annotate docs/man3/SDL_DisplayFormatAlpha.3 @ 3950:9d9e15ab1697 SDL-1.2

Check if yasm supports a nasm-specific syntax we use (it doesn't in 0.5.0, which is still common in Linux distros, and does in 0.6.0). Disable it if we don't, attempting to fallback to using nasm. Thanks to Mike Frysinger for the patch. Fixes Bugzilla #393.
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 04 Jun 2007 11:06:48 +0000
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children 546f7c1eb755
rev   line source
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1 .TH "SDL_DisplayFormatAlpha" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_DisplayFormatAlpha\- Convert a surface to the display format
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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 \fBSDL_Surface *\fBSDL_DisplayFormatAlpha\fP\fR(\fBSDL_Surface *surface\fR);
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9 .SH "DESCRIPTION"
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10 .PP
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11 This function takes a surface and copies it to a new surface of the pixel format and colors of the video framebuffer plus an alpha channel, suitable for fast blitting onto the display surface\&. It calls \fISDL_ConvertSurface\fR
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12 .PP
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13 If you want to take advantage of hardware colorkey or alpha blit acceleration, you should set the colorkey and alpha value before calling this function\&.
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14 .PP
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15 This function can be used to convert a colourkey to an alpha channel, if the \fBSDL_SRCCOLORKEY\fP flag is set on the surface\&. The generated surface will then be transparent (alpha=0) where the pixels match the colourkey, and opaque (alpha=255) elsewhere\&.
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16 .SH "RETURN VALUE"
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17 .PP
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18 If the conversion fails or runs out of memory, it returns \fBNULL\fR
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19 .SH "SEE ALSO"
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20 .PP
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21 \fISDL_ConvertSurface\fR, \fISDL_SetAlpha\fR, \fISDL_SetColorKey\fR, \fISDL_DisplayFormat\fR, \fISDL_Surface\fR
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22 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01