annotate docs/man3/SDL_BlitSurface.3 @ 934:af585d6efec8

Date: Thu, 17 Jun 2004 11:38:51 -0700 (PDT) From: Eric Wing <ewing2121@yahoo.com> Subject: New OS X patch (was Re: [SDL] Bug with inverted mouse coordinates in I have a new patch for OS X I would like to submit. First, it appears no further action has been taken on my fix from Apple on the OpenGL windowed mode mouse inversion problem. The fix would reunify the code, and no longer require case checking for which version of the OS you are running. This is probably a good fix because the behavior with the old code could change again with future versions of the OS, so those fixes are included in this new patch. But in addition, when I was at Apple, I asked them about the ability to distinguish between the modifier keys on the left and right sides of the keyboard (e.g. Left Shift, Right Shift, Left/Right Alt, L/R Cmd, L/R Ctrl). They told me that starting with Panther, the OS began supporting this feature. This has always been a source of annoyance for me when bringing a program that comes from Windows or Linux to OS X when the keybindings happened to need distinguishable left-side and right-side keys. So the rest of the patch I am submitting contains new code to support this feature on Panther (and presumably later versions of the OS). So after removing the OS version checks for the mouse inversion problem, I reused the OS version checks to activate the Left/Right detection of modifier keys. If you are running Panther (or above), the new code will attempt to distinguish between sides. For the older OS's, the code path reverts to the original code. I've tested with Panther on a G4 Cube, G5 dual processor, and Powerbook Rev C. The Cube and G5 keyboards demonstrated the ability to distinguish between sides. The Powerbook seems to only have left-side keys, but the patch was still able to handle it by producing the same results as before the patch. I also wanted to test a non-Apple keyboard. Unfortunately, I don't have any PC USB keyboards. However, I was able to borrow a Sun Microsystems USB keyboard, so I tried that out on the G5, and I got the correct behavior for left and right sides. I'm expecting that if it worked with a Sun keyboard, most other keyboards should work with no problems.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 20 Aug 2004 22:35:23 +0000
parents e5bc29de3f0a
children 546f7c1eb755
rev   line source
181
e5bc29de3f0a Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents: 55
diff changeset
1 .TH "SDL_BlitSurface" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference"
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
2 .SH "NAME"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
3 SDL_BlitSurface\- This performs a fast blit from the source surface to the destination surface\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
4 .SH "SYNOPSIS"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
5 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
6 \fB#include "SDL\&.h"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
7 .sp
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
8 \fBint \fBSDL_BlitSurface\fP\fR(\fBSDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect\fR);
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
9 .SH "DESCRIPTION"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
10 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
11 This performs a fast blit from the source surface to the destination surface\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
12 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
13 Only the position is used in the \fBdstrect\fR (the width and height are ignored)\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
14 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
15 If either \fBsrcrect\fR or \fBdstrect\fR are \fBNULL\fP, the entire surface (\fBsrc\fR or \fBdst\fR) is copied\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
16 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
17 The final blit rectangle is saved in \fBdstrect\fR after all clipping is performed (\fBsrcrect\fR is not modified)\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
18 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
19 The blit function should not be called on a locked surface\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
20 .PP
55
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
21 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\&.
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
22 .PP
55
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
23 .nf
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
24 \f(CWif (source surface has SDL_SRCALPHA set) {
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
25 if (source surface has alpha channel (that is, format->Amask != 0))
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
26 blit using per-pixel alpha, ignoring any colour key
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
27 else {
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
28 if (source surface has SDL_SRCCOLORKEY set)
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
29 blit using the colour key AND the per-surface alpha value
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
30 else
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
31 blit using the per-surface alpha value
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
32 }
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
33 } else {
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
34 if (source surface has SDL_SRCCOLORKEY set)
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
35 blit using the colour key
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
36 else
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
37 ordinary opaque rectangular blit
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
38 }\fR
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
39 .fi
55f1f1b3e27d Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents: 0
diff changeset
40 .PP
0
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
41 .SH "RETURN VALUE"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
42 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
43 If the blit is successful, it returns \fB0\fR, otherwise it returns \fB-1\fR\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
44 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
45 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:
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
46 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
47 .nf
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
48 \f(CW while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
49 while ( SDL_LockSurface(image)) < 0 )
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
50 Sleep(10);
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
51 -- Write image pixels to image->pixels --
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
52 SDL_UnlockSurface(image);
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
53 }\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
54 .fi
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
55 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
56 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\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
57 .SH "SEE ALSO"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
58 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
59 \fI\fBSDL_LockSurface\fP\fR, \fI\fBSDL_FillRect\fP\fR, \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_Rect\fR\fR
181
e5bc29de3f0a Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents: 55
diff changeset
60 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01