OpenCL: Difference between revisions

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===Linux===
===Linux===
https://gist.github.com/Brainiarc7/dc80b023af5b4e0d02b33923de7ba1ed
https://gist.github.com/Brainiarc7/dc80b023af5b4e0d02b33923de7ba1ed
<pre>
sudo apt install ocl-icd-opencl-dev opencl-headers
sudo apt install opencl-c-headers opencl-clhpp-headers
</pre>


==Getting Started==
==Getting Started==
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===C++===
===C++===
[https://github.khronos.org/OpenCL-CLHPP/index.html#intro C++ Bindings]<br>
[https://github.khronos.org/OpenCL-CLHPP/index.html#intro C++ Bindings]<br>
While you can use the C bindings in your C++ application, Khronos also provides a set of C++ bindings in <code>CL/cl.hpp</code> (or <code>CL/cl2.hpp</code>) which are much easier to use alongside std containers such as <code>std::vector</code>. When using C++ bindings, you also do not need to worry about releasing buffers since these are reference-counted.
While you can use the C bindings in your C++ application, Khronos also provides a set of C++ bindings in <code>CL/cl.hpp</code> (or <code>CL/cl2.hpp</code>) which are much easier to use alongside std containers such as <code>std::vector</code>.
When using C++ bindings, you also do not need to worry about releasing buffers since these are reference-counted.
{{hidden | C++ example |
{{hidden | C++ example |
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
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===Python===
See [https://documen.tician.de/pyopencl/index.html pyopencl].


===Julia===
===Julia===
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==OpenGL Interop==
==OpenGL Interop==
Setting up OpenCL/OpenGL interop is fairly complicated and very hard to debug. 
You will also need to manage synchronizing OpenGL/OpenCL so they do not access the same memory at the same time. 
If you can, just use OpenGL compute shaders rather than OpenCL to simplify your life.
===Textures===
See [https://software.intel.com/content/www/us/en/develop/articles/opencl-and-opengl-interoperability-tutorial.html OpenCL™ and OpenGL* Interoperability Tutoria].
See [https://software.intel.com/content/www/us/en/develop/articles/opencl-and-opengl-interoperability-tutorial.html OpenCL™ and OpenGL* Interoperability Tutoria].


In C++, you can use [https://github.khronos.org/OpenCL-CLHPP/classcl_1_1_image_g_l.html <code>cl::ImageGL</code>] to access textures in OpenGL.   
In C++, you can use [https://github.khronos.org/OpenCL-CLHPP/classcl_1_1_image_g_l.html <code>cl::ImageGL</code>] to access textures in OpenGL.   
Note that <code>cl::Image</code> and <code>cl::Buffer</code> are not the same thing. A buffer is a contiguous section of memory whereas an image is a mipmapped texture. Interchanging them will result in <code>CL_INVALID_MEM_OBJECT</code> errors or similar.
Note that <code>cl::Image</code> and <code>cl::Buffer</code> are not the same thing. Interchanging them will result in <code>CL_INVALID_MEM_OBJECT</code> errors or similar.
I recommend writing to a separate buffer and copying to images.
I recommend writing to a separate buffer and copying to images.
See [https://www.khronos.org/registry/OpenCL/sdk/2.2/docs/man/html/clCreateFromGLTexture.html clCreateFromGLTexture] to get a list of compatible pixel formats. 
If in doubt, use <code>GL_RGBA8</code> which is the most likely format to be supported.
===Buffers===
[https://web.engr.oregonstate.edu/~mjb/cs575/Handouts/opencl.opengl.vbo.1pp.pdf Oregon State VBO Interop] 
[https://github.khronos.org/OpenCL-CLHPP/classcl_1_1_buffer_g_l.html cl::BufferGL]


==Advanced Topics==
==Advanced Topics==
====Local Memory v. Global Memory====
====Local Memory v. Global Memory====
[[Category:Programming languages]]
[[Category:GPU Programming languages]]