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view docs/man3/SDL_QuitEvent.3 @ 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 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
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.TH "SDL_QuitEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" .SH "NAME" SDL_QuitEvent\- Quit requested event .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct{ Uint8 type } SDL_QuitEvent;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBtype\fR \fBSDL_QUIT\fP .SH "DESCRIPTION" .PP \fBSDL_QuitEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used whan an event of type \fBSDL_QUIT\fP is reported\&. .PP As can be seen, the SDL_QuitEvent structure serves no useful purpose\&. The event itself, on the other hand, is very important\&. If you filter out or ignore a quit event then it is impossible for the user to close the window\&. On the other hand, if you do accept a quit event then the application window will be closed, and screen updates will still report success event though the application will no longer be visible\&. .PP .RS \fBNote: .PP The macro \fBSDL_QuitRequested\fP will return non-zero if a quit event is pending .RE .SH "SEE ALSO" .PP \fI\fBSDL_Event\fR\fR, \fI\fBSDL_SetEventFilter\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59