Mercurial > sdl-ios-xcode
annotate src/video/SDL_alphamult.c @ 3539:f2846bf19360
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> |
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date | Fri, 11 Dec 2009 08:03:43 +0000 |
parents | cd863dd2082b |
children | f7b03b6838cb |
rev | line source |
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3054
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1 /* |
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2 SDL - Simple DirectMedia Layer |
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3 Copyright (C) 1997-2009 Sam Lantinga |
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4 |
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5 This library is free software; you can redistribute it and/or |
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6 modify it under the terms of the GNU Lesser General Public |
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7 License as published by the Free Software Foundation; either |
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8 version 2.1 of the License, or (at your option) any later version. |
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9 |
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10 This library is distributed in the hope that it will be useful, |
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
8d93bfecb9dc
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13 Lesser General Public License for more details. |
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14 |
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15 You should have received a copy of the GNU Lesser General Public |
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16 License along with this library; if not, write to the Free Software |
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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18 |
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19 Sam Lantinga |
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20 slouken@libsdl.org |
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21 */ |
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22 #include "SDL_config.h" |
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23 |
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24 #include "SDL_blit.h" |
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25 #include "SDL_alphamult.h" |
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26 |
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27 /* Functions to pre-multiply the alpha channel into the color channels */ |
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28 |
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29 #define DEFINE_PREMULTIPLY_FUNC(fmt) \ |
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30 void \ |
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31 SDL_PreMultiplyAlpha##fmt(int w, int h, Uint32 *pixels, int pitch) \ |
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32 { \ |
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33 pitch /= 4; \ |
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34 while (h--) { \ |
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35 int n; \ |
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36 Uint32 *row = pixels; \ |
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37 Uint32 pixel; \ |
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38 unsigned r, g, b, a; \ |
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39 \ |
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40 for (n = w; n--; ) { \ |
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41 pixel = *row; \ |
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42 RGBA_FROM_##fmt(pixel, r, g, b, a); \ |
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43 r = (r * a) / 255; \ |
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44 g = (g * a) / 255; \ |
8d93bfecb9dc
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parents:
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45 b = (b * a) / 255; \ |
8d93bfecb9dc
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parents:
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46 fmt##_FROM_RGBA(*row, r, g, b, a); \ |
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47 ++row; \ |
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48 } \ |
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49 pixels += pitch; \ |
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Fixed alpha blending textures with the GDI renderer
Sam Lantinga <slouken@libsdl.org>
parents:
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50 } \ |
8d93bfecb9dc
Fixed alpha blending textures with the GDI renderer
Sam Lantinga <slouken@libsdl.org>
parents:
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51 } |
8d93bfecb9dc
Fixed alpha blending textures with the GDI renderer
Sam Lantinga <slouken@libsdl.org>
parents:
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52 |
3055 | 53 /* *INDENT-OFF* */ |
3054
8d93bfecb9dc
Fixed alpha blending textures with the GDI renderer
Sam Lantinga <slouken@libsdl.org>
parents:
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54 DEFINE_PREMULTIPLY_FUNC(ARGB8888) |
8d93bfecb9dc
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Sam Lantinga <slouken@libsdl.org>
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55 DEFINE_PREMULTIPLY_FUNC(RGBA8888) |
8d93bfecb9dc
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56 DEFINE_PREMULTIPLY_FUNC(ABGR8888) |
8d93bfecb9dc
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Sam Lantinga <slouken@libsdl.org>
parents:
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57 DEFINE_PREMULTIPLY_FUNC(BGRA8888) |
3055 | 58 /* *INDENT-ON* */ |
3054
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Fixed alpha blending textures with the GDI renderer
Sam Lantinga <slouken@libsdl.org>
parents:
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59 |
8d93bfecb9dc
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Sam Lantinga <slouken@libsdl.org>
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60 /* vi: set ts=4 sw=4 expandtab: */ |