glLineWidth - doesn't work !

Help! I've been trying to sort out this problem for ages, and I am _not_ getting anywhere!

It seems that
glLineWidth(5.0f);
does not have any effect on lines, and they remain just one pixel thick (even if I try a whole range of numbers).

glPointSize(5.0f) works perfectly, and enabling GL_LINE_SMOOTH doesn't seem to make any difference other than slightly thicker lines.

Can anyone help?

[UrbanLedgend]

Works for me onserveral Unix and Windows platforms.

Perhaps if you post a little more info such as OS,graphics, a little code we may be able to help more

[Tron]

the only width which is guaranteed is 1.0
support for other is implemantation depedent

[Bob]

Maybe your implementation does not support thick lines. Try the following piece of code to see how thick lines you can use.

float lineWidth[2];
glGetFloatv(GL_LINE_WIDTH_RANGE, lineWidth);

lineWidth[0] is the minimum width, and lineWidth[1] is the maximum.

I'm using opengl on a mac, with a voodoo 2 card. The actual procedures are like so:


GLvoid DrawBuilding(int by, int bx)
{
glPushMatrix();
glTranslatef(bx * griddist,by * griddist,0.0f);
glEnable(GL_LINE_SMOOTH);
glLineWidth(160000/(px*px));
{where px is your distance away, a value ranging from anything up to a distance of 600}

glBegin(GL_LINES);
glVertex3f( 0.0f, 0.0f, 0.0f);
glVertex3f( 0.0f, 0.0f, 500.0f);
glEnd();
glPopMatrix();
}

This is then used to draw a large grid of vertical lines, disappearing into the distance. It works perfectly, except the line widths do not change. Replacing GL_LINES with GL_POINTS and glLineWidth with glPointSize gives a series of points which get bigger when you get closer, and I was hoping to do this also with lines.

[Lev]

You'll get errors and even more errors with V2, 3dfx drivers suck.

-Lev

How do I change the minimum and maximum linewidths? I tried out the previous procedure and recieved 0.0 for min and 10.0 for max... is it a fault with the driver? (I know that on some ati drivers, points come out as squares even with GL_POINT_SMOOTH enabled, is this a similar case?) I appreciate your comments

Even staying within the range of 0.0 and 10.0, I'm getting just single thickness lines (using glLineWidth(8.0f) for example). There aren't any other variables to enable beforehand ?

[wedge]

"How do I change the minimum and maximum linewidths?"

You can't change this values the Proc
glGetFloatv(GL_LINE_WIDTH_RANGE, lineWidth);
say you what your OpenGL implementatin suport.

O I have forgotten, there is a way to change the values by a other Graphic Card *g*

Sorry , I suppose I meant it the other way round (getting the values first and then asking the question) .