view README.Porting @ 4388:1524d3237820 SDL-1.2

Fixed bug #896 John Popplewell 2009-12-08 23:05:50 PST Originally reported by AKFoerster on the mailing list. Error decoding UTF8 Russian text to UTF-16LE on Windows, but specifically on platforms without iconv support (the default on Windows). Valid UTF8 characters are flagged as being overlong and then substituted by the UNKNOWN_UNICODE character. After studying the testiconv.c example program, reading the RFCs and putting some printf statements in SDL_iconv.c the problem is in a test for 'Maximum overlong sequences', specifically 4.2.1, which is carried out by the following code: } else if ( p[0] >= 0xC0 ) { if ( (p[0] & 0xE0) != 0xC0 ) { /* Skip illegal sequences return SDL_ICONV_EILSEQ; */ ch = UNKNOWN_UNICODE; } else { if ( (p[0] & 0xCE) == 0xC0 ) { <<<<<<<< here overlong = SDL_TRUE; } ch = (Uint32)(p[0] & 0x1F); left = 1; } } else { Here is the 2-byte encoding of a character in range 00000080 - 000007FF 110xxxxx 10xxxxxx The line in question is supposed to be checking for an overlong sequence which would be less than 11000001 10111111 which should be represented as a single byte. BUT, the mask value (0xCE) is wrong, it isn't checking the top-most bit: 11000001 value 11001110 mask (incorrect) ^ and should be (0xDE): 11000001 value 11011110 mask (correct) making the above code: } else if ( p[0] >= 0xC0 ) { if ( (p[0] & 0xE0) != 0xC0 ) { /* Skip illegal sequences return SDL_ICONV_EILSEQ; */ ch = UNKNOWN_UNICODE; } else { if ( (p[0] & 0xDE) == 0xC0 ) { <<<<<<<< here overlong = SDL_TRUE; } ch = (Uint32)(p[0] & 0x1F); left = 1; } } else { I can supply a test program and/or a patch if required, best regards, John Popplewell
author Sam Lantinga <slouken@libsdl.org>
date Fri, 11 Dec 2009 08:00:57 +0000
parents b2b476a4a73c
children 103760c3a5dc
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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/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)