LWJGL 3 Compute & XR Bindings: OpenCL, OpenXR, EGL

// Enumerate platforms and pick the first GPU
CLPlatform platform = CLPlatform.getPlatforms().get(0);
CLDevice device = platform.getDevices(CL10.CL_DEVICE_TYPE_GPU).get(0);

// Create context and command queue
long context = CL10.clCreateContext(null, device, null, NULL, null);
long queue   = CL10.clCreateCommandQueue(context, device, 0, null);

// Compile a kernel from source
String src = "__kernel void add(__global float* a, __global float* b, __global float* c) {"
           + "  int i = get_global_id(0); c[i] = a[i] + b[i]; }";
long program = CL10.clCreateProgramWithSource(context, src, null);
CL10.clBuildProgram(program, device, "", null, NULL);
long kernel = CL10.clCreateKernel(program, "add", null);

// Per-frame: wait, begin, locate views, render, end
XrFrameState frameState = XrFrameState.calloc(stack);
XR10.xrWaitFrame(session, null, frameState);
XR10.xrBeginFrame(session, null);

// Locate views (eye poses and FOVs)
XrViewState viewState = XrViewState.calloc(stack);
XrView.Buffer views = XrView.calloc(2, stack);
// ... fill viewLocateInfo, call xrLocateViews ...

// Render each eye into swapchain images, then submit
// ... acquire swapchain image, render, release ...

XrFrameEndInfo endInfo = XrFrameEndInfo.calloc(stack)
    .type(XR10.XR_TYPE_FRAME_END_INFO)
    .displayTime(frameState.predictedDisplayTime())
    .environmentBlendMode(XR10.XR_ENVIRONMENT_BLEND_MODE_OPAQUE)
    .layers(layers);
XR10.xrEndFrame(session, endInfo);

EGLDisplay
  └── EGLConfig (surface capabilities: color depth, depth buffer, stencil, MSAA)
        ├── EGLSurface (window surface, pbuffer, or pixmap)
        └── EGLContext (bound to a surface for rendering)

long display = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
EGL14.eglInitialize(display, null, 0, null, 0);

int[] attribs = { EGL14.EGL_SURFACE_TYPE, EGL14.EGL_PBUFFER_BIT,
                  EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
                  EGL14.EGL_NONE };
EGLConfig[] configs = new EGLConfig[1];
EGL14.eglChooseConfig(display, attribs, 0, configs, 0, 1, null, 0);

int[] pbAttribs = { EGL14.EGL_WIDTH, 1920, EGL14.EGL_HEIGHT, 1080, EGL14.EGL_NONE };
EGLSurface surface = EGL14.eglCreatePbufferSurface(display, configs[0], pbAttribs, 0);

int[] ctxAttribs = { EGL14.EGL_CONTEXT_CLIENT_VERSION, 3, EGL14.EGL_NONE };
EGLContext ctx = EGL14.eglCreateContext(display, configs[0], EGL14.EGL_NO_CONTEXT, ctxAttribs, 0);
EGL14.eglMakeCurrent(display, surface, surface, ctx);