/*******************************************************
 * 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>
#define USE_FORGE_CPU_COPY_HELPERS
#include <ComputeCopy.h>
#include <complex>
#include <cmath>
#include <vector>
#include <iostream>

const unsigned DIMX = 640;
const unsigned DIMY = 480;
const float PI = 3.14159265359;
const float MINIMUM = 1.0f;
const float MAXIMUM = 20.f;
const float STEP    = 2.0f;
const float NELEMS  = (MAXIMUM-MINIMUM+1)/STEP;
const unsigned DPOINTS[] = {5, 5, 5, 15, 15, 5, 15, 15};

using namespace std;

void generatePoints(std::vector<float> &points, std::vector<float> &dirs)
{
    points.clear();

    for (int j=0; j<NELEMS; ++j) {
        float y = MINIMUM + j*STEP;
        for (int i=0; i<NELEMS; ++i) {
            float x = MINIMUM + i*STEP;
            points.push_back(x);
            points.push_back(y);
            dirs.push_back(sin(2*PI*x/10.f));
            dirs.push_back(sin(2*PI*y/10.f));
        }
    }
}

int main(void)
{
    /*
     * 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, "Vector Field Demo");
    wnd.makeCurrent();

    forge::Chart chart(FG_CHART_2D);
    chart.setAxesLimits(MINIMUM-1.0f, MAXIMUM, MINIMUM-1.0f, MAXIMUM);
    chart.setAxesTitles("x-axis", "y-axis");

    forge::Plot divPoints = chart.plot(4, forge::u32, FG_PLOT_SCATTER, FG_MARKER_CIRCLE);
    divPoints.setColor(0.9f, 0.9f, 0.0f, 1.f);
    divPoints.setLegend("Convergence Points");
    divPoints.setMarkerSize(24);

    forge::VectorField field = chart.vectorField(NELEMS*NELEMS, forge::f32);
    field.setColor(0.f, 0.6f, 0.3f, 1.f);

    std::vector<float> points;
    std::vector<float> dirs;
    generatePoints(points, dirs);

    GfxHandle* handles[3];

    createGLBuffer(&handles[0], divPoints.vertices(), FORGE_VERTEX_BUFFER);
    createGLBuffer(&handles[1], field.vertices(), FORGE_VERTEX_BUFFER);
    createGLBuffer(&handles[2], field.directions(), FORGE_VERTEX_BUFFER);

    copyToGLBuffer(handles[0], (ComputeResourceHandle)DPOINTS, divPoints.verticesSize());
    copyToGLBuffer(handles[1], (ComputeResourceHandle)points.data(), field.verticesSize());
    copyToGLBuffer(handles[2], (ComputeResourceHandle)dirs.data(), field.directionsSize());

    do {
        wnd.draw(chart);
    } while(!wnd.close());

    // destroy GL-cpu interop buffers
    releaseGLBuffer(handles[0]);
    releaseGLBuffer(handles[1]);
    releaseGLBuffer(handles[2]);

    return 0;
}
