<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Unify the format conversion code" href="https://bugs.freedesktop.org/show_bug.cgi?id=84566#c34">Comment # 34</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Unify the format conversion code" href="https://bugs.freedesktop.org/show_bug.cgi?id=84566">bug 84566</a> from <a class="email" href="mailto:jason@jlekstrand.net" title="Jason Ekstrand <jason@jlekstrand.net>"> Jason Ekstrand</a> <pre>(In reply to Samuel Iglesias from <a href="show_bug.cgi?id=84566#c33">comment #33</a>) > Jason, I would like to know your opinion about the integer RGBA clamping > done in pack.c (_mesa_pack_rgba_span_from_ints()). > > glReadPixels() and glGetTexImage() specs said (for example, in OpenGL 3.3. > core specification) that for an integer RGBA color, each component is > clamped to the representable range of type. > > Those GL functions end up calling pack.c's functions for performing the > conversion (mesa_pack_rgba_span_from_ints() and others). > > It's possible to replace some of those pack.c's conversion functions by the > master conversion but the problem is in the clamping operation. I would like > to add a boolean argument called "clamp" to the master conversion function > which is passed to _mesa_swizzle_and_convert() where each of its > convert_{uint,int,byte,ubyte,short,ushort}() do the right thing when "clamp" > is true. > > This "clamp" parameter would be false for every call to either master > conversion function or _mesa_swizzle_and_convert() except when they are > being called from pack.c. > > What do you think? Supporting clamping is probably fine. I think we determined we needed a clamp parameter anyway for some of the float conversions. I guess it makes sense for integers too. Let's watch out for performance when we implement it though. Changing the loop inside mesa_swizzle_and_convert without hurting performance can be tricky. The teximage-colors test in Piglit has a -benchmark flag that can be used for testing that.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>