annotate src/hermes/README @ 688:c0522010bb6d
Date: Tue, 12 Aug 2003 14:26:19 +0200 (MEST)
From: "Mattias Engdeg?rd"
Subject: bug in SDL_GetRGB/GetRGBA
There's an embarrassing bug in GetRGB/GetRGBA which apparently has been there
for years. It incorrectly converts colours with < 8 bits/channel.
It came to my attention today in #sdl.
What it does now is (for each channel):
rv = (pixel & fmt->Rmask) >> fmt->Rshift;
*r = (rv << fmt->Rloss) + (rv >> (8 - fmt->Rloss));
which is wrong; the last line should be
*r = (rv << fmt->Rloss) + (rv >> (8 - (fmt->Rloss << 1)));
| author |
Sam Lantinga <slouken@libsdl.org> |
| date |
Tue, 12 Aug 2003 15:17:20 +0000 |
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74212992fb08 |
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line source |
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1 HERMES 1.2.4 (c)1998 Christian Nentwich (brn) (c.nentwich@cs.ucl.ac.uk)
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2 and quite a few assembler routines (c) Glenn Fielder (gaffer@gaffer.org)
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3
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4 This library and all the files enclosed in this package are free software
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5 under the terms of the GNU Library General Public License (LGPL). Please
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6 refer to the included file COPYING.LIB for the exact terms.
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7 ----------------------------------------------------------------------------
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8
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9 This is a stripped down version of HERMES, including only the x86 assembler
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10 converters, for use with Simple DirectMedia Layer.
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11
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12 The full HERMES library is available at: http://hermes.terminal.at/
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