<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [HSW, regression, bisected] i965/pixel_read: Use meta_pbo_GetTexSubImage for PBO ReadPixels (ef0499af255ecd)" href="https://bugs.freedesktop.org/show_bug.cgi?id=89314#c12">Comment # 12</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [HSW, regression, bisected] i965/pixel_read: Use meta_pbo_GetTexSubImage for PBO ReadPixels (ef0499af255ecd)" href="https://bugs.freedesktop.org/show_bug.cgi?id=89314">bug 89314</a> from <a class="email" href="mailto:neil@linux.intel.com" title="Neil Roberts <neil@linux.intel.com>"> Neil Roberts</a> <pre>Created <a href="attachment.cgi?id=116319" name="attach_116319" title="Example showing the error with GL_R16 to unsigned byte">attachment 116319</a> <a href="attachment.cgi?id=116319&action=edit" title="Example showing the error with GL_R16 to unsigned byte">[details]</a> Example showing the error with GL_R16 to unsigned byte It looks like there is a similar problem if we convert from a 16-bit component to 8 bits as well. Here is a test which creates a texture with an internal format of GL_R16, uploads all possible 16-bit values and then calls glGetTexImage with a type of GL_UNSIGNED_BYTE. It does this with and without a PBO. There are a bunch of cases where the results differ like this: source_value=63095 float=245.505844 expected=246 without_pbo=246 with_pbo=245 source_value=63351 float=246.501953 expected=247 without_pbo=247 with_pbo=246 source_value=63608 float=247.501953 expected=248 without_pbo=248 with_pbo=247</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>