/**
* Create a GLX extension string for a set of enable bits.
*
* Creates a GLX extension string for the set of bit in \c enable_bits. This
* string is then stored in \c buffer if buffer is not \c NULL. This allows
* two-pass operation. On the first pass the caller passes \c NULL for
* \c buffer, and the function determines how much space is required to store
* the extension string. The caller allocates the buffer and calls the
* function again.
*
* \param enable_bits Bits representing the enabled extensions.
* \param buffer Buffer to store the extension string. May be \c NULL.
*
* \return
* The number of characters in \c buffer that were written to. If \c buffer
* is \c NULL, this is the size of buffer that must be allocated by the
* caller.
*/
int
__glXGetExtensionString(const unsigned char *enable_bits, char *buffer)
{
unsigned i;
int length = 0;
for (i = 0; known_glx_extensions[i].name != NULL; i++) {
const unsigned bit = known_glx_extensions[i].bit;
const size_t len = known_glx_extensions[i].name_len;
if (EXT_ENABLED(bit, enable_bits)) {
if (buffer != NULL) {
(void) memcpy(&buffer[length], known_glx_extensions[i].name,
len);
buffer[length + len + 0] = ' ';
buffer[length + len + 1] = '\0';
}
length += len + 1;
}
}
return length + 1;
}
/**
* Check if a certain extension is enabled in a given context.
*
*/
GLboolean
__glExtensionBitIsEnabled(struct glx_context *gc, unsigned bit)
{
GLboolean enabled = GL_FALSE;
if (gc != NULL) {
enabled = EXT_ENABLED(bit, gc->gl_extension_bits);
}
return enabled;
}
/**
* Check if a certain extension is enabled on a given screen.
*
* \param psc Pointer to GLX per-screen record.
* \param bit Bit index in the direct-support table.
* \returns If the extension bit is enabled for the screen, \c GL_TRUE is
* returned. If the extension bit is not enabled or if \c psc is
* \c NULL, then \c GL_FALSE is returned.
*/
GLboolean
__glXExtensionBitIsEnabled(struct glx_screen * psc, unsigned bit)
{
GLboolean enabled = GL_FALSE;
if (psc != NULL) {
__glXExtensionsCtr();
__glXExtensionsCtrScreen(psc);
enabled = EXT_ENABLED(bit, psc->direct_support);
}
return enabled;
}
/**
* Convert a bit-field to a string of supported extensions.
*/
static char *
__glXGetStringFromTable(const struct extension_info *ext,
const unsigned char *supported)
{
unsigned i;
unsigned ext_str_len;
char *ext_str;
char *point;
ext_str_len = 0;
for (i = 0; ext[i].name != NULL; i++) {
if (EXT_ENABLED(ext[i].bit, supported)) {
ext_str_len += ext[i].name_len + 1;
}
}
ext_str = malloc(ext_str_len + 1);
if (ext_str != NULL) {
point = ext_str;
for (i = 0; ext[i].name != NULL; i++) {
if (EXT_ENABLED(ext[i].bit, supported)) {
(void) memcpy(point, ext[i].name, ext[i].name_len);
point += ext[i].name_len;
*point = ' ';
point++;
}
}
*point = '\0';
}
return ext_str;
}