mrmBot-Matrix/natives/meme.cc

#include "common.h"

#include <vips/vips8>

using namespace std;
using namespace vips;

char *Meme(string type, char *BufferData, size_t BufferLength,
           ArgumentMap Arguments, size_t *DataSize) {
  string top = GetArgument<string>(Arguments, "top");
  string bottom = GetArgument<string>(Arguments, "bottom");
  string font = GetArgument<string>(Arguments, "font");
  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 / 9;
  int dividedWidth = width / 1000;
  int rad = 1;
  vector<double> zeroVec = {0, 0, 0, 0};

  string font_string =
      (font == "roboto" ? "Roboto Condensed" : font) + ", Twemoji Color Font " +
      (font != "impact" ? "bold" : "normal") + " " + to_string(size);

  VImage mask = VImage::black(rad * 2 + 1, rad * 2 + 1) + 128;
  mask.draw_circle({255}, rad, rad, rad, VImage::option()->set("fill", true));

  VImage altMask;

  if (dividedWidth >= 1) {
    altMask = VImage::black(dividedWidth * 2 + 1, dividedWidth * 2 + 1) + 128;
    altMask.draw_circle({255}, dividedWidth, dividedWidth, dividedWidth,
                        VImage::option()->set("fill", true));
  }

  auto findResult = fontPaths.find(font);
  if (findResult != fontPaths.end()) {
    VImage::text(".", VImage::option()->set(
                          "fontfile", (basePath + findResult->second).c_str()));
  }

  VImage topText;
  if (top != "") {
    VImage topIn = VImage::text(
        ("<span foreground=\"white\">" + top + "</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", width));

    topIn = topIn.embed(rad + 10, rad + 10, (topIn.width() + 2 * rad) + 20,
                        (topIn.height() + 2 * rad) + 20);

    VImage topOutline =
        topIn.morph(mask, VIPS_OPERATION_MORPHOLOGY_DILATE)
            .gaussblur(0.5, VImage::option()->set("min_ampl", 0.1));
    if (dividedWidth >= 1) {
      topOutline = topOutline.morph(altMask, VIPS_OPERATION_MORPHOLOGY_DILATE);
    }
    topOutline = (topOutline == zeroVec);
    VImage topInvert = topOutline.extract_band(3).invert();
    topOutline =
        topOutline
            .extract_band(0, VImage::option()->set("n", topOutline.bands() - 1))
            .bandjoin(topInvert);
    topText = topOutline.composite2(topIn, VIPS_BLEND_MODE_OVER);
  }

  VImage bottomText;
  if (bottom != "") {
    VImage bottomIn = VImage::text(
        ("<span foreground=\"white\">" + bottom + "</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", width));
    bottomIn =
        bottomIn.embed(rad + 10, rad + 10, (bottomIn.width() + 2 * rad) + 20,
                       (bottomIn.height() + 2 * rad) + 20);
    VImage bottomOutline =
        bottomIn.morph(mask, VIPS_OPERATION_MORPHOLOGY_DILATE)
            .gaussblur(0.5, VImage::option()->set("min_ampl", 0.1));
    if (dividedWidth >= 1) {
      bottomOutline =
          bottomOutline.morph(altMask, VIPS_OPERATION_MORPHOLOGY_DILATE);
    }
    bottomOutline = (bottomOutline == zeroVec);
    VImage bottomInvert = bottomOutline.extract_band(3).invert();
    bottomOutline =
        bottomOutline
            .extract_band(0,
                          VImage::option()->set("n", bottomOutline.bands() - 1))
            .bandjoin(bottomInvert);
    bottomText = bottomOutline.composite2(bottomIn, VIPS_BLEND_MODE_OVER);
  }

  vector<VImage> img;
  for (int i = 0; i < nPages; i++) {
    VImage img_frame =
        type == "gif" ? in.crop(0, i * pageHeight, width, pageHeight) : in;
    if (top != "") {
      img_frame = img_frame.composite2(
          topText, VIPS_BLEND_MODE_OVER,
          VImage::option()->set("x", (width / 2) - (topText.width() / 2)));
    }
    if (bottom != "") {
      img_frame = img_frame.composite2(
          bottomText, VIPS_BLEND_MODE_OVER,
          VImage::option()
              ->set("x", (width / 2) - (bottomText.width() / 2))
              ->set("y", pageHeight - bottomText.height()));
    }
    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(
      ("." + type).c_str(), &buf, DataSize,
      type == "gif" ? VImage::option()->set("dither", 0)->set("reoptimise", 1)
                    : 0);

  vips_error_clear();
  vips_thread_shutdown();
  return (char *)buf;
}