Mercurial > sdl-ios-xcode
view docs/man3/SDL_BlitSurface.3 @ 4240:cb44bf8f8a0f SDL-1.2
Fixed bug #719
Mike Blaguszewski 2009-03-23 13:32:22 PDT
Patch to 1.2 HEAD that fixes the issue
Fixes bug in SDL 1.2.13 where clicking on an app's title bar to activate the
app, when cursor capturing is enabled, will cause the window to jump. This is
because SDL's handler for activate events calls a low-level Quartz function to
move the cursor. Calling this when the mouse is down in the title bar confuses
the WindowServer into thinking the title bar has been dragged. The patch defers
processing of activate events in this case.
The bottom line is that CGWarpMouseCursorPosition() is not safe to call when
the mouse in down in a window's title bar.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 23 Sep 2009 07:18:02 +0000 |
parents | 4e3b250c950e |
children | 1238da4a7112 |
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.TH "SDL_BlitSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_BlitSurface \- This performs a fast blit from the source surface to the destination surface\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBint \fBSDL_BlitSurface\fP\fR(\fBSDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect\fR); .SH "DESCRIPTION" .PP This performs a fast blit from the source surface to the destination surface\&. .PP Only the position is used in the \fBdstrect\fR (the width and height are ignored)\&. .PP If either \fBsrcrect\fR or \fBdstrect\fR are \fBNULL\fP, the entire surface (\fBsrc\fR or \fBdst\fR) is copied\&. .PP The final blit rectangle is saved in \fBdstrect\fR after all clipping is performed (\fBsrcrect\fR is not modified)\&. .PP The blit function should not be called on a locked surface\&. .PP The results of blitting operations vary greatly depending on whether \fBSDL_SRCAPLHA\fP is set or not\&. See \fISDL_SetAlpha\fR for an explaination of how this affects your results\&. Colorkeying and alpha attributes also interact with surface blitting, as the following pseudo-code should hopefully explain\&. .PP .nf \f(CWif (source surface has SDL_SRCALPHA set) { if (source surface has alpha channel (that is, format->Amask != 0)) blit using per-pixel alpha, ignoring any colour key else { if (source surface has SDL_SRCCOLORKEY set) blit using the colour key AND the per-surface alpha value else blit using the per-surface alpha value } } else { if (source surface has SDL_SRCCOLORKEY set) blit using the colour key else ordinary opaque rectangular blit }\fR .fi .PP .SH "RETURN VALUE" .PP If the blit is successful, it returns \fB0\fR, otherwise it returns \fB-1\fR\&. .PP If either of the surfaces were in video memory, and the blit returns \fB-2\fR, the video memory was lost, so it should be reloaded with artwork and re-blitted: .PP .nf \f(CW while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) { while ( SDL_LockSurface(image)) < 0 ) Sleep(10); -- Write image pixels to image->pixels -- SDL_UnlockSurface(image); }\fR .fi .PP This happens under DirectX 5\&.0 when the system switches away from your fullscreen application\&. Locking the surface will also fail until you have access to the video memory again\&. .SH "SEE ALSO" .PP \fI\fBSDL_LockSurface\fP\fR, \fI\fBSDL_FillRect\fP\fR, \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_Rect\fR\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01