/**
* 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]. Return -1 if error/problem.
*
* \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
* Check parameter_signature.
*/
int
_glapi_add_dispatch( const char * const * function_names,
const char * parameter_signature )
{
const struct mapi_stub *function_stubs[8];
const struct mapi_stub *alias = NULL;
unsigned i;
(void) memset(function_stubs, 0, sizeof(function_stubs));
/* find the missing stubs, and decide the alias */
for (i = 0; function_names[i] != NULL && i < 8; i++) {
const char * funcName = function_names[i];
const struct mapi_stub *stub;
int slot;
if (!funcName || funcName[0] != 'g' || funcName[1] != 'l')
return -1;
funcName += 2;
stub = stub_find_public(funcName);
if (!stub)
stub = stub_find_dynamic(funcName, 0);
slot = (stub) ? stub_get_slot(stub) : -1;
if (slot >= 0) {
if (alias && stub_get_slot(alias) != slot)
return -1;
/* use the first existing stub as the alias */
if (!alias)
alias = stub;
function_stubs[i] = stub;
}
}
/* generate missing stubs */
for (i = 0; function_names[i] != NULL && i < 8; i++) {
const char * funcName = function_names[i] + 2;
struct mapi_stub *stub;
if (function_stubs[i])
continue;
stub = stub_find_dynamic(funcName, 1);
if (!stub)
return -1;
stub_fix_dynamic(stub, alias);
if (!alias)
alias = stub;
}
return (alias) ? stub_get_slot(alias) : -1;
}
static const struct mapi_stub *
get_stub(const char *name, const struct mapi_stub *alias)
{
const struct mapi_stub *stub;
stub = stub_find_public(name);
if (!stub) {
struct mapi_stub *dyn = stub_find_dynamic(name, 1);
if (dyn) {
stub_fix_dynamic(dyn, alias);
stub = dyn;
}
}
return stub;
}