8677c4d6d6
GL_GENERATE_MIPMAP_SGIS is very slow (over half a second for a 720*576 texture). However, glGenerateMipmapEXT() performs well (16ms for the same texture), so I have modified the attached files to use Texture::generateMipmap() if glGenerateMipmapEXT is supported, instead of enabling & disabling GL_GENERATE_MIPMAP_SGIS." Notes, from Robert Osfield, I've tested the out of the previous path using GL_GENERATE_MIPMAP_SGIS and non power of two textures on NVidia 7800GT and Nvidia linux drivers with the image size 720x576 and only get compile times of 56ms, so the above half second speed looks to be a driver bug. With Muchael's changes the cost goes done to less than 5ms, so it's certainly an effective change, even given that Michael's poor expereiences with GL_GENERATE_MIP_SGIS do look to be a driver bug.
Welcome to the OpenSceneGraph (OSG).
For up-to-date information on the project, in-depth details on how to
compile and run libraries and examples, see the documentation on the
OpenSceneGraph website:
http://www.openscenegraph.org
For the impatient, read the simplified build notes below. For support
subscribe to our public mailing list:
http://www.openscenegraph.org/projects/osg/wiki/MailingLists
Robert Osfield.
Project Lead.
25th April 2008.
--
How to build the OpenSceneGraph
===============================
The OpenSceneGraph uses the CMake build system to generate a
platform-specific build environment. CMake reads the CMakeLists.txt
files that you'll find throughout the OpenSceneGraph directories,
checks for installed dependenciesand then generates the appropriate
build system.
If you don't already have CMake installed on your system you can grab
it from http://www.cmake.org, use version 2.4.6 or later. Details on the
OpenSceneGraph's CMake build can be found at:
http://www.openscenegraph.org/projects/osg/wiki/Build/CMake
Under unices (i.e. Linux, IRIX, Solaris, Free-BSD, HP-Ux, AIX, OSX)
use the cmake or ccmake command-line utils, or use the included tiny
configure script that'll run cmake for you. The configure script
simply runs 'cmake . -DCMAKE_BUILD_TYPE=Release' to ensure that you
get the best performance from your final libraries/applications.
cd OpenSceneGraph
./configure
make
sudo make install
Alternatively, you can create an out-of-source build directory and run
cmake or ccmake from there. The advantage to this approach is that the
temporary files created by CMake won't clutter the OpenSceneGraph
source directory, and also makes it possible to have multiple
independent build targets by creating multiple build directories. In a
directory alongside the OpenSceneGraph use:
mkdir build
cd build
cmake ../OpenSceneGraph -DCMAKE_BUILD_TYPE=Release
make
sudo make install
Under Windows use the GUI tool CMakeSetup to build your VisualStudio
files. The following page on our wiki dedicated to the CMake build
system should help guide you through the process:
http://www.openscenegraph.org/projects/osg/wiki/Support/PlatformSpecifics/VisualStudio
Under OSX you can either use the CMake build system above, or use the
Xcode projects that you will find in the OpenSceneGraph/Xcode
directory.
For further details on compilation, installation and platform-specific
information read "Getting Started" guide:
http://www.openscenegraph.org/projects/osg/wiki/Support/GettingStarted