weird problem with ofPoint

beginners
#1

Hey everyone,

I’m currently having an issue with ofPoint’s set method.

I have a class called IRTracker that looks like this:

NOTE: ofpoint_srcPoints and ofpoint_dstPoints are arrays of ofPoint with a length of 4

  
  
  
#include "IRTracker.h"  
  
IRTracker::IRTracker() {  
	b_cameraSetup		= false;  
	b_videoSetup		= false;  
	f_playerBlobArea	        = 100.00;  
}  
  
void IRTracker::setupCamera(int i_deviceNumber) {  
	  
	// setup device  
	ofvidGrab_irFeed.setDeviceID(i_deviceNumber);  
	  
	// setup video grabber:  
	ofvidGrab_irFeed.initGrabber(320, 240);  
	  
	// get the width and height, and allocate color and grayscale images:   
	i_width	= ofvidGrab_irFeed.width;   
	i_height = ofvidGrab_irFeed.height;		  
}  
  
void IRTracker::setupCV() {  
	  
	// setup video grabber:  
	ofvidGrab_irFeed.initGrabber(320, 240);  
	  
	// get the width and height, and allocate color and grayscale images:   
	i_width = ofvidGrab_irFeed.width;   
	i_height = ofvidGrab_irFeed.height;  
	  
	ofxCvColor_irColorImage.allocate(i_width, i_height);  
	ofxCvGray_irGrayImage.allocate(i_width, i_height);  
	ofxCvGray_irGrayImagePreWarp.allocate(i_width, i_height);  
	ofxCvGray_videoBgImage.allocate(i_width, i_height);  
	ofxCvGray_irDiffImage.allocate(i_width, i_height);  
	  
	  
	// set Default points  
	ofpoint_srcPoints[0].set(0.0, 0.0, 0.0);  
	ofpoint_srcPoints[1].set(320.0, 0.0, 0.0);  
	ofpoint_srcPoints[2].set(320.0, 240.0, 0.0);  
	ofpoint_srcPoints[3].set(0.0, 240.0, 0.0);  
	  
	ofpoint_dstPoints[0].set(0.0, 0.0, 0.0);  
	ofpoint_dstPoints[1].set(320.0, 0.0, 0.0);  
	ofpoint_dstPoints[2].set(320.0, 240.0, 0.0);  
	ofpoint_dstPoints[3].set(0.0, 240.0, 0.0);  
	  
	for(int i=0; i<4; i++)  
	{  
	    printf("setup src pnts: %d, %d \n", ofpoint_srcPoints[i].x,ofpoint_srcPoints[i].y);  
	}  
}  
  
//process the incoming frame and look for a laser	  
void IRTracker::processFrame() {  
	  
	///////////////////////////////////////////////////////////  
	// Part 1 - get the video data  
	///////////////////////////////////////////////////////////  
	bool bLearnBg			= false;  
	int threshold			        = 196;  
	int minBlobSize			= 25;  
	int maxBlobSize			= 1000;  
	int nBlobsConsidered	        = 2;  
	  
	  
	ofvidGrab_irFeed.update();  
	  
	if (ofvidGrab_irFeed.isFrameNew()){  
		  
		ofxCvColor_irColorImage.setFromPixels(ofvidGrab_irFeed.getPixels(), i_width, i_height);  
		ofxCvGray_irGrayImage = ofxCvColor_irColorImage;  
		ofxCvGray_irGrayImage.warpIntoMe(ofxCvGray_irGrayImagePreWarp, ofpoint_srcPoints, ofpoint_dstPoints);  
		  
		if (bLearnBg){   
			ofxCvGray_videoBgImage = ofxCvGray_irGrayImage;  
		}  
		  
		if (ofGetElapsedTimef() < 1.5){  
			ofxCvGray_videoBgImage = ofxCvGray_irGrayImage;  
		}  
		  
		ofxCvGray_irDiffImage.absDiff(ofxCvGray_irGrayImage, ofxCvGray_videoBgImage);  
		ofxCvGray_irDiffImage.threshold(threshold);  
		  
		ofxCvContourFind_contourFinder.findContours(ofxCvGray_irDiffImage, minBlobSize, maxBlobSize, nBlobsConsidered, false, true);  
		  
	}  
	  
}   
  
void IRTracker::drawFeed() {  
	  
	ofxCvGray_irGrayImage.draw(20,20, 320,240);  
	ofxCvGray_videoBgImage.draw(320+40, 20, 320, 240);  
	ofxCvGray_irDiffImage.draw(20,240+40);  
	ofxCvContourFind_contourFinder.draw(20,240+40);  
  
}  
  
int IRTracker::getPlayerBlobX() {  
	  
	// Assumes a cv has been set up and frame processed  
	  
	int f_x_pos_returned;  
	  
	for (int i = 0; i <  ofxCvContourFind_contourFinder.nBlobs; i++){  
		if(ofxCvContourFind_contourFinder.blobs[i].area >= f_playerBlobArea)  
		{  
			f_x_pos_returned = ofxCvContourFind_contourFinder.blobs[i].centroid.x;  
		}  
		else  
		{  
			f_x_pos_returned = 0;  
		}  
	}  
	  
	return ((int) f_x_pos_returned);  
	  
}  
  
int IRTracker::getPlayerBlobY() {  
	  
	// Assumes a cv has been set up and frame processed  
	  
	int f_y_pos_returned;  
	  
	for (int i = 0; i <  ofxCvContourFind_contourFinder.nBlobs; i++){  
		if(ofxCvContourFind_contourFinder.blobs[i].area >= f_playerBlobArea)  
		{  
			f_y_pos_returned = ofxCvContourFind_contourFinder.blobs[i].centroid.y;  
		}  
		else  
		{  
			f_y_pos_returned = 0;  
		}  
	}  
	  
	return ((int) f_y_pos_returned);  
	  
}  
  
void IRTracker::setSourcePoint(int i_point_adjusting, int i_x, int i_y) {  
	ofpoint_srcPoints[i_point_adjusting].set((float) i_x, (float) i_y);  
	printf("Params are: %d, %d \n", i_x, i_y);  
	printf("Source points after set: %d, %d \n", ofpoint_srcPoints[i_point_adjusting].x, ofpoint_srcPoints[i_point_adjusting].y);  
}

My problem lies in the setupCV() method. when i set each point in ofpoint_srcPoints (or in ofpoint_dstPoints for that matter) and then print them out i dont get the values i set them to, but something like this:

  
  
setup src pnts: 0, 0   
setup src pnts: 0, 1081344000   
setup src pnts: 0, 1081344000   
setup src pnts: 0, 0

A similar thing happens when I set the source points on a mouse click the value it gets set to is not the x or y of the mouse location.

Has anybody had a situation like this or possible sees something i dont see?

#2

you’re trying to print the point coordinates as integers while they are floats, try with:

  
printf("setup src pnts: %f, %f \n", ofpoint_srcPoints[i].x,ofpoint_srcPoints[i].y);
#3

Thanks arturo! That was it.

#4

One way to completely avoid this problem is just to use iostream functions. If you’re coming from Processing, printf() might look similar to println()… but the closest thing is really cout:

  
  
cout << "setup src pnts: " << ofpoint_srcPoints[i].x << ", " << ofpoint_srcPoints[i].y << endl;