Mercurial > sdl-ios-xcode
view docs/man3/SDL_GetRGBA.3 @ 4392:2b8c1aea633b SDL-1.2
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_GetRGBA" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_GetRGBA \- Get RGBA values from a pixel in the specified pixel format\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBvoid \fBSDL_GetRGBA\fP\fR(\fBUint32 pixel, SDL_PixelFormat *fmt, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a\fR); .SH "DESCRIPTION" .PP Get RGBA component values from a pixel stored in the specified pixel format\&. .PP This function uses the entire 8-bit [0\&.\&.255] range when converting color components from pixel formats with less than 8-bits per RGB component (e\&.g\&., a completely white pixel in 16-bit RGB565 format would return [0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8])\&. .PP If the surface has no alpha component, the alpha will be returned as 0xff (100% opaque)\&. .SH "SEE ALSO" .PP \fISDL_GetRGB\fR, \fISDL_MapRGB\fR, \fISDL_MapRGBA\fR, \fISDL_PixelFormat\fR .\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01