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• By elect
Hi,
ok, so, we are having problems with our current mirror reflection implementation.
At the moment we are doing it very simple, so for the i-th frame, we calculate the reflection vectors given the viewPoint and some predefined points on the mirror surface (position and normal).
Then, using the least squared algorithm, we find the point that has the minimum distance from all these reflections vectors. This is going to be our virtual viewPoint (with the right orientation).
After that, we render offscreen to a texture by setting the OpenGL camera on the virtual viewPoint.
And finally we use the rendered texture on the mirror surface.
So far this has always been fine, but now we are having some more strong constraints on accuracy.
What are our best options given that:
- we have a dynamic scene, the mirror and parts of the scene can change continuously from frame to frame
- we have about 3k points (with normals) per mirror, calculated offline using some cad program (such as Catia)
- all the mirror are always perfectly spherical (with different radius vertically and horizontally) and they are always convex
- a scene can have up to 10 mirror
- it should be fast enough also for vr (Htc Vive) on fastest gpus (only desktops)

Looking around, some papers talk about calculating some caustic surface derivation offline, but I don't know if this suits my case
Also, another paper, used some acceleration structures to detect the intersection between the reflection vectors and the scene, and then adjust the corresponding texture coordinate. This looks the most accurate but also very heavy from a computational point of view.

Other than that, I couldn't find anything updated/exhaustive around, can you help me?

• Hello all,
I am currently working on a game engine for use with my game development that I would like to be as flexible as possible.  As such the exact requirements for how things should work can't be nailed down to a specific implementation and I am looking for, at least now, a default good average case scenario design.
Here is what I have implemented:
Deferred rendering using OpenGL Arbitrary number of lights and shadow mapping Each rendered object, as defined by a set of geometry, textures, animation data, and a model matrix is rendered with its own draw call Skeletal animations implemented on the GPU.   Model matrix transformation implemented on the GPU Frustum and octree culling for optimization Here are my questions and concerns:
Doing the skeletal animation on the GPU, currently, requires doing the skinning for each object multiple times per frame: once for the initial geometry rendering and once for the shadow map rendering for each light for which it is not culled.  This seems very inefficient.  Is there a way to do skeletal animation on the GPU only once across these render calls? Without doing the model matrix transformation on the CPU, I fail to see how I can easily batch objects with the same textures and shaders in a single draw call without passing a ton of matrix data to the GPU (an array of model matrices then an index for each vertex into that array for transformation purposes?) If I do the matrix transformations on the CPU, It seems I can't really do the skinning on the GPU as the pre-transformed vertexes will wreck havoc with the calculations, so this seems not viable unless I am missing something Overall it seems like simplest solution is to just do all of the vertex manipulation on the CPU and pass the pre-transformed data to the GPU, using vertex shaders that do basically nothing.  This doesn't seem the most efficient use of the graphics hardware, but could potentially reduce the number of draw calls needed.

Really, I am looking for some advice on how to proceed with this, how something like this is typically handled.  Are the multiple draw calls and skinning calculations not a huge deal?  I would LIKE to save as much of the CPU's time per frame so it can be tasked with other things, as to keep CPU resources open to the implementation of the engine.  However, that becomes a moot point if the GPU becomes a bottleneck.

• Hello!
I would like to introduce Diligent Engine, a project that I've been recently working on. Diligent Engine is a light-weight cross-platform abstraction layer between the application and the platform-specific graphics API. Its main goal is to take advantages of the next-generation APIs such as Direct3D12 and Vulkan, but at the same time provide support for older platforms via Direct3D11, OpenGL and OpenGLES. Diligent Engine exposes common front-end for all supported platforms and provides interoperability with underlying native API. Shader source code converter allows shaders authored in HLSL to be translated to GLSL and used on all platforms. Diligent Engine supports integration with Unity and is designed to be used as a graphics subsystem in a standalone game engine, Unity native plugin or any other 3D application. It is distributed under Apache 2.0 license and is free to use. Full source code is available for download on GitHub.
Features:
True cross-platform Exact same client code for all supported platforms and rendering backends No #if defined(_WIN32) ... #elif defined(LINUX) ... #elif defined(ANDROID) ... No #if defined(D3D11) ... #elif defined(D3D12) ... #elif defined(OPENGL) ... Exact same HLSL shaders run on all platforms and all backends Modular design Components are clearly separated logically and physically and can be used as needed Only take what you need for your project (do not want to keep samples and tutorials in your codebase? Simply remove Samples submodule. Only need core functionality? Use only Core submodule) No 15000 lines-of-code files Clear object-based interface No global states Key graphics features: Automatic shader resource binding designed to leverage the next-generation rendering APIs Multithreaded command buffer generation 50,000 draw calls at 300 fps with D3D12 backend Descriptor, memory and resource state management Modern c++ features to make code fast and reliable The following platforms and low-level APIs are currently supported:
Windows Desktop: Direct3D11, Direct3D12, OpenGL Universal Windows: Direct3D11, Direct3D12 Linux: OpenGL Android: OpenGLES MacOS: OpenGL iOS: OpenGLES API Basics
Initialization
The engine can perform initialization of the API or attach to already existing D3D11/D3D12 device or OpenGL/GLES context. For instance, the following code shows how the engine can be initialized in D3D12 mode:
#include "RenderDeviceFactoryD3D12.h" using namespace Diligent; // ...  GetEngineFactoryD3D12Type GetEngineFactoryD3D12 = nullptr; // Load the dll and import GetEngineFactoryD3D12() function LoadGraphicsEngineD3D12(GetEngineFactoryD3D12); auto *pFactoryD3D11 = GetEngineFactoryD3D12(); EngineD3D12Attribs EngD3D12Attribs; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[0] = 1024; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[1] = 32; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[2] = 16; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[3] = 16; EngD3D12Attribs.NumCommandsToFlushCmdList = 64; RefCntAutoPtr<IRenderDevice> pRenderDevice; RefCntAutoPtr<IDeviceContext> pImmediateContext; SwapChainDesc SwapChainDesc; RefCntAutoPtr<ISwapChain> pSwapChain; pFactoryD3D11->CreateDeviceAndContextsD3D12( EngD3D12Attribs, &pRenderDevice, &pImmediateContext, 0 ); pFactoryD3D11->CreateSwapChainD3D12( pRenderDevice, pImmediateContext, SwapChainDesc, hWnd, &pSwapChain ); Creating Resources
Device resources are created by the render device. The two main resource types are buffers, which represent linear memory, and textures, which use memory layouts optimized for fast filtering. To create a buffer, you need to populate BufferDesc structure and call IRenderDevice::CreateBuffer(). The following code creates a uniform (constant) buffer:
BufferDesc BuffDesc; BufferDesc.Name = "Uniform buffer"; BuffDesc.BindFlags = BIND_UNIFORM_BUFFER; BuffDesc.Usage = USAGE_DYNAMIC; BuffDesc.uiSizeInBytes = sizeof(ShaderConstants); BuffDesc.CPUAccessFlags = CPU_ACCESS_WRITE; m_pDevice->CreateBuffer( BuffDesc, BufferData(), &m_pConstantBuffer ); Similar, to create a texture, populate TextureDesc structure and call IRenderDevice::CreateTexture() as in the following example:
TextureDesc TexDesc; TexDesc.Name = "My texture 2D"; TexDesc.Type = TEXTURE_TYPE_2D; TexDesc.Width = 1024; TexDesc.Height = 1024; TexDesc.Format = TEX_FORMAT_RGBA8_UNORM; TexDesc.Usage = USAGE_DEFAULT; TexDesc.BindFlags = BIND_SHADER_RESOURCE | BIND_RENDER_TARGET | BIND_UNORDERED_ACCESS; TexDesc.Name = "Sample 2D Texture"; m_pRenderDevice->CreateTexture( TexDesc, TextureData(), &m_pTestTex ); Initializing Pipeline State
Diligent Engine follows Direct3D12 style to configure the graphics/compute pipeline. One big Pipelines State Object (PSO) encompasses all required states (all shader stages, input layout description, depth stencil, rasterizer and blend state descriptions etc.)
To create a shader, populate ShaderCreationAttribs structure. An important member is ShaderCreationAttribs::SourceLanguage. The following are valid values for this member:
SHADER_SOURCE_LANGUAGE_DEFAULT  - The shader source format matches the underlying graphics API: HLSL for D3D11 or D3D12 mode, and GLSL for OpenGL and OpenGLES modes. SHADER_SOURCE_LANGUAGE_HLSL  - The shader source is in HLSL. For OpenGL and OpenGLES modes, the source code will be converted to GLSL. See shader converter for details. SHADER_SOURCE_LANGUAGE_GLSL  - The shader source is in GLSL. There is currently no GLSL to HLSL converter. To allow grouping of resources based on the frequency of expected change, Diligent Engine introduces classification of shader variables:
Static variables (SHADER_VARIABLE_TYPE_STATIC) are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. Mutable variables (SHADER_VARIABLE_TYPE_MUTABLE) define resources that are expected to change on a per-material frequency. Examples may include diffuse textures, normal maps etc. Dynamic variables (SHADER_VARIABLE_TYPE_DYNAMIC) are expected to change frequently and randomly. This post describes the resource binding model in Diligent Engine.
The following is an example of shader initialization:
To create a pipeline state object, define instance of PipelineStateDesc structure. The structure defines the pipeline specifics such as if the pipeline is a compute pipeline, number and format of render targets as well as depth-stencil format:
// This is a graphics pipeline PSODesc.IsComputePipeline = false; PSODesc.GraphicsPipeline.NumRenderTargets = 1; PSODesc.GraphicsPipeline.RTVFormats[0] = TEX_FORMAT_RGBA8_UNORM_SRGB; PSODesc.GraphicsPipeline.DSVFormat = TEX_FORMAT_D32_FLOAT; The structure also defines depth-stencil, rasterizer, blend state, input layout and other parameters. For instance, rasterizer state can be defined as in the code snippet below:
// Init rasterizer state RasterizerStateDesc &RasterizerDesc = PSODesc.GraphicsPipeline.RasterizerDesc; RasterizerDesc.FillMode = FILL_MODE_SOLID; RasterizerDesc.CullMode = CULL_MODE_NONE; RasterizerDesc.FrontCounterClockwise = True; RasterizerDesc.ScissorEnable = True; //RSDesc.MultisampleEnable = false; // do not allow msaa (fonts would be degraded) RasterizerDesc.AntialiasedLineEnable = False; When all fields are populated, call IRenderDevice::CreatePipelineState() to create the PSO:
Shader resource binding in Diligent Engine is based on grouping variables in 3 different groups (static, mutable and dynamic). Static variables are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. They are bound directly to the shader object:

m_pPSO->CreateShaderResourceBinding(&m_pSRB); Dynamic and mutable resources are then bound through SRB object:
m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "tex2DDiffuse")->Set(pDiffuseTexSRV); m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "cbRandomAttribs")->Set(pRandomAttrsCB); The difference between mutable and dynamic resources is that mutable ones can only be set once for every instance of a shader resource binding. Dynamic resources can be set multiple times. It is important to properly set the variable type as this may affect performance. Static variables are generally most efficient, followed by mutable. Dynamic variables are most expensive from performance point of view. This post explains shader resource binding in more details.
Setting the Pipeline State and Invoking Draw Command
Before any draw command can be invoked, all required vertex and index buffers as well as the pipeline state should be bound to the device context:
// Clear render target const float zero[4] = {0, 0, 0, 0}; m_pContext->ClearRenderTarget(nullptr, zero); // Set vertex and index buffers IBuffer *buffer[] = {m_pVertexBuffer}; Uint32 offsets[] = {0}; Uint32 strides[] = {sizeof(MyVertex)}; m_pContext->SetVertexBuffers(0, 1, buffer, strides, offsets, SET_VERTEX_BUFFERS_FLAG_RESET); m_pContext->SetIndexBuffer(m_pIndexBuffer, 0); m_pContext->SetPipelineState(m_pPSO); Also, all shader resources must be committed to the device context:
m_pContext->CommitShaderResources(m_pSRB, COMMIT_SHADER_RESOURCES_FLAG_TRANSITION_RESOURCES); When all required states and resources are bound, IDeviceContext::Draw() can be used to execute draw command or IDeviceContext::DispatchCompute() can be used to execute compute command. Note that for a draw command, graphics pipeline must be bound, and for dispatch command, compute pipeline must be bound. Draw() takes DrawAttribs structure as an argument. The structure members define all attributes required to perform the command (primitive topology, number of vertices or indices, if draw call is indexed or not, if draw call is instanced or not, if draw call is indirect or not, etc.). For example:
DrawAttribs attrs; attrs.IsIndexed = true; attrs.IndexType = VT_UINT16; attrs.NumIndices = 36; attrs.Topology = PRIMITIVE_TOPOLOGY_TRIANGLE_LIST; pContext->Draw(attrs); Tutorials and Samples
The GitHub repository contains a number of tutorials and sample applications that demonstrate the API usage.

AntTweakBar sample demonstrates how to use AntTweakBar library to create simple user interface.

Atmospheric scattering sample is a more advanced example. It demonstrates how Diligent Engine can be used to implement various rendering tasks: loading textures from files, using complex shaders, rendering to textures, using compute shaders and unordered access views, etc.

The repository includes Asteroids performance benchmark based on this demo developed by Intel. It renders 50,000 unique textured asteroids and lets compare performance of D3D11 and D3D12 implementations. Every asteroid is a combination of one of 1000 unique meshes and one of 10 unique textures.

Integration with Unity
Diligent Engine supports integration with Unity through Unity low-level native plugin interface. The engine relies on Native API Interoperability to attach to the graphics API initialized by Unity. After Diligent Engine device and context are created, they can be used us usual to create resources and issue rendering commands. GhostCubePlugin shows an example how Diligent Engine can be used to render a ghost cube only visible as a reflection in a mirror.

• By Yxjmir
I'm trying to load data from a .gltf file into a struct to use to load a .bin file. I don't think there is a problem with how the vertex positions are loaded, but with the indices. This is what I get when drawing with glDrawArrays(GL_LINES, ...):

Also, using glDrawElements gives a similar result. Since it looks like its drawing triangles using the wrong vertices for each face, I'm assuming it needs an index buffer/element buffer. (I'm not sure why there is a line going through part of it, it doesn't look like it belongs to a side, re-exported it without texture coordinates checked, and its not there)
I'm using jsoncpp to load the GLTF file, its format is based on JSON. Here is the gltf struct I'm using, and how I parse the file:
glBindVertexArray(g_pGame->m_VAO);
glDrawElements(GL_LINES, g_pGame->m_indices.size(), GL_UNSIGNED_BYTE, (void*)0); // Only shows with GL_UNSIGNED_BYTE
glDrawArrays(GL_LINES, 0, g_pGame->m_vertexCount);
So, I'm asking what type should I use for the indices? it doesn't seem to be unsigned short, which is what I selected with the Khronos Group Exporter for blender. Also, am I reading part or all of the .bin file wrong?
Test.gltf
Test.bin

• That means how do I use base DirectX or OpenGL api's to make a physics based destruction simulation?
Will it be just smart rendering or something else is required?

# OpenGL wglChoosePixelFormatARB Problem

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## Recommended Posts

Hi everybody, hopefully someone here can help me out with this issue I'm having with WGL. I've tried to get a pixel format back from wglChoosePixelFormatARB, but it comes up with no results, when it should based on the attributes I provided. I've created a simple window test program that isolates this issue to the GLEW 1.6 library, which is what I'm using:

 #ifndef GLEW_STATIC #define GLEW_STATIC #endif #include <GL\glew.h> #include <GL\wglew.h> static const TCHAR g_szAppName[] = TEXT("Pixel Format Test"); static const TCHAR g_szClassName[50] = TEXT("OGL_CLASS"); static const int g_nWinWidth = 800; static const int g_nWinHeight = 600; HWND g_hWnd; HGLRC g_hRC; HDC g_hDC; HINSTANCE g_hInstance; WNDCLASS g_windClass; RECT g_windowRect; bool g_ContinueRendering; /////////////////////////////////////////////////////////////////////////////// // Callback functions to handle all window functions this app cares about. // Once complete, pass message on to next app in the hook chain. LRESULT CALLBACK WndProc( HWND hWnd, // Handle For This Window UINT uMsg, // Message For This Window WPARAM wParam, // Additional Message Information LPARAM lParam) // Additional Message Information { // Pass All Unhandled Messages To DefWindowProc return DefWindowProc(hWnd,uMsg,wParam,lParam); } /////////////////////////////////////////////////////////////////////////////// // Main program function, called on startup // Test the window setup, then exit int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { TCHAR *szBuffer; bool bRun = true; int nWindowX = 0; int nWindowY = 0; int *nPixelFormat = NULL; PIXELFORMATDESCRIPTOR pfd; DWORD dwExtStyle; DWORD dwWindStyle; HINSTANCE g_hInstance = GetModuleHandle(NULL); // setup window class g_windClass.lpszClassName = g_szClassName; // Set the name of the Class g_windClass.lpfnWndProc = (WNDPROC)WndProc; g_windClass.hInstance = g_hInstance; // Use this module for the module handle g_windClass.hCursor = LoadCursor(NULL, IDC_ARROW);// Pick the default mouse cursor g_windClass.hIcon = LoadIcon(NULL, IDI_WINLOGO);// Pick the default windows icons g_windClass.hbrBackground = NULL; // No Background g_windClass.lpszMenuName = NULL; // No menu for this window g_windClass.style = CS_HREDRAW | CS_OWNDC | // set styles for this class, specifically to catch CS_VREDRAW; // window redraws, unique DC, and resize g_windClass.cbClsExtra = 0; // Extra class memory g_windClass.cbWndExtra = 0; // Extra window memory // Register the newly defined class if(!RegisterClass( &g_windClass )) bRun = false; dwExtStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; dwWindStyle = WS_OVERLAPPEDWINDOW; g_windowRect.left = nWindowX; g_windowRect.right = nWindowX + 800; g_windowRect.top = nWindowY; g_windowRect.bottom = nWindowY + 600; // Setup window width and height AdjustWindowRectEx(&g_windowRect, dwWindStyle, FALSE, dwExtStyle); //Adjust for adornments int nWindowWidth = g_windowRect.right - g_windowRect.left; int nWindowHeight = g_windowRect.bottom - g_windowRect.top; // Create window g_hWnd = CreateWindowEx(dwExtStyle, // Extended style g_szClassName, // class name g_szAppName, // window name dwWindStyle | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,// window stlye nWindowX, // window position, x nWindowY, // window position, y nWindowWidth, // height nWindowHeight, // width NULL, // Parent window NULL, // menu g_hInstance, // instance NULL); // pass this to WM_CREATE // now that we have a window, setup the pixel format descriptor g_hDC = GetDC(g_hWnd); // Set a dummy pixel format so that we can get access to wgl functions SetPixelFormat( g_hDC, 1,&pfd); // Create OGL context and make it current g_hRC = wglCreateContext( g_hDC ); wglMakeCurrent( g_hDC, g_hRC ); if (g_hDC == 0 || g_hDC == 0) { bRun = false; MessageBox(NULL, TEXT("!!! An error accured creating an OpenGL window.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } // Setup GLEW which loads OGL function pointers GLenum err = glewInit(); if (GLEW_OK != err) { /* Problem: glewInit failed, something is seriously wrong. */ bRun = false; wsprintf (szBuffer, TEXT ("Error: %s\n"), glewGetErrorString(err)); MessageBox(NULL, szBuffer, TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } // Now that extensions are setup, delete window and start over picking a real format. wglMakeCurrent(NULL, NULL); wglDeleteContext(g_hRC); ReleaseDC(g_hWnd, g_hDC); DestroyWindow(g_hWnd); AdjustWindowRectEx(&g_windowRect, dwWindStyle, FALSE, dwExtStyle); // Create the window again g_hWnd = CreateWindowEx(dwExtStyle, // Extended style g_szClassName, // class name g_szAppName, // window name dwWindStyle | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,// window stlye nWindowX, // window position, x nWindowY, // window position, y nWindowWidth, // height nWindowHeight, // width NULL, // Parent window NULL, // menu g_hInstance, // instance NULL); // pass this to WM_CREATE g_hDC = GetDC(g_hWnd); int nPixCount = 0; // Specify the important attributes we care about int pixAttribs[] = { WGL_SUPPORT_OPENGL_ARB, 1, // Must support OGL rendering WGL_DRAW_TO_WINDOW_ARB, 1, // pf that can run a window WGL_ACCELERATION_ARB, 1, // must be HW accelerated WGL_COLOR_BITS_ARB, 24, // 8 bits of each R, G and B WGL_DEPTH_BITS_ARB, 16, // 16 bits of depth precision for window WGL_DOUBLE_BUFFER_ARB, GL_TRUE, // Double buffered context WGL_SAMPLE_BUFFERS_ARB, GL_TRUE, // MSAA on WGL_SAMPLES_ARB, 8, // 8x MSAA WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB, // pf should be RGBA type 0}; // NULL termination // Ask OpenGL to find the most relevant format matching our attribs // Only get one format back. wglChoosePixelFormatARB(g_hDC, pixAttribs, NULL, 1, nPixelFormat, (UINT*)&nPixCount); if(nPixelFormat == NULL) { MessageBox(NULL, TEXT("!!! An error occurred trying to find a MSAA pixel format with the requested attribs.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); // Try again without MSAA pixAttribs[15] = 1; wglChoosePixelFormatARB(g_hDC, pixAttribs, NULL, 1, nPixelFormat, (UINT*)&nPixCount); if(nPixelFormat == NULL) { // Couldn't find a format, perhaps no 3D HW or drivers are installed g_hDC = 0; g_hDC = 0; bRun = false; MessageBox(NULL, TEXT("!!! An error occurred trying to find a pixel format with the requested attribs.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } } if(nPixelFormat != NULL) { // Check for MSAA int attrib[] = { WGL_SAMPLES_ARB }; int nResults = 0; wglGetPixelFormatAttribivARB(g_hDC, *nPixelFormat, 0, 1, attrib, &nResults); // Got a format, now set it as the current one SetPixelFormat( g_hDC, *nPixelFormat, &pfd ); GLint attribs[] = {WGL_CONTEXT_MAJOR_VERSION_ARB, 3, WGL_CONTEXT_MINOR_VERSION_ARB, 3, 0 }; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.3 context.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); attribs[3] = 2; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.2 context.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); attribs[3] = 1; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.1 context.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); attribs[3] = 0; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.0 context.\n!!! OpenGL 3.0 and higher are not supported on this system.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } } } } wglMakeCurrent( g_hDC, g_hRC ); } if (g_hDC == 0 || g_hDC == 0) { bRun = false; MessageBox(NULL, TEXT("!!! An error occured creating an OpenGL window."), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } // If everything went as planned, display the window if( bRun ) { ShowWindow( g_hWnd, SW_SHOW ); SetForegroundWindow( g_hWnd ); SetFocus( g_hWnd ); g_ContinueRendering = true; } //Cleanup OGL RC if(g_hRC) { wglMakeCurrent(NULL, NULL); wglDeleteContext(g_hRC); g_hRC = NULL; } // release the DC if(g_hDC) { ReleaseDC(g_hWnd, g_hDC); g_hDC = NULL; } // Destroy the window if(g_hWnd) { DestroyWindow(g_hWnd); g_hWnd = NULL;; } // Delete the window class UnregisterClass(g_szClassName, g_hInstance); g_hInstance = NULL; return 0; } 
I have no clue what could be causing this problem. I could spend hours of hair-pulling trying to find some sort of syntax error, but I'd rather that one of the WGL experts here help me out.

I'm using Visual C++ 2010 Express, as well as an nVidia GeForce 8500GT with Windows 7, and have even reinstalled to the latest drivers in order to fix this problem, but to no avail. And the freeglut library starts up fine, but obviously I have other motives for using WGL.

Keep in mind that I've installed the glew dll in system32 and have linked to glew32s.lib, glu32.lib, and opengl32.lib to prevent linking trouble. In the case that this is a linking issue, here's the build log, which includes only a few warnings, but compiles successfully anyway:
[font="Consolas"][size="1"][font="Consolas"][size="1"]1>------ Rebuild All started: Project: Windows GL 2, Configuration: Debug Win32 ------

1> main.cpp

1>c:\users\...\documents\visual studio 2010\projects\windows gl 2\windows gl 2\main.cpp(127): warning C4700: uninitialized local variable 'szBuffer' used

1>LINK : warning LNK4098: defaultlib 'LIBCMT' conflicts with use of other libs; use /NODEFAULTLIB:library

1>LINK : warning LNK4098: defaultlib 'LIBCMT' conflicts with use of other libs; use /NODEFAULTLIB:library

1> Windows GL 2.vcxproj -> c:\users\...\documents\visual studio 2010\Projects\Windows GL 2\Debug\Windows GL 2.exe

========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

[font="Arial"]The errors that the program recieves are as follows:

[/font][font="Arial"]!!! An error occured trying to find a MSAA pixel format with the requested attribs.
!!! An error occured trying to find a pixel format with the requested attribs.
!!! An error occured creating an OpenGL window.

Thanks to anyone who can help me out with this, can't wait to do a lot more with OpenGL once this problem is cleared up.[/font][/font][/font]

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You cannot set pixelformat to values you like. You should call ChoosePixelFormat() with "your" format and Windows will return the closest match.

What is retrieved by ChoosePixelFormat() forward to SetPixelFormat() and it will work!

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ChoosePixelFormat worked, thanks! But why didn't wglChoosePixelFormatARB work? How can I turn MSAA on and off now?

Here's the resulting code. I've commented out the wglChoosePixelFormatARB, as well as the MSAA error checking, since I don't know how to enable/disable MSAA with a pfd:

 #ifndef GLEW_STATIC #define GLEW_STATIC #endif #include <GL\glew.h> #include <GL\wglew.h> static const TCHAR g_szAppName[] = TEXT("Pixel Format Test"); static const TCHAR g_szClassName[50] = TEXT("OGL_CLASS"); static const int g_nWinWidth = 800; static const int g_nWinHeight = 600; HWND g_hWnd; HGLRC g_hRC; HDC g_hDC; HINSTANCE g_hInstance; WNDCLASS g_windClass; RECT g_windowRect; bool g_ContinueRendering; /////////////////////////////////////////////////////////////////////////////// // Callback functions to handle all window functions this app cares about. // Once complete, pass message on to next app in the hook chain. LRESULT CALLBACK WndProc( HWND hWnd, // Handle For This Window UINT uMsg, // Message For This Window WPARAM wParam, // Additional Message Information LPARAM lParam) // Additional Message Information { // Pass All Unhandled Messages To DefWindowProc return DefWindowProc(hWnd,uMsg,wParam,lParam); } /////////////////////////////////////////////////////////////////////////////// // Main program function, called on startup // Test the window setup, then exit int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { TCHAR *szBuffer; bool bRun = true; int nWindowX = 0; int nWindowY = 0; int nPixelFormat; PIXELFORMATDESCRIPTOR pfdDummy; DWORD dwExtStyle; DWORD dwWindStyle; HINSTANCE g_hInstance = GetModuleHandle(NULL); // setup window class g_windClass.lpszClassName = g_szClassName; // Set the name of the Class g_windClass.lpfnWndProc = (WNDPROC)WndProc; g_windClass.hInstance = g_hInstance; // Use this module for the module handle g_windClass.hCursor = LoadCursor(NULL, IDC_ARROW);// Pick the default mouse cursor g_windClass.hIcon = LoadIcon(NULL, IDI_WINLOGO);// Pick the default windows icons g_windClass.hbrBackground = NULL; // No Background g_windClass.lpszMenuName = NULL; // No menu for this window g_windClass.style = CS_HREDRAW | CS_OWNDC | // set styles for this class, specifically to catch CS_VREDRAW; // window redraws, unique DC, and resize g_windClass.cbClsExtra = 0; // Extra class memory g_windClass.cbWndExtra = 0; // Extra window memory // Register the newly defined class if(!RegisterClass( &g_windClass )) bRun = false; dwExtStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; dwWindStyle = WS_OVERLAPPEDWINDOW; g_windowRect.left = nWindowX; g_windowRect.right = nWindowX + 800; g_windowRect.top = nWindowY; g_windowRect.bottom = nWindowY + 600; // Setup window width and height AdjustWindowRectEx(&g_windowRect, dwWindStyle, FALSE, dwExtStyle); //Adjust for adornments int nWindowWidth = g_windowRect.right - g_windowRect.left; int nWindowHeight = g_windowRect.bottom - g_windowRect.top; // Create window g_hWnd = CreateWindowEx(dwExtStyle, // Extended style g_szClassName, // class name g_szAppName, // window name dwWindStyle | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,// window stlye nWindowX, // window position, x nWindowY, // window position, y nWindowWidth, // height nWindowHeight, // width NULL, // Parent window NULL, // menu g_hInstance, // instance NULL); // pass this to WM_CREATE // now that we have a window, setup the pixel format descriptor g_hDC = GetDC(g_hWnd); // Set a dummy pixel format so that we can get access to wgl functions SetPixelFormat( g_hDC, 1,&pfdDummy); // Create OGL context and make it current g_hRC = wglCreateContext( g_hDC ); wglMakeCurrent( g_hDC, g_hRC ); if (g_hDC == 0 || g_hDC == 0) { bRun = false; MessageBox(NULL, TEXT("!!! An error accured creating an OpenGL window.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } // Setup GLEW which loads OGL function pointers GLenum err = glewInit(); if (GLEW_OK != err) { /* Problem: glewInit failed, something is seriously wrong. */ bRun = false; wsprintf (szBuffer, TEXT ("Error: %s\n"), glewGetErrorString(err)); MessageBox(NULL, szBuffer, TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } // Now that extensions are setup, delete window and start over picking a real format. wglMakeCurrent(NULL, NULL); wglDeleteContext(g_hRC); ReleaseDC(g_hWnd, g_hDC); DestroyWindow(g_hWnd); AdjustWindowRectEx(&g_windowRect, dwWindStyle, FALSE, dwExtStyle); // Create the window again g_hWnd = CreateWindowEx(dwExtStyle, // Extended style g_szClassName, // class name g_szAppName, // window name dwWindStyle | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,// window stlye nWindowX, // window position, x nWindowY, // window position, y nWindowWidth, // height nWindowHeight, // width NULL, // Parent window NULL, // menu g_hInstance, // instance NULL); // pass this to WM_CREATE g_hDC = GetDC(g_hWnd); int nPixCount = 1; //// Specify the important attributes we care about //int pixAttribs[] = { WGL_SUPPORT_OPENGL_ARB, 1, // Must support OGL rendering // WGL_DRAW_TO_WINDOW_ARB, 1, // pf that can run a window // WGL_ACCELERATION_ARB, 1, // must be HW accelerated // WGL_COLOR_BITS_ARB, 24, // 8 bits of each R, G and B // WGL_DEPTH_BITS_ARB, 16, // 16 bits of depth precision for window // WGL_DOUBLE_BUFFER_ARB, GL_TRUE, // Double buffered context // WGL_SAMPLE_BUFFERS_ARB, GL_TRUE, // MSAA on // WGL_SAMPLES_ARB, 8, // 8x MSAA // WGL_PIXEL_TYPE_ARB, WGL_TYPE_RGBA_ARB, // pf should be RGBA type // 0}; // NULL termination //// Ask OpenGL to find the most relevant format matching our attribs //// Only get one format back. //wglChoosePixelFormatARB(g_hDC, pixAttribs, NULL, 1, &nPixelFormat, (UINT*)&nPixCount); PIXELFORMATDESCRIPTOR pfd = { sizeof(PIXELFORMATDESCRIPTOR), // size of this pfd 1, // version number PFD_DRAW_TO_WINDOW | // support window PFD_SUPPORT_OPENGL | // support OpenGL PFD_DOUBLEBUFFER, // double buffered PFD_TYPE_RGBA, // RGBA type 24, // 24-bit color depth 0, 0, 0, 0, 0, 0, // color bits ignored 0, // no alpha buffer 0, // shift bit ignored 0, // no accumulation buffer 0, 0, 0, 0, // accum bits ignored 32, // 32-bit z-buffer 0, // no stencil buffer 0, // no auxiliary buffer PFD_MAIN_PLANE, // main layer 0, // reserved 0, 0, 0 // layer masks ignored }; nPixelFormat = ChoosePixelFormat(g_hDC, &pfd); //if(nPixelFormat == NULL) //{ // MessageBox(NULL, // TEXT("!!! An error occurred trying to find a MSAA pixel format with the requested attribs.\n"), // TEXT("ERROR"), // MB_OK|MB_ICONEXCLAMATION); // // Try again without MSAA // pixAttribs[15] = 1; // wglChoosePixelFormatARB(g_hDC, pixAttribs, NULL, 1, &nPixelFormat, (UINT*)&nPixCount); if(nPixelFormat == NULL) { // Couldn't find a format, perhaps no 3D HW or drivers are installed g_hDC = 0; g_hDC = 0; bRun = false; MessageBox(NULL, TEXT("!!! An error occurred trying to find a pixel format with the requested attribs.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } //} if(nPixelFormat != NULL) { // Check for MSAA int attrib[] = { WGL_SAMPLES_ARB }; int nResults = 0; wglGetPixelFormatAttribivARB(g_hDC, nPixelFormat, 0, 1, attrib, &nResults); // Got a format, now set it as the current one SetPixelFormat( g_hDC, nPixelFormat, &pfd ); GLint attribs[] = {WGL_CONTEXT_MAJOR_VERSION_ARB, 3, WGL_CONTEXT_MINOR_VERSION_ARB, 3, 0 }; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.3 context.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); attribs[3] = 2; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.2 context.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); attribs[3] = 1; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.1 context.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); attribs[3] = 0; g_hRC = wglCreateContextAttribsARB(g_hDC, 0, attribs); if (g_hRC == NULL) { MessageBox(NULL, TEXT("!!! Could not create an OpenGL 3.0 context.\n!!! OpenGL 3.0 and higher are not supported on this system.\n"), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } } } } wglMakeCurrent( g_hDC, g_hRC ); } if (g_hDC == 0 || g_hDC == 0) { bRun = false; MessageBox(NULL, TEXT("!!! An error occured creating an OpenGL window."), TEXT("ERROR"), MB_OK|MB_ICONEXCLAMATION); } // If everything went as planned, display the window if( bRun ) { ShowWindow( g_hWnd, SW_SHOW ); SetForegroundWindow( g_hWnd ); SetFocus( g_hWnd ); g_ContinueRendering = true; } //Cleanup OGL RC if(g_hRC) { wglMakeCurrent(NULL, NULL); wglDeleteContext(g_hRC); g_hRC = NULL; } // release the DC if(g_hDC) { ReleaseDC(g_hWnd, g_hDC); g_hDC = NULL; } // Destroy the window if(g_hWnd) { DestroyWindow(g_hWnd); g_hWnd = NULL;; } // Delete the window class UnregisterClass(g_szClassName, g_hInstance); g_hInstance = NULL; return 0; } 

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32-bit z-buffer setting is what makes trouble to you!

Set freely WGL_COLOR_BITS_ARB to 32 bit, but never set to WGL_DEPTH_BITS_ARB !!! I suggest 24, unless you are dealing with very very old graphics card.

I don't know any graphics card that supports 32-bit depth buffer under Windows (I have no experience with other operating systems).

Also, set WGL_SAMPLES_ARB to arbitrary value, e.g. 16 (if you deal with mighty card, or 4-8 if your card is not such) and try to wglChoosePixelFormatARB(). If it returns valid value and the number of supported formats is greater or equal 1, than you can use returned pixel format. If there is no format supporting 16x AA, then reduce value and try again.

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32-bit z-buffer setting is what makes trouble to you!

Set freely WGL_COLOR_BITS_ARB to 32 bit, but never set to WGL_DEPTH_BITS_ARB !!! I suggest 24, unless you are dealing with very very old graphics card.

I don't know any graphics card that supports 32-bit depth buffer under Windows (I have no experience with other operating systems).

Both ATI and nVidia support 32 bit depth buffer for a few years now. Check all your pixelformats and I'm sure you'll find one.

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I've found the problem. The WGL_ACCELERATION_ARB attribute needed to be set to WGL_FULL_ACCELERATION_ARB, not 1. Glad that it was only a syntax error.

Thanks for all the help anyway! I'm sure I'll be back with more problems, count on that.

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Both ATI and nVidia support 32 bit depth buffer for a few years now. Check all your pixelformats and I'm sure you'll find one.

Would you be so kind and direct me to some pixel format that supports 32-bit depth buffer, double buffering and OpenGL version greater than 1.1?

I'm a very pragmatic guy, so I'm not relaying on what is written elsewhere. I have tried to get useful 32-bit depth buffer configuration and I failed.

Yes, there are even 3 pixel formats with 32-bit depth buffer and double buffering (93, 97, and 101), but they are probably for software renderers, because they supports only GL 1.1.

So I must repeat again: I HAVEN'T FOUND ANY GRAPHICS CARD (DRIVER) THAT SUPPORTS PIXEL FORMAT WITH 32-bit DEPTH BUFFER.

Nevertheless, 32-bit depth buffer is not such a great thing. 24-bits have just enough precision for all rendering I have to deal with.

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I am probably wrong about nVidia. Checking on my current laptop, I'm not seeing any hw accelerated 32 bit depth support, which is weird. My old ATI in my desktop did support it.
On the web, all I found is this http://homepage.mac.com/arekkusu/bugs/GLInfo.html
and if you scroll down to the Depth Buffer Modes (bpp) section, you'll see 0, 16, 24, 32 for the ATI/AMD cards
but the nVidia cards are 0, 16, 24.

I wonder if nVidia really does support 32 bit depth textures or if it fakes it with 24 bit.

Nevertheless, 32-bit depth buffer is not such a great thing. 24-bits have just enough precision for all rendering I have to deal with.[/quote]
Yes, the difference between the 2 is very small. It won't really help with depth fighting but since GPU tend to prefer 32 bit chunks rather than 24 bit, they pad the left over 8 bit with either junk or if you ask for a stencil buffer, they make a D24S8 buffer. I really expected my machine to give some 32 bit support but I guess not.

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I'm sorry I was rude.

Since the first release of GF cards, I have got only NVIDIA cards, so I don't know if AMD supports it, but I really doubt.

Even on Fermi based cards there is no hardware accelerated pixel formats with 32-bit depth buffer. But never mind, I just have to stress that setting 32-bit depth will cause failure of wglChoosePixelFormatARB on all NV cards.