mrmBot-Matrix/natives/snapchat.cc

#include <vips/vips8>

#include "common.h"

using namespace std;
using namespace vips;

ArgumentMap Snapchat(string type, string *outType, char *BufferData,
               size_t BufferLength, ArgumentMap Arguments, size_t *DataSize) {
  string caption = GetArgument<string>(Arguments, "caption");
  float pos = GetArgumentWithFallback<float>(Arguments, "pos", 0.5);
  string basePath = GetArgument<string>(Arguments, "basePath");

  VOption *options = VImage::option()->set("access", "sequential");

  VImage in =
      VImage::new_from_buffer(BufferData, BufferLength, "",
                              type == "gif" ? options->set("n", -1) : options)
          .colourspace(VIPS_INTERPRETATION_sRGB);
  if (!in.has_alpha()) in = in.bandjoin(255);

  int width = in.width();
  int pageHeight = vips_image_get_page_height(in.get_image());
  int nPages = vips_image_get_n_pages(in.get_image());
  int size = width / 20;
  int textWidth = width - ((width / 25) * 2);

  string font_string = "Helvetica Neue, Twemoji Color Font " + to_string(size);

  VImage textIn = VImage::text(
      ".", VImage::option()->set(
               "fontfile", (basePath + "assets/fonts/caption2.ttf").c_str()));
  textIn = VImage::text(
      ("<span foreground=\"white\" background=\"#000000B2\">" + caption +
       "</span>")
          .c_str(),
      VImage::option()
          ->set("rgba", true)
          ->set("align", VIPS_ALIGN_CENTRE)
          ->set("font", font_string.c_str())
          ->set("fontfile", (basePath + "assets/fonts/twemoji.otf").c_str())
          ->set("width", textWidth));
  int bgHeight = textIn.height() + (width / 25);
  textIn = ((textIn == (vector<double>){0, 0, 0, 0}).bandand())
               .ifthenelse({0, 0, 0, 178}, textIn)
               .embed((width / 2) - (textIn.width() / 2),
                      (bgHeight / 2) - (textIn.height() / 2), width, bgHeight,
                      VImage::option()
                          ->set("extend", "background")
                          ->set("background", (vector<double>){0, 0, 0, 178}));

  vector<VImage> img;
  for (int i = 0; i < nPages; i++) {
    VImage img_frame =
        type == "gif" ? in.crop(0, i * pageHeight, width, pageHeight) : in;
    img_frame = img_frame.composite2(
        textIn, VIPS_BLEND_MODE_OVER,
        VImage::option()->set("x", 0)->set("y", pageHeight * pos));
    img.push_back(img_frame);
  }
  VImage final = VImage::arrayjoin(img, VImage::option()->set("across", 1));
  final.set(VIPS_META_PAGE_HEIGHT, pageHeight);

  void *buf;
  final.write_to_buffer(
      ("." + *outType).c_str(), &buf, DataSize,
      *outType == "gif"
          ? VImage::option()->set("dither", 0)->set("reoptimise", 1)
          : 0);

  ArgumentMap output;
  output["buf"] = (char *)buf;
  output["width"] = width;
  output["height"] = pageHeight;

  return output;
}