Texture stretched when drawn outside viewport in OpenGL - c++

Question

I've got a following problem - I'm creating a GUI in OpenGL, I have a Window component which can be dragged around the screen. Normally it looks like this:
Everything is ok unless you try to move it to left so that part of it disappears outside the viewport - For example left button in horizontal scroll is a separate texture and when we move Window to left so far that a whole button disappears, then first pixel of it's texture is being stretched across a whole screen, like this:
My CBackground::draw() method looks like this:
bool CBackground::draw(const CPoint &pos, unsigned int width, unsigned int height)
{
if(width <= 0 || height <= 0)
return false;
GLfloat maxTexCoordWidth = (float)width/m_width;
GLfloat maxTexCoordHeight = (float)height/m_height;
glPushMatrix();
glBindTexture(GL_TEXTURE_2D, m_texture); // Select Our Texture
switch(m_rotation)
{
case BACKGROUND_ROTATION_0_DG:
glBegin(GL_QUADS);
glTexCoord2f(0.0f, maxTexCoordHeight); glVertex2d(pos.x, pos.y + height);
glTexCoord2f(0.0f, 0.0f); glVertex2d(pos.x, pos.y);
glTexCoord2f(maxTexCoordWidth, 0.0f); glVertex2d(pos.x + width, pos.y);
glTexCoord2f(maxTexCoordWidth, maxTexCoordHeight); glVertex2d(pos.x + width, pos.y + height);
glEnd();
break;
}
glPopMatrix();
return true;
}
I tried to add such code just before glPushMatrix():
if((pos.x <= 0 && pos.x + width <= 0)
return false;
So that it shouldn't even draw this one pixel (I'm leaving a method with return), but it still draws this stretched texture.

Answer 1

Your width and height are both unsigned, which means this check has no effect for values other than precisely zero:
if(width <= 0 || height <= 0)
return false;
Most likely, you have some width which would otherwise be negative, but due to the unsigned nature of your variables is wrapping around and becoming very large. This would explain why you seem to have a bar stretching out very far to the right (large positive value in the horizontal dimension).
A good solution would be to make the width and height signed, which would prevent this type of issues. Otherwise, you'll have to move such checks to (all places) where the widths and heights are calculated. After all, you are not likely to have a window with width and height beyond what can be represented with a signed int.