• Advertisement
Sign in to follow this  

OpenGL Requesting list of useful extensions

This topic is 3958 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I'm still learning my way around inside OpenGL, and trying to distill down the big list of extensions. Right now, I'm working with a 6800GT, affording me about 71 potential extensions (only counting ARB and EXT) in OpenGL 2.0.3. Can everyone make a list of extensions you find useful, or use a lot of the time? Also, could you give a brief description of what each does? On a side note, does anyone know which ones have been depreciated? For example, I'd heard GL_ARB_non_power_of_two is no longer needed since it's part of the core, but I'm not sure. Thanks for any help you can provide. ;)

Share this post


Link to post
Share on other sites
Advertisement
im only using one extension VBO ( at the most the number of extensions yould typically need u could count on your hand )
youll find if u use opengl2.0 (with glsl) a lot of the old extensions arent needed

Share this post


Link to post
Share on other sites
Some useful extensions:

Vertex Buffer Objects
Extension: GL_ARB_vertex_buffer_object
This was promoted to core in OpenGL 1.5.
This extension allows you to store your data (e.g. vertices, normals, texture coordinates) in a fast memory that is directly accessible to the GPU. This basically means that you can render much faster than you would be able to if the data was stored in system memory.
This is preferred method of storing data to be rendered nowadays. I haven't seen code which does not use VBO (except for very simple examples) in quite a while.

GLSL Shading Language
Extension: GL_ARB_shading_language_100
Promoted to core in Gl 2.0.
Presence of this extension determines if your hardware supports GLSL.

Extension: GL_ARB_shader_objects
Promoted to core in OpenGL 2.0.
This extension defines all entry points you need when working with GLSL shaders. It allows you to create, manage and use GLSL shaders.

Floating-Point Textures
Extension: GL_ARB_texture_float
As the name suggests, this allows you to create and use textures with floating-point data format (colour componetes can be 16 or 32 bit floats). This can be used when working with a lot of modern techniques like HDR, deferred rendering etc.
When using fp textures you will probably need GL_ARB_color_buffer_float which adds various pixel format options that control clamping of the colour components.

Rectangular and non-power-of-two textures
Extensions:
GL_ARB_texture_rectangle
GL_ARB_texture_non_power_of_two
These extensions alow you to use non-power-of-two textures that do not have to be square. NPOT extension was promoted to core in GL 2.0.

Multiple render targets
Extension: GL_ARB_draw_buffers
This was promoted to core in GL 2.0.
This extensions allows you to write output from your shaders to multiple outputs at once. For example, you can write colour of the pixel to one output and normal to another. Very useful for many advanced techniques.

Multitexturing
Extension: GL_ARB_multitexture
Promoted to core in OpenGL 1.3 (old :). This allows you to use multiple textures simultaneously (d'oh).

WGL Extensions List
Extension: WGL_ARB_extensions_string
Windows only. This extension allows you to query list of WGL extensions supported by your drivers and hardware. If you are using some sort of extension loader (e.g. GLEW), you will not need it.

Pixel Buffer Objects
Extension: WGL_ARB_pbuffer
Windows extension only. This allows you to create offscreen buffer to which you can output your rendering calls. Pixel buffer is basically an "invisible" equivalent of the window.

Render to texture
Extension: WGL_ARB_render_texture
Windows extension only. As the name suggests, this allows you to "redirect" your output to a texture. This texture can later be used just as any normal texture.

===========

Of course, this list is not exhaustive. All ARB extensions can be found in official extension registry. Newer extensions defined by NVIDIA can be found on a special page here. Similar page for ATI extensions can be found here.

Extensions that have been promoted to the core can be found at the end of the OpenGL specification. Newest specs can be found on this page.

Share this post


Link to post
Share on other sites
Thanks for the suggestions so far. I plan to use GL_EXT_frame_buffer_object because of all the good things I'd heard about it, and all the bad things I'd heard about pixel buffers.

One little question. If you have NPOT (particularly in GL2.0) then why do you need texture rectangle?

Share this post


Link to post
Share on other sites
Quote:
Original post by b2b3
Pixel Buffer Objects
Extension: WGL_ARB_pbuffer
Windows extension only. This allows you to create offscreen buffer to which you can output your rendering calls. Pixel buffer is basically an "invisible" equivalent of the window.


No, wrong.

WGL_ARB_pBuffer is for a pbuffer, this is NOT the same as a PBO or pixel buffer object.

PBOs are a method of performing Async transfers from the GPU and buffer to buffer copies on the GPU (such as textures to vertex buffers).

And frankly, unless you need a seperate context, you won't want to be using pbuffers, instead you want Frame Buffer Objects (FBO), which are the newer and much improved method of rendering to a texture.

There is also a short series of articles on FBOs written by some really top guy [grin]

Share this post


Link to post
Share on other sites
Okay, a couple more questions:
1.) What is sRGB, and why is it significant to OpenGL?

2.) PBOs. What is the most common use of them? Is there a place with a decent explanation? Are they to textures what VBOs are to geometry?

3.) How well supported is GL_EXT_texture_compression_s3tc across GPUs?

Share this post


Link to post
Share on other sites
I should probably look at sRGB at some point, however to answer the others;

2) PBOs are used for async copies of data to and from the graphics card (and from one buffer type to another). Textures already exist in video ram, PBOs just help with the uploading (so that the various functions don't block CPU execution).

3) The texture compression extensions have been supported for many generations now, I think even the orignal GeForce cards had support for it.

Share this post


Link to post
Share on other sites
Quote:

What is sRGB, and why is it significant to OpenGL?

sRGB is an ISO standarized non-linear colour space. In a normal RGB8 image, the colour distribution is completely linear. Each of the possible 255 increments is exactly the same over the entire dark to white range: 1/255.

However, the colour response of a display device (often being the final target for all OpenGL rendered content) is not linear. This is why usually gamma correction is applied on the final rendering.

A linear colour space such as RGB8 thus wastes a lot of values for brightness ranges the human eye cannot even distinguish due to the non-linearity of the screen, while lacking precision in other ranges. The solution would be to go to RGB16 or RGB16F, but this comes with a significant memory overhead.

The new sRGB formats try to find a middle ground. They distribute the dynamic ranges of the image in a way that matches the response curve of a screen more closely than plain RGB8. The net result is a higher quality of smooth gradients (ie. less banding) while the memory consumption stays the same.


[Edited by - Yann L on March 21, 2007 5:52:02 PM]

Share this post


Link to post
Share on other sites
Quote:
Original post by phantom
Quote:
Original post by b2b3
Pixel Buffer Objects
Extension: WGL_ARB_pbuffer
Windows extension only. This allows you to create offscreen buffer to which you can output your rendering calls. Pixel buffer is basically an "invisible" equivalent of the window.


No, wrong.

WGL_ARB_pBuffer is for a pbuffer, this is NOT the same as a PBO or pixel buffer object.

PBOs are a method of performing Async transfers from the GPU and buffer to buffer copies on the GPU (such as textures to vertex buffers).

And frankly, unless you need a seperate context, you won't want to be using pbuffers, instead you want Frame Buffer Objects (FBO), which are the newer and much improved method of rendering to a texture.

There is also a short series of articles on FBOs written by some really top guy [grin]


You are right, I got them mixed up [embarrass].

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
  • Advertisement
  • Popular Now

  • Advertisement
  • Similar Content

    • By reenigne
      For those that don't know me. I am the individual who's two videos are listed here under setup for https://wiki.libsdl.org/Tutorials
      I also run grhmedia.com where I host the projects and code for the tutorials I have online.
      Recently, I received a notice from youtube they will be implementing their new policy in protecting video content as of which I won't be monetized till I meat there required number of viewers and views each month.

      Frankly, I'm pretty sick of youtube. I put up a video and someone else learns from it and puts up another video and because of the way youtube does their placement they end up with more views.
      Even guys that clearly post false information such as one individual who said GLEW 2.0 was broken because he didn't know how to compile it. He in short didn't know how to modify the script he used because he didn't understand make files and how the requirements of the compiler and library changes needed some different flags.

      At the end of the month when they implement this I will take down the content and host on my own server purely and it will be a paid system and or patreon. 

      I get my videos may be a bit dry, I generally figure people are there to learn how to do something and I rather not waste their time. 
      I used to also help people for free even those coming from the other videos. That won't be the case any more. I used to just take anyone emails and work with them my email is posted on the site.

      I don't expect to get the required number of subscribers in that time or increased views. Even if I did well it wouldn't take care of each reoccurring month.
      I figure this is simpler and I don't plan on putting some sort of exorbitant fee for a monthly subscription or the like.
      I was thinking on the lines of a few dollars 1,2, and 3 and the larger subscription gets you assistance with the content in the tutorials if needed that month.
      Maybe another fee if it is related but not directly in the content. 
      The fees would serve to cut down on the number of people who ask for help and maybe encourage some of the people to actually pay attention to what is said rather than do their own thing. That actually turns out to be 90% of the issues. I spent 6 hours helping one individual last week I must have asked him 20 times did you do exactly like I said in the video even pointed directly to the section. When he finally sent me a copy of the what he entered I knew then and there he had not. I circled it and I pointed out that wasn't what I said to do in the video. I didn't tell him what was wrong and how I knew that way he would go back and actually follow what it said to do. He then reported it worked. Yea, no kidding following directions works. But hey isn't alone and well its part of the learning process.

      So the point of this isn't to be a gripe session. I'm just looking for a bit of feed back. Do you think the fees are unreasonable?
      Should I keep the youtube channel and do just the fees with patreon or do you think locking the content to my site and require a subscription is an idea.

      I'm just looking at the fact it is unrealistic to think youtube/google will actually get stuff right or that youtube viewers will actually bother to start looking for more accurate videos. 
    • By Balma Alparisi
      i got error 1282 in my code.
      sf::ContextSettings settings; settings.majorVersion = 4; settings.minorVersion = 5; settings.attributeFlags = settings.Core; sf::Window window; window.create(sf::VideoMode(1600, 900), "Texture Unit Rectangle", sf::Style::Close, settings); window.setActive(true); window.setVerticalSyncEnabled(true); glewInit(); GLuint shaderProgram = createShaderProgram("FX/Rectangle.vss", "FX/Rectangle.fss"); float vertex[] = { -0.5f,0.5f,0.0f, 0.0f,0.0f, -0.5f,-0.5f,0.0f, 0.0f,1.0f, 0.5f,0.5f,0.0f, 1.0f,0.0f, 0.5,-0.5f,0.0f, 1.0f,1.0f, }; GLuint indices[] = { 0,1,2, 1,2,3, }; GLuint vao; glGenVertexArrays(1, &vao); glBindVertexArray(vao); GLuint vbo; glGenBuffers(1, &vbo); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER, sizeof(vertex), vertex, GL_STATIC_DRAW); GLuint ebo; glGenBuffers(1, &ebo); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,GL_STATIC_DRAW); glVertexAttribPointer(0, 3, GL_FLOAT, false, sizeof(float) * 5, (void*)0); glEnableVertexAttribArray(0); glVertexAttribPointer(1, 2, GL_FLOAT, false, sizeof(float) * 5, (void*)(sizeof(float) * 3)); glEnableVertexAttribArray(1); GLuint texture[2]; glGenTextures(2, texture); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture[0]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); sf::Image* imageOne = new sf::Image; bool isImageOneLoaded = imageOne->loadFromFile("Texture/container.jpg"); if (isImageOneLoaded) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageOne->getSize().x, imageOne->getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageOne->getPixelsPtr()); glGenerateMipmap(GL_TEXTURE_2D); } delete imageOne; glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture[1]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); sf::Image* imageTwo = new sf::Image; bool isImageTwoLoaded = imageTwo->loadFromFile("Texture/awesomeface.png"); if (isImageTwoLoaded) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageTwo->getSize().x, imageTwo->getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageTwo->getPixelsPtr()); glGenerateMipmap(GL_TEXTURE_2D); } delete imageTwo; glUniform1i(glGetUniformLocation(shaderProgram, "inTextureOne"), 0); glUniform1i(glGetUniformLocation(shaderProgram, "inTextureTwo"), 1); GLenum error = glGetError(); std::cout << error << std::endl; sf::Event event; bool isRunning = true; while (isRunning) { while (window.pollEvent(event)) { if (event.type == event.Closed) { isRunning = false; } } glClear(GL_COLOR_BUFFER_BIT); if (isImageOneLoaded && isImageTwoLoaded) { glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture[0]); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture[1]); glUseProgram(shaderProgram); } glBindVertexArray(vao); glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, nullptr); glBindVertexArray(0); window.display(); } glDeleteVertexArrays(1, &vao); glDeleteBuffers(1, &vbo); glDeleteBuffers(1, &ebo); glDeleteProgram(shaderProgram); glDeleteTextures(2,texture); return 0; } and this is the vertex shader
      #version 450 core layout(location=0) in vec3 inPos; layout(location=1) in vec2 inTexCoord; out vec2 TexCoord; void main() { gl_Position=vec4(inPos,1.0); TexCoord=inTexCoord; } and the fragment shader
      #version 450 core in vec2 TexCoord; uniform sampler2D inTextureOne; uniform sampler2D inTextureTwo; out vec4 FragmentColor; void main() { FragmentColor=mix(texture(inTextureOne,TexCoord),texture(inTextureTwo,TexCoord),0.2); } I was expecting awesomeface.png on top of container.jpg

    • By khawk
      We've just released all of the source code for the NeHe OpenGL lessons on our Github page at https://github.com/gamedev-net/nehe-opengl. code - 43 total platforms, configurations, and languages are included.
      Now operated by GameDev.net, NeHe is located at http://nehe.gamedev.net where it has been a valuable resource for developers wanting to learn OpenGL and graphics programming.

      View full story
    • By TheChubu
      The Khronos™ Group, an open consortium of leading hardware and software companies, announces from the SIGGRAPH 2017 Conference the immediate public availability of the OpenGL® 4.6 specification. OpenGL 4.6 integrates the functionality of numerous ARB and EXT extensions created by Khronos members AMD, Intel, and NVIDIA into core, including the capability to ingest SPIR-V™ shaders.
      SPIR-V is a Khronos-defined standard intermediate language for parallel compute and graphics, which enables content creators to simplify their shader authoring and management pipelines while providing significant source shading language flexibility. OpenGL 4.6 adds support for ingesting SPIR-V shaders to the core specification, guaranteeing that SPIR-V shaders will be widely supported by OpenGL implementations.
      OpenGL 4.6 adds the functionality of these ARB extensions to OpenGL’s core specification:
      GL_ARB_gl_spirv and GL_ARB_spirv_extensions to standardize SPIR-V support for OpenGL GL_ARB_indirect_parameters and GL_ARB_shader_draw_parameters for reducing the CPU overhead associated with rendering batches of geometry GL_ARB_pipeline_statistics_query and GL_ARB_transform_feedback_overflow_querystandardize OpenGL support for features available in Direct3D GL_ARB_texture_filter_anisotropic (based on GL_EXT_texture_filter_anisotropic) brings previously IP encumbered functionality into OpenGL to improve the visual quality of textured scenes GL_ARB_polygon_offset_clamp (based on GL_EXT_polygon_offset_clamp) suppresses a common visual artifact known as a “light leak” associated with rendering shadows GL_ARB_shader_atomic_counter_ops and GL_ARB_shader_group_vote add shader intrinsics supported by all desktop vendors to improve functionality and performance GL_KHR_no_error reduces driver overhead by allowing the application to indicate that it expects error-free operation so errors need not be generated In addition to the above features being added to OpenGL 4.6, the following are being released as extensions:
      GL_KHR_parallel_shader_compile allows applications to launch multiple shader compile threads to improve shader compile throughput WGL_ARB_create_context_no_error and GXL_ARB_create_context_no_error allow no error contexts to be created with WGL or GLX that support the GL_KHR_no_error extension “I’m proud to announce OpenGL 4.6 as the most feature-rich version of OpenGL yet. We've brought together the most popular, widely-supported extensions into a new core specification to give OpenGL developers and end users an improved baseline feature set. This includes resolving previous intellectual property roadblocks to bringing anisotropic texture filtering and polygon offset clamping into the core specification to enable widespread implementation and usage,” said Piers Daniell, chair of the OpenGL Working Group at Khronos. “The OpenGL working group will continue to respond to market needs and work with GPU vendors to ensure OpenGL remains a viable and evolving graphics API for all its customers and users across many vital industries.“
      The OpenGL 4.6 specification can be found at https://khronos.org/registry/OpenGL/index_gl.php. The GLSL to SPIR-V compiler glslang has been updated with GLSL 4.60 support, and can be found at https://github.com/KhronosGroup/glslang.
      Sophisticated graphics applications will also benefit from a set of newly released extensions for both OpenGL and OpenGL ES to enable interoperability with Vulkan and Direct3D. These extensions are named:
      GL_EXT_memory_object GL_EXT_memory_object_fd GL_EXT_memory_object_win32 GL_EXT_semaphore GL_EXT_semaphore_fd GL_EXT_semaphore_win32 GL_EXT_win32_keyed_mutex They can be found at: https://khronos.org/registry/OpenGL/index_gl.php
      Industry Support for OpenGL 4.6
      “With OpenGL 4.6 our customers have an improved set of core features available on our full range of OpenGL 4.x capable GPUs. These features provide improved rendering quality, performance and functionality. As the graphics industry’s most popular API, we fully support OpenGL and will continue to work closely with the Khronos Group on the development of new OpenGL specifications and extensions for our customers. NVIDIA has released beta OpenGL 4.6 drivers today at https://developer.nvidia.com/opengl-driver so developers can use these new features right away,” said Bob Pette, vice president, Professional Graphics at NVIDIA.
      "OpenGL 4.6 will be the first OpenGL release where conformant open source implementations based on the Mesa project will be deliverable in a reasonable timeframe after release. The open sourcing of the OpenGL conformance test suite and ongoing work between Khronos and X.org will also allow for non-vendor led open source implementations to achieve conformance in the near future," said David Airlie, senior principal engineer at Red Hat, and developer on Mesa/X.org projects.

      View full story
    • By _OskaR
      Hi,
      I have an OpenGL application but without possibility to wite own shaders.
      I need to perform small VS modification - is possible to do it in an alternative way? Do we have apps or driver modifictions which will catch the shader sent to GPU and override it?
  • Advertisement