mrmBot-Matrix/natives/watermark.cc

#include <Magick++.h>
#include <napi.h>

#include <iostream>
#include <list>

using namespace std;
using namespace Magick;

Napi::Value Watermark(const Napi::CallbackInfo &info) {
  Napi::Env env = info.Env();

  Napi::Object obj = info[0].As<Napi::Object>();
  string path = obj.Get("path").As<Napi::String>().Utf8Value();
  string water = obj.Get("water").As<Napi::String>().Utf8Value();
  int gravity = obj.Get("gravity").As<Napi::Number>().Int32Value();
  bool resize =
      obj.Has("resize") ? obj.Get("resize").As<Napi::Boolean>().Value() : false;
  bool append =
      obj.Has("append") ? obj.Get("append").As<Napi::Boolean>().Value() : false;
  bool mc = obj.Has("mc") ? obj.Get("mc").As<Napi::Boolean>().Value() : false;
  string type = obj.Get("type").As<Napi::String>().Utf8Value();
  int delay =
      obj.Has("delay") ? obj.Get("delay").As<Napi::Number>().Int32Value() : 0;

  Blob blob;

  list<Image> frames;
  list<Image> coalesced;
  list<Image> mid;
  Image watermark;
  readImages(&frames, path);
  watermark.read(water);
  if (resize && append) {
    string query(to_string(frames.front().baseColumns()) + "x");
    watermark.scale(Geometry(query));
  } else if (resize) {
    string query("x" + to_string(frames.front().baseRows()));
    watermark.scale(Geometry(query));
  }
  coalesceImages(&coalesced, frames.begin(), frames.end());

  for (Image &image : coalesced) {
    Image final;
    if (append) {
      list<Image> to_append;
      to_append.push_back(image);
      to_append.push_back(watermark);
      appendImages(&final, to_append.begin(), to_append.end(), true);
      final.repage();
    } else if (mc) {
      image.backgroundColor("white");
      image.extent(Geometry(image.columns(), image.rows() + 15));
      image.composite(watermark, Magick::GravityType(gravity),
                      Magick::OverCompositeOp);
      final = image;
    } else {
      image.composite(watermark, Magick::GravityType(gravity),
                      Magick::OverCompositeOp);
      final = image;
    }
    image.magick(type);
    final.animationDelay(delay == 0 ? image.animationDelay() : delay);
    mid.push_back(final);
  }

  optimizeTransparency(mid.begin(), mid.end());

  if (type == "gif") {
    for (Image &image : mid) {
      image.quantizeDitherMethod(FloydSteinbergDitherMethod);
      image.quantize();
    }
  }

  writeImages(mid.begin(), mid.end(), &blob);

  Napi::Object result = Napi::Object::New(env);
  result.Set("data",
          Napi::Buffer<char>::Copy(env, (char *)blob.data(), blob.length()));
  result.Set("type", type);
  return result;
}