view docs/man3/SDL_GL_GetProcAddress.3 @ 1240:3b8a43c428bb

From Bug #36: There are a couple of issues with the selection of Altivec alpha-blitting routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c. 1) There's no check for the presence of Altivec when checking if the Blit32to565PixelAlphaAltivec() routine can be selected. 2) Altivec cannot be used in video memory, and there's no check if the destination surface is a hardware surface. (Alpha-blitting to a hardware surface with GPU support is a bad idea, but somebody's bound to do it anyway.) Patch to fix these attached.
author Ryan C. Gordon <icculus@icculus.org>
date Sun, 08 Jan 2006 21:18:15 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.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