void render(unsigned int width, unsigned int height)
{
    // Allocate space for target image
    float *pixel_data = new float[width * height * 3];

    // Do other stuff

    // Main rendering loop
    float calculated_data[3];
    for (unsigned int y = 0; y < height; ++y)
    {
        for (unsigned int x = 0; x < width; ++x)
        {
            // Calculate stuff
            // and store in calculated_data

            // Write pixel
            unsigned int pixel_index = (x + y*width)*3;
            pixel_data[pixel_index + 0] = calculated_data[0];
            pixel_data[pixel_index + 1] = calculated_data[1];
            pixel_data[pixel_index + 2] = calculated_data[2];
        }
    }

    // Write image to png/bmp/...

    // Free memory (would be WAY more involved for a 3D array)
    delete [] pixel_data;
}