Function main

examples/opencl/histogram.cpp:257–346

}

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, "Histogram Demo");
        wnd.makeCurrent();

        forge::Image img(IMGW, IMGH, FG_RGBA, forge::u8);

        forge::Chart chart(FG_CHART_2D);

        chart.setAxesLabelFormat("%3.1f", "%.2e");

        /* set x axis limits to maximum and minimum values of data
         * and y axis limits to range [0, number of pixels ideally]
         * but practically total number of pixels as y range will skew
         * the histogram graph vertically. Therefore setting it to
         * 25% of total number of pixels */
        chart.setAxesLimits(0, 1, 0, IMGW*IMGH/(float)(NBINS/4.0));

        /*
         * Create histogram object specifying number of bins
         */
        forge::Histogram hist = chart.histogram(NBINS, forge::s32);
        /*
         * Set histogram colors
         */
        hist.setColor(FG_YELLOW);

        /*
         * 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 image(context, CL_MEM_READ_WRITE, IMG_SIZE);
        cl::Buffer baseNoise(context, CL_MEM_READ_WRITE, IMG_SIZE);
        cl::Buffer perlinNoise(context, CL_MEM_READ_WRITE, IMG_SIZE);
        cl::Buffer histOut(context, CL_MEM_READ_WRITE, NBINS * sizeof(int));
        cl::Buffer colors(context, CL_MEM_READ_WRITE, 3 * NBINS * sizeof(float));

        GfxHandle* handles[3];

        createGLBuffer(&handles[0], img.pixels(), FORGE_IMAGE_BUFFER);
        createGLBuffer(&handles[1], hist.vertices(), FORGE_VERTEX_BUFFER);
        createGLBuffer(&handles[2], hist.colors(), FORGE_VERTEX_BUFFER);

        unsigned frame = 0;
        do {