path: root/xc/lib/GL/glx/glxextensions.c

/*
 * (c) Copyright IBM Corporation 2002
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *    Ian Romanick <idr@us.ibm.com>
 */
/* $XFree86:$ */

#include "packsingle.h"
#include "glxclient.h"
#include <extutil.h>
#include <Xext.h>
#include <string.h>
#include "glapi.h"
#include "glxextensions.h"
#include "simple_list.h"

#define SET_BIT(m,b)   (m[ (b) / 8 ] |=  (1U << ((b) % 8)))
#define CLR_BIT(m,b)   (m[ (b) / 8 ] &= ~(1U << ((b) % 8)))
#define IS_SET(m,b)    ((m[ (b) / 8 ] & (1U << ((b) % 8))) != 0)
#define CONCAT(a,b) a ## b
#define GLX(n) "GLX_" # n, CONCAT(n,_bit)
#define GLX2(n,b) "GLX_" # n, CONCAT(b,_bit)
#define VER(a,b)  a, b
#define Y  1
#define N  0
#define EXT_ENABLED(bit,supported) ((bit < 255) && IS_SET( supported, bit ))

struct glx_extension {
   struct glx_extension * next;
   struct glx_extension * prev;
   
   char * name;
   GLuint      name_len;

   unsigned char bit;
   unsigned char version_major;
   unsigned char version_minor;
};

static struct {
   const char * const name;

   unsigned char  bit;

   /* This is the lowest version of GLX that "requires" this extension.
    * For example, GLX 1.3 requires SGIX_fbconfig, SGIX_pbuffer, and
    * SGI_make_current_read.  If the extension is not required by any known
    * version of GLX, use 0, 0.
    */
   unsigned char  version_major;
   unsigned char  version_minor;
   unsigned char  client_support:1;
   unsigned char  direct_support:1;
   unsigned char  client_only:1;     /** Is the extension client-side only? */
   unsigned char  direct_only:1;     /** Is the extension for direct
				      * contexts only?
				      */
} default_glx_extensions[] = {
   { GLX(ARB_get_proc_address),        VER(1,4), Y, N, Y, N },
   { GLX(ARB_multisample),             VER(0,0), Y, N, N, N },
   { GLX(ARB_render_texture),          VER(0,0), N, N, N, N },
   { GLX(ATI_pixel_format_float),      VER(0,0), N, N, N, N },
   { GLX(EXT_import_context),          VER(0,0), Y, Y, N, N },
   { GLX(EXT_visual_info),             VER(0,0), Y, Y, N, N },
   { GLX(EXT_visual_rating),           VER(0,0), Y, Y, N, N },
   { GLX(MESA_agp_offset),             VER(0,0), N, N, N, Y },
   { GLX(MESA_copy_sub_buffer),        VER(0,0), N, N, N, N }, /* Depricated? */
   { GLX(MESA_pixmap_colormap),        VER(0,0), N, N, N, N }, /* Depricated */
   { GLX(MESA_release_buffers),        VER(0,0), N, N, N, N }, /* Depricated */
   { GLX(MESA_set_3dfx_mode),          VER(0,0), N, N, N, N }, /* Depricated */
   { GLX(MESA_swap_control),           VER(0,0), Y, N, N, Y },
   { GLX(MESA_swap_frame_usage),       VER(0,0), Y, N, N, Y },
   { GLX(NV_float_buffer),             VER(0,0), N, N, N, N },
   { GLX(NV_render_depth_texture),     VER(0,0), N, N, N, N },
   { GLX(NV_render_texture_rectangle), VER(0,0), N, N, N, N },
   { GLX(NV_vertex_array_range),       VER(0,0), N, N, N, Y },
   { GLX(OML_swap_method),             VER(0,0), Y, N, N, N },
   { GLX(OML_sync_control),            VER(0,0), Y, N, N, Y },
   { GLX(SGI_cushion),                 VER(0,0), N, N, N, N },
   { GLX(SGI_make_current_read),       VER(1,3), N, N, N, N },
   { GLX(SGI_swap_control),            VER(0,0), Y, N, N, N },
   { GLX(SGI_video_sync),              VER(0,0), Y, N, N, Y },
   { GLX(SGIS_blended_overlay),        VER(0,0), N, N, N, N },
   { GLX(SGIS_color_range),            VER(0,0), N, N, N, N },
   { GLX(SGIS_multisample),            VER(0,0), Y, N, N, N },
   { GLX(SGIX_dm_buffer),              VER(0,0), N, N, N, N },
   { GLX(SGIX_fbconfig),               VER(1,3), Y, N, N, N },
   { GLX(SGIX_pbuffer),                VER(1,3), N, N, N, N },
   { GLX(SGIX_swap_barrier),           VER(0,0), N, N, N, N },
   { GLX(SGIX_swap_group),             VER(0,0), N, N, N, N },
   { GLX(SGIX_video_resize),           VER(0,0), N, N, N, N },
   { GLX(SGIX_video_source),           VER(0,0), N, N, N, N },
   { GLX(SGIX_visual_select_group),    VER(0,0), Y, N, N, N },
   { GLX(SUN_get_transparent_index),   VER(0,0), N, N, N, N },
   { NULL }
};

static struct glx_extension  ext_list;
static GLboolean ext_list_first_time = GL_TRUE;
static GLuint next_bit = 0;

static unsigned char client_support[8];
static unsigned char direct_support[8];
static unsigned char client_only[8];
static unsigned char direct_only[8];

static const char * __glXGLXClientExtensions = NULL;

static void __glXExtensionsCtr( void );
static void __glXProcessServerString( const char * server_string,
    unsigned char * server_support );

/**
 * Set the state of a GLX extension.
 *
 * \param name      Name of the extension.
 * \param name_len  Length, in characters, of the extension name.
 * \param state     New state (either enabled or disabled) of the extension.
 * \param supported Table in which the state of the extension is to be set.
 */
static void
set_glx_extension( const char * name, unsigned name_len, GLboolean state,
		   unsigned char * supported )
{
   struct glx_extension * i;


   foreach( i, & ext_list ) {
      if ( (name_len == i->name_len)
	   && (strncmp( i->name, name, name_len ) == 0) ) {
	 if ( state ) {
	    SET_BIT( supported, i->bit );
	 }
	 else {
	    CLR_BIT( supported, i->bit );
	 }

	 return;
      }
   }
}


#define NUL '\0'
#define SEPARATOR ' '

/**
 * Convert the server's extension string to a bit-field.
 * 
 * \param server_string   GLX extension string from the server.
 * \param server_support  Bit-field of supported extensions.
 */
static void
__glXProcessServerString( const char * server_string,
			  unsigned char * server_support )
{
   unsigned  base;
   unsigned  len;

   (void) memset( server_support, 0, sizeof( server_support ) );
   
   for ( base = 0 ; server_string[ base ] != NUL ; /* empty */ ) {
      /* Determine the length of the next extension name.
       */
      for ( len = 0
	    ; (server_string[ base + len ] != SEPARATOR)
	    && (server_string[ base + len ] != NUL)
	    ; len++ ) {
	 /* empty */
      }

      /* Set the bit for the extension in the server_support table.
       */
      set_glx_extension( & server_string[ base ], len, GL_TRUE,
			 server_support );
      
      /* Advance to the next extension string.  This means that we skip
       * over the previous string and any trialing white-space.
       */
      for ( base += len ;
	    (server_string[ base ] == SEPARATOR)
	    && (server_string[ base ] != NUL)
	    ; base++ ) {
	 /* empty */
      }
   }
}


/**
 * Enable a named GLX extension.
 * 
 * \param name  Name of the extension to enable.
 * \param force_client  Enable client-side suuport also.  If this is set
 *                      to GL_TRUE, then the driver MUST supply function
 *                      entry-points via \c __glXRegisterGLXFunction.
 * \sa __glXRegisterGLXFunction, __glXDisableExtension
 */
void
__glXEnableExtension( const char * name, GLboolean force_client )
{
   if ( __glXGLXClientExtensions == NULL ) {
      __glXExtensionsCtr();
      set_glx_extension( name, strlen( name ), GL_TRUE, direct_support );
      if ( force_client ) {
	 set_glx_extension( name, strlen( name ), GL_TRUE, client_support );
      }
   }
}


/**
 * Disable a named GLX extension.
 * 
 * \param name  Name of the extension to disable.
 * \sa __glXEnableExtension
 */
void
__glXDisableExtension( const char * name )
{
   if ( __glXGLXClientExtensions == NULL ) {
      __glXExtensionsCtr();
      set_glx_extension( name, strlen( name ), GL_FALSE, direct_support );
   }
}


/**
 * Add an extension to the global list of known GLX extensions.
 * 
 * \param enabled  Default state of the extension.
 * \param name     Text name of the extension.
 * \param version_major  Major GLX version that requires this extension.
 * \param version_minor  Minor GLX version that requires this extension.
 * \param bit      Bit number in the global table that is set if this
 *                 extension is enabled.
 * \param client_only_flag  Is this extension client-side only?
 */
static void
add_extension( const char * name, GLuint version_major, GLuint version_minor,
	       GLuint bit,
	       GLboolean client_enabled_flag, GLboolean direct_enabled_flag,
	       GLboolean client_only_flag, GLboolean direct_only_flag )
{
   struct glx_extension * ext;
   unsigned   name_len;
   
   
   name_len = strlen( name );
   ext = Xmalloc( sizeof( *ext ) + name_len + 1 );
   if ( ext != NULL ) {
      ext->bit = bit;
      ext->version_major = version_major;
      ext->version_minor = version_minor;

      if ( client_enabled_flag ) {
	 SET_BIT( client_support, bit );
      }
      else {
	 CLR_BIT( client_support, bit );
      }

      if ( direct_enabled_flag ) {
	 SET_BIT( direct_support, bit );
      }
      else {
	 CLR_BIT( direct_support, bit );
      }

      if ( client_only_flag ) {
	 SET_BIT( client_only, bit );
      }
      else {
	 CLR_BIT( client_only, bit );
      }

      if ( direct_only_flag ) {
	 SET_BIT( direct_only, bit );
      }
      else {
	 CLR_BIT( direct_only, bit );
      }

      ext->name = (char *)(ext + 1);
      (void) memcpy( ext->name, name, name_len );
      ext->name[ name_len ] = '\0';
      ext->name_len = name_len;
      
      insert_at_tail( & ext_list, ext );
   }
}




/**
 * Add a new extension string to the set of possible strings.  This is
 * intended to be used by drivers to advertise support for unlisted,
 * proprietary extensions.
 * 
 * \param enabled      Is the extension enabled by default?
 * \param name         Name of the extension.
 * \param client_only  Is the extension client-side only?
 */
void
__glXAddExtension( GLboolean enabled, const char * name, 
		   GLboolean client_only )
{
   if ( __glXGLXClientExtensions == NULL ) {
      GLuint bit;

      __glXExtensionsCtr();

      bit = next_bit;
      if ( next_bit < 255 ) {
	 next_bit++;
      }

      add_extension( name, 0, 0, bit, enabled, enabled,
		     client_only, GL_TRUE );
   }
}




static void
__glXExtensionsCtr( void )
{
   unsigned   i;
   
   
   if ( ext_list_first_time ) {
      ext_list_first_time = GL_FALSE;

      (void) memset( client_support, 0, sizeof( client_support ) );
      (void) memset( direct_support, 0, sizeof( direct_support ) );
      (void) memset( client_only,    0, sizeof( client_only ) );
      (void) memset( direct_only,    0, sizeof( direct_only ) );

      make_empty_list( & ext_list );

      for ( i = 0 ; default_glx_extensions[i].name != NULL ; i++ ) {
	 add_extension(	default_glx_extensions[i].name,
			default_glx_extensions[i].version_major,
			default_glx_extensions[i].version_minor,
			default_glx_extensions[i].bit,
			default_glx_extensions[i].client_support,
			default_glx_extensions[i].direct_support,
			default_glx_extensions[i].client_only,
			default_glx_extensions[i].direct_only );
	 if ( default_glx_extensions[i].bit >= next_bit ) {
	    next_bit = default_glx_extensions[i].bit + 1;
	 }
      }
   }
}




GLboolean
__glXExtensionBitIsEnabled( unsigned bit )
{
   __glXExtensionsCtr();
   return EXT_ENABLED( bit, direct_support );
}




/**
 * Convert a bit-field to a string of supported extensions.
 */
static char *
__glXGetStringFromTable( const unsigned char * supported )
{
   struct glx_extension * i;
   unsigned   ext_str_len;
   char * ext_str;
   char * point;


   ext_str_len = 0;
   foreach( i, & ext_list ) {
      if ( EXT_ENABLED( i->bit, supported ) ) {
	 ext_str_len += i->name_len + 1;
      }
   }

   ext_str = Xmalloc( ext_str_len + 1 );
   if ( ext_str != NULL ) {
      point = ext_str;

      foreach( i, & ext_list ) {
	 if ( EXT_ENABLED( i->bit, supported ) ) {
	    (void) memcpy( point, i->name, i->name_len );
	    point += i->name_len;

	    *point = ' ';
	    point++;
	 }
      }

      *point = '\0';
   }

   return ext_str;
}
    

/**
 * Get the string of client library supported extensions.
 */
const char *
__glXGetClientExtensions( void )
{
   if ( __glXGLXClientExtensions == NULL ) {
      __glXExtensionsCtr();
      __glXGLXClientExtensions = __glXGetStringFromTable( client_support );
   }

   return __glXGLXClientExtensions;
}


/**
 * Get the list of application usable extensions.
 * 
 * \returns A pointer to the string.
 */
char *
__glXGetUsableExtensions( const char * server_string )
{
   unsigned char server_support[8];
   unsigned char usable[8];
   unsigned      i;

   __glXExtensionsCtr();
   __glXProcessServerString( server_string, server_support );

   /* An extension is supported if the client-side (i.e., libGL) supports
    * it and the "server" supports it.  In this case that means that either
    * the true server supports it or it is only for direct-rendering and
    * the direct rendering driver supports it.
    */
   for ( i = 0 ; i < 8 ; i++ ) {
      usable[i] = (client_support[i] & client_only[i])
	  | (client_support[i] & (direct_support[i] & server_support[i]))
	  | (client_support[i] & (direct_support[i] & direct_only[i]));
   }

   return __glXGetStringFromTable( usable );
}