Vec operators mean() and cross() throw 'is not a function'

[fakob]

Hi, sorry it is me again.
Thanks for fixing the Mat.mean() issue. Now I wanted to use the vec mean() operator and got the following error:

Uncaught Exception:
TypeError: mat.mean(...).mean is not a function

I then tested out all the other vec operators and found that cross() also throws the same exception.
All other operators worked fine. Am I doing something wrong?
First I was calculating mat.mean() which gave me Vec4 { z: 0, y: 0, x: 0, w: 0 }
The result I then used for the vec operator like so mat.mean().mean().

[justadudewhohacks]

Ah yeah, the Vec classes don't implement mean. Yet another fix to be done.

[dnguneratne]

I'd like to work on this. Any tips on how/where to get started?

[justadudewhohacks]

Mean is already implemented for Mat. You could simply take that implementation as an example and adjust it for the Vector classes:

opencv4nodejs/cc/core/MatBindings.h

Lines 767 to 792 in c07bb63

	struct MeanWorker : public CatchCvExceptionWorker {
	public:
	cv::Mat self;
	MeanWorker(cv::Mat self) {
	this->self = self;
	}
	cv::Mat mask = cv::noArray().getMat();
	cv::Scalar mean;
	std::string executeCatchCvExceptionWorker() {
	mean = cv::mean(self, mask);
	return "";
	}
	v8::Local<v8::Value> getReturnValue() {
	return Vec4::Converter::wrap(cv::Vec4d(mean));
	}
	bool unwrapOptionalArgs(Nan::NAN_METHOD_ARGS_TYPE info) {
	return (
	Mat::Converter::optArg(0, &mask, info)
	);
	}
	};

opencv4nodejs/cc/core/Mat.cc

Lines 798 to 812 in f564125

	NAN_METHOD(Mat::Mean) {
	FF::SyncBinding(
	std::make_shared<MatBindings::MeanWorker>(Mat::Converter::unwrap(info.This())),
	"Mat::Mean",
	info
	);
	}
	NAN_METHOD(Mat::MeanAsync) {
	FF::AsyncBinding(
	std::make_shared<MatBindings::MeanWorker>(Mat::Converter::unwrap(info.This())),
	"Mat::MeanAsync",
	info
	);
	}

[dnguneratne]

Hey, I started working on this but I need some help.

What does Mat::Converter do in opencv4nodejs/cc/core/Mat.cc? I'm trying to adapt it to Vec.cc.

NAN_METHOD(Mat::Mean) {
	FF::SyncBinding(
		std::make_shared<MatBindings::MeanWorker>(Mat::Converter::unwrap(info.This())),
		"Mat::Mean",
		info
	);
}

So far I created a VecBindings.h file, which I'm not quite sure how to proceed with:

#include "Vec.h"

#ifndef __FF_VECBINDINGS_H__
#define __FF_VECBINDINGS_H__

namespace VecBindings {
  struct MeanWorker : public CatchCvExceptionWorker {
  public:
	  cv::Mat self;
	  MeanWorker(cv::Mat self) {
		  this->self = self;
      return("test");
	  }
  };
}

Then I added the Mean method to Vec.h

class Vec : public Nan::ObjectWrap {
public:
  static NAN_MODULE_INIT(Init);
  static NAN_METHOD(New);
	static NAN_METHOD(NewVec2);
	static NAN_METHOD(NewVec3);
	static NAN_METHOD(NewVec4);
	
	static NAN_METHOD(Mean);