mrmBot-Matrix/natives/togif.cc

56 lines
1.6 KiB
C++

#include <napi.h>
#include <vips/vips8>
using namespace std;
using namespace vips;
Napi::Value ToGif(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 type = obj.Get("type").As<Napi::String>().Utf8Value();
if (type == "gif") {
Napi::Object result = Napi::Object::New(env);
result.Set("data", data);
result.Set("type", "gif");
return result;
}
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 pageHeight = vips_image_get_page_height(in.get_image());
vector<VImage> img;
img.push_back(in);
VImage final = VImage::arrayjoin(img, VImage::option()->set("across", 1));
final.set(VIPS_META_PAGE_HEIGHT, pageHeight + in.height());
void *buf;
size_t length;
final.write_to_buffer(
("." + type).c_str(), &buf, &length, VImage::option()->set("dither", 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", "gif");
return result;
} catch (std::exception const &err) {
throw Napi::Error::New(env, err.what());
} catch (...) {
throw Napi::Error::New(env, "Unknown error");
}
}