view docs/man3/SDL_DisplayFormatAlpha.3 @ 1754:c67921b517c3

Date: Sun, 30 Apr 2006 14:20:05 +1000 From: Rob Subject: [SDL] SDL pre-release OpenGL fails on the zipped pre-release source accessible from http://www.libsdl.org/svn.php. Appears to be following lines in sdl_wing.c (lines 341-345): wglext = (const char *)this->glGetString(GL_EXTENSIONS); if ( !SDL_strstr(wglext, "WGL_EXT_swap_control") ) { this->gl_data->wglSwapIntervalEXT = NULL; this->gl_data->wglGetSwapIntervalEXT = NULL; } glGetString is a null pointer, as are other gl function pointers, so call fails. Never looked at sdl source before, so no further than that as yet.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 01 May 2006 07:15:35 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_DisplayFormatAlpha" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_DisplayFormatAlpha\- Convert a surface to the display format
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBSDL_Surface *\fBSDL_DisplayFormatAlpha\fP\fR(\fBSDL_Surface *surface\fR);
.SH "DESCRIPTION"
.PP
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
.PP
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\&.
.PP
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\&.
.SH "RETURN VALUE"
.PP
If the conversion fails or runs out of memory, it returns \fBNULL\fR
.SH "SEE ALSO"
.PP
\fISDL_ConvertSurface\fR, \fISDL_SetAlpha\fR, \fISDL_SetColorKey\fR, \fISDL_DisplayFormat\fR, \fISDL_Surface\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01