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view docs/man3/SDL_Palette.3 @ 1543:98f9b16f565c
From: "Alex Volkov"
Date: Thu, 10 Nov 2005 21:53:40 -0500
Subject: [SDL] BUG[?]: 32bpp RGBA->RGB colorkey blit, no SDL_SRCALPHA
It seems there is either a documentation vs. reality mismatch or a real bug
in SDL_blit_N.c:BlitNtoNKey().
The exact blit in question is a 32bpp RGBA->RGB, where RGBA has SDL_COLORKEY
and *no* SDL_SRCALPHA flags. The doc in SDL_video.h states:
* RGBA->RGB:
* SDL_SRCALPHA not set:
* copy RGB.
* if SDL_SRCCOLORKEY set, only copy the pixels matching the
* RGB values of the source colour key, ignoring alpha in the
* comparison.
BlitNtoNKey(), however, forgets to "ignore alpha in the comparison". The
documentation makes perfect sense, so I think it is the code that is faulty.
The attached patch corrects the code.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Wed, 15 Mar 2006 15:43:15 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
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.TH "SDL_Palette" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_Palette\- Color palette for 8-bit pixel formats .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct{ int ncolors; SDL_Color *colors; } SDL_Palette;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBncolors\fR Number of colors used in this palette .TP 20 \fBcolors\fR Pointer to \fI\fBSDL_Color\fR\fR structures that make up the palette\&. .SH "DESCRIPTION" .PP Each pixel in an 8-bit surface is an index into the \fBcolors\fR field of the \fBSDL_Palette\fR structure store in \fI\fBSDL_PixelFormat\fR\fR\&. A \fBSDL_Palette\fR should never need to be created manually\&. It is automatically created when SDL allocates a \fBSDL_PixelFormat\fR for a surface\&. The colors values of a \fI\fBSDL_Surface\fR\fRs palette can be set with the \fI\fBSDL_SetColors\fP\fR\&. .SH "SEE ALSO" .PP \fI\fBSDL_Color\fR\fR, \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_SetColors\fP\fR \fI\fBSDL_SetPalette\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01