Random Coordinates C++ Node.JS AddOn

randomcoords.cpp

#include <node.h>
#include <v8.h>
#include <stdio.h>
#include <stdlib.h>

using namespace v8;

Handle<Value> getRandomCoords2D(const Arguments& args) {
    HandleScope scope;
    
   if (args.Length() < 2) {
        ThrowException(Exception::TypeError(String::New("Wrong number of arguments")));
        return scope.Close(Undefined());
    }

    if (!args[0]->IsNumber() || !args[1]->IsNumber()) {
        ThrowException(Exception::TypeError(String::New("Wrong arguments")));
        return scope.Close(Undefined());
    }

    Local<Object> obj = Object::New();
    obj->Set(String::NewSymbol("x"), Number::New( 1 + (rand() % xBound->IntegerValue() )));
    obj->Set(String::NewSymbol("y"), Number::New( 1 + (rand() % yBound->IntegerValue() )));

    return scope.Close(obj);
}

Handle<Value> getRandomCoords3D(const Arguments& args) {
    HandleScope scope;

    if (args.Length() < 3) {
        ThrowException(Exception::TypeError(String::New("Wrong number of arguments")));
        return scope.Close(Undefined());
    }

    if (!args[0]->IsNumber() || !args[1]->IsNumber() || !args[2]->IsNumber()) {
        ThrowException(Exception::TypeError(String::New("Wrong arguments")));
        return scope.Close(Undefined());
    }

    Local<Number> xBound = args[0]->ToNumber();
    Local<Number> yBound = args[1]->ToNumber();
    Local<Number> zBound = args[2]->ToNumber();

    Local<Object> obj = Object::New();
    obj->Set(String::NewSymbol("x"), Number::New( 1 + (rand() % xBound->IntegerValue() )));
    obj->Set(String::NewSymbol("y"), Number::New( 1 + (rand() % yBound->IntegerValue() )));
    obj->Set(String::NewSymbol("z"), Number::New( 1 + (rand() % zBound->IntegerValue() )));
    return scope.Close(obj);
}


void init(Handle<Object> target) {
    target->Set(String::NewSymbol("getRandomCoords3D"),
        FunctionTemplate::New(getRandomCoords3D)->GetFunction());

    target->Set(String::NewSymbol("getRandomCoords2D"),
        FunctionTemplate::New(getRandomCoords2D)->GetFunction());
}
NODE_MODULE(randomcoords, init)

Good example, thanks for sharing!

Here's the related article:
http://www.benfarrell.com/2013/01/03/c-and-node-js-an-unholy-combination-but-oh-so-right/

Thanks for the useful article. Haven't tried to run this yet but it seems getRandomCoords2D is missing these lines:

Local<Number> xBound = args[0]->ToNumber();
Local<Number> yBound = args[1]->ToNumber();

In fact you can do fine with just the 3D function. Whenever you need 2D coordinates you just ignore the z axis. Cuts down on code duplication.

That's great! I'm still preparing myself for my first Node project, and I'll sure build some nasty addons to boost performance in some heavy calculations

Nice example