stack smashing detected, abort, OpenGl freeglut

Question

So I have the following code for graphics perspective projection:

#include <GL/glut.h>
#include <iostream>
#include <unistd.h>
#include <math.h> 

#define UpperBD 5 
#define PI      3.1415926 
#define Num_pts 10

float Xe = 200.0f;
float Ye = 200.0f;
float Ze = 200.0f;
float Rho = sqrt(pow(Xe, 2) + pow(Ye, 2) + pow(Ze, 2));
float D_focal = 20.0f;

typedef struct {
    float X[UpperBD];
    float Y[UpperBD];
    float Z[UpperBD];
} pworld;

typedef struct {
    float X[UpperBD];
    float Y[UpperBD];
    float Z[UpperBD];
} pviewer;

typedef struct {
    float X[UpperBD];
    float Y[UpperBD];
} pperspective;

void mydisplay()
{
    // define x-y coordinate 
    float p1x = -1.0f, p1y = 0.0f;
    float p2x = 1.0f, p2y = 0.0f;
    float p3x = 0.0f, p3y = 1.0f;
    float p4x = 0.0f, p4y = -1.0f;

    glClear(GL_COLOR_BUFFER_BIT);
    glLoadIdentity();

    pworld  world;
    pviewer viewer;
    pperspective perspective;

    //define the x-y-z world coordinate 
    world.X[0] = 0.0;    world.Y[0] = 0.0;   world.Z[0] = 0.0;    // origin  
    world.X[1] = 50.0;   world.Y[1] = 0.0;   world.Z[1] = 0.0;    // x-axis
    world.X[2] = 0.0;    world.Y[2] = 50.0;  world.Z[2] = 0.0;    // y-axis    
    world.X[3] = 0.0;    world.Y[3] = 0.0;   world.Z[3] = 50.0;   // y-axis 

    float sPheta = Ye / sqrt(pow(Xe, 2) + pow(Ye, 2));
    float cPheta = Xe / sqrt(pow(Xe, 2) + pow(Ye, 2));
    float sPhi = sqrt(pow(Xe, 2) + pow(Ye, 2)) / Rho;
    float cPhi = Ze / Rho;

    float xMin = 1000.0, xMax = -1000.0;
    float yMin = 1000.0, yMax = -1000.0;

    for (int i = 0; i <= UpperBD; i++)
    {
        viewer.X[i] = -sPheta * world.X[i] + cPheta * world.Y[i];
        viewer.Y[i] = -cPheta * cPhi * world.X[i]
            - cPhi * sPheta * world.Y[i]
            + sPhi * world.Z[i];
        viewer.Z[i] = -sPhi * cPheta * world.X[i]
            - sPhi * cPheta * world.Y[i]
            - cPheta * world.Z[i] + Rho;
    }

    for (int i = 0; i <= UpperBD; i++)
    {
        perspective.X[i] = D_focal * viewer.X[i] / viewer.Z[i];
        perspective.Y[i] = D_focal * viewer.Y[i] / viewer.Z[i];
        if (perspective.X[i] > xMax) xMax = perspective.X[i];
        if (perspective.X[i] < xMin) xMin = perspective.X[i];
        if (perspective.Y[i] > yMax) yMax = perspective.Y[i];
        if (perspective.Y[i] < yMin) yMin = perspective.Y[i];
        /*
        std::cout << "xMin " << xMin << std::endl;
        std::cout << "xMax " << xMax << std::endl;
        std::cout << "yMin " << yMin << std::endl;
        std::cout << "yMax " << yMax << std::endl;
        */
    }
    for (int i = 0; i <= UpperBD; i++)
    {
        if ((xMax - xMin) != 0) perspective.X[i] = perspective.X[i] / (xMax - xMin);
        if ((yMax - yMin) != 0) perspective.Y[i] = perspective.Y[i] / (yMax - yMin);
        //std::cout << i << perspective.X[i] << perspective.Y[i] << std::endl;
    }


    glBegin(GL_LINES);
    // cross at the display screen 
    //glVertex2f(p1x,p1y);  
    //glVertex2f(p2x,p2y);
    //glVertex2f(p3x, p3y);
    //glVertex2f(p4x, p4y);


    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(1.0, 0.0, 0.0);
    glVertex2f(perspective.X[0], perspective.Y[0]);
    glVertex2f(perspective.X[1], perspective.Y[1]);
    glColor3f(0.0, 1.0, 0.0);
    glVertex2f(perspective.X[0], perspective.Y[0]);
    glVertex2f(perspective.X[2], perspective.Y[2]);
    glColor3f(0.0, 0.0, 1.0);
    glVertex2f(perspective.X[0], perspective.Y[0]);
    glVertex2f(perspective.X[3], perspective.Y[3]);

    glEnd();

    glFlush();

}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutCreateWindow("132 transformation pipeline");
    glutDisplayFunc(mydisplay);
    glutMainLoop();
}

I am able to compile this code, but whenever I run it I get the error "stack smashing detected". I have no idea why this is happening. Also other people got this same exact code to work, but it's not working for me. I am using ubuntu for this. Any help with this error would be highly appreciated.

Because arrys in C++ range from 0 to N-1, code like `for (int i = 0; i <= UpperBD; i++)` is always suspect. This allows the index variable `i` to equal `UpperBD`, which will allow stepping past the end of an array. — user4581301, Sep 28 '18 at 00:01
If you see "stack smashing", there's a good chance you have an array that is being written past its bounds (and overwriting the stack frame). Compilers put in some buffer space to test if this kind of thing is happening. It's for security, but it can happen by accident as you discovered. — Humphrey Winnebago, Sep 28 '18 at 00:08
*Also other people got this same exact code to work,* -- You need go to these "other people" and inform them to fix their program. Writing beyond the bounds of an array is *undefined behavior*. — PaulMcKenzie, Sep 28 '18 at 00:21
Undefined behaviour is really neat stuff. Sometimes it looks like it works. Sometimes it clearly doesn't work. Sometimes you can see the [nasal demons](http://www.catb.org/jargon/html/N/nasal-demons.html) dancing. Sometimes it looks so close to correct that you don't notice it isn't until the pilot takes emergency action to keep the airplane from slamming into the side of a mountain. — user4581301, Sep 28 '18 at 03:48

score 1 · Accepted Answer · answered Sep 28 '18 at 00:06

1

replace :

for (int i = 0; i <= UpperBD; i++)

with :

for (int i = 0; i < UpperBD; i++)

in all instances.

answered Sep 28 '18 at 00:06

rmoro

393
1
11

stack smashing detected, abort, OpenGl freeglut

1 Answers1