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view README.Porting @ 2359:b70b96e615d2 gsoc2008_iphone
These files are the OpenGL ES render driver. You should be able to use them on any platform that supports OpenGL ES -- not just iPhone. The driver is based off the OpenGL render driver.
There are a few differences between OpenGL and OpenGL ES that present difficulties for this driver:
- OpenGL ES does NOT support many pixel formats (for example, no GL_BGR). Also, when using texture functions format and internalFormat must be the same -- this means 32 bit packed formats like SDL_PIXELFORMAT_BGR888 cannot be automatically converted to GL_RGB (which is 24bpp).
- OpenGL ES doesn't have GL_PACK_ROW_LENGTH, which means data must be reformatted before uploading changes to dirty rects. This change has been added.
- OpenGL ES doesn't support paletted textures, though there is an extension. I'm looking into this.
Some other notable differences:
- OpenGL ES has an extension called GL_OES_draw_texture which allows for quicker 2D sprite-type drawing. I use this in GL_RenderCopy when it is available. The iPhone supports the extension, but the iPhone Simulator does not (presently).
- No glBegin() / glEnd() and no GL_QUADS! I'm using glDrawArrays with GL_TRIANGLE_STRIP instead!
| author | Holmes Futrell <hfutrell@umail.ucsb.edu> |
|---|---|
| date | Thu, 17 Jul 2008 23:31:42 +0000 |
| parents | 103760c3a5dc |
| children |
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* Porting To A New Platform The first thing you have to do when porting to a new platform, is look at include/SDL_platform.h and create an entry there for your operating system. The standard format is __PLATFORM__, where PLATFORM is the name of the OS. Ideally SDL_platform.h will be able to auto-detect the system it's building on based on C preprocessor symbols. There are two basic ways of building SDL at the moment: 1. The "UNIX" way: ./configure; make; make install If you have a GNUish system, then you might try this. Edit configure.in, take a look at the large section labelled: "Set up the configuration based on the target platform!" Add a section for your platform, and then re-run autogen.sh and build! 2. Using an IDE: If you're using an IDE or other non-configure build system, you'll probably want to create a custom SDL_config.h for your platform. Edit SDL_config.h, add a section for your platform, and create a custom SDL_config_{platform}.h, based on SDL_config.h.minimal and SDL_config.h.in Add the top level include directory to the header search path, and then add the following sources to the project: src/*.c src/audio/*.c src/cdrom/*.c src/cpuinfo/*.c src/events/*.c src/file/*.c src/joystick/*.c src/stdlib/*.c src/thread/*.c src/timer/*.c src/video/*.c src/audio/disk/*.c src/audio/dummy/*.c src/video/dummy/*.c src/joystick/dummy/*.c src/cdrom/dummy/*.c src/thread/generic/*.c src/timer/dummy/*.c src/loadso/dummy/*.c Once you have a working library without any drivers, you can go back to each of the major subsystems and start implementing drivers for your platform. If you have any questions, don't hesitate to ask on the SDL mailing list: http://www.libsdl.org/mailing-list.php Enjoy! Sam Lantinga (slouken@libsdl.org)