diff options
Diffstat (limited to 'xorg-server/glx/glapi.c')
| -rw-r--r-- | xorg-server/glx/glapi.c | 1026 |
1 files changed, 516 insertions, 510 deletions
diff --git a/xorg-server/glx/glapi.c b/xorg-server/glx/glapi.c index 9e219f680..c11454b1f 100644 --- a/xorg-server/glx/glapi.c +++ b/xorg-server/glx/glapi.c @@ -1,510 +1,516 @@ -/* - * Mesa 3-D graphics library - * Version: 6.5 - * - * Copyright (C) 1999-2006 Brian Paul 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 - * the rights to use, copy, modify, merge, publish, distribute, sublicense, - * 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 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 NONINFRINGEMENT. IN NO EVENT SHALL - * BRIAN PAUL 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. - */ - -/* - * This file manages the OpenGL API dispatch layer. There are functions - * to set/get the current dispatch table for the current thread and to - * manage registration/dispatch of dynamically added extension functions. - * - * This code was originally general enough to be shared with Mesa, but - * they diverged long ago, so this is now just enough support to make - * indirect GLX work. - */ - -#include <dix-config.h> -#include <X11/Xfuncproto.h> -#include <os.h> -#define PUBLIC _X_EXPORT - -#include <stdlib.h> -#include <string.h> -#ifdef DEBUG -#include <assert.h> -#endif - -#include "glapi.h" -#include "glapioffsets.h" -#include "glapitable.h" - -#if defined(PTHREADS) || defined(GLX_USE_TLS) -static void init_glapi_relocs(void); -#endif - -/** - * \name Current dispatch and current context control variables - * - * Depending on whether or not multithreading is support, and the type of - * support available, several variables are used to store the current context - * pointer and the current dispatch table pointer. In the non-threaded case, - * the variables \c _glapi_Dispatch and \c _glapi_Context are used for this - * purpose. - * - * In the "normal" threaded case, the variables \c _glapi_Dispatch and - * \c _glapi_Context will be \c NULL if an application is detected as being - * multithreaded. Single-threaded applications will use \c _glapi_Dispatch - * and \c _glapi_Context just like the case without any threading support. - * When \c _glapi_Dispatch and \c _glapi_Context are \c NULL, the thread state - * data \c _gl_DispatchTSD and \c ContextTSD are used. Drivers and the - * static dispatch functions access these variables via \c _glapi_get_dispatch - * and \c _glapi_get_context. - * - * In the TLS case, the variables \c _glapi_Dispatch and \c _glapi_Context are - * hardcoded to \c NULL. Instead the TLS variables \c _glapi_tls_Dispatch and - * \c _glapi_tls_Context are used. Having \c _glapi_Dispatch and - * \c _glapi_Context be hardcoded to \c NULL maintains binary compatability - * between TLS enabled loaders and non-TLS DRI drivers. - */ -/*@{*/ -#if defined(GLX_USE_TLS) - -PUBLIC TLS struct _glapi_table * _glapi_tls_Dispatch = NULL; - -PUBLIC TLS void * _glapi_tls_Context; - -PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL; -PUBLIC const void *_glapi_Context = NULL; - -#else - -#if defined(THREADS) - -_glthread_TSD _gl_DispatchTSD; /**< Per-thread dispatch pointer */ -static _glthread_TSD ContextTSD; /**< Per-thread context pointer */ - -#if defined(WIN32_THREADS) -void FreeTSD(_glthread_TSD *p); -void FreeAllTSD(void) -{ - FreeTSD(&_gl_DispatchTSD); - FreeTSD(&ContextTSD); -} -#endif /* defined(WIN32_THREADS) */ - -#endif /* defined(THREADS) */ - -PUBLIC struct _glapi_table *_glapi_Dispatch = NULL; -PUBLIC void *_glapi_Context = NULL; - -#endif /* defined(GLX_USE_TLS) */ -/*@}*/ - -/* - * xserver's gl is not multithreaded, we promise. - */ -PUBLIC void -_glapi_check_multithread(void) -{ -} - -/** - * Set the current context pointer for this thread. - * The context pointer is an opaque type which should be cast to - * void from the real context pointer type. - */ -PUBLIC void -_glapi_set_context(void *context) -{ -#if defined(GLX_USE_TLS) - _glapi_tls_Context = context; -#elif defined(THREADS) - _glthread_SetTSD(&ContextTSD, context); - _glapi_Context = context; -#else - _glapi_Context = context; -#endif -} - - - -/** - * Get the current context pointer for this thread. - * The context pointer is an opaque type which should be cast from - * void to the real context pointer type. - */ -PUBLIC void * -_glapi_get_context(void) -{ -#if defined(GLX_USE_TLS) - return _glapi_tls_Context; -#else - return _glapi_Context; -#endif -} - - - -/** - * Set the global or per-thread dispatch table pointer. - */ -PUBLIC void -_glapi_set_dispatch(struct _glapi_table *dispatch) -{ -#if defined(PTHREADS) || defined(GLX_USE_TLS) - static pthread_once_t once_control = PTHREAD_ONCE_INIT; - pthread_once( & once_control, init_glapi_relocs ); -#endif - -#if defined(GLX_USE_TLS) - _glapi_tls_Dispatch = dispatch; -#elif defined(THREADS) - _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch); - _glapi_Dispatch = dispatch; -#else /*THREADS*/ - _glapi_Dispatch = dispatch; -#endif /*THREADS*/ -} - - - -/** - * Return pointer to current dispatch table for calling thread. - */ -PUBLIC struct _glapi_table * -_glapi_get_dispatch(void) -{ - struct _glapi_table * api; -#if defined(GLX_USE_TLS) - api = _glapi_tls_Dispatch; -#else - api = _glapi_Dispatch; -#endif - return api; -} - - - -/*** - *** The rest of this file is pretty much concerned with GetProcAddress - *** functionality. - ***/ - -#if defined(USE_X64_64_ASM) && defined(GLX_USE_TLS) -# define DISPATCH_FUNCTION_SIZE 16 -#elif defined(USE_X86_ASM) -# if defined(THREADS) && !defined(GLX_USE_TLS) -# define DISPATCH_FUNCTION_SIZE 32 -# else -# define DISPATCH_FUNCTION_SIZE 16 -# endif -#endif - - -/* The code in this file is auto-generated with Python */ -#include "glprocs.h" - - -/** - * Search the table of static entrypoint functions for the named function - * and return the corresponding glprocs_table_t entry. - */ -static const glprocs_table_t * -find_entry( const char * n ) -{ - GLuint i; - for (i = 0; static_functions[i].Name_offset >= 0; i++) { - const char *testName = gl_string_table + static_functions[i].Name_offset; - if (strcmp(testName, n) == 0) { - return &static_functions[i]; - } - } - return NULL; -} - - -/** - * Return dispatch table offset of the named static (built-in) function. - * Return -1 if function not found. - */ -static GLint -get_static_proc_offset(const char *funcName) -{ - const glprocs_table_t * const f = find_entry( funcName ); - if (f) { - return f->Offset; - } - return -1; -} - - - -/********************************************************************** - * Extension function management. - */ - -/* - * Number of extension functions which we can dynamically add at runtime. - */ -#define MAX_EXTENSION_FUNCS 300 - - -/* - * The dispatch table size (number of entries) is the size of the - * _glapi_table struct plus the number of dynamic entries we can add. - * The extra slots can be filled in by DRI drivers that register new extension - * functions. - */ -#define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS) - - -/** - * Track information about a function added to the GL API. - */ -struct _glapi_function { - /** - * Name of the function. - */ - const char * name; - - /** - * Text string that describes the types of the parameters passed to the - * named function. Parameter types are converted to characters using the - * following rules: - * - 'i' for \c GLint, \c GLuint, and \c GLenum - * - 'p' for any pointer type - * - 'f' for \c GLfloat and \c GLclampf - * - 'd' for \c GLdouble and \c GLclampd - */ - const char * parameter_signature; - - /** - * Offset in the dispatch table where the pointer to the real function is - * located. If the driver has not requested that the named function be - * added to the dispatch table, this will have the value ~0. - */ - unsigned dispatch_offset; -}; - -static struct _glapi_function ExtEntryTable[MAX_EXTENSION_FUNCS]; -static GLuint NumExtEntryPoints = 0; - -/** - * Generate new entrypoint - * - * Use a temporary dispatch offset of ~0 (i.e. -1). Later, when the driver - * calls \c _glapi_add_dispatch we'll put in the proper offset. If that - * never happens, and the user calls this function, he'll segfault. That's - * what you get when you try calling a GL function that doesn't really exist. - * - * \param funcName Name of the function to create an entry-point for. - * - * \sa _glapi_add_entrypoint - */ - -static struct _glapi_function * -add_function_name( const char * funcName ) -{ - struct _glapi_function * entry = NULL; - - if (NumExtEntryPoints < MAX_EXTENSION_FUNCS) { - entry = &ExtEntryTable[NumExtEntryPoints]; - - ExtEntryTable[NumExtEntryPoints].name = strdup(funcName); - ExtEntryTable[NumExtEntryPoints].parameter_signature = NULL; - ExtEntryTable[NumExtEntryPoints].dispatch_offset = ~0; - NumExtEntryPoints++; - } - - return entry; -} - - -/** - * Fill-in the dispatch stub for the named function. - * - * This function is intended to be called by a hardware driver. When called, - * a dispatch stub may be created created for the function. A pointer to this - * dispatch function will be returned by glXGetProcAddress. - * - * \param function_names Array of pointers to function names that should - * share a common dispatch offset. - * \param parameter_signature String representing the types of the parameters - * passed to the named function. Parameter types - * are converted to characters using the following - * rules: - * - 'i' for \c GLint, \c GLuint, and \c GLenum - * - 'p' for any pointer type - * - 'f' for \c GLfloat and \c GLclampf - * - 'd' for \c GLdouble and \c GLclampd - * - * \returns - * The offset in the dispatch table of the named function. A pointer to the - * driver's implementation of the named function should be stored at - * \c dispatch_table[\c offset]. - * - * \sa glXGetProcAddress - * - * \warning - * This function can only handle up to 8 names at a time. As far as I know, - * the maximum number of names ever associated with an existing GL function is - * 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT, - * \c glPointParameterfARB, and \c glPointParameterf), so this should not be - * too painful of a limitation. - * - * \todo - * Determine whether or not \c parameter_signature should be allowed to be - * \c NULL. It doesn't seem like much of a hardship for drivers to have to - * pass in an empty string. - * - * \todo - * Determine if code should be added to reject function names that start with - * 'glX'. - * - * \bug - * Add code to compare \c parameter_signature with the parameter signature of - * a static function. In order to do that, we need to find a way to \b get - * the parameter signature of a static function. - */ - -PUBLIC int -_glapi_add_dispatch( const char * const * function_names, - const char * parameter_signature ) -{ - static int next_dynamic_offset = _gloffset_FIRST_DYNAMIC; - const char * const real_sig = (parameter_signature != NULL) - ? parameter_signature : ""; - struct _glapi_function * entry[8]; - GLboolean is_static[8]; - unsigned i; - unsigned j; - int offset = ~0; - int new_offset; - - - (void) memset(is_static, 0, sizeof(is_static)); - (void) memset(entry, 0, sizeof(entry)); - - for (i = 0 ; function_names[i] != NULL ; i++) { - /* Do some trivial validation on the name of the function. */ - - if (function_names[i][0] != 'g' || function_names[i][1] != 'l') - return GL_FALSE; - - /* Determine if the named function already exists. If the function does - * exist, it must have the same parameter signature as the function - * being added. - */ - - new_offset = get_static_proc_offset(function_names[i]); - if (new_offset >= 0) { - /* FIXME: Make sure the parameter signatures match! How do we get - * FIXME: the parameter signature for static functions? - */ - - if ((offset != ~0) && (new_offset != offset)) { - return -1; - } - - is_static[i] = GL_TRUE; - offset = new_offset; - } - - for (j = 0; j < NumExtEntryPoints; j++) { - if (strcmp(ExtEntryTable[j].name, function_names[i]) == 0) { - /* The offset may be ~0 if the function name was added by - * glXGetProcAddress but never filled in by the driver. - */ - - if (ExtEntryTable[j].dispatch_offset != ~0) { - if (strcmp(real_sig, ExtEntryTable[j].parameter_signature) != 0) - return -1; - - if ((offset != ~0) && (ExtEntryTable[j].dispatch_offset != offset)) { - return -1; - } - - offset = ExtEntryTable[j].dispatch_offset; - } - - entry[i] = & ExtEntryTable[j]; - break; - } - } - } - - if (offset == ~0) { - offset = next_dynamic_offset; - next_dynamic_offset++; - } - - for (i = 0 ; function_names[i] != NULL ; i++) { - if (!is_static[i]) { - if (entry[i] == NULL) { - entry[i] = add_function_name(function_names[i]); - if (entry[i] == NULL) - return -1; - } - - entry[i]->parameter_signature = strdup(real_sig); - entry[i]->dispatch_offset = offset; - } - } - - return offset; -} - -/* - * glXGetProcAddress doesn't exist in the protocol, the drivers never call - * this themselves, and neither does the server. warn if it happens though. - */ -PUBLIC _glapi_proc -_glapi_get_proc_address(const char *funcName) -{ - ErrorF("_glapi_get_proc_address called!\n"); - return NULL; -} - -/** - * Return size of dispatch table struct as number of functions (or - * slots). - */ -PUBLIC GLuint -_glapi_get_dispatch_table_size(void) -{ - return DISPATCH_TABLE_SIZE; -} - -#if defined(PTHREADS) || defined(GLX_USE_TLS) -/** - * Perform platform-specific GL API entry-point fixups. - */ -static void -init_glapi_relocs( void ) -{ -#if defined(USE_X86_ASM) && defined(GLX_USE_TLS) && !defined(GLX_X86_READONLY_TEXT) - extern unsigned long _x86_get_dispatch(void); - char run_time_patch[] = { - 0x65, 0xa1, 0, 0, 0, 0 /* movl %gs:0,%eax */ - }; - GLuint *offset = (GLuint *) &run_time_patch[2]; /* 32-bits for x86/32 */ - const GLubyte * const get_disp = (const GLubyte *) run_time_patch; - GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start; - - *offset = _x86_get_dispatch(); - while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) { - (void) memcpy( curr_func, get_disp, sizeof(run_time_patch)); - curr_func += DISPATCH_FUNCTION_SIZE; - } -#endif -} -#endif /* defined(PTHREADS) || defined(GLX_USE_TLS) */ +/*
+ * Mesa 3-D graphics library
+ * Version: 6.5
+ *
+ * Copyright (C) 1999-2006 Brian Paul 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
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * 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 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 NONINFRINGEMENT. IN NO EVENT SHALL
+ * BRIAN PAUL 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.
+ */
+
+/*
+ * This file manages the OpenGL API dispatch layer. There are functions
+ * to set/get the current dispatch table for the current thread and to
+ * manage registration/dispatch of dynamically added extension functions.
+ *
+ * This code was originally general enough to be shared with Mesa, but
+ * they diverged long ago, so this is now just enough support to make
+ * indirect GLX work.
+ */
+
+#include <dix-config.h>
+#include <X11/Xfuncproto.h>
+#include <os.h>
+#ifdef _MSC_VER
+#define PUBLIC _declspec(dllexport)
+#else
+#define PUBLIC _X_EXPORT
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#ifdef DEBUG
+#include <assert.h>
+#endif
+#include <unistd.h>
+
+#include "glapi.h"
+#include "glapitable.h"
+
+#define _gloffset_FIRST_DYNAMIC (sizeof(struct _glapi_table) / sizeof(void *))
+
+#if defined(PTHREADS) || defined(GLX_USE_TLS)
+static void init_glapi_relocs(void);
+#endif
+
+/**
+ * \name Current dispatch and current context control variables
+ *
+ * Depending on whether or not multithreading is support, and the type of
+ * support available, several variables are used to store the current context
+ * pointer and the current dispatch table pointer. In the non-threaded case,
+ * the variables \c _glapi_Dispatch and \c _glapi_Context are used for this
+ * purpose.
+ *
+ * In the "normal" threaded case, the variables \c _glapi_Dispatch and
+ * \c _glapi_Context will be \c NULL if an application is detected as being
+ * multithreaded. Single-threaded applications will use \c _glapi_Dispatch
+ * and \c _glapi_Context just like the case without any threading support.
+ * When \c _glapi_Dispatch and \c _glapi_Context are \c NULL, the thread state
+ * data \c _gl_DispatchTSD and \c ContextTSD are used. Drivers and the
+ * static dispatch functions access these variables via \c _glapi_get_dispatch
+ * and \c _glapi_get_context.
+ *
+ * In the TLS case, the variables \c _glapi_Dispatch and \c _glapi_Context are
+ * hardcoded to \c NULL. Instead the TLS variables \c _glapi_tls_Dispatch and
+ * \c _glapi_tls_Context are used. Having \c _glapi_Dispatch and
+ * \c _glapi_Context be hardcoded to \c NULL maintains binary compatability
+ * between TLS enabled loaders and non-TLS DRI drivers.
+ */
+/*@{*/
+#if defined(GLX_USE_TLS)
+
+PUBLIC TLS struct _glapi_table * _glapi_tls_Dispatch = NULL;
+
+PUBLIC TLS void * _glapi_tls_Context;
+
+PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL;
+PUBLIC const void *_glapi_Context = NULL;
+
+#else
+
+#if defined(THREADS)
+
+_glthread_TSD _gl_DispatchTSD; /**< Per-thread dispatch pointer */
+static _glthread_TSD ContextTSD; /**< Per-thread context pointer */
+
+#if defined(WIN32_THREADS)
+void FreeTSD(_glthread_TSD *p);
+void FreeAllTSD(void)
+{
+ FreeTSD(&_gl_DispatchTSD);
+ FreeTSD(&ContextTSD);
+}
+#endif /* defined(WIN32_THREADS) */
+
+#endif /* defined(THREADS) */
+
+PUBLIC struct _glapi_table *_glapi_Dispatch = NULL;
+PUBLIC void *_glapi_Context = NULL;
+
+#endif /* defined(GLX_USE_TLS) */
+/*@}*/
+
+/*
+ * xserver's gl is not multithreaded, we promise.
+ */
+PUBLIC void
+_glapi_check_multithread(void)
+{
+}
+
+/**
+ * Set the current context pointer for this thread.
+ * The context pointer is an opaque type which should be cast to
+ * void from the real context pointer type.
+ */
+void
+_glapi_set_context(void *context)
+{
+#if defined(GLX_USE_TLS)
+ _glapi_tls_Context = context;
+#elif defined(THREADS)
+ _glthread_SetTSD(&ContextTSD, context);
+ _glapi_Context = context;
+#else
+ _glapi_Context = context;
+#endif
+}
+
+
+
+/**
+ * Get the current context pointer for this thread.
+ * The context pointer is an opaque type which should be cast from
+ * void to the real context pointer type.
+ */
+void *
+_glapi_get_context(void)
+{
+#if defined(GLX_USE_TLS)
+ return _glapi_tls_Context;
+#else
+ return _glapi_Context;
+#endif
+}
+
+
+
+/**
+ * Set the global or per-thread dispatch table pointer.
+ */
+void
+_glapi_set_dispatch(struct _glapi_table *dispatch)
+{
+#if defined(PTHREADS) || defined(GLX_USE_TLS)
+ static pthread_once_t once_control = PTHREAD_ONCE_INIT;
+ pthread_once( & once_control, init_glapi_relocs );
+#endif
+
+#if defined(GLX_USE_TLS)
+ _glapi_tls_Dispatch = dispatch;
+#elif defined(THREADS)
+ _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch);
+ _glapi_Dispatch = dispatch;
+#else /*THREADS*/
+ _glapi_Dispatch = dispatch;
+#endif /*THREADS*/
+}
+
+
+
+/**
+ * Return pointer to current dispatch table for calling thread.
+ */
+struct _glapi_table *
+_glapi_get_dispatch(void)
+{
+ struct _glapi_table * api;
+#if defined(GLX_USE_TLS)
+ api = _glapi_tls_Dispatch;
+#else
+ api = _glapi_Dispatch;
+#endif
+ return api;
+}
+
+
+
+/***
+ *** The rest of this file is pretty much concerned with GetProcAddress
+ *** functionality.
+ ***/
+
+#if defined(USE_X64_64_ASM) && defined(GLX_USE_TLS)
+# define DISPATCH_FUNCTION_SIZE 16
+#elif defined(USE_X86_ASM)
+# if defined(THREADS) && !defined(GLX_USE_TLS)
+# define DISPATCH_FUNCTION_SIZE 32
+# else
+# define DISPATCH_FUNCTION_SIZE 16
+# endif
+#endif
+
+
+/* The code in this file is auto-generated with Python */
+#include "glprocs.h"
+
+
+/**
+ * Search the table of static entrypoint functions for the named function
+ * and return the corresponding glprocs_table_t entry.
+ */
+static const glprocs_table_t *
+find_entry( const char * n )
+{
+ GLuint i;
+ for (i = 0; static_functions[i].Name_offset >= 0; i++) {
+ const char *testName = gl_string_table + static_functions[i].Name_offset;
+ if (strcmp(testName, n) == 0) {
+ return &static_functions[i];
+ }
+ }
+ return NULL;
+}
+
+
+/**
+ * Return dispatch table offset of the named static (built-in) function.
+ * Return -1 if function not found.
+ */
+static GLint
+get_static_proc_offset(const char *funcName)
+{
+ const glprocs_table_t * const f = find_entry( funcName );
+ if (f) {
+ return f->Offset;
+ }
+ return -1;
+}
+
+
+
+/**********************************************************************
+ * Extension function management.
+ */
+
+/*
+ * Number of extension functions which we can dynamically add at runtime.
+ */
+#define MAX_EXTENSION_FUNCS 300
+
+
+/*
+ * The dispatch table size (number of entries) is the size of the
+ * _glapi_table struct plus the number of dynamic entries we can add.
+ * The extra slots can be filled in by DRI drivers that register new extension
+ * functions.
+ */
+#define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS)
+
+
+/**
+ * Track information about a function added to the GL API.
+ */
+struct _glapi_function {
+ /**
+ * Name of the function.
+ */
+ const char * name;
+
+ /**
+ * Text string that describes the types of the parameters passed to the
+ * named function. Parameter types are converted to characters using the
+ * following rules:
+ * - 'i' for \c GLint, \c GLuint, and \c GLenum
+ * - 'p' for any pointer type
+ * - 'f' for \c GLfloat and \c GLclampf
+ * - 'd' for \c GLdouble and \c GLclampd
+ */
+ const char * parameter_signature;
+
+ /**
+ * Offset in the dispatch table where the pointer to the real function is
+ * located. If the driver has not requested that the named function be
+ * added to the dispatch table, this will have the value ~0.
+ */
+ unsigned dispatch_offset;
+};
+
+static struct _glapi_function ExtEntryTable[MAX_EXTENSION_FUNCS];
+static GLuint NumExtEntryPoints = 0;
+
+/**
+ * Generate new entrypoint
+ *
+ * Use a temporary dispatch offset of ~0 (i.e. -1). Later, when the driver
+ * calls \c _glapi_add_dispatch we'll put in the proper offset. If that
+ * never happens, and the user calls this function, he'll segfault. That's
+ * what you get when you try calling a GL function that doesn't really exist.
+ *
+ * \param funcName Name of the function to create an entry-point for.
+ *
+ * \sa _glapi_add_entrypoint
+ */
+
+static struct _glapi_function *
+add_function_name( const char * funcName )
+{
+ struct _glapi_function * entry = NULL;
+
+ if (NumExtEntryPoints < MAX_EXTENSION_FUNCS) {
+ entry = &ExtEntryTable[NumExtEntryPoints];
+
+ ExtEntryTable[NumExtEntryPoints].name = strdup(funcName);
+ ExtEntryTable[NumExtEntryPoints].parameter_signature = NULL;
+ ExtEntryTable[NumExtEntryPoints].dispatch_offset = ~0;
+ NumExtEntryPoints++;
+ }
+
+ return entry;
+}
+
+
+/**
+ * Fill-in the dispatch stub for the named function.
+ *
+ * This function is intended to be called by a hardware driver. When called,
+ * a dispatch stub may be created created for the function. A pointer to this
+ * dispatch function will be returned by glXGetProcAddress.
+ *
+ * \param function_names Array of pointers to function names that should
+ * share a common dispatch offset.
+ * \param parameter_signature String representing the types of the parameters
+ * passed to the named function. Parameter types
+ * are converted to characters using the following
+ * rules:
+ * - 'i' for \c GLint, \c GLuint, and \c GLenum
+ * - 'p' for any pointer type
+ * - 'f' for \c GLfloat and \c GLclampf
+ * - 'd' for \c GLdouble and \c GLclampd
+ *
+ * \returns
+ * The offset in the dispatch table of the named function. A pointer to the
+ * driver's implementation of the named function should be stored at
+ * \c dispatch_table[\c offset].
+ *
+ * \sa glXGetProcAddress
+ *
+ * \warning
+ * This function can only handle up to 8 names at a time. As far as I know,
+ * the maximum number of names ever associated with an existing GL function is
+ * 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT,
+ * \c glPointParameterfARB, and \c glPointParameterf), so this should not be
+ * too painful of a limitation.
+ *
+ * \todo
+ * Determine whether or not \c parameter_signature should be allowed to be
+ * \c NULL. It doesn't seem like much of a hardship for drivers to have to
+ * pass in an empty string.
+ *
+ * \todo
+ * Determine if code should be added to reject function names that start with
+ * 'glX'.
+ *
+ * \bug
+ * Add code to compare \c parameter_signature with the parameter signature of
+ * a static function. In order to do that, we need to find a way to \b get
+ * the parameter signature of a static function.
+ */
+
+PUBLIC int
+_glapi_add_dispatch( const char * const * function_names,
+ const char * parameter_signature )
+{
+ static int next_dynamic_offset = _gloffset_FIRST_DYNAMIC;
+ const char * const real_sig = (parameter_signature != NULL)
+ ? parameter_signature : "";
+ struct _glapi_function * entry[8];
+ GLboolean is_static[8];
+ unsigned i;
+ unsigned j;
+ int offset = ~0;
+ int new_offset;
+
+
+ (void) memset(is_static, 0, sizeof(is_static));
+ (void) memset(entry, 0, sizeof(entry));
+
+ for (i = 0 ; function_names[i] != NULL ; i++) {
+ /* Do some trivial validation on the name of the function. */
+
+ if (function_names[i][0] != 'g' || function_names[i][1] != 'l')
+ return GL_FALSE;
+
+ /* Determine if the named function already exists. If the function does
+ * exist, it must have the same parameter signature as the function
+ * being added.
+ */
+
+ new_offset = get_static_proc_offset(function_names[i]);
+ if (new_offset >= 0) {
+ /* FIXME: Make sure the parameter signatures match! How do we get
+ * FIXME: the parameter signature for static functions?
+ */
+
+ if ((offset != ~0) && (new_offset != offset)) {
+ return -1;
+ }
+
+ is_static[i] = GL_TRUE;
+ offset = new_offset;
+ }
+
+ for (j = 0; j < NumExtEntryPoints; j++) {
+ if (strcmp(ExtEntryTable[j].name, function_names[i]) == 0) {
+ /* The offset may be ~0 if the function name was added by
+ * glXGetProcAddress but never filled in by the driver.
+ */
+
+ if (ExtEntryTable[j].dispatch_offset != ~0) {
+ if (strcmp(real_sig, ExtEntryTable[j].parameter_signature) != 0)
+ return -1;
+
+ if ((offset != ~0) && (ExtEntryTable[j].dispatch_offset != offset)) {
+ return -1;
+ }
+
+ offset = ExtEntryTable[j].dispatch_offset;
+ }
+
+ entry[i] = & ExtEntryTable[j];
+ break;
+ }
+ }
+ }
+
+ if (offset == ~0) {
+ offset = next_dynamic_offset;
+ next_dynamic_offset++;
+ }
+
+ for (i = 0 ; function_names[i] != NULL ; i++) {
+ if (!is_static[i]) {
+ if (entry[i] == NULL) {
+ entry[i] = add_function_name(function_names[i]);
+ if (entry[i] == NULL)
+ return -1;
+ }
+
+ entry[i]->parameter_signature = strdup(real_sig);
+ entry[i]->dispatch_offset = offset;
+ }
+ }
+
+ return offset;
+}
+
+/*
+ * glXGetProcAddress doesn't exist in the protocol, the drivers never call
+ * this themselves, and neither does the server. warn if it happens though.
+ */
+_GLAPI_EXPORT _glapi_proc
+_glapi_get_proc_address(const char *funcName)
+{
+ ErrorF("_glapi_get_proc_address called!\n");
+ return NULL;
+}
+
+/**
+ * Return size of dispatch table struct as number of functions (or
+ * slots).
+ */
+GLuint
+_glapi_get_dispatch_table_size(void)
+{
+ return DISPATCH_TABLE_SIZE;
+}
+
+#if defined(PTHREADS) || defined(GLX_USE_TLS)
+/**
+ * Perform platform-specific GL API entry-point fixups.
+ */
+static void
+init_glapi_relocs( void )
+{
+#if defined(USE_X86_ASM) && defined(GLX_USE_TLS) && !defined(GLX_X86_READONLY_TEXT)
+ extern unsigned long _x86_get_dispatch(void);
+ char run_time_patch[] = {
+ 0x65, 0xa1, 0, 0, 0, 0 /* movl %gs:0,%eax */
+ };
+ GLuint *offset = (GLuint *) &run_time_patch[2]; /* 32-bits for x86/32 */
+ const GLubyte * const get_disp = (const GLubyte *) run_time_patch;
+ GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start;
+
+ *offset = _x86_get_dispatch();
+ while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) {
+ (void) memcpy( curr_func, get_disp, sizeof(run_time_patch));
+ curr_func += DISPATCH_FUNCTION_SIZE;
+ }
+#endif
+}
+#endif /* defined(PTHREADS) || defined(GLX_USE_TLS) */
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