Mercurial > sdl-ios-xcode
view docs/man3/SDL_GetKeyState.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_GetKeyState" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" .SH "NAME" SDL_GetKeyState\- Get a snapshot of the current keyboard state .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBUint8 *\fBSDL_GetKeyState\fP\fR(\fBint *numkeys\fR); .SH "DESCRIPTION" .PP Gets a snapshot of the current keyboard state\&. The current state is return as a pointer to an array, the size of this array is stored in \fBnumkeys\fR\&. The array is indexed by the \fI\fBSDLK_*\fP\fR symbols\&. A value of 1 means the key is pressed and a value of 0 means its not\&. The pointer returned is a pointer to an internal SDL array and should not be freed by the caller\&. .PP .RS \fBNote: .PP Use \fI\fBSDL_PumpEvents\fP\fR to update the state array\&. .RE .SH "EXAMPLE" .PP .PP .nf \f(CWUint8 *keystate = SDL_GetKeyState(NULL); if ( keystate[SDLK_RETURN] ) printf("Return Key Pressed\&. ");\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL Key Symbols\fP\fR, \fI\fBSDL_PumpEvents\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59