ceph/src/boost/boost/compute/interop/opengl/context.hpp

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2013-2014 Kyle Lutz <kyle.r.lutz@gmail.com>
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 //
   8 // See http://boostorg.github.com/compute for more information.
   9 //---------------------------------------------------------------------------//
  10
  11 #ifndef BOOST_COMPUTE_INTEROP_OPENGL_CONTEXT_HPP
  12 #define BOOST_COMPUTE_INTEROP_OPENGL_CONTEXT_HPP
  13
  14 #include <boost/throw_exception.hpp>
  15
  16 #include <boost/compute/device.hpp>
  17 #include <boost/compute/system.hpp>
  18 #include <boost/compute/context.hpp>
  19 #include <boost/compute/exception/unsupported_extension_error.hpp>
  20 #include <boost/compute/interop/opengl/cl_gl.hpp>
  21
  22 #ifdef __APPLE__
  23 #include <OpenCL/cl_gl_ext.h>
  24 #include <OpenGL/OpenGL.h>
  25 #endif
  26
  27 #ifdef __linux__
  28 #include <GL/glx.h>
  29 #endif
  30
  31 namespace boost {
  32 namespace compute {
  33
  34 /// Creates a shared OpenCL/OpenGL context for the currently active
  35 /// OpenGL context.
  36 ///
  37 /// Once created, the shared context can be used to create OpenCL memory
  38 /// objects which can interact with OpenGL memory objects (e.g. VBOs).
  39 ///
  40 /// \throws unsupported_extension_error if no CL-GL sharing capable devices
  41 ///         are found.
  42 inline context opengl_create_shared_context()
  43 {
  44     // name of the OpenGL sharing extension for the system
  45 #if defined(__APPLE__)
  46     const char *cl_gl_sharing_extension = "cl_APPLE_gl_sharing";
  47 #else
  48     const char *cl_gl_sharing_extension = "cl_khr_gl_sharing";
  49 #endif
  50
  51 #if defined(__APPLE__)
  52     // get OpenGL share group
  53     CGLContextObj cgl_current_context = CGLGetCurrentContext();
  54     CGLShareGroupObj cgl_share_group = CGLGetShareGroup(cgl_current_context);
  55
  56     cl_context_properties properties[] = {
  57         CL_CONTEXT_PROPERTY_USE_CGL_SHAREGROUP_APPLE,
  58         (cl_context_properties) cgl_share_group,
  59         0
  60     };
  61
  62     cl_int error = 0;
  63     cl_context cl_gl_context = clCreateContext(properties, 0, 0, 0, 0, &error);
  64     if(!cl_gl_context){
  65         BOOST_THROW_EXCEPTION(opencl_error(error));
  66     }
  67
  68     return context(cl_gl_context, false);
  69 #else
  70     typedef cl_int(*GetGLContextInfoKHRFunction)(
  71         const cl_context_properties*, cl_gl_context_info, size_t, void *, size_t *
  72     );
  73
  74     std::vector<platform> platforms = system::platforms();
  75     for(size_t i = 0; i < platforms.size(); i++){
  76         const platform &platform = platforms[i];
  77
  78         // check whether this platform supports OpenCL/OpenGL sharing
  79         if (!platform.supports_extension("cl_gl_sharing_extension"))
  80           continue;
  81
  82         // load clGetGLContextInfoKHR() extension function
  83         GetGLContextInfoKHRFunction GetGLContextInfoKHR =
  84             reinterpret_cast<GetGLContextInfoKHRFunction>(
  85                 reinterpret_cast<size_t>(
  86                     platform.get_extension_function_address("clGetGLContextInfoKHR")
  87                 )
  88             );
  89         if(!GetGLContextInfoKHR){
  90             continue;
  91         }
  92
  93         // create context properties listing the platform and current OpenGL display
  94         cl_context_properties properties[] = {
  95             CL_CONTEXT_PLATFORM, (cl_context_properties) platform.id(),
  96         #if defined(__linux__)
  97             CL_GL_CONTEXT_KHR, (cl_context_properties) glXGetCurrentContext(),
  98             CL_GLX_DISPLAY_KHR, (cl_context_properties) glXGetCurrentDisplay(),
  99         #elif defined(_WIN32)
 100             CL_GL_CONTEXT_KHR, (cl_context_properties) wglGetCurrentContext(),
 101             CL_WGL_HDC_KHR, (cl_context_properties) wglGetCurrentDC(),
 102         #endif
 103             0
 104         };
 105
 106         // lookup current OpenCL device for current OpenGL context
 107         cl_device_id gpu_id;
 108         cl_int ret = GetGLContextInfoKHR(
 109             properties,
 110             CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR,
 111             sizeof(cl_device_id),
 112             &gpu_id,
 113             0
 114         );
 115         if(ret != CL_SUCCESS){
 116             continue;
 117         }
 118
 119         // create device object for the GPU and ensure it supports CL-GL sharing
 120         device gpu(gpu_id, false);
 121         if(!gpu.supports_extension("cl_gl_sharing_extension")){
 122             continue;
 123         }
 124
 125         // return CL-GL sharing context
 126         return context(gpu, properties);
 127     }
 128 #endif
 129
 130     // no CL-GL sharing capable devices found
 131     BOOST_THROW_EXCEPTION(
 132         unsupported_extension_error("cl_gl_sharing_extension")
 133     );
 134 }
 135
 136 } // end compute namespace
 137 } // end boost namespace
 138
 139 #endif // BOOST_COMPUTE_INTEROP_OPENGL_CONTEXT_HPP