Error with ofPixels

bugs, errors
#1

Hi!
I got this error and it opens the ofPixels.h file at line 795
c.set( pixel[0], pixel[1], pixel[2] );

error.jpg1092×728 431 KB

Actually without changing anything in the code the error occurs like 2 in 3 times, not every time.

I am on PC with visual studio. I am working with this tutorial : http://openframeworks.cc/ofBook/chapters/generativemesh.html and I started customize it by adding these lines in the void ofApp::draw()

    int numVerts = mesh.getNumVertices();

    for (int i = 0; i < numVerts; ++i) {

        ofVec3f vert = mesh.getVertex(i);

        int x = int(vert.x);
        int y = int(vert.y);

        ofColor couleur = image.getColor(x, y);
        ofSetColor(couleur);
        ofFill();

        ofDrawEllipse(vert.x, vert.y, 10, 10);

    }

The problem seems to be with the getColor function maybe

I am a beginner with openframeworks and visual studio

If you have any question or if I am not clear, ask me

Thanks

#2

I was getting that same error a few days ago, although on Xcode. Cleaning and rebuilding the project fixed it.

#3

Thanks! But it didn’t work. I cleaned and rebuilt both the solution and the project but it’s still not working. Now it never works.
I don’t have the Microsoft Visual Studio warning window anymore, but it is stuck at the same line.
I am with of 0.9.2

error1.jpg940×288 87.3 KB

Edit : I cleaned the openframeworks lib and it worked well once but now it’s still doing the same error

#4

This is odd.
I cant see any problem in the code.

@arturo do you have any idea about what might be going on?

Best

#5

that’s usually because you are trying to access a position in the pixels that doesn’t exist. try printing out the values or at least storing them in a variable so you can see them in the debugger:

auto pixelIndex = image.getPixels().getPixelIndex(x,y);
auto maxIndex = image.getPixels().size();

if pixelIndex is >= than maxIndex then you are outside of the pixels memory. you can also use an if condition to not try to get the color in that case

#6

Both the pixelIndex and the maxIndex are 48600, which is quite strange because my image is originally 1600654px, I resized it to 200x81px (so 16 200px). 48600 is 162003 but I don’t see if there’s a link.

I think the problem happens the first time as you say, when I tried to access position of pixels that doesn’t exist, with this code (because I had a strange color pattern) :
for (int i = 0; i < numVerts*2; ++i) {
…
}
But even after I have changed it and cleaned the project it seems to be like it is still “in cache”.

Edit : I scaled ofColor couleur = image.getColor(x, y); to ofColor couleur = image.getColor(x/8, y/8); (8 is the factor I used for resizing) and it works, the problem should initially come from that.

Thanks!