#include "image_utils.h"

namespace image
{
    image::Image<uint16_t> blend_images(image::Image<uint16_t> img1, image::Image<uint16_t> img2)
    {
        size_t width = std::min<int>(img1.width(), img2.width());
        size_t height = std::min<int>(img1.height(), img2.height());
        image::Image<uint16_t> img_b(width, height, img1.channels());
        for (int c = 0; c < img1.channels(); c++)
        {
            for (size_t i = 0; i < height * width; i++)
            {
                if (img1.channel(c)[i] == 0)
                    img_b.channel(c)[i] = img2.channel(c)[i];
                else if (img2.channel(c)[i] == 0)
                    img_b.channel(c)[i] = img1.channel(c)[i];
                else
                    img_b.channel(c)[i] = (size_t(img1.channel(c)[i]) + size_t(img2.channel(c)[i])) / 2;
            }
        }
        return img_b;
    }

    image::Image<uint16_t> merge_images_opacity(image::Image<uint16_t> img1, image::Image<uint16_t> img2, float op)
    {
        size_t width = std::min<int>(img1.width(), img2.width());
        size_t height = std::min<int>(img1.height(), img2.height());
        image::Image<uint16_t> img_b(width, height, img1.channels());
        for (int c = 0; c < img1.channels(); c++)
        {
            for (size_t i = 0; i < height * width; i++)
            {
                if (op == 1.0)
                {
                    if (img2.channel(c)[i] != 0)
                        img_b.channel(c)[i] = img2.channel(c)[i];
                    else
                        img_b.channel(c)[i] = img1.channel(c)[i];
                }
                else if (op == 0.0)
                {
                    if (img1.channel(c)[i] != 0)
                        img_b.channel(c)[i] = img1.channel(c)[i];
                    else
                        img_b.channel(c)[i] = img2.channel(c)[i];
                }
                else
                    img_b.channel(c)[i] = std::min<int>(65535, img1.channel(c)[i] * (1.0f - op) + img2.channel(c)[i] * op);
            }
        }
        return img_b;
    }
}