/*******************************************************
 * Copyright (c) 2015-2019, ArrayFire
 * All rights reserved.
 *
 * This file is distributed under 3-clause BSD license.
 * The complete license agreement can be obtained at:
 * http://arrayfire.com/licenses/BSD-3-Clause
 ********************************************************/

#include <forge.h>
#include "cl_helpers.h"
#include <mutex>
#include <complex>
#include <cmath>
#include <vector>
#include <iostream>
#include <iterator>
#include <algorithm>

const unsigned DIMX = 1000;
const unsigned DIMY = 800;

static const float ZMIN = 0.1f;
static const float ZMAX = 10.f;

const float DX = 0.005;
static const unsigned ZSIZE = (ZMAX-ZMIN)/DX+1;

using namespace std;

#define USE_FORGE_OPENCL_COPY_HELPERS
#include <ComputeCopy.h>

static const std::string sincos_surf_kernel =
"kernel void generateCurve(global float* out, const float t, const float dx, const float zmin, const unsigned SIZE)\n"
"{\n"
"    int offset = get_global_id(0);\n"
"\n"
"    float z = zmin + offset*dx;\n"
"    if (offset < SIZE) {\n"
"       out[offset*3 + 0] = cos(z*t+t)/z;\n"
"       out[offset*3 + 1] = sin(z*t+t)/z;\n"
"       out[offset*3 + 2] = z + 0.1*sin(t);\n"
"    }\n"
"}\n";

inline int divup(int a, int b)
{
    return (a+b-1)/b;
}

void kernel(cl::Buffer& devOut, cl::CommandQueue& queue, float t)
{
    static std::once_flag   compileFlag;
    static cl::Program      prog;
    static cl::Kernel       kern;

    std::call_once(compileFlag,
        [queue]() {
        prog = cl::Program(queue.getInfo<CL_QUEUE_CONTEXT>(), sincos_surf_kernel, true);
            kern = cl::Kernel(prog, "generateCurve");
        });

    NDRange global(ZSIZE);

    kern.setArg(0, devOut);
    kern.setArg(1, t);
    kern.setArg(2, DX);
    kern.setArg(3, ZMIN);
    kern.setArg(4, ZSIZE);
    queue.enqueueNDRangeKernel(kern, cl::NullRange, global);
}

int main(void)
{
    try {

        /*
         * First Forge call should be a window creation call
         * so that necessary OpenGL context is created for any
         * other forge::* object to be created successfully
         */
        forge::Window wnd(DIMX, DIMY, "Three dimensional line plot demo");
        wnd.makeCurrent();

        forge::Chart chart(FG_CHART_3D);
        chart.setAxesLimits(-1.1f, 1.1f, -1.1f, 1.1f, 0.f, 10.f);
        chart.setAxesTitles("x-axis", "y-axis", "z-axis");

        forge::Plot plot3 = chart.plot(ZSIZE, forge::f32);

        /*
         * Helper function to create a CLGL interop context.
         * This function checks for if the extension is available
         * and creates the context on the appropriate device.
         * Note: context and queue are defined in cl_helpers.h
         */
        context = createCLGLContext(wnd);
        Device device = context.getInfo<CL_CONTEXT_DEVICES>()[0];
        queue = CommandQueue(context, device);

        cl::Buffer devOut(context, CL_MEM_READ_WRITE, sizeof(float) * ZSIZE * 3);
        static float t=0;
        kernel(devOut, queue, t);

        GfxHandle* handle;
        createGLBuffer(&handle, plot3.vertices(), FORGE_VERTEX_BUFFER);
        /* copy your data into the pixel buffer object exposed by
         * forge::Surface class and then proceed to rendering.
         * To help the users with copying the data from compute
         * memory to display memory, Forge provides copy headers
         * along with the library to help with this task
         */
        copyToGLBuffer(handle, (ComputeResourceHandle)devOut(), plot3.verticesSize());

        do {
            t+=0.01;
            kernel(devOut, queue, t);
            copyToGLBuffer(handle, (ComputeResourceHandle)devOut(), plot3.verticesSize());
            wnd.draw(chart);
        } while(!wnd.close());

        releaseGLBuffer(handle);

    }catch (forge::Error err) {
        std::cout << err.what() << "(" << err.err() << ")" << std::endl;
    } catch (cl::Error err) {
        std::cout << err.what() << "(" << err.err() << ")" << std::endl;
    }
    return 0;
}
