<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Black squares in the Spec Ops: The Line chapter select screen" href="https://bugs.freedesktop.org/show_bug.cgi?id=97338#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Black squares in the Spec Ops: The Line chapter select screen" href="https://bugs.freedesktop.org/show_bug.cgi?id=97338">bug 97338</a> from <a class="email" href="mailto:nhaehnle@gmail.com" title="Nicolai Hähnle <nhaehnle@gmail.com>"> Nicolai Hähnle</a> <pre>Created <a href="attachment.cgi?id=126172" name="attach_126172" title="Problematic fragment shader">attachment 126172</a> <a href="attachment.cgi?id=126172&action=edit" title="Problematic fragment shader">[details]</a> Problematic fragment shader Okay, so here's a bit more detail of what is happening: the attached fragment shader (shader object 31) samples a 2D vector from PSampler2 (texture object 3153) and does some computations on it involving inversesqrt, under the assumption that the dot product of the vector is <= 1. This is false: looking at level 0 of texture 3153 reveals e.g. a unorm value (142, 255) at texel 155,263. The likely cause here is that this is a port from D3D, which specifies that rsq should take the absolute value of its argument, to GLSL, which says that inversesqrt is undefined for values <= 0.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>