mrmBot-Matrix/natives/meme.cc

144 lines
No EOL
5.4 KiB
C++

#include <napi.h>
#include <vips/vips8>
using namespace std;
using namespace vips;
Napi::Value Meme(const Napi::CallbackInfo &info) {
Napi::Env env = info.Env();
try {
Napi::Object obj = info[0].As<Napi::Object>();
Napi::Buffer<char> data = obj.Get("data").As<Napi::Buffer<char>>();
string top = obj.Get("top").As<Napi::String>().Utf8Value();
string bottom = obj.Get("bottom").As<Napi::String>().Utf8Value();
string font = obj.Get("font").As<Napi::String>().Utf8Value();
string type = obj.Get("type").As<Napi::String>().Utf8Value();
VOption *options = VImage::option()->set("access", "sequential");
VImage in =
VImage::new_from_buffer(data.Data(), data.Length(), "",
type == "gif" ? options->set("n", -1) : options)
.colourspace(VIPS_INTERPRETATION_sRGB);
if (!in.has_alpha()) in = in.bandjoin(255);
int width = in.width();
int page_height = vips_image_get_page_height(in.get_image());
int n_pages = vips_image_get_n_pages(in.get_image());
int size = width / 9;
int dividedWidth = width / 1000;
int rad = 1;
string font_string = (font == "roboto" ? "Roboto Condensed" : 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));
}
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("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 == (vector<double>){0, 0, 0, 0});
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("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 == (vector<double>){0, 0, 0, 0});
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 < n_pages; i++) {
VImage img_frame =
type == "gif" ? in.crop(0, i * page_height, width, page_height) : 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", page_height - bottomText.height()));
}
img.push_back(img_frame);
}
VImage final = VImage::arrayjoin(img, VImage::option()->set("across", 1));
final.set(VIPS_META_PAGE_HEIGHT, page_height);
void *buf;
size_t length;
final.write_to_buffer(
("." + type).c_str(), &buf, &length,
type == "gif" ? VImage::option()->set("dither", 0) : 0);
vips_thread_shutdown();
Napi::Object result = Napi::Object::New(env);
result.Set("data", Napi::Buffer<char>::Copy(env, (char *)buf, length));
result.Set("type", type);
return result;
} catch (std::exception const &err) {
throw Napi::Error::New(env, err.what());
} catch (...) {
throw Napi::Error::New(env, "Unknown error");
}
}