annotate docs/man3/SDL_GLattr.3 @ 1544:ab1e4c41ab71

Fixed bug #33 Mike Frysinger wrote: > with libsdl-1.2.9, some games (like bomberclone) started > segfaulting in Gentoo [...snip...] > the last change in the last hunk: [...snip...] > if i change the statement to read: > (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures() > bomberclone no longer segfaults on my box Alex Volkov wrote: > The test "(table[which].blit_features & GetBlitFeatures()) == > table[which].blit_features)" is correct, and the previous > "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken. I think there is potentially a slightly different cause of the above problem. During the introduction of the Altivec code, the blit_table struct field 'alpha' got changed from a straightforward enum to a bitmask, which makes perfect sense by itself. However, now the table driven blitter selection code in SDL_CalculateBlitN() can choose the wrong blitters when searching for a NO_ALPHA blitter because of the following code: int a_need = 0; ... (a_need & table[which].alpha) == a_need && When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing alpha channel bits to appear in a non-alpha destination surface. I suppose this could theoretically be an indirect cause of the segfault mentioned above. I *think* this can be fixed by changing to int a_need = NO_ALPHA;
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Mar 2006 15:47:49 +0000
parents e5bc29de3f0a
children 546f7c1eb755
rev   line source
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1 .TH "SDL_GLattr" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_GLattr\- SDL GL Attributes
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4 .SH "ATTRIBUTES"
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5 .TP 20
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6 \fBSDL_GL_RED_SIZE\fP
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7 Size of the framebuffer red component, in bits
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8 .TP 20
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9 \fBSDL_GL_GREEN_SIZE\fP
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10 Size of the framebuffer green component, in bits
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11 .TP 20
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12 \fBSDL_GL_BLUE_SIZE\fP
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13 Size of the framebuffer blue component, in bits
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14 .TP 20
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15 \fBSDL_GL_ALPHA_SIZE\fP
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16 Size of the framebuffer alpha component, in bits
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17 .TP 20
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18 \fBSDL_GL_DOUBLEBUFFER\fP
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19 0 or 1, enable or disable double buffering
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20 .TP 20
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21 \fBSDL_GL_BUFFER_SIZE\fP
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22 Size of the framebuffer, in bits
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23 .TP 20
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24 \fBSDL_GL_DEPTH_SIZE\fP
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25 Size of the depth buffer, in bits
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26 .TP 20
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27 \fBSDL_GL_STENCIL_SIZE\fP
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28 Size of the stencil buffer, in bits
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29 .TP 20
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30 \fBSDL_GL_ACCUM_RED_SIZE\fP
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31 Size of the accumulation buffer red component, in bits
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32 .TP 20
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33 \fBSDL_GL_ACCUM_GREEN_SIZE\fP
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34 Size of the accumulation buffer green component, in bits
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35 .TP 20
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36 \fBSDL_GL_ACCUM_BLUE_SIZE\fP
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37 Size of the accumulation buffer blue component, in bits
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38 .TP 20
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39 \fBSDL_GL_ACCUM_ALPHA_SIZE\fP
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40 Size of the accumulation buffer alpha component, in bits
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41 .SH "DESCRIPTION"
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42 .PP
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43 While you can set most OpenGL attributes normally, the attributes list above must be known \fIbefore\fP SDL sets the video mode\&. These attributes a set and read with \fI\fBSDL_GL_SetAttribute\fP\fR and \fI\fBSDL_GL_GetAttribute\fP\fR\&.
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44 .SH "SEE ALSO"
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45 .PP
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46 \fI\fBSDL_GL_SetAttribute\fP\fR, \fI\fBSDL_GL_GetAttribute\fP\fR
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47 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01