annotate docs/man3/SDL_BlitSurface.3 @ 34:27cb016592f9

Minor crash bugfix
author Sam Lantinga <slouken@lokigames.com>
date Wed, 23 May 2001 00:06:08 +0000
parents 74212992fb08
children 55f1f1b3e27d
rev   line source
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1 .TH "SDL_BlitSurface" "3" "Mon 12 Mar 2001, 01:04" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_BlitSurface\- This performs a fast blit from the source surface to the destination surface\&.
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4 .SH "SYNOPSIS"
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5 .PP
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6 \fB#include "SDL\&.h"
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7 .sp
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8 \fBint \fBSDL_BlitSurface\fP\fR(\fBSDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect\fR);
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9 .SH "DESCRIPTION"
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10 .PP
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11 This performs a fast blit from the source surface to the destination surface\&.
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12 .PP
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13 Only the position is used in the \fBdstrect\fR (the width and height are ignored)\&.
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14 .PP
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15 If either \fBsrcrect\fR or \fBdstrect\fR are \fBNULL\fP, the entire surface (\fBsrc\fR or \fBdst\fR) is copied\&.
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16 .PP
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17 The final blit rectangle is saved in \fBdstrect\fR after all clipping is performed (\fBsrcrect\fR is not modified)\&.
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18 .PP
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19 The blit function should not be called on a locked surface\&.
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20 .PP
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21 .RS
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22 \fBNote:
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23 .PP
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24 The results of blitting operations vary greatly depending on whether \fBSDL_SRCAPLHA\fP is set or not\&. See \fISDL_SetAlpha\fR\&.
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25 .RE
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26 .SH "RETURN VALUE"
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27 .PP
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28 If the blit is successful, it returns \fB0\fR, otherwise it returns \fB-1\fR\&.
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29 .PP
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30 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:
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31 .PP
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32 .nf
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33 \f(CW while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
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34 while ( SDL_LockSurface(image)) < 0 )
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35 Sleep(10);
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36 -- Write image pixels to image->pixels --
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37 SDL_UnlockSurface(image);
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38 }\fR
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39 .fi
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40 .PP
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41 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\&.
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42 .SH "SEE ALSO"
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43 .PP
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44 \fI\fBSDL_LockSurface\fP\fR, \fI\fBSDL_FillRect\fP\fR, \fI\fBSDL_Surface\fR\fR, \fI\fBSDL_Rect\fR\fR
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45 ...\" created by instant / docbook-to-man, Mon 12 Mar 2001, 01:04