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annotate docs/man3/SDL_DisplayFormatAlpha.3 @ 3197:434ce3242e1c

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Alexei Tereschenko Why not to use hardware vertex processing instead of software one if it is available in D3D render driver? With hardware processing testsprite2 runs three times faster on all videocards which I could test.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 16 Jun 2009 14:34:15 +0000
parents 546f7c1eb755
children 1238da4a7112
rev   line source
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e5bc29de3f0a Updated from the SDL Documentation Project
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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