Uncaught C++ Exception

Technical C/C++
1

I have vision code that will detect the target and will spit the number of particles found to the console. But whenever it looses targets, it gives the following error:

(FRC_RobotTask): Uncaught C++ Exception (#1)!

It then says the memory addresses of the call stack.

Here’s my code

#include "Vision.h"
#include "../Robotmap.h"

Vision::Vision() : Subsystem("Vision") {
	printDebug("Initializing Camera Settings.");
	
	// Get an instance of the camera
	AxisCamera &camera = AxisCamera::GetInstance(CAMERA_IP);
	
	// Write some configuration to the camera
	camera.WriteResolution(CAMERA_RESOLUTION);
	camera.WriteCompression(CAMERA_COMPRESSION);
	camera.WriteBrightness(CAMERA_BRIGHTNESS);
	camera.WriteMaxFPS(CAMERA_FPS);
	camera.WriteColorLevel(CAMERA_COLOR_LEVEL);
	
	
	printDebug("Done Configuring Camera.");
	
	lightRing = new Relay(DEFAULT_DIGITAL_MODULE, LIGHT_RING_PORT, Relay::kForwardOnly);
}
    
void Vision::InitDefaultCommand() {
	// Set the default command for a subsystem here.
	//SetDefaultCommand(new MySpecialCommand());
}

vector<ParticleAnalysisReport> Vision::particleAnalysis()
{
	// Get an instance of the Axis Camera
	AxisCamera &camera = AxisCamera::GetInstance(CAMERA_IP);
	
	// check if there is a new image
	if (camera.IsFreshImage())
	{
		// Get the Image
		ColorImage *colorImage = camera.GetImage();
		BinaryImage *binImage = colorImage->ThresholdRGB(0,175,175,255,0,175);
		
		printDebug("Getting Particle Analysis Report.");
		vector<ParticleAnalysisReport> *temp = binImage->GetOrderedParticleAnalysisReports();
		particles = *temp;
		delete temp;
		
		printDebug("Stepping through particle report to remove particles with area too small.");
		// Step through the particles and elimate any that are too small
		for (UINT8 i = 0; i<particles.size(); i++) {
			if(particles.at(i).particleArea<MIN_PARTICLE_AREA)
			{
				// Erase the current particle from view
				particles.erase(particles.begin()+i-1);
				
				// Because erasing an element actually adjusts all elements
				// after the current one, we need to bump <tt>i</tt> down one
				i--;
			}
		}
		
	}
	
	printDebug("Done processing image.");
	
	targetParticle = particles.at(0);
	
	return particles;
}

void Vision::setTargetParticle(int index)
{
	targetParticle = particles.at(index);
}

double Vision::getNormalizedPosition()
{
	return targetParticle.center_mass_x_normalized;
}
2

Hi,
I have some concern about the idea of assigning ‘particles = *temp’ and deleting temp rather than simply USING temp-> in the routine and then deleting temp at the end, but that isn’t looking like the culprit. I see


			targetParticle = particles.at(0);

as a big issue – when there are no particles at all in the image, particles.size() or temp->size() if not deleted are zero. This means you CANNOT assign targetParticle = particles.at(0); as there is NO ZEROTH ELEMENT at that time. If you, instead, carefully deal with placing that part inside an



if (particles.size()) {
  targetParticle = particles.at(0);
  flagNoParticles = false;
}
else
  flagNoParticles = true;

then that part won’t crash. HOWEVER, it seems that elsewhere in the code you are counting on targetParticle to be valid. You might have to be a little creative (using a flag or re-thinking your logic) in treating this special case such that where you are counting on targetParticle, you are checking to see if you are in the situation where there are none instead and just returning in those cases. It’s a little hard to describe in words…if this isn’t clear, maybe we could talk it out on the phone.

bob

3