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Fixed bug #898 Jeremiah Morris 2009-12-09 16:07:17 PST No-op GlobalToLocal translations in fullscreen mode On my MacBook Pro running 10.6, I noticed a small upward bias on mouse movement in a fullscreen SDL application. The app uses WarpCursor and GetMouseState in a loop to measure relative movement. I tracked it down to NSWindow's convertBaseToScreen: routine, which added a 2-pixel offset on the Y coordinate instead of the expected (+0,+0) translation. In fullscreen mode, QZ_PrivateWarpCursor() does not translate the desired position through QZ_PrivateGlobalToLocal() before passing it to the Core Graphics system. However, QZ_GetMouseLocation() does call the reverse QZ_PrivateLocalToGlobal() even in fullscreen mode. This asymmetry caused problems each time the mouse was moved.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 11 Dec 2009 15:31:37 +0000
parents 1238da4a7112
children
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.TH "SDL_DisplayFormatAlpha" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_DisplayFormatAlpha \- Convert a surface to the display format
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBSDL_Surface *\fBSDL_DisplayFormatAlpha\fP\fR(\fBSDL_Surface *surface\fR);
.SH "DESCRIPTION"
.PP
This function takes a surface and copies it to a new surface of the pixel format and colors of the video framebuffer plus an alpha channel, suitable for fast blitting onto the display surface\&. It calls \fISDL_ConvertSurface\fR
.PP
If you want to take advantage of hardware colorkey or alpha blit acceleration, you should set the colorkey and alpha value before calling this function\&.
.PP
This function can be used to convert a colourkey to an alpha channel, if the \fBSDL_SRCCOLORKEY\fP flag is set on the surface\&. The generated surface will then be transparent (alpha=0) where the pixels match the colourkey, and opaque (alpha=255) elsewhere\&.
.SH "RETURN VALUE"
.PP
If the conversion fails or runs out of memory, it returns \fBNULL\fR
.SH "SEE ALSO"
.PP
\fISDL_ConvertSurface\fR, \fISDL_SetAlpha\fR, \fISDL_SetColorKey\fR, \fISDL_DisplayFormat\fR, \fISDL_Surface\fR
.\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01