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    • By Achivai
      Hey, I am semi-new to 3d-programming and I've hit a snag. I have one object, let's call it Object A. This object has a long int array of 3d xyz-positions stored in it's vbo as an instanced attribute. I am using these numbers to instance object A a couple of thousand times. So far so good. 
      Now I've hit a point where I want to remove one of these instances of object A while the game is running, but I'm not quite sure how to go about it. At first my thought was to update the instanced attribute of Object A and change the positions to some dummy number that I could catch in the vertex shader and then decide there whether to draw the instance of Object A or not, but I think that would be expensive to do while the game is running, considering that it might have to be done several times every frame in some cases. 
      I'm not sure how to proceed, anyone have any tips?
    • By ThunderTwonk
      Hello everyone, I am working on a game idea and since I am still in the process of learning C# and the features available in unity I was hoping some of you might be able to offer me a little insight on things in general for getting started.
      I guess the basic components of what I'm wanting to create would be a Multi-levels management/city builder/rpg.
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    • By INFRA
      SCAN. DRILL. SURVIVE.   ISOLATED Release in May 1st 2018   https://store.steampowered.com/app/805950/Isolated/   A game by Jérémie Bertrand Music & Sound Design by Pierrick Querolle *** Our solar system has been invaded by strangers. For the purpose of a possible negotiation, a team of astronauts is sent to the moon. Alas, they are shot before even arriving on the scene. Only one astronaut survives the crash and his only goal will be to go home...   GAMEPLAY   Shoot enemy ships to avoid being invaded. Be precise in your movements, because it's better to lose a bit of life at the top than to lose it all at the bottom. Take out your drill to destroy the stones in your path. Validate your identity to cross the different laboratories. Reach the flag before losing your three lives.   And all that... at the same time! Will you be able to go home? If the answer is yes, how long will it take?
    • By fleissi
      Hey guys!

      I'm new here and I recently started developing my own rendering engine. It's open source, based on OpenGL/DirectX and C++.
      The full source code is hosted on github:

      I would appreciate if people with experience in game development / engine desgin could take a look at my source code. I'm looking for honest, constructive criticism on how to improve the engine.
      I'm currently writing my master's thesis in computer science and in the recent year I've gone through all the basics about graphics programming, learned DirectX and OpenGL, read some articles on Nvidia GPU Gems, read books and integrated some of this stuff step by step into the engine.

      I know about the basics, but I feel like there is some missing link that I didn't get yet to merge all those little pieces together.

      Features I have so far:
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      - Rendering large amounts of static meshes
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      - Limited support for dynamic (i.e. moving) meshes
      - Normal, Parallax and Relief Mapping implementations
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      - A very basic integration of the Bullet physics engine
      - Procedural Grass generation
      - Some post processing effects (Depth of Field, Light Volumes, Screen Space Reflections, God Rays)
      - Caching mechanisms for textures, shaders, materials and meshes

      Features I would like to have:
      - Global illumination methods
      - Scalable physics
      - Occlusion culling
      - A nice procedural terrain generator
      - Scripting
      - Level Editing
      - Sound system
      - Optimization techniques

      Books I have so far:
      - Real-Time Rendering Third Edition
      - 3D Game Programming with DirectX 11
      - Vulkan Cookbook (not started yet)

      I hope you guys can take a look at my source code and if you're really motivated, feel free to contribute :-)
      There are some videos on youtube that demonstrate some of the features:
      Procedural grass on the GPU
      Procedural Terrain Engine
      Quadtree detail and view frustum culling

      The long term goal is to turn this into a commercial game engine. I'm aware that this is a very ambitious goal, but I'm sure it's possible if you work hard for it.


    • By tj8146
      I have attached my project in a .zip file if you wish to run it for yourself.
      I am making a simple 2d top-down game and I am trying to run my code to see if my window creation is working and to see if my timer is also working with it. Every time I run it though I get errors. And when I fix those errors, more come, then the same errors keep appearing. I end up just going round in circles.  Is there anyone who could help with this? 
      Errors when I build my code:
      1>Renderer.cpp 1>c:\users\documents\opengl\game\game\renderer.h(15): error C2039: 'string': is not a member of 'std' 1>c:\program files (x86)\windows kits\10\include\10.0.16299.0\ucrt\stddef.h(18): note: see declaration of 'std' 1>c:\users\documents\opengl\game\game\renderer.h(15): error C2061: syntax error: identifier 'string' 1>c:\users\documents\opengl\game\game\renderer.cpp(28): error C2511: 'bool Game::Rendering::initialize(int,int,bool,std::string)': overloaded member function not found in 'Game::Rendering' 1>c:\users\documents\opengl\game\game\renderer.h(9): note: see declaration of 'Game::Rendering' 1>c:\users\documents\opengl\game\game\renderer.cpp(35): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>c:\users\documents\opengl\game\game\renderer.cpp(36): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>c:\users\documents\opengl\game\game\renderer.cpp(43): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>Done building project "Game.vcxproj" -- FAILED. ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========  
      #include <GL/glew.h> #include <GLFW/glfw3.h> #include "Renderer.h" #include "Timer.h" #include <iostream> namespace Game { GLFWwindow* window; /* Initialize the library */ Rendering::Rendering() { mClock = new Clock; } Rendering::~Rendering() { shutdown(); } bool Rendering::initialize(uint width, uint height, bool fullscreen, std::string window_title) { if (!glfwInit()) { return -1; } /* Create a windowed mode window and its OpenGL context */ window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL); if (!window) { glfwTerminate(); return -1; } /* Make the window's context current */ glfwMakeContextCurrent(window); glViewport(0, 0, (GLsizei)width, (GLsizei)height); glOrtho(0, (GLsizei)width, (GLsizei)height, 0, 1, -1); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glfwSwapInterval(1); glEnable(GL_SMOOTH); glEnable(GL_DEPTH_TEST); glEnable(GL_BLEND); glDepthFunc(GL_LEQUAL); glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); glEnable(GL_TEXTURE_2D); glLoadIdentity(); return true; } bool Rendering::render() { /* Loop until the user closes the window */ if (!glfwWindowShouldClose(window)) return false; /* Render here */ mClock->reset(); glfwPollEvents(); if (mClock->step()) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glfwSwapBuffers(window); mClock->update(); } return true; } void Rendering::shutdown() { glfwDestroyWindow(window); glfwTerminate(); } GLFWwindow* Rendering::getCurrentWindow() { return window; } } Renderer.h
      #pragma once namespace Game { class Clock; class Rendering { public: Rendering(); ~Rendering(); bool initialize(uint width, uint height, bool fullscreen, std::string window_title = "Rendering window"); void shutdown(); bool render(); GLFWwindow* getCurrentWindow(); private: GLFWwindow * window; Clock* mClock; }; } Timer.cpp
      #include <GL/glew.h> #include <GLFW/glfw3.h> #include <time.h> #include "Timer.h" namespace Game { Clock::Clock() : mTicksPerSecond(50), mSkipTics(1000 / mTicksPerSecond), mMaxFrameSkip(10), mLoops(0) { mLastTick = tick(); } Clock::~Clock() { } bool Clock::step() { if (tick() > mLastTick && mLoops < mMaxFrameSkip) return true; return false; } void Clock::reset() { mLoops = 0; } void Clock::update() { mLastTick += mSkipTics; mLoops++; } clock_t Clock::tick() { return clock(); } } TImer.h
      #pragma once #include "Common.h" namespace Game { class Clock { public: Clock(); ~Clock(); void update(); bool step(); void reset(); clock_t tick(); private: uint mTicksPerSecond; ufloat mSkipTics; uint mMaxFrameSkip; uint mLoops; uint mLastTick; }; } Common.h
      #pragma once #include <cstdio> #include <cstdlib> #include <ctime> #include <cstring> #include <cmath> #include <iostream> namespace Game { typedef unsigned char uchar; typedef unsigned short ushort; typedef unsigned int uint; typedef unsigned long ulong; typedef float ufloat; }  
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OpenGL Trouble with OpenGL + threads...

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Hi guys, im having a little problem fixing a bug in my program since i multi-threaded it. The app is a little video converter i wrote for fun. To help you understand the problem, ill first explain how the program is made. Im using Delphi to do the GUI/Windows part of the code, then im loading a c++ dll for the video conversion. The problem is not related to the video conversion, but with OpenGL only. The code work like this:


DWORD WINAPI JobThread(void *params)
    for each files {
      _ConvertVideo(input_name, output_name);

void EXP_FUNC _ConvertVideo(char *input_fname, char *output_fname)
	// Note that im re-initializing and cleaning up OpenGL each time this function is called...
	CGLEngine GLEngine; 
	// Initialize OpenGL
	GLEngine.CreateTexture(dst_width, dst_height, 4);
	// decode the video and render the frames...
	for each frames {

		GLEngine.UpdateTexture(pY, pU, pV);

 	// video cleanup code...


With a single thread, everything work fine. The problem arise when im starting the thread for a second time, nothing get rendered, but the encoding work fine. For example, if i start the thread with 3 files to process, all of them render fine, but if i start the thread again (with the same batch of files or not...), OpenGL fail to render anything.

Im pretty sure it has something to do with the rendering context (or maybe the window DC?). Here a snippet of my OpenGL class:

bool CGLEngine::Initialize(HWND hWnd)
	hDC = GetDC(hWnd);

		ReleaseDC(hWnd, hDC);
		return false;

	hRC = wglCreateContext(hDC);
	wglMakeCurrent(hDC, hRC);	                        

	// more code ...

	return true;

void CGLEngine::Shutdown()
	// some code...

	if(hDC){ReleaseDC(hWnd, hDC);}
	hDC = hRC = NULL;


The full source code is available here. The most relevant files are:

-OpenGL class (header / source)

-Main code (header / source)


Thx in advance if anyone can help me.

Edited by Vortez

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I was not deeply into your code, but at first glance I could not see any context sharing.

This is the main piece when doing multithreaded OpenGL programs.

When sharing contexts most of the objects will be shared except containers (you'll have to recreate these containers on both contexts if needed).

For more information see this link and this one.

For creating such shared context, use glXCreateContext or (since you seem to be under Windows) its equivalent one.

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33 minutes ago, _Silence_ said:

I was not deeply into your code, but at first glance I could not see any context sharing.

Not sure what you mean by this, since i don't think i need any sharing.

That's what im trying to explain, im only using a secondary thread to do the conversion and rendering, so the main thread is not blocked, but im not lauching more than one (secondary) thread at once. ie:


Step 1: User add file(s) he want to convert in a listbox

Step 2: Main thread launch secondary thread and do it's thing until it finish (the main thread is not blocked)

    (User interface is disabled until the thread dies)

    (Secondary thread encode all the files in the list, work well the first time for one or multiple files)

Step 3: Just before the thread exit, it post a message to the main thread so the user interface is re-enabled again

Then you can go to step 1 again (that's where opengl don't work anymore), or close the application, whatever.


Hope this clear things a bit.


Edited by Vortez

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1 hour ago, Vortez said:

Not sure what you mean by this, since i don't think i need any sharing.

That's what im trying to explain, im only using a secondary thread to do the conversion and rendering, so the main thread is not blocked, but im not lauching more than one (secondary) thread at once. ie:

OK. This was not clear to me. And things are still not clear enough:

On which thread do you create your OpenGL window (which thread own the context). The thread were the window and the context was created and first made current, must be the same thread that renders. Note that most of the times APIs that allow to create OpenGL windows will create it in the caller thread, which is usually the main thread.

On which thread do you render (from reading you, it seems to be the second thread) ? If so, this second thread must create the window, the context and makes it current.

Do you create any OpenGL objects on the non-rendering thread ?


Hope that could help a bit more :)

Edited by _Silence_

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