OpenGL ES Libraries
(New page: = OpenGL ES 2.x Game Development on Nokia N900 = I wanted to start developing a game for the Nokia N900 using OpenGL ES 2.0. However I didn't really know where to start and had to learn a...) |
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- | = OpenGL ES | + | = OpenGL ES Game Development on Nokia N900 = |
- | + | Want to start developing a game for the Nokia N900 using OpenGL ES 2.0 but don't know where to start? | |
- | + | Here is some information about the various libraries and APIs that are available on the N900. | |
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- | Here | + | |
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== Library Support == | == Library Support == | ||
- | Here | + | Here is a partial list of library options: |
=== SDL === | === SDL === | ||
- | Apparently SDL 1.3 supports OpenGL ES 1.x (not sure about 2.x) | + | Apparently SDL 1.3 supports OpenGL ES 1.x (not sure about 2.x). |
=== OpenGL ES 1.x utilies === | === OpenGL ES 1.x utilies === | ||
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=== Clutter === | === Clutter === | ||
- | libclutter supports OpenGL ES 2.x | + | libclutter supports OpenGL ES 2.x. It seems oriented towards toolkits and applications with user interface elements. |
- | === X11 === | + | === Xlib (X11) === |
- | You could go with plain | + | You could go with plain Xlib (X11) and utilise the EGL library for context creation along with OpenGL ES. This is what the Bounce Evolution game uses. |
+ | |||
+ | This is probably the fastest method as you have control over everything. However programming with pure Xlib is more work. | ||
+ | You can use OpenGL ES version 1 or 2 directly without worrying about the version that is supported by the library. | ||
=== PVRShell === | === PVRShell === | ||
- | The Khronos OpenGL ES 2.0 SDK includes a simple API for window creation called PVRShell. They also include additional tools for more advanced computer graphics applications. It is much simpler to create an OpenGL ES 2.0 application using PVRShell | + | The Khronos OpenGL ES 2.0 SDK includes a simple API for window creation called PVRShell. They also include additional tools for more advanced computer graphics applications. It is much simpler to create an OpenGL ES 2.0 application using PVRShell. It doesn't seem to have much support for handling events. |
== Notes == | == Notes == | ||
+ | When you create a X11 window the hildon compositor should be disabled. This can be done by setting the property _HILDON_NON_COMPOSITED_WINDOW. There is an example Xlib application with this property set available at http://exoticorn.de/simpleglv2.tgz (http://talk.maemo.org/showthread.php?t=37356&page=2). | ||
- | + | It appears that OpenGL ES 1.x code gets translated into OpenGL ES 2.x code using an emulation library on the Nokia N900. Is this true? If so is there a performance impact? | |
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OpenGL and OpenGL ES are very different and are not compatible. | OpenGL and OpenGL ES are very different and are not compatible. | ||
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WARNING: If you try to run an OpenGL application with scratchbox then it will most likely work. This is because it uses the native operating system OpenGL libraries to execute. However, if you try and run it on the device it will not work as it only has OpenGL ES libraries. | WARNING: If you try to run an OpenGL application with scratchbox then it will most likely work. This is because it uses the native operating system OpenGL libraries to execute. However, if you try and run it on the device it will not work as it only has OpenGL ES libraries. | ||
- | WARNING: OpenGL ES doesn't run natively on a desktop computer. It is possible to get some kind of emulation library from the Khronos OpenGL ES 2.0 SDK | + | WARNING: OpenGL ES doesn't run natively on a desktop computer. It is possible to get some kind of emulation library from the Khronos OpenGL ES 2.0 SDK so that you can test on a desktop computer. |
OpenGL ES 1.x and OpenGL ES 2.x are also different. OpenGL ES 1.x has a fixed pipeline whereas OpenGL ES 2.x uses shaders. The matrix stack has also been removed and you have to manage it yourself. | OpenGL ES 1.x and OpenGL ES 2.x are also different. OpenGL ES 1.x has a fixed pipeline whereas OpenGL ES 2.x uses shaders. The matrix stack has also been removed and you have to manage it yourself. | ||
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=== Killing hildon === | === Killing hildon === | ||
- | This | + | This doesn't need to be done anymore if the _HILDON_NON_COMPOSITED_WINDOW attribute is set. This is included for reference. |
You can kill the hildon window manager with: | You can kill the hildon window manager with: | ||
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== Installation and Examples == | == Installation and Examples == | ||
- | Here are some notes about packages required for OpenGL ES development and some simple examples to help get you started. | + | Here are some notes about packages required for OpenGL ES development and some simple examples to help get you started. You can compile OpenGL ES applications with scratchbox. The ESBox IDE makes it much easier to execute the application on the device. It automates copying the binary onto the device and execution. |
- | Firstly you want to install the following packages on scratchbox | + | Firstly you want to install the following packages on scratchbox. |
- | + | [sbox-FREMANTLE_ARMEL: ~] > fakeroot apt-get install libgles2-sgx-img-dev | |
- | This is the OpenGL ES 2.x development files required for compiling. Note: you need to add the nokia-binaries repository to install this. | + | This is the OpenGL ES 2.x development files required for compiling. Note: you need to add the nokia-binaries repository to install this in scratchbox. |
- | + | [sbox-FREMANTLE_ARMEL: ~] > fakeroot apt-get install opengles-sgx-img-common-dev | |
- | This installs the EGL library (used for portable context creation, see the docs) and PowerVR development files. | + | This installs the EGL library (used for portable context creation, see the docs) and PowerVR development files. It also includes some simple demos. This also requires nokia-binaries. |
+ | |||
+ | Nokia-N900-42-11:~# apt-get install libgles1-sgx-img opengles-sgx-img-common | ||
+ | |||
+ | Installs the required libraries to use OpenGL ES on the N900. | ||
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You need to install libqt4-opengl-dev. | You need to install libqt4-opengl-dev. | ||
- | It doesn't install any examples, so | + | It doesn't install any examples, so download the hellogl_es2 example from here: http://qt.gitorious.org/qt/qt/trees/4.5/examples/opengl/hellogl_es2 |
- | + | You need to modify glwidget.h and change #include <QGLWidget> to #include <QtOpenGL/QGLWidget>. Also, in the hellogl_es2.pro file you should add: | |
LIBS += -lGLESv2 -lQtOpenGL | LIBS += -lGLESv2 -lQtOpenGL | ||
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main: main.o | main: main.o | ||
- | In the PowerVR SDK TrainingCourse directory there are a number of examples. The first two use only | + | In the PowerVR SDK TrainingCourse directory there are a number of examples. The first two use only Xlib. The rest make use of PowerVR libraries which have to be linked in with the program. |
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- | + | There is a nice simple example at the Maemo Talk page (http://talk.maemo.org/showthread.php?t=37356). You can download it from http://exoticorn.de/simpleglv2.tgz | |
== Resources == | == Resources == | ||
- | Here are some resources | + | Here are some resources. |
*http://www.unrealvoodoo.org/hiteck/projects/maemo/ (NOTE: Links to the git repositories are broken. You can find them at http://www.unrealvoodoo.org/git/) | *http://www.unrealvoodoo.org/hiteck/projects/maemo/ (NOTE: Links to the git repositories are broken. You can find them at http://www.unrealvoodoo.org/git/) |
Revision as of 04:35, 22 December 2009
Contents |
OpenGL ES Game Development on Nokia N900
Want to start developing a game for the Nokia N900 using OpenGL ES 2.0 but don't know where to start?
Here is some information about the various libraries and APIs that are available on the N900.
Library Support
Here is a partial list of library options:
SDL
Apparently SDL 1.3 supports OpenGL ES 1.x (not sure about 2.x).
OpenGL ES 1.x utilies
http://www.unrealvoodoo.org/hiteck/projects/maemo/
Sami Kyöstilä has developed a number of utilities. This includes SDL with OpenGL ES 1.x support, libglutes, python-opengles and several translators to convert OpenGL ES and OpenGL.
Qt
You can use Qt with OpenGL ES 2.x on the Nokia N900. There is an example application called hellogl_es2 (http://qt.gitorious.org/qt/qt/trees/4.5/examples/opengl/hellogl_es2) which shows how to use OpenGL ES with a QtWidget.
Clutter
libclutter supports OpenGL ES 2.x. It seems oriented towards toolkits and applications with user interface elements.
Xlib (X11)
You could go with plain Xlib (X11) and utilise the EGL library for context creation along with OpenGL ES. This is what the Bounce Evolution game uses.
This is probably the fastest method as you have control over everything. However programming with pure Xlib is more work. You can use OpenGL ES version 1 or 2 directly without worrying about the version that is supported by the library.
PVRShell
The Khronos OpenGL ES 2.0 SDK includes a simple API for window creation called PVRShell. They also include additional tools for more advanced computer graphics applications. It is much simpler to create an OpenGL ES 2.0 application using PVRShell. It doesn't seem to have much support for handling events.
Notes
When you create a X11 window the hildon compositor should be disabled. This can be done by setting the property _HILDON_NON_COMPOSITED_WINDOW. There is an example Xlib application with this property set available at http://exoticorn.de/simpleglv2.tgz (http://talk.maemo.org/showthread.php?t=37356&page=2).
It appears that OpenGL ES 1.x code gets translated into OpenGL ES 2.x code using an emulation library on the Nokia N900. Is this true? If so is there a performance impact?
OpenGL and OpenGL ES are very different and are not compatible.
WARNING: If you try to run an OpenGL application with scratchbox then it will most likely work. This is because it uses the native operating system OpenGL libraries to execute. However, if you try and run it on the device it will not work as it only has OpenGL ES libraries.
WARNING: OpenGL ES doesn't run natively on a desktop computer. It is possible to get some kind of emulation library from the Khronos OpenGL ES 2.0 SDK so that you can test on a desktop computer.
OpenGL ES 1.x and OpenGL ES 2.x are also different. OpenGL ES 1.x has a fixed pipeline whereas OpenGL ES 2.x uses shaders. The matrix stack has also been removed and you have to manage it yourself.
Killing hildon
This doesn't need to be done anymore if the _HILDON_NON_COMPOSITED_WINDOW attribute is set. This is included for reference.
You can kill the hildon window manager with:
dsmetool -k /usr/bin/hildon-desktop
Restore with:
dsmetool -t /usr/bin/hildon-desktop
Installation and Examples
Here are some notes about packages required for OpenGL ES development and some simple examples to help get you started. You can compile OpenGL ES applications with scratchbox. The ESBox IDE makes it much easier to execute the application on the device. It automates copying the binary onto the device and execution.
Firstly you want to install the following packages on scratchbox.
[sbox-FREMANTLE_ARMEL: ~] > fakeroot apt-get install libgles2-sgx-img-dev
This is the OpenGL ES 2.x development files required for compiling. Note: you need to add the nokia-binaries repository to install this in scratchbox.
[sbox-FREMANTLE_ARMEL: ~] > fakeroot apt-get install opengles-sgx-img-common-dev
This installs the EGL library (used for portable context creation, see the docs) and PowerVR development files. It also includes some simple demos. This also requires nokia-binaries.
Nokia-N900-42-11:~# apt-get install libgles1-sgx-img opengles-sgx-img-common
Installs the required libraries to use OpenGL ES on the N900.
Qt Example
You need to install libqt4-opengl-dev.
It doesn't install any examples, so download the hellogl_es2 example from here: http://qt.gitorious.org/qt/qt/trees/4.5/examples/opengl/hellogl_es2
You need to modify glwidget.h and change #include <QGLWidget> to #include <QtOpenGL/QGLWidget>. Also, in the hellogl_es2.pro file you should add:
LIBS += -lGLESv2 -lQtOpenGL
Then run:
qmake -project
qmake
make
Which will (hopefully) compile hellogl_es2. Then you can copy the binary to the device and run it.
X11 Examples
You can usually compile any X11 examples with a simple Makefile like:
CC=g++ LDLIBS=-lEGL -lX11 -lGLESv2 all: main main: main.o
In the PowerVR SDK TrainingCourse directory there are a number of examples. The first two use only Xlib. The rest make use of PowerVR libraries which have to be linked in with the program.
There is a nice simple example at the Maemo Talk page (http://talk.maemo.org/showthread.php?t=37356). You can download it from http://exoticorn.de/simpleglv2.tgz
Resources
Here are some resources.
- http://www.unrealvoodoo.org/hiteck/projects/maemo/ (NOTE: Links to the git repositories are broken. You can find them at http://www.unrealvoodoo.org/git/)
- http://qt.gitorious.org/qt/qt/trees/4.5/examples/opengl/hellogl_es2 - hellogl_es2 example for Qt 4.5
- http://wiki.maemo.org/OpenGL-ES - OpenGL ES page an the maemo wiki with useful information
- http://www.imgtec.com/powervr/insider/sdk/KhronosOpenGLES2xSGX.asp - Khronos OpenGL ES 2.0 SDK has useful examples and a good way to start
- http://talk.maemo.org/showthread.php?t=37356 - Thread discussing performance of OpenGL ES
- http://wiki.maemo.org/Game_development - Page describing game development. However seems more oriented for 2D games but has some useful information.
- http://www.forum.nokia.com/info/sw.nokia.com/id/0ea5ec64-2d35-4363-94c0-dd2560c6524b/Get_started_with_Maemo_5.html - If you don't know how to start with Maemo development in general look here.
- http://repository.maemo.org/ - Information about repositories
- http://www.khronos.org/opengles/sdk/docs/man/ - OpenGL ES 2.0 Reference Page
- http://www.khronos.org/opengles/sdk/1.1/docs/man/ - OpenGL ES 1.1 Reference Page. It also has information about EGL.
- http://n2.nabble.com/Fremantle-OpenGL-wrapper-td3013572.html - Thread discussing ideas about OpenGL and Maemo.