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    • By racarate
      Hey everybody!
      I am trying to replicate all these cool on-screen debug visuals I see in all the SIGGRAPH and GDC talks, but I really don't know where to start.  The only resource I know of is almost 16 years old:
      http://number-none.com/product/Interactive Profiling, Part 1/index.html
      Does anybody have a more up-to-date reference?  Do people use minimal UI libraries like Dear ImgGui?  Also, If I am profiling OpenGL ES 3.0 (which doesn't have timer queries) is there really anything I can do to measure performance GPU-wise?  Or should I just chart CPU-side frame time?  I feel like this is something people re-invent for every game there has gotta be a tutorial out there... right?
       
       
    • 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 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:
      https://github.com/fleissna/flyEngine

      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:
      - Dynamic shader generation based on material properties
      - Dynamic sorting of meshes to be renderd based on shader and material
      - Rendering large amounts of static meshes
      - Hierarchical culling (detail + view frustum)
      - Limited support for dynamic (i.e. moving) meshes
      - Normal, Parallax and Relief Mapping implementations
      - Wind animations based on vertex displacement
      - 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.

      Bye,

      Phil
    • 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 ==========  
       
      Renderer.cpp
      #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; }  
      Game.zip
    • By lxjk
      Hi guys,
      There are many ways to do light culling in tile-based shading. I've been playing with this idea for a while, and just want to throw it out there.
      Because tile frustums are general small compared to light radius, I tried using cone test to reduce false positives introduced by commonly used sphere-frustum test.
      On top of that, I use distance to camera rather than depth for near/far test (aka. sliced by spheres).
      This method can be naturally extended to clustered light culling as well.
      The following image shows the general ideas

       
      Performance-wise I get around 15% improvement over sphere-frustum test. You can also see how a single light performs as the following: from left to right (1) standard rendering of a point light; then tiles passed the test of (2) sphere-frustum test; (3) cone test; (4) spherical-sliced cone test
       

       
      I put the details in my blog post (https://lxjk.github.io/2018/03/25/Improve-Tile-based-Light-Culling-with-Spherical-sliced-Cone.html), GLSL source code included!
       
      Eric
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OpenGL Re-loading textures fails

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Exhibits:

Exhibit 1: Exhibit 1
Exhibit 2: Exhibit 2
Exhibit 3:
struct rgl_header {
        unsigned long width;
        unsigned long height;
        unsigned long colorkey;

        //signed long xclip;
        //signed long yclip;
        //unsigned long wclip;
        //unsigned long hclip;
    };




Exhibit 4:
void texture::_save_raw(unsigned char *data) {
    std::ofstream output(m_raw_filename.c_str(), std::ios::binary);
    if (output.bad() || output.fail())
        return;
    #ifdef _DEBUG_
    texture_log << "\n{\n\tsaving raw file with filename: " <<
        m_raw_filename << "\n}\n";
    #endif

    rgl_header header;

    header.width = w();
    header.height = h();
    header.colorkey = m_colorkey;

    //header.xclip = m_clip.x;
    //header.yclip = m_clip.y;
    //header.wclip = m_clip.w;
    //header.hclip = m_clip.h;

    #ifdef _DEBUG_
    texture_log << "\nrgl header (write) {\n\t"
        << "header.w " << header.width << "\n\t"
        << "header.h " << header.height << "\n\t"
        << "header.colorkey " << header.colorkey << "\n}\n";//\t"
        //<< "header.xclip " << header.xclip << "\n\t"
        //<< "header.yclip " << header.yclip << "\n\t"
        //<< "header.wclip " << header.wclip << "\n\t"
        //<< "header.hclip " << header.hclip << "\n}\n";
    #endif

    // valid rgl file
    output.write("RGL", 4);
    // header
    output.write((char*)&header, sizeof(rgl_header));
    // actual data
    output.write((char*)data, header.width * header.height * 4);
}

bool texture::_load_raw(const std::string &filename) {
    #ifdef _DEBUG_
    texture_log << "\n{\n\tloading: " << filename << "\n}\n";
    #endif

    std::ifstream input(filename.c_str(), std::ios::binary);
    if (input.bad() || input.fail() || !input.good()) {
        #ifdef _DEBUG_
        texture_log << "\n{\n\tcannot open raw file: " <<
            filename << "\n}\n";
        #endif
        return false;
    }

    char valid[4];
    // is it a valid rgl file
    input.read(valid, 4);
    if (valid[0] != 'R' || valid[1] != 'G' || valid[2] != 'L') {
        #ifdef _DEBUG_
        texture_log << "\n{\n\tinvalid .rgl file header: " <<
            valid << "\n}\n";
        #endif
        return false;
    }

    // unload previous file
    if (m_loaded || m_id) {
        unload();
    }

    // read the header
    rgl_header header = {0, 0, 0};
    input.read((char*)&header, sizeof(rgl_header));

    #ifdef _DEBUG_
    texture_log << "\nrgl header (read) {\n\t"
        << "header.w " << header.width << "\n\t"
        << "header.h " << header.height << "\n\t"
        << "header.colorkey " << header.colorkey << "\n}\n";//\t"
        //<< "header.xclip " << header.xclip << "\n\t"
        //<< "header.yclip " << header.yclip << "\n\t"
        //<< "header.wclip " << header.wclip << "\n\t"
        //<< "header.hclip " << header.hclip << "\n}\n";
    #endif

    // set up
    m_width = header.width;
    m_height = header.height;
    m_colorkey = header.colorkey;

    //m_clip.x = header.xclip;
    //m_clip.y = header.yclip;
    //m_clip.w = header.wclip;
    //m_clip.h = header.hclip;

    // get the actual data
    const unsigned long SIZE = w() * h() * 4;
    unsigned char *data = new unsigned char[SIZE];
    input.read((char*)data, SIZE);

    // reserve id for texture
    glGenTextures(1, &m_id);

    // bind it so we can get to work!
    this->bind();

    // now it's time for some setting
    // set the data onto the texture
    glTexImage2D(
        GL_TEXTURE_2D,
        0, // mip-map level
        GL_RGBA8, // 4 color components, each taking 8 bits (1 byte)
        m_width,
        m_height,
        0, // border
        GL_RGBA, // type of data
        GL_UNSIGNED_BYTE, // each pixel (or, texel) is an unsigned char
        data
    );

    // set up filtering
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, /*GL_NEAREST*/GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, /*GL_NEAREST*/GL_LINEAR);

    m_loaded = true;
    return true;
}



Problem:

Hello all! I'm having a slight OpenGL-related problem. As you can see in Exhibit 1, loading a texture and displaying it works fine. This means that my loading function(s) work(s) correctly. However, in Exhibit 2 you see the same scene, but with a messed up texture. What I do in my image loading function(s) is check too see if there is a file with the filename passed in, but instead of with .bmp with .rgl. If there is, load the .rgl file, otherwise, load the .bmp file and make a .rgl file. The first time I run my program, all is fine because the bitmap loads and the .rgl file is made. But the second time I run it, the program sees the .rgl file and loads it, giving me Exhibit 2. Exhibit 3 and 4 are how I save the .rgl file. I pass _save_raw() in the exact data that I pass in to OpenGL's glTexImage2D(). Then when I load I pass in the .rgl filename to _load_raw() and it's supposed to load it. However, I get the garbled mess displayed in Exhibit 2. Does anyone have an idea as to why? I'm sure OpenGL is set up correctly, as if I load from the bitmap all is fine... Thank you, and have a nice day!

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Are you sure that the image you're saving has four channels? BMP files only support three. Can we see your BMP loading code?

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Quote:
Original post by Kalidor
Are you sure that the image you're saving has four channels? BMP files only support three. Can we see your BMP loading code?


100% sure.

I load the image into an SDL surface and then create another 32-bit surface which is "fixed" specially for OpenGL. The "fixed" surface has 32 bits in order RGBA.

Anyways, here is the loading code just in case (it relates to SDL, but I'm sure the problem is more on my & OpenGL's side rather than SDL's):

bool texture::load(const std::string &filename) {
if (m_loaded)
unload();

// does an rgl file exist?
m_raw_filename = filename.substr(0, filename.find(".bmp")) + ".rgl";
std::ifstream check(m_raw_filename.c_str(), std::ios::binary);
if (!check.fail() && !check.bad() && check.is_open() && check.good()) {
check.close();
return _load_raw(m_raw_filename);
} else {
check.close();
}

SDL_Surface *raw, *fixed;

raw = SDL_LoadBMP(filename.c_str());
if (!raw) {
#ifdef _DEBUG_
texture_log << "\n{\n\tfailed at loading texture: " << filename
<< "\n\t(.bmp is the only format supported)\n}\n";
#endif
return false;
}

// opengl's y is inverted, so we must flip the data
flipv(raw);

int width = 1, height = 1;
// optimise for square textures: loop only once
while (width < raw->w || height < raw->h) {
if (width < raw->w) width <<= 1;
if (height < raw->h) height <<= 1;
}

m_clip.x = 0;
m_clip.y = 0;
m_clip.w = width;
m_clip.h = height;

m_width = width;
m_height = height;

fixed = SDL_CreateRGBSurface(
SDL_HWSURFACE, // won't be doing any pixel operations
width, height, 32, // w, h, bpp (bpp == 32, using alpha)
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
0xff000000,
0x00ff0000,
0x0000ff00,
0x000000ff
#else
0x000000ff,
0x0000ff00,
0x00ff0000,
0xff000000
#endif
);

if (!fixed) {
#ifdef _DEBUG_
texture_log << "\n{\n\tcould not generate fixed surface for: " << filename
<< "\n}\n";
#endif
return false;
}

// copy the surface onto the other one
SDL_BlitSurface(raw, NULL, fixed, NULL);
// free the old surface
SDL_FreeSurface(raw);

if (SDL_MUSTLOCK(fixed))
while(SDL_LockSurface(fixed));

// rgl
// save the rgl file
_save_raw((unsigned char*)fixed->pixels);

// reserve id for texture
glGenTextures(1, &m_id);

// bind it so we can get to work!
this->bind();

// now it's time for some setting
// set the data onto the texture
glTexImage2D(
GL_TEXTURE_2D,
0, // mip-map level
GL_RGBA8, // 4 color components, each taking 8 bits (1 byte)
width,
height,
0, // border
GL_RGBA, // type of data
GL_UNSIGNED_BYTE, // each pixel (or, texel) is an unsigned char
(unsigned char*)fixed->pixels
);

if (SDL_MUSTLOCK(fixed))
SDL_UnlockSurface(fixed);

// free the new surface
SDL_FreeSurface(fixed);

// set up filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, /*GL_NEAREST*/GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, /*GL_NEAREST*/GL_LINEAR);

m_loaded = true;

return true;
}

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I'll give a quick *bump* before I have to go...

This is sorta stopping me from coding since I want to optimise stuff.... Anyways, thanks in advance.

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0) don't optimise prematurely.
1) you should glDeleteTexture before trying to reload or you'll have a memory leak in the ICD.
2) to me, it looks as if your texture coordinates are messed up, not your loading code.
3) try changing the last GL_RGBA to GL_RGB

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Quote:
Original post by silvermace
0) don't optimise prematurely.

Got it.
Quote:

1) you should glDeleteTexture before trying to reload or you'll have a memory leak in the ICD.

Affirmative -

bool texture::load(const std::string &filename) {
if (m_loaded)
unload();
[...]
}

Quote:

2) to me, it looks as if your texture coordinates are messed up, not your loading code.

I'm 100% sure they are not. Infact, all I do is set the clip rect to 0, 0, width, height - which includes the whole image.
Quote:

3) try changing the last GL_RGBA to GL_RGB

I'll try it, I can't get to the code right now, but I'll reply when I do.

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Quote:
Original post by silvermace
2) to me, it looks as if your texture coordinates are messed up, not your loading code.


Hmm... I looked into this a little more, and guess what? You're right!!! (Rate++ follows after this post.)

I was loading from my constructor, which sets the clip rect to (0, 0, 1, 1). Since my _load_raw() function does NOT do anything with the clip rect, it was just displaying the first pixel of the texture... [lol]. Anyways, saving the rect along with the data (as I did before, but commented out for no true reason) fixed everything.

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