mrmBot-Matrix/natives/whisper.cc

97 lines
No EOL
3.4 KiB
C++

#include <napi.h>
#include <vips/vips8>
using namespace std;
using namespace vips;
Napi::Value Whisper(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 caption = obj.Get("caption").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 / 6;
int dividedWidth = width / 175;
int rad = 1;
string font_string = "Upright " + to_string(size);
VImage mask;
if (dividedWidth >= 1) {
mask = VImage::black(dividedWidth * 2 + 1, dividedWidth * 2 + 1) + 128;
mask.draw_circle({255}, dividedWidth, dividedWidth, dividedWidth,
VImage::option()->set("fill", true));
} else {
mask = VImage::black(rad * 2 + 1, rad * 2 + 1) + 128;
mask.draw_circle({255}, rad, rad, rad,
VImage::option()->set("fill", true));
}
VImage textIn = VImage::text(
("<span foreground=\"white\">" + caption + "</span>").c_str(),
VImage::option()
->set("rgba", true)
->set("align", VIPS_ALIGN_CENTRE)
->set("font", font_string.c_str())
->set("width", width));
textIn = textIn.embed(rad + 10, rad + 10, (textIn.width() + 2 * rad) + 20,
(textIn.height() + 2 * rad) + 20);
VImage outline =
textIn.morph(mask, VIPS_OPERATION_MORPHOLOGY_DILATE)
.gaussblur(0.5, VImage::option()->set("min_ampl", 0.1));
outline = (outline == (vector<double>){0, 0, 0, 0});
VImage invert = outline.extract_band(3).invert();
outline =
outline.extract_band(0, VImage::option()->set("n", outline.bands() - 1))
.bandjoin(invert);
VImage textImg = outline.composite2(textIn, 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;
img_frame = img_frame.composite2(
textImg, VIPS_BLEND_MODE_OVER,
VImage::option()
->set("x", (width / 2) - (textImg.width() / 2))
->set("y", (page_height / 2) - (textImg.height() / 2)));
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");
}
}