修改來自OpenCL內核的VBO數據

Question

我希望我的OpenCL程序的輸出直接在屏幕上繪製，而不需要從GPU下載然後再次上傳。我如何將數據放入內核的頂點數組中？我在C++中使用glfw3，並與nVidia的默認OpenCL庫一起使用。

Answer 1

該示例可以幫助：http://enja.org/2010/08/27/adventures-in-opencl-part-2-particles-with-opengl/

關鍵要求是成立CL/GL共享的上下文。根據您的GL主機上，你需要不同的屬性設置爲CL背景：

蘋果：

cl_context_properties props[] = 
    { 
     CL_CONTEXT_PROPERTY_USE_CGL_SHAREGROUP_APPLE, (cl_context_properties)kCGLShareGroup, 
     0 
    }; 

的Windows：

cl_context_properties props[] = 
     { 
      CL_GL_CONTEXT_KHR, (cl_context_properties)wglGetCurrentContext(), 
      CL_WGL_HDC_KHR, (cl_context_properties)wglGetCurrentDC(), 
      CL_CONTEXT_PLATFORM, (cl_context_properties)(platforms[0])(), 
      0 
     }; 

其他：

cl_context_properties props[] = 
     { 
      CL_GL_CONTEXT_KHR, (cl_context_properties)glXGetCurrentContext(), 
      CL_GLX_DISPLAY_KHR, (cl_context_properties)glXGetCurrentDisplay(), 
      CL_CONTEXT_PLATFORM, (cl_context_properties)(platforms[0])(), 
      0 
     }; 

然後，您創建上下文並使用GL緩衝區（每次獲取並釋放它們）：

context = cl::Context(CL_DEVICE_TYPE_GPU, props); 
cl::BufferGL glbuffer(context, CL_MEM_READ_WRITE, myvbo, &err); 

for (each frame){ 
    queue.enqueueAcquireGLObjects(&glbuffer); 
    //use glbuffer as if it is a clbuffer 
    queue.enqueueReleaseGLObjects(&glbuffer); 
}