mrmBot-Matrix/natives/reverse.cc

71 lines
No EOL
2.3 KiB
C++

#include <napi.h>
#include <vips/vips8>
using namespace std;
using namespace vips;
Napi::Value Reverse(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>>();
bool soos =
obj.Has("soos") ? obj.Get("soos").As<Napi::Boolean>().Value() : false;
VOption *options =
VImage::option()->set("access", "sequential")->set("n", -1);
VImage in = VImage::new_from_buffer(data.Data(), data.Length(), "", options)
.colourspace(VIPS_INTERPRETATION_sRGB);
int width = in.width();
int pageHeight = vips_image_get_page_height(in.get_image());
int nPages = vips_image_get_n_pages(in.get_image());
vector<VImage> split;
// todo: find a better way of getting individual frames (or at least getting the frames in reverse order)
for (int i = 0; i < nPages; i++) {
VImage img_frame = in.crop(0, i * pageHeight, width, pageHeight);
split.push_back(img_frame);
}
vector<int> delays = in.get_array_int("delay");
if (soos) {
vector<VImage> copy = split;
vector<int> copy2 = delays;
reverse(copy.begin(), copy.end());
reverse(copy2.begin(), copy2.end());
copy.pop_back();
copy2.pop_back();
copy.erase(copy.begin());
copy2.erase(copy2.begin());
split.insert(split.end(), copy.begin(), copy.end());
delays.insert(delays.end(), copy2.begin(), copy2.end());
} else {
reverse(split.begin(), split.end());
reverse(delays.begin(), delays.end());
}
VImage final = VImage::arrayjoin(split, VImage::option()->set("across", 1));
final.set(VIPS_META_PAGE_HEIGHT, pageHeight);
final.set("delay", delays);
void *buf;
size_t length;
final.write_to_buffer(".gif", &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");
}
}