view docs/man3/SDL_GL_GetProcAddress.3 @ 3335:b8d313de8a65

Adam Strzelecki to SDL Since current DirectFB implementation is incomplete for YUV surfaces (actually causes segmentation faults when trying Lock and use YUV planar textures) I decided to fix it a bit. Here's a patch that should make DirectFB properly support YUV both packed and planar (3 planes). (1) Removed SDL_BYTESPERPIXEL at all in favor of DFB_BYTES_PER_PIXEL(SDLToDFBPixelFormat(fmt)) which does return always proper BPP for YUVs too, coz SDL_BYTESPERPIXEL returns incorrect values for FOURCCs (2) Fixed data->pixels allocation for planar YUVs in CreateTexture, it should allocate 150% more space (3) Copy other planes for planar YUVs in UpdateTexture (4) Moved checking if format is supported at all with DirectFB on CreateTexture at the beginning of the code Waiting for comments, -- Adam Strzelecki | nanoant.com
author Sam Lantinga <slouken@libsdl.org>
date Sun, 04 Oct 2009 04:03:37 +0000
parents 546f7c1eb755
children 1238da4a7112
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.TH "SDL_GL_GetProcAddress" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_GL_GetProcAddress \- Get the address of a GL function
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBvoid *\fBSDL_GL_GetProcAddress\fP\fR(\fBconst char* proc\fR);
.SH "DESCRIPTION"
.PP
Returns the address of the GL function \fBproc\fR, or \fBNULL\fR if the function is not found\&. If the GL library is loaded at runtime, with \fI\fBSDL_GL_LoadLibrary\fP\fR, then \fIall\fP GL functions must be retrieved this way\&. Usually this is used to retrieve function pointers to OpenGL extensions\&.
.SH "EXAMPLE"
.PP
.nf
\f(CWtypedef void (*GL_ActiveTextureARB_Func)(unsigned int);
GL_ActiveTextureARB_Func glActiveTextureARB_ptr = 0;
int has_multitexture=1;
\&.
\&.
\&.
/* Get function pointer */
glActiveTextureARB_ptr=(GL_ActiveTextureARB_Func) SDL_GL_GetProcAddress("glActiveTextureARB");

/* Check for a valid function ptr */
if(!glActiveTextureARB_ptr){
  fprintf(stderr, "Multitexture Extensions not present\&.
");
  has_multitexture=0;
}
\&.
\&.
\&.
\&.
if(has_multitexture){
  glActiveTextureARB_ptr(GL_TEXTURE0_ARB);
  \&.
  \&.
}
else{
  \&.
  \&.
}\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\fI\fBSDL_GL_LoadLibrary\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01