Mercurial > sdl-ios-xcode
view docs/man3/SDL_Surface.3 @ 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 | 1238da4a7112 |
children |
line wrap: on
line source
.TH "SDL_Surface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_Surface \- Graphical Surface Structure .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct SDL_Surface { Uint32 flags; /* Read-only */ SDL_PixelFormat *format; /* Read-only */ int w, h; /* Read-only */ Uint16 pitch; /* Read-only */ void *pixels; /* Read-write */ /* clipping information */ SDL_Rect clip_rect; /* Read-only */ /* Reference count -- used when freeing surface */ int refcount; /* Read-mostly */ /* This structure also contains private fields not shown here */ } SDL_Surface;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBflags\fR Surface flags .TP 20 \fBformat\fR Pixel \fIformat\fR .TP 20 \fBw, h\fR Width and height of the surface .TP 20 \fBpitch\fR Length of a surface scanline in bytes .TP 20 \fBpixels\fR Pointer to the actual pixel data .TP 20 \fBclip_rect\fR surface clip \fIrectangle\fR .SH "DESCRIPTION" .PP \fBSDL_Surface\fR\&'s represent areas of "graphical" memory, memory that can be drawn to\&. The video framebuffer is returned as a \fBSDL_Surface\fR by \fI\fBSDL_SetVideoMode\fP\fR and \fI\fBSDL_GetVideoSurface\fP\fR\&. Most of the fields should be pretty obvious\&. \fBw\fR and \fBh\fR are the width and height of the surface in pixels\&. \fBpixels\fR is a pointer to the actual pixel data, the surface should be \fIlocked\fR before accessing this field\&. The \fBclip_rect\fR field is the clipping rectangle as set by \fI\fBSDL_SetClipRect\fP\fR\&. .PP The following are supported in the \fBflags\fR field\&. .TP 20 \fBSDL_SWSURFACE\fP Surface is stored in system memory .TP 20 \fBSDL_HWSURFACE\fP Surface is stored in video memory .TP 20 \fBSDL_ASYNCBLIT\fP Surface uses asynchronous blits if possible .TP 20 \fBSDL_ANYFORMAT\fP Allows any pixel-format (Display surface) .TP 20 \fBSDL_HWPALETTE\fP Surface has exclusive palette .TP 20 \fBSDL_DOUBLEBUF\fP Surface is double buffered (Display surface) .TP 20 \fBSDL_FULLSCREEN\fP Surface is full screen (Display Surface) .TP 20 \fBSDL_OPENGL\fP Surface has an OpenGL context (Display Surface) .TP 20 \fBSDL_OPENGLBLIT\fP Surface supports OpenGL blitting (Display Surface) .TP 20 \fBSDL_RESIZABLE\fP Surface is resizable (Display Surface) .TP 20 \fBSDL_HWACCEL\fP Surface blit uses hardware acceleration .TP 20 \fBSDL_SRCCOLORKEY\fP Surface use colorkey blitting .TP 20 \fBSDL_RLEACCEL\fP Colorkey blitting is accelerated with RLE .TP 20 \fBSDL_SRCALPHA\fP Surface blit uses alpha blending .TP 20 \fBSDL_PREALLOC\fP Surface uses preallocated memory .SH "SEE ALSO" .PP \fI\fBSDL_PixelFormat\fR\fR .\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01