Mercurial > sdl-ios-xcode
view docs/man3/SDL_DisplayYUVOverlay.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 |
line wrap: on
line source
.TH "SDL_DisplayYUVOverlay" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_DisplayYUVOverlay\- Blit the overlay to the display .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_DisplayYUVOverlay\fP\fR(\fBSDL_Overlay *overlay, SDL_Rect *dstrect\fR); .SH "DESCRIPTION" .PP Blit the \fBoverlay\fR to the surface specified when it was \fIcreated\fR\&. The \fI\fBSDL_Rect\fR\fR structure, \fBdstrect\fR, specifies the position and size of the destination\&. If the \fBdstrect\fR is a larger or smaller than the overlay then the overlay will be scaled, this is optimized for 2x scaling\&. .SH "RETURN VALUES" .PP Returns 0 on success .SH "SEE ALSO" .PP \fI\fBSDL_Overlay\fR\fR, \fI\fBSDL_CreateYUVOverlay\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01