Smooth lines with width = 0.5

OpenGL OpenGL: Basic Coding
1

Hi All,

Looks like not all the hardwares support GL_LINE_SMOOTH with glLineWidth(0.5f). On some machine we see the line thinner than one pixel on others one pixel. Is there any technical reason for this ?

Thanks,

Alberto

2

Advanced Line Rendering is often disabled on mainstream GPUs, so that it can be advertised as a feature of high-end GPUs (such as nVidias Quadro cards and ATIs Firewhatever cards).

Technically it is more difficult to do these things, so maybe some GPUs are actually not capable to do it, but sometimes it’s simply done by the driver to convince you to buy more expensive cards.

Jan.

3

See the implementation-specific limit GL_SMOOTH_LINE_WIDTH_RANGE.

4

GL_SMOOTH_LINE_WIDTH_RANGE:

We get 1-63 with ATI FireGL 7200 and 0.5-10 with OpenGL Software (Microsoft Implementation).

Strange… I believed that ATI driver was more capable of the MS implementation…

Thanks,

Alberto