mrmBot-Matrix/natives/resize.cc

69 lines
2.2 KiB
C++

#include <napi.h>
#include <vips/vips8>
using namespace std;
using namespace vips;
Napi::Value Resize(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 stretch = obj.Has("stretch")
? obj.Get("stretch").As<Napi::Boolean>().Value()
: false;
bool wide =
obj.Has("wide") ? obj.Get("wide").As<Napi::Boolean>().Value() : false;
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);
VImage out;
int width = in.width();
int totalHeight = in.height();
int pageHeight = vips_image_get_page_height(in.get_image());
int finalHeight;
if (stretch) {
out = in.resize(
512.0 / (double)width,
VImage::option()->set("vscale", 512.0 / (double)pageHeight));
finalHeight = 512;
} else if (wide) {
out = in.resize(9.5, VImage::option()->set("vscale", 0.5));
finalHeight = pageHeight / 2;
} else {
VImage small = in.resize(0.1);
out =
small.resize((double)width / small.width(),
VImage::option()
->set("vscale", (double)totalHeight / small.height())
->set("kernel", VIPS_KERNEL_NEAREST));
finalHeight = pageHeight;
}
out.set(VIPS_META_PAGE_HEIGHT, finalHeight);
void *buf;
size_t length;
out.write_to_buffer(("." + type).c_str(), &buf, &length);
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");
}
}