Cannot access data struct members after looping a couple times.

[snow 56767]

Hi guys,
I have a a loop that creates OpenGL display lists and uses a data structure with data structures in it to create them, but every time I near the end of the loop, I get a segmentation fault. I looked through my locals/watchers and see that one of the data structures is unreadable even though it hasn't been changed. I'm quite confused as to why this is happening.

Here is the code:

        void CSprite::GenerateGLDisplayList(SGfxSprite *aSprite, int aNumFrames)
        {
            uint displayList = glGenLists(aNumFrames);

            for(int i = 0; i < aNumFrames; ++i)
            {
                glNewList((displayList+i), GL_COMPILE);
                    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
                    glBindTexture(GL_TEXTURE_2D, aSprite->iGLTextures[i]);

                    glTexCoord2i(0, 0);
                    glVertex2f(aSprite->gfxObject->sPoly->sPosition->nX, aSprite->gfxObject->sPoly->sPosition->nY); // At the end of the loop, this is the line that seg faults. My locals/watchers are showing me that sPoly is NULL.

                    glTexCoord2i(1, 0);
                    glVertex2f(aSprite->gfxObject->sPoly->sDimensions->nX, aSprite->gfxObject->sPoly->sPosition->nY);

                    glTexCoord2i(1, 1);
                    glVertex2f(aSprite->gfxObject->sPoly->sDimensions->nX, aSprite->gfxObject->sPoly->sDimensions->nY);

                    glTexCoord2i(0, 1);
                    glVertex2f(aSprite->gfxObject->sPoly->sPosition->nX, aSprite->gfxObject->sPoly->sDimensions->nY);
                glEndList();

                aSprite->iFrames[i] = (displayList+i);
            }

            aSprite->currentFrame = 0;
        }

SGfxSprite declaration:

            struct SGfxSprite
            {
                uint *iGLTextures; // These are the OpenGL textures.
                uint iFrames[]; // These the OpenGL display lists.
                int currentFrame; // This is used when drawing to determine what frame of the sprite to draw.
                std::string str_Name; // The object name;
                SGraphicsObject *gfxObject; // The SGraphicsObject used for drawing.

                SGfxSprite(std::string aName, SGraphicsObject *aGfxObj) :
                    str_Name(aName), gfxObject(aGfxObj) {}
            };

SGraphicsObject declaration:

    struct SGraphicsObject
    {
        EPhysicsObjectShape eShape; // This enum tells what kind of object is being drawn.
        SPoly *sPoly; // This the polygon of which is used for drawing.
        SGraphicsObject(EPhysicsObjectShape aeShape, SPoly *asPoly) : eShape(aeShape), sPoly(asPoly) {}
    };

SPoly declaration:

    struct SPoly
    {
        SVec2D *sPosition; // The object's position in pixels.
        SVec2D *sDimensions; // IF OBJECT IS CIRCLE -> X = radius, Y = -1 ELSE dimensions are for quadrillaterals. (in pixels)
        bool isCircle; // Is this object a circle?

        SPoly(SVec2D *aPos, SVec2D *aDimen, bool abIsCircle = false) :
            sPosition(aPos), sDimensions(aDimen), isCircle(abIsCircle) {}
    };

SVec2D declaration:

    struct SVec2D
    {
        float nX;
        float nY;

        SVec2D(int aX, int aY) : nX(aX), nY(aY) {}
    };

I hope you guys can make sense as to why this is happening because I can't. I don't see how a member of a data structure can suddenly (even after no manipulation has happened) become NULL.

[snow 56767]

I have figured it out. All it took was time :)
It turns out that when I was writing to aSprite->iFrames[i] I was corrupting memory. (uh duhhh)
This was due to the member iFrames not being initialized on the heap. So it overwrote other members which was what causes such an error.