() { var form = new RenderForm("SharpDX - MiniCubeTexture Direct3D11 Sample"); ... Basically, I split out all the Main() code into a separate method which creates a RenderForm and two delegates (a render delegate, and a dispose delegate), and bundles them all together into a struct. I call this method twice, each time from a separate, new thread. Then I just have one RenderLoop on each new thread. I was thinking this wouldn't work because of the [STAThread] declaration -- I thought I would need to create the RenderForm on the main (STA) thread, and run only a single RenderLoop on that thread. Fortunately, it seems I was wrong. This works quite well -- if you drag one of the forms around, it stops rendering while being dragged, but starts again when you drop it; and the other form keeps chugging away. My questions are pretty basic: Is this a reasonable approach, or is there some lurking threading issue that might make trouble? My code simply duplicates all the setup code -- it makes a duplicate SwapChain, Device, Texture2D, vertex buffer, everything. I don't have a problem with this level of duplication -- my app is not intensive enough to suffer resource issues -- but nonetheless, is there a better practice? Is there any good reference for which DirectX structures can safely be shared, and which can't? It appears that RenderLoop.Run calls the render delegate in a tight loop. Is there any standard way to limit the frame rate of RenderLoop.Run, if you don't want a 400FPS app eating 100% of your CPU? Should I just Thread.Sleep(30) in the render delegate? (I asked on the sharpdx.org forums as well, but Alexandre is on vacation for two weeks, and my sister wants me to do a performance with my app at her wedding in three and a half weeks, so I'm mighty incented here! http://robjsoftware.org for details of what I'm building....)

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  • glsl shader to allow color change of skydome ogre3d

    - by Tim
    I'm still very new to all this but learning a lot. I'm putting together an application using Ogre3d as the rendering engine. So far I've got it running, with a simple scene, a day/night cycle system which is working okay. I'm now moving on to looking at changing the color of the skydome material based on the time of day. What I've done so far is to create a struct to hold the ColourValues for the different aspects of the scene. struct todColors { Ogre::ColourValue sky; Ogre::ColourValue ambient; Ogre::ColourValue sun; }; I created an array to store all the colours todColors sceneColours [4]; I populated the array with the colours I want to use for the various times of the day. For instance DayTime (when the sun is high in the sky) sceneColours[2].sky = Ogre::ColourValue(135/255, 206/255, 235/255, 255); sceneColours[2].ambient = Ogre::ColourValue(135/255, 206/255, 235/255, 255); sceneColours[2].sun = Ogre::ColourValue(135/255, 206/255, 235/255, 255); I've got code to work out the time of the day using a float currentHours to store the current hour of the day 10.5 = 10:30 am. This updates constantly and updates the sun as required. I am then calculating the appropriate colours for the time of day when relevant using else if( currentHour >= 4 && currentHour < 7) { // Lerp from night to morning Ogre::ColourValue lerp = Ogre::Math::lerp<Ogre::ColourValue, float>(sceneColours[GT_TOD_NIGHT].sky , sceneColours[GT_TOD_MORNING].sky, (currentHour - 4) / (7 - 4)); } My original attempt to get this to work was to dynamically generate a material with the new colour and apply that material to the skydome. This, as you can probably guess... didn't go well. I know it's possible to use shaders where you can pass information such as colour to the shader from the code but I am unsure if there is an existing simple shader to change a colour like this or if I need to create one. What is involved in creating a shader and material definition that would allow me to change the colour of a material without the overheads of dynamically generating materials all the time? EDIT : I've created a glsl vertex and fragment shaders as follows. Vertex uniform vec4 newColor; void main() { gl_FrontColor = newColor; gl_Position = ftransform(); } Fragment void main() { gl_FragColor = gl_Color; } I can pass a colour to it using ShaderDesigner and it seems to work. I now need to investigate how to use it within Ogre as a material. EDIT : I created a material file like this : vertex_program colour_vs_test glsl { source test.vert default_params { param_named newColor float4 0.0 0.0 0.0 1 } } fragment_program colour_fs_glsl glsl { source test.frag } material Test/SkyColor { technique { pass { lighting off fragment_program_ref colour_fs_glsl { } vertex_program_ref colour_vs_test { } } } } In the code I have tried : Ogre::MaterialPtr material = Ogre::MaterialManager::getSingleton().getByName("Test/SkyColor"); Ogre::GpuProgramParametersSharedPtr params = material->getTechnique(0)->getPass(0)->getVertexProgramParameters(); params->setNamedConstant("newcolor", Ogre::Vector4(0.7, 0.5, 0.3, 1)); I've set that as the Skydome material which seems to work initially. I am doing the same with the code that is attempting to lerp between colours, but when I include it there, it all goes black. Seems like there is now a problem with my colour lerping.

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  • XNA 4.0 - Normal mapping shader - strange texture artifacts

    - by Taylor
    I recently started using custom shader. Shader can do diffuse and specular lighting and normal mapping. But normal mapping is causing really ugly artifacts (some sort of pixeling noise) for textures in greater distance. It looks like this: Image link This is HLSL code: // Matrix float4x4 World : World; float4x4 View : View; float4x4 Projection : Projection; //Textury texture2D ColorMap; sampler2D ColorMapSampler = sampler_state { Texture = <ColorMap>; MinFilter = Anisotropic; MagFilter = Linear; MipFilter = Linear; MaxAnisotropy = 16; }; texture2D NormalMap; sampler2D NormalMapSampler = sampler_state { Texture = <NormalMap>; MinFilter = Anisotropic; MagFilter = Linear; MipFilter = Linear; MaxAnisotropy = 16; }; // Light float4 AmbientColor : Color; float AmbientIntensity; float3 DiffuseDirection : LightPosition; float4 DiffuseColor : Color; float DiffuseIntensity; float4 SpecularColor : Color; float3 CameraPosition : CameraPosition; float Shininess; // The input for the VertexShader struct VertexShaderInput { float4 Position : POSITION0; float2 TexCoord : TEXCOORD0; float3 Normal : NORMAL0; float3 Binormal : BINORMAL0; float3 Tangent : TANGENT0; }; // The output from the vertex shader, used for later processing struct VertexShaderOutput { float4 Position : POSITION0; float2 TexCoord : TEXCOORD0; float3 View : TEXCOORD1; float3x3 WorldToTangentSpace : TEXCOORD2; }; // The VertexShader. VertexShaderOutput VertexShaderFunction(VertexShaderInput input, float3 Normal : NORMAL) { VertexShaderOutput output; float4 worldPosition = mul(input.Position, World); float4 viewPosition = mul(worldPosition, View); output.Position = mul(viewPosition, Projection); output.TexCoord = input.TexCoord; output.WorldToTangentSpace[0] = mul(normalize(input.Tangent), World); output.WorldToTangentSpace[1] = mul(normalize(input.Binormal), World); output.WorldToTangentSpace[2] = mul(normalize(input.Normal), World); output.View = normalize(float4(CameraPosition,1.0) - worldPosition); return output; } // The Pixel Shader float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0 { float4 color = tex2D(ColorMapSampler, input.TexCoord); float3 normalMap = 2.0 *(tex2D(NormalMapSampler, input.TexCoord)) - 1.0; normalMap = normalize(mul(normalMap, input.WorldToTangentSpace)); float4 normal = float4(normalMap,1.0); float4 diffuse = saturate(dot(-DiffuseDirection,normal)); float4 reflect = normalize(2*diffuse*normal-float4(DiffuseDirection,1.0)); float4 specular = pow(saturate(dot(reflect,input.View)), Shininess); return color * AmbientColor * AmbientIntensity + color * DiffuseIntensity * DiffuseColor * diffuse + color * SpecularColor * specular; } // Techniques technique Lighting { pass Pass1 { VertexShader = compile vs_2_0 VertexShaderFunction(); PixelShader = compile ps_2_0 PixelShaderFunction(); } } Any advice? Thanks!

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  • Error X3650 when compiling shader in XNA

    - by Saikai
    I'm attempting to convert the XBDEV.NET Mosaic Shader for use in my XNA project and having trouble. The compiler errors out because of the half globals. At first I tried replacing the globals and just writing the variables explicitly in the code, but that garbles the Output. Next I tried replacing all the half with float vars, but that still garbles the resulting Image. I call the effect file from SpriteBatch.Begin(). Is there a way to convert this shader to the new pixel shader conventions? Are there any good tutorials for this topic? Here is the shader file for reference: /*****************************************************************************/ /* File: tiles.fx Details: Modified version of the NVIDIA Composer FX Demo Program 2004 Produces a tiled mosaic effect on the output. Requires: Vertex Shader 1.1 Pixel Shader 2.0 Modified by: [email protected] (www.xbdev.net) */ /*****************************************************************************/ float4 ClearColor : DIFFUSE = { 0.0f, 0.0f, 0.0f, 1.0f}; float ClearDepth = 1.0f; /******************************** TWEAKABLES *********************************/ half NumTiles = 40.0; half Threshhold = 0.15; half3 EdgeColor = {0.7f, 0.7f, 0.7f}; /*****************************************************************************/ texture SceneMap : RENDERCOLORTARGET < float2 ViewportRatio = { 1.0f, 1.0f }; int MIPLEVELS = 1; string format = "X8R8G8B8"; string UIWidget = "None"; >; sampler SceneSampler = sampler_state { texture = <SceneMap>; AddressU = CLAMP; AddressV = CLAMP; MIPFILTER = NONE; MINFILTER = LINEAR; MAGFILTER = LINEAR; }; /***************************** DATA STRUCTS **********************************/ struct vertexInput { half3 Position : POSITION; half3 TexCoord : TEXCOORD0; }; /* data passed from vertex shader to pixel shader */ struct vertexOutput { half4 HPosition : POSITION; half2 UV : TEXCOORD0; }; /******************************* Vertex shader *******************************/ vertexOutput VS_Quad( vertexInput IN) { vertexOutput OUT = (vertexOutput)0; OUT.HPosition = half4(IN.Position, 1); OUT.UV = IN.TexCoord.xy; return OUT; } /********************************** pixel shader *****************************/ half4 tilesPS(vertexOutput IN) : COLOR { half size = 1.0/NumTiles; half2 Pbase = IN.UV - fmod(IN.UV,size.xx); half2 PCenter = Pbase + (size/2.0).xx; half2 st = (IN.UV - Pbase)/size; half4 c1 = (half4)0; half4 c2 = (half4)0; half4 invOff = half4((1-EdgeColor),1); if (st.x > st.y) { c1 = invOff; } half threshholdB = 1.0 - Threshhold; if (st.x > threshholdB) { c2 = c1; } if (st.y > threshholdB) { c2 = c1; } half4 cBottom = c2; c1 = (half4)0; c2 = (half4)0; if (st.x > st.y) { c1 = invOff; } if (st.x < Threshhold) { c2 = c1; } if (st.y < Threshhold) { c2 = c1; } half4 cTop = c2; half4 tileColor = tex2D(SceneSampler,PCenter); half4 result = tileColor + cTop - cBottom; return result; } /*****************************************************************************/ technique tiles { pass p0 { VertexShader = compile vs_1_1 VS_Quad(); ZEnable = false; ZWriteEnable = false; CullMode = None; PixelShader = compile ps_2_0 tilesPS(); } }

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  • Projective texture and deferred lighting

    - by Vodácek
    In my previous question, I asked whether it is possible to do projective texturing with deferred lighting. Now (more than half a year later) I have a problem with my implementation of the same thing. I am trying to apply this technique in light pass. (my projector doesn't affect albedo). I have this projector View a Projection matrix: Matrix projection = Matrix.CreateOrthographicOffCenter(-halfWidth * Scale, halfWidth * Scale, -halfHeight * Scale, halfHeight * Scale, 1, 100000); Matrix view = Matrix.CreateLookAt(Position, Target, Vector3.Up); Where halfWidth and halfHeight is are half of the texture's width and height, Position is the Projector's position and target is the projector's target. This seems to be ok. I am drawing full screen quad with this shader: float4x4 InvViewProjection; texture2D DepthTexture; texture2D NormalTexture; texture2D ProjectorTexture; float4x4 ProjectorViewProjection; sampler2D depthSampler = sampler_state { texture = <DepthTexture>; minfilter = point; magfilter = point; mipfilter = point; }; sampler2D normalSampler = sampler_state { texture = <NormalTexture>; minfilter = point; magfilter = point; mipfilter = point; }; sampler2D projectorSampler = sampler_state { texture = <ProjectorTexture>; AddressU = Clamp; AddressV = Clamp; }; float viewportWidth; float viewportHeight; // Calculate the 2D screen position of a 3D position float2 postProjToScreen(float4 position) { float2 screenPos = position.xy / position.w; return 0.5f * (float2(screenPos.x, -screenPos.y) + 1); } // Calculate the size of one half of a pixel, to convert // between texels and pixels float2 halfPixel() { return 0.5f / float2(viewportWidth, viewportHeight); } struct VertexShaderInput { float4 Position : POSITION0; }; struct VertexShaderOutput { float4 Position :POSITION0; float4 PositionCopy : TEXCOORD1; }; VertexShaderOutput VertexShaderFunction(VertexShaderInput input) { VertexShaderOutput output; output.Position = input.Position; output.PositionCopy=output.Position; return output; } float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0 { float2 texCoord =postProjToScreen(input.PositionCopy) + halfPixel(); // Extract the depth for this pixel from the depth map float4 depth = tex2D(depthSampler, texCoord); //return float4(depth.r,0,0,1); // Recreate the position with the UV coordinates and depth value float4 position; position.x = texCoord.x * 2 - 1; position.y = (1 - texCoord.y) * 2 - 1; position.z = depth.r; position.w = 1.0f; // Transform position from screen space to world space position = mul(position, InvViewProjection); position.xyz /= position.w; //compute projection float3 projection=tex2D(projectorSampler,postProjToScreen(mul(position,ProjectorViewProjection)) + halfPixel()); return float4(projection,1); } In first part of pixel shader is recovered position from G-buffer (this code I am using in other shaders without any problem) and then is tranformed to projector viewprojection space. Problem is that projection doesn't appear. Here is an image of my situation: The green lines are the rendered projector frustum. Where is my mistake hidden? I am using XNA 4. Thanks for advice and sorry for my English. EDIT: Shader above is working but projection was too small. When I changed the Scale property to a large value (e.g. 100), the projection appears. But when the camera moves toward the projection, the projection expands, as can bee seen on this YouTube video.

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  • std::vector::size with glDrawElements crashes?

    - by NoobScratcher
    ( win32 / OpenGL 3.3 / GLSL 330 ) I decided after a long time of trying to do a graphical user interface using just opengl graphics to go back to a gui toolkit and so in the process have had to port alot of my code to win32. But I have a problem with my glDrawElement function. my program compiles and runs fine until it gets to glDrawElements then crashes.. which is rather annoying right. so I was trying to figure out why and I found out its std::vector::size member not returning the correct amount of faces in the unsigned interger vector eg, "vector<unsigned int>faces; " so when I use cout << faces.size() << endl; I got 68 elements???? instead of 24 as you can see here in this .obj file: # Blender v2.61 (sub 0) OBJ File: '' # www.blender.org v 1.000000 -1.000000 -1.000000 v 1.000000 -1.000000 1.000000 v -1.000000 -1.000000 1.000000 v -1.000000 -1.000000 -1.000000 v 1.000000 1.000000 -0.999999 v 0.999999 1.000000 1.000001 v -1.000000 1.000000 1.000000 v -1.000000 1.000000 -1.000000 s off f 1 2 3 4 f 5 8 7 6 f 1 5 6 2 f 2 6 7 3 <--- 24 Faces not 68? f 3 7 8 4 f 5 1 4 8 I'm using a parser I created to get the faces/vertexes in my .obj file: char modelbuffer [20000]; int MAX_BUFF = 20000; unsigned int face[3]; FILE * pfile; pfile = fopen(szFileName, "rw"); while(fgets(modelbuffer, MAX_BUFF, pfile) != NULL) { if('v') { Point p; sscanf(modelbuffer, "v %f %f %f", &p.x, &p.y, &p.z); points.push_back(p); cout << " p.x = " << p.x << " p.y = " << p.y << " p.z = " << p.x << endl; } if('f') { sscanf(modelbuffer, "f %d %d %d %d", &face[0], &face[1], &face[2], &face[3]); cout << "face[0] = " << face[0] << " face[1] = " << face[1] << " face[2] = " << face[2] << " face[3] = " << face[3] << "\n"; faces.push_back(face[0] - 1); faces.push_back(face[1] - 1); faces.push_back(face[2] - 1); faces.push_back(face[3] - 1); cout << face[0] - 1 << face[1] - 1 << face[2] - 1 << face[3] - 1 << endl; } } using this struct to store the x,y,z positions also this vector was used with Point: vector<Point>points; struct Point { float x, y, z; }; If someone could tell me why its not working and how to fix it that would be awesome I also provide a pastebin to the full source code if you want a closer look. http://pastebin.com/gznYLVw7

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  • Mimicking the UltraGridColumnChooser's drag & drop ability

    - by Sören Kuklau
    (Infragistics 2008 Vol. 3, CLR 2.0) Infragistics's UltraGrid comes with a column chooser user control, which is simply a vertical arrangement of columns with checkboxes that toggle a column's hidden state. In addition, it allows you to pick a column and drag it directly to the grid so you don't have to manually position it afterwards. (This is particularly handy when you already have a lot of visible columns and have no clue where the new one ended up.) I'm building my own column chooser based on an UltraTree. Getting the checkboxes to behave the same wasn't an issue, but I haven't found a way to drag a column from the tree to the grid and have it accept it. In my tree, each UltraTreeNode has a Tag with the following struct: Private Structure DraggableGridColumn Public NodeKey As String Public NodeName As String Public ParentKey As String Public Column As UltraGridColumn End Structure I then have an event as follows: Private Sub columnsTree_SelectionDragStart(ByVal sender As Object, ByVal e As System.EventArgs) Handles columnsTree.SelectionDragStart If columnsTree.SelectedNodes.Count <> 1 Then Return End If If Not TypeOf columnsTree.SelectedNodes(0).Tag Is DraggableGridColumn Then Return End If Dim column As UltraGridColumn = CType(columnsTree.SelectedNodes(0).Tag, DraggableGridColumn).Column columnsTree.DoDragDrop(column, DragDropEffects.All) End Sub In the DoDragDrop call, neither column (of type UltraGridColumn) nor column.Header (of type ColumnHeader) get accepted by the grid. I assume I'm sending the wrong type, and/or that the grid expects a special struct with some additional information. Unfortunately, I've also failed to catch an event (both on the column chooser side as well as on the grid side) where Infragistics's normal column chooser does this properly; the normal drag & drop events never seem to fire.

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  • Partial template specialization of free functions - best practices

    - by Poita_
    As most C++ programmers should know, partial template specialization of free functions is disallowed. For example, the following is illegal C++: template <class T, int N> T mul(const T& x) { return x * N; } template <class T> T mul<T, 0>(const T& x) { return T(0); } // error: function template partial specialization ‘mul<T, 0>’ is not allowed However, partial template specialization of classes/structs is allowed, and can be exploited to mimic the functionality of partial template specialization of free functions. For example, the target objective in the last example can be achieved by using: template <class T, int N> struct mul_impl { static T fun(const T& x) { return x * N; } }; template <class T> struct mul_impl<T, 0> { static T fun(const T& x) { return T(0); } }; template <class T, int N> T mul(const T& x) { return mul_impl<T, N>::fun(x); } It's more bulky and less concise, but it gets the job done -- and as far as users of mul are concerned, they get the desired partial specialization. My questions is: when writing templated free functions (that are intended to be used by others), should you automatically delegate the implementation to a static method function of a class, so that users of your library may implement partial specializations at will, or do you just write the templated function the normal way, and live with the fact that people won't be able to specialize them?

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  • Compressing IplImage to JPEG using libjpeg in OpenCV

    - by Petar
    Hi everybody. So I have this problem. I have an IplImage that i want to compress to JPEG and do something with it. I use libjpeg. I found a lot of answers "read through examples and docs" and such and did that. And successfully written a function for that. FILE* convert2jpeg(IplImage* frame) { FILE* outstream = NULL; outstream=malloc(frame-imageSize*frame-nChannels*sizeof(char)) unsigned char *outdata = (uchar *) frame->imageData; struct jpeg_error_mgr jerr; struct jpeg_compress_struct cinfo; int row_stride; JSAMPROW row_ptr[1]; jpeg_create_compress(&cinfo); jpeg_stdio_dest(&cinfo, outstream); cinfo.image_width = frame->width; cinfo.image_height = frame->height; cinfo.input_components = frame->nChannels; cinfo.in_color_space = JCS_RGB; jpeg_set_defaults(&cinfo); jpeg_start_compress(&cinfo, TRUE); row_stride = frame->width * frame->nChannels; while (cinfo.next_scanline < cinfo.image_height) { row_ptr[0] = &outdata[cinfo.next_scanline * row_stride]; jpeg_write_scanlines(&cinfo, row_ptr, 1); } jpeg_finish_compress(&cinfo); jpeg_destroy_compress(&cinfo); return outstream; } Now this function is straight from the examples (except the part of allocating memory, but i need that since i'm not writnig to a file), but it still doesn't work. It dies on jpeg_start_compress(&cinfo, TRUE); part? Can anybody help?

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  • How to get skin tone color pixel in iPhone?

    - by aman-gupta
    Hi In my application I m using following way to get red pixel in a image // // PixelsAccessAppDelegate.h // PixelsAccess // // Created by Fortune1 on 14/04/10. // Copyright MyCompanyName 2010. All rights reserved. // import @class clsPixelAccess; NSUInteger numberOfRedPixels; NSUInteger numberOfRedPixels1; NSUInteger numberOfRedPixels2; NSUInteger numberOfRedPixels3; NSUInteger numberOfRedPixels4; NSUInteger numberOfRedPixels5; NSUInteger numberOfRedPixels6; NSUInteger numberOfRedPixels7; NSUInteger numberOfRedPixels8; NSUInteger numberOfRedPixels9; NSUInteger numberOfRedPixels10; NSUInteger numberOfRedPixels11; NSUInteger numberOfRedPixels12; NSUInteger numberOfRedPixels13; NSUInteger numberOfRedPixels14; NSUInteger numberOfRedPixels15; NSUInteger numberOfRedPixels16; NSUInteger numberOfRedPixels17; NSUInteger numberOfRedPixels18; NSUInteger numberOfRedPixels19; NSUInteger numberOfRedPixels20; NSUInteger numberOfRedPixels21; NSUInteger numberOfRedPixels22; NSUInteger numberOfRedPixels23; NSUInteger numberOfRedPixels24; NSUInteger numberOfRedPixels25; NSUInteger numberOfRedPixels26; NSUInteger numberOfRedPixels27; NSUInteger numberOfRedPixels28; NSUInteger numberOfRedPixels29; NSUInteger numberOfRedPixels30; NSUInteger numberOfRedPixels31; @interface PixelsAccessAppDelegate : NSObject { UIWindow *window; clsPixelAccess *obj; } @property (nonatomic, retain) IBOutlet UIWindow *window; -(IBAction)processImage:(id)sender; @end //////////////////// // // PixelsAccessAppDelegate.m // PixelsAccess // // Created by Fortune1 on 14/04/10. // Copyright MyCompanyName 2010. All rights reserved. // import "PixelsAccessAppDelegate.h" import "clsPixelAccess.h" @implementation PixelsAccessAppDelegate @synthesize window; (IBAction)processImage:(id)sender { NSUInteger retVal; obj = [[clsPixelAccess alloc] init]; NSInteger imageSend =[obj processImage1:[UIImage imageNamed:@"s.jpg"]]; NSInteger iamgeCall =[obj getPixelData:retVal]; NSUInteger *numberOfRedPixels = retVal; //lblPixelCount.text = [NSString stringWithFormat: @"There are %d red pixels in the image", numberOfRedPixels]; } (void)applicationDidFinishLaunching:(UIApplication *)application { // Override point for customization after application launch [window makeKeyAndVisible]; } (void)dealloc { [window release]; [super dealloc]; } @end /////////////// // // clsPixelsAccess.h // PixelsAccess // // Created by Fortune1 on 14/04/10. // Copyright 2010 MyCompanyName. All rights reserved. // import @interface clsPixelAccess : NSObject { } -(NSInteger) processImage1: (UIImage*) image; -(NSInteger)getPixelData:(NSUInteger *)pixelCount; @end ///////// // // clsPixelsAccess.m // PixelsAccess // // Created by Fortune1 on 14/04/10. // Copyright 2010 MyCompanyName. All rights reserved. // import "clsPixelAccess.h" import "PixelsAccessAppDelegate.h" @implementation clsPixelAccess struct pixel { //unsigned char r, g, b,a; Byte r, g, b, a; int count; }; -(NSInteger)getPixelData:(NSUInteger *)pixelCount { *pixelCount =numberOfRedPixels; return 1; } // Process the image and return the number of pure red pixels in it. (NSInteger) processImage1: (UIImage*) image { // Allocate a buffer big enough to hold all the pixels struct pixel* pixels = (struct pixel*) calloc(1, image.size.width * image.size.height * sizeof(struct pixel)); if (pixels != nil) { // Create a new bitmap CGContextRef context = CGBitmapContextCreate( (void*) pixels, image.size.width, image.size.height, 8, image.size.width * 4, CGImageGetColorSpace(image.CGImage), kCGImageAlphaPremultipliedLast ); //NSLog(@"1=%d, 2=%d, 3=%d", CGImageGetBitsPerComponent(image), CGImageGetBitsPerPixel(image),CGImageGetBytesPerRow(image)); if (context != NULL) { // Draw the image in the bitmap CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, image.size.width, image.size.height), image.CGImage); NSUInteger numberOfPixels = image.size.width * image.size.height; NSMutableArray *numberOfPixelsArray = [[[NSMutableArray alloc] initWithCapacity:numberOfPixelsArray] autorelease]; NSLog( @"Pixel data %d", numberOfPixelsArray); /* NSMatrix *newMatrix = [[NSMatrix alloc] initWithFrame:NSMakeRect(138.0f, 85.0f, 0.0f, 0.0f) mode:NSRadioModeMatrix prototype:prototypeButtonCell numberOfRows: numberOfColumns:]; */ while (numberOfPixels &gt; 0) { if (pixels-&gt;r &gt; 0 &amp;&amp; pixels-&gt;r &lt;= 7) { numberOfRedPixels++; } NSLog( @"Red pixel data %d",numberOfRedPixels); if (pixels-&gt;r &gt;= 8 &amp;&amp; pixels-&gt;r &lt;= 15) { numberOfRedPixels1++; } NSLog( @"Red pixel data1 %d",numberOfRedPixels1); if (pixels-&gt;r &gt;= 16 &amp;&amp; pixels-&gt;r &lt;=23 ) { numberOfRedPixels2++; } NSLog( @"Red pixel data2 %d",numberOfRedPixels2); if (pixels-&gt;r &gt;= 24 &amp;&amp; pixels-&gt;r &lt;=31 ) { numberOfRedPixels3++; } NSLog( @"Red pixel data3 %d",numberOfRedPixels3); if (pixels-&gt;r &gt;= 32 &amp;&amp; pixels-&gt;r &lt;= 39) { numberOfRedPixels4++; } NSLog( @"Red pixel data4 %d",numberOfRedPixels4); if (pixels-&gt;r &gt;= 40 &amp;&amp; pixels-&gt;r &lt;= 47) { numberOfRedPixels5++; } NSLog( @"Red pixel data5 %d",numberOfRedPixels5); if (pixels-&gt;r &gt;= 48 &amp;&amp; pixels-&gt;r &lt;= 55) { numberOfRedPixels6++; } NSLog( @"Red pixel data6 %d",numberOfRedPixels6); if(pixels-&gt;r &gt;= 56 &amp;&amp; pixels-&gt;r &lt;= 63) { numberOfRedPixels7++; } NSLog( @"Red pixel data7 %d",numberOfRedPixels7); if (pixels-&gt;r &gt;= 64 &amp;&amp; pixels-&gt;r &lt;= 71) { numberOfRedPixels8++; } NSLog( @"Red pixel data8 %d",numberOfRedPixels8); if (pixels-&gt;r &gt;= 72 &amp;&amp; pixels-&gt;r &lt;= 79) { numberOfRedPixels9++; } NSLog( @"Red pixel data9 %d",numberOfRedPixels9); if (pixels-&gt;r &gt;= 80 &amp;&amp; pixels-&gt;r &lt;= 87) { numberOfRedPixels10++; } NSLog( @"Red pixel data10 %d",numberOfRedPixels10); if (pixels-&gt;r &gt;= 88 &amp;&amp; pixels-&gt;r &lt;= 95) { numberOfRedPixels11++; } NSLog( @"Red pixel data11 %d",numberOfRedPixels11); if (pixels-&gt;r &gt;= 96 &amp;&amp; pixels-&gt;r &lt;= 103) { numberOfRedPixels12++; } NSLog( @"Red pixel data12 %d",numberOfRedPixels12); if (pixels-&gt;r &gt;= 104 &amp;&amp; pixels-&gt;r &lt;= 111) { numberOfRedPixels13++; } NSLog( @"Red pixel data13 %d",numberOfRedPixels13); if (pixels-&gt;r &gt;= 112 &amp;&amp; pixels-&gt;r &lt;= 119) { numberOfRedPixels14++; } NSLog( @"Red pixel data14 %d",numberOfRedPixels14); if (pixels-&gt;r &gt;= 120 &amp;&amp; pixels-&gt;r &lt;= 127) { numberOfRedPixels15++; } NSLog( @"Red pixel data15 %d",numberOfRedPixels15); if (pixels-&gt;r &gt; 128 &amp;&amp; pixels-&gt;r &lt;= 135) { numberOfRedPixels16++; } NSLog( @"Red pixel data16 %d",numberOfRedPixels16); if (pixels-&gt;r &gt;= 136 &amp;&amp; pixels-&gt;r &lt;= 143) { numberOfRedPixels17++; } NSLog( @"Red pixel data17 %d",numberOfRedPixels17); if (pixels-&gt;r &gt;= 144 &amp;&amp; pixels-&gt;r &lt;=151) { numberOfRedPixels18++; } NSLog( @"Red pixel data18 %d",numberOfRedPixels18); if (pixels-&gt;r &gt;= 152 &amp;&amp; pixels-&gt;r &lt;=159 ) { numberOfRedPixels19++; } NSLog( @"Red pixel data19 %d",numberOfRedPixels19); if (pixels-&gt;r &gt;= 160 &amp;&amp; pixels-&gt;r &lt;= 167) { numberOfRedPixels20++; } NSLog( @"Red pixel data20 %d",numberOfRedPixels20); if (pixels-&gt;r &gt;= 168 &amp;&amp; pixels-&gt;r &lt;= 175) { numberOfRedPixels21++; } NSLog( @"Red pixel data21 %d",numberOfRedPixels21); if (pixels-&gt;r &gt;= 176 &amp;&amp; pixels-&gt;r &lt;= 199) { numberOfRedPixels22++; } NSLog( @"Red pixel data22 %d",numberOfRedPixels22); if(pixels-&gt;r &gt;= 184 &amp;&amp; pixels-&gt;r &lt;= 191) { numberOfRedPixels23++; } NSLog( @"Red pixel data23 %d",numberOfRedPixels23); if (pixels-&gt;r &gt;= 192 &amp;&amp; pixels-&gt;r &lt;= 199) { numberOfRedPixels24++; } NSLog( @"Red pixel data24 %d",numberOfRedPixels24); if (pixels-&gt;r &gt;= 200 &amp;&amp; pixels-&gt;r &lt;= 207) { numberOfRedPixels25++; } NSLog( @"Red pixel data25 %d",numberOfRedPixels25); if (pixels-&gt;r &gt;= 208 &amp;&amp; pixels-&gt;r &lt;= 215) { numberOfRedPixels26++; } NSLog( @"Red pixel data26 %d",numberOfRedPixels26); if (pixels-&gt;r &gt;= 216 &amp;&amp; pixels-&gt;r &lt;= 223) { numberOfRedPixels27++; } NSLog( @"Red pixel data27 %d",numberOfRedPixels27); if (pixels-&gt;r &gt;= 224 &amp;&amp; pixels-&gt;r &lt;= 231) { numberOfRedPixels28++; } NSLog( @"Red pixel data28 %d",numberOfRedPixels28); if (pixels-&gt;r &gt;= 232 &amp;&amp; pixels-&gt;r &lt;= 239) { numberOfRedPixels29++; } NSLog( @"Red pixel data29 %d",numberOfRedPixels29); if (pixels-&gt;r &gt;= 240 &amp;&amp; pixels-&gt;r &lt;= 247) { numberOfRedPixels30++; } NSLog( @"Red pixel data30 %d",numberOfRedPixels30); if (pixels-&gt;r &gt;= 248) { numberOfRedPixels31++; } NSLog( @"Red pixel data31 %d",numberOfRedPixels31); pixels++; numberOfPixels--; } CGContextRelease(context); } free(pixels); } return 1; } @end My problem is I want skin Tone Pixel how it could be possible Please help me out. Thanks in Advance

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  • Compile time Meta-programming, with string literals.

    - by Hassan Syed
    I'm writing some code which could really do with some simple compile time metaprogramming. It is common practise to use empty-struct tags as compile time symbols. I need to decorate the tags with some run-time config elements. static variables seem the only way to go (to enable meta-programming), however static variables require global declarations. to side step this Scott Myers suggestion (from the third edition of Effective C++), about sequencing the initialization of static variables by declaring them inside a function instead of as class variables, came to mind. So I came up with the following code, my hypothesis is that it will let me have a compile-time symbols with string literals use-able at runtime. I'm not missing anything I hope. template<class Instance> class TheBestThing { public: void set_name(const char * name_in) { get_name() = std::string(name_in); } void set_fs_location(const char * fs_location_in) { get_fs_location() = std::string(fs_location_in); } std::string & get_fs_location() { static std::string fs_location; return fs_location; } std::string & get_name() { static std::string name; return name; } }; struct tag {}; int main() { TheBestThing<tag> x; x.set_name("xyz"); x.set_fs_location("/etc/lala"); ImportantObject<x> SinceSlicedBread; }

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  • Spikes in Socket Performance

    - by Harun Prasad
    We are facing random spikes in high throughput transaction processing system using sockets for IPC. Below is the setup used for the run: The client opens and closes new connection for every transaction, and there are 4 exchanges between the server and the client. We have disabled the TIME_WAIT, by setting the socket linger (SO_LINGER) option via getsockopt as we thought that the spikes were caused due to the sockets waiting in TIME_WAIT. There is no processing done for the transaction. Only messages are passed. OS used Centos 5.4 The average round trip time is around 3 milli seconds, but some times the round trip time ranges from 100 milli seconds to couple of seconds. Steps used for Execution and Measurement and output Starting the server $ python sockServerLinger.py /dev/null & Starting the client to post 1 million transactions to the server. And logs the time for a transaction in the client.log file. $ python sockClient.py 1000000 client.log Once the execution finishes the following command will show the execution time greater than 100 milliseconds in the format <line_number>:<execution_time>. $ grep -n "0.[1-9]" client.log | less Below is the example code for Server and Client. Server # File: sockServerLinger.py import socket, traceback,time import struct host = '' port = 9999 l_onoff = 1 l_linger = 0 lingeropt = struct.pack('ii', l_onoff, l_linger) s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) s.setsockopt(socket.SOL_SOCKET, socket.SO_LINGER, lingeropt) s.bind((host, port)) s.listen(1) while 1: try: clientsock, clientaddr = s.accept() print "Got connection from", clientsock.getpeername() data = clientsock.recv(1024*1024*10) #print "asdasd",data numsent=clientsock.send(data) data1 = clientsock.recv(1024*1024*10) numsent=clientsock.send(data) ret = 1 while(ret>0): data1 = clientsock.recv(1024*1024*10) ret = len(data) clientsock.close() except KeyboardInterrupt: raise except: print traceback.print_exc() continue Client # File: sockClient.py import socket, traceback,sys import time i = 0 while 1: try: st = time.time() s = socket.socket(socket.AF_INET,socket.SOCK_STREAM) while (s.connect_ex(('127.0.0.1',9999)) != 0): continue numsent=s.send("asd"*1000) response = s.recv(6000) numsent=s.send("asd"*1000) response = s.recv(6000) i+=1 if i == int(sys.argv[1]): break except KeyboardInterrupt: raise except: print "in exec:::::::::::::",traceback.print_exc() continue print time.time() -st

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  • Why is the compiler not selecting my function-template overload in the following example?

    - by Steve Guidi
    Given the following function templates: #include <vector> #include <utility> struct Base { }; struct Derived : Base { }; // #1 template <typename T1, typename T2> void f(const T1& a, const T2& b) { }; // #2 template <typename T1, typename T2> void f(const std::vector<std::pair<T1, T2> >& v, Base* p) { }; Why is it that the following code always invokes overload #1 instead of overload #2? void main() { std::vector<std::pair<int, int> > v; Derived derived; f(100, 200); // clearly calls overload #1 f(v, &derived); // always calls overload #1 } Given that the second parameter of f is a derived type of Base, I was hoping that the compiler would choose overload #2 as it is a better match than the generic type in overload #1. Are there any techniques that I could use to rewrite these functions so that the user can write code as displayed in the main function (i.e., leveraging compiler-deduction of argument types)?

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  • Implicit conversion : const reference vs non-const reference vs non-reference

    - by Nawaz
    Consider this code, struct A {}; struct B { B(const A&) {} }; void f(B) { cout << "f()"<<endl; } void g(A &a) { cout << "g()" <<endl; f(a); //a is implicitly converted into B. } int main() { A a; g(a); } This compiles fine, runs fine. But if I change f(B) to f(B&), it doesn't compile. If I write f(const B&), it again compiles fine, runs fine. Why is the reason and rationale? Summary: void f(B); //okay void f(B&); //error void f(const B&); //okay I would like to hear reasons, rationale and reference(s) from the language specification, for each of these cases. Of course, the function signatures themselves are not incorrect. Rather A implicitly converts into B and const B&, but not into B&, and that causes the compilation error.

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  • How do I check to see if my subview is being touched?

    - by Amy
    I went through this tutorial about how to animate sprites: http://icodeblog.com/2009/07/24/iphone-programming-tutorial-animating-a-game-sprite/ I've been attempting to expand on the tutorial by trying to make Ryu animate only when he is touched. However, the touch is not even being registered and I believe it has something to do with it being a subview. Here is my code: -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ UITouch *touch = [touches anyObject]; if([touch view] == ryuView){ NSLog(@"Touch"); } else { NSLog(@"No touch"); } } -(void) ryuAnims{ NSArray *imageArray = [[NSArray alloc] initWithObjects: [UIImage imageNamed:@"1.png"], [UIImage imageNamed:@"2.png"], [UIImage imageNamed:@"3.png"], [UIImage imageNamed:@"4.png"], [UIImage imageNamed:@"5.png"], [UIImage imageNamed:@"6.png"], [UIImage imageNamed:@"7.png"], [UIImage imageNamed:@"8.png"], [UIImage imageNamed:@"9.png"], [UIImage imageNamed:@"10.png"], [UIImage imageNamed:@"11.png"], [UIImage imageNamed:@"12.png"], nil]; ryuView.animationImages = imageArray; ryuView.animationDuration = 1.1; [ryuView startAnimating]; } -(void)viewDidLoad { [super viewDidLoad]; UIImageView *image = [[UIImageView alloc] initWithFrame: CGRectMake(100, 125, 150, 130)]; ryuView = image; ryuView.image = [UIImage imageNamed:@"1.png"]; ryuView.contentMode = UIViewContentModeBottomLeft; [self.view addSubview:ryuView]; [image release]; } This code compiles fine, however, when touching or clicking on ryu, nothing happens. I've also tried if([touch view] == ryuView.image) but that gives me this error: "Comparison of distinct Objective-C type 'struct UIImage *' and 'struct UIView *' lacks a cast." What am I doing wrong?

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  • Any way for a class to prevent outside code from declaring variables of its type?

    - by supercat
    Is it possible for a class of exposing a type for function returns, without allowing users of that class to create variables of that type? A couple usage scenarios: A Fluent interface on a large class; a statement like "foo=bar.WithX(5).WithY(9).WithZ(19);" would be inefficient if it had to create three new instances of the class, but could be much more efficient if the WithX could create one instance, and the other statements could simply use it. A class may wish to support a statement like "foo[19].x = 9;" even when foo itself isn't an array, and does not hold the data in class instances that can be exposed to the public; one way to do that is to have foo[19] return a struct which holds a reference to 'foo' and the value '19', and has a member property 'x' which could call "foo.SetXValue(19, 9);" Such a struct could have a conversion operator to convert itself to the "apparent" type of foo[19]. In both of these scenarios, storing the value returned by a method or property into a variable and then using it more than once would cause strange behavior. It would be desirable if the designer of the class exposing such methods or properties could ensure that callers wouldn't be able to use them more than once. Is there any practical way to accomplish that?

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  • C# wrapper and Callbacks

    - by fergs
    I'm in the process of writing a C# wrapper for Dallmeier Common API light (Camera & Surviellance systems) and I've never written a wrapper before, but I have used the Canon EDSDK C# wrapper. So I'm using the Canon wrapper as a guide to writing the Dallmeier wrapper. I'm currently having issues with wrapping a callback. In the API manual it has the following: dlm_connect int(unsigned long uLWindowHandle, const char * strIP, const char* strUser1, const char* strPwd1, const char* strUser2, const char* strPwd2, void (*callback)(void *pParameters, void *pResult, void *pInput), void * pInput) Arguments - ulWindowhandle - handle of the window that is passed to the ViewerSDK to display video and messages there - strUser1/2 - names of the users to log in. If only single user login is used strUser2 is - NULL - strPwd1/2 - passwords of both users. If strUser2 is NULL strPwd2 is ignored. Return This function creates a SessionHandle that has to be passed Callback pParameters will be structured: - unsigned long ulFunctionID - unsigned long ulSocketHandle, //handle to socket of the established connection - unsigned long ulWindowHandle, - int SessionHandle, //session handle of the session created - const char * strIP, - const char* strUser1, - const char* strPwd1, - const char* strUser2, - const char * strPWD2 pResult is a pointer to an integer, representing the result of the operation. Zero on success. Negative values are error codes. So from what I've read on the Net and Stack Overflow - C# uses delegates for the purpose of callbacks. So I create a my Callback function : public delegate uint DallmeierCallback(DallPparameters pParameters, IntPtr pResult, IntPtr pInput); I create the connection function [DllImport("davidapidis.dll")] public extern static int dlm_connect(ulong ulWindowHandle, string strIP, string strUser1, string strPwd1, string strUser2, string strPwd2, DallmeierCallback inDallmeierFunc And (I think) the DallPParameters as a struct : [StructLayout(LayoutKind.Sequential)] public struct DallPParameters { public ulong ulfunctionID; public ulong ulsocketHandle; public ulong ulWindowHandle; ... } All of this is in my wrapper class. Am I heading in the right direction or is this completely wrong?

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  • Model Binding, a simple, simple question

    - by Paul Hatcherian
    I have a struct which works much like the System.Nullable type: public struct SpecialProperty<T> { public static implicit operator T(SpecialProperty<T> value) { return value.Value; } public static implicit operator SpecialProperty<T>(T value) { return new TrackChanges<T> { Value = value }; } T internalValue; public T Value { get { return internalValue; } set { internalValue = value; } } public override bool Equals(object other) { return Value.Equals(other); } public override int GetHashCode() { return Value.GetHashCode(); } public override string ToString() { return Value.ToString(); } } I'm trying to use it with ASP.NET MVC binding. Using the default customer model binder the property will always yield null. I can fix this by adding ".Value" to the end of every form input name, but I just want it to bind to the new type directly using some sort of custom model binder, but all the solutions I've tried seemed needlessly complex. I feel like I should be able to extend the default binder and with a few lines of code redirect the property binding to the entire model using implicit conversion. I don't quite get the binding paradigm of the default binder, but it seems really stuck on this distinction between the model and model properties. What is the simplest method to do this? Thanks!

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  • XML RPC c# Call returns array of strings and int

    - by chillconsulting
    I'm doing an XML RPC call in ASP.net with c# and the call returns an Array called userinfo with strings and integers in it and I can't seem to figure out how to parse the data and put it into string and int objects... The only thing that compiles is if I make it an Object in the struct. The int returns fines and is referenced easily. Any help would be appreciated - this is what I got. public Page_Load(object sender, EventArgs e){ IValidateSSO proxy = XmlRpcProxyGen.Create<IValidateSSO>(); UserInfoSSOValue ret2 = proxy.UserInfoSSO(ssoAuth, ssoValue); int i = ret2.isonid; } public struct UserInfoSSOValue { public Object userinfo; public int isonid; } [XmlRpcUrl("host")] public interface IValidateSSO : IXmlRpcProxy { [XmlRpcMethod("sso.session_userinfo")] UserInfoSSOValue UserInfoSSO(string ssoauth, string sid); } Here is what the xml rpc calls returns (I know it's in php... I'm trying to implement in c#): sso.session_userinfo(string $ssoauth, string $sid) string $ssoauth - authentication string (assigned by ONID support) string $sid - sid to get info on Returns: Array ( [userinfo] => Array ( [lastname] => College [expire_time] => 1118688011 [osuuid] => 12345678901 [sid_length] => 3600 [ip] => 10.0.0.1 [sid] => WiT7ppAEUKS3rJ2lNz3Ue64sGPxnnLL0 [username] => collegej [firstname] => Joe [fullname] => College, Joe Student [email] => [email protected] [create_time] => 1118684410 ) [isonid] => 1 ) array userinfo - array containing basic user information

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