Uses either the GLX_SGI_make_current_read or GLX 1.3 interface,
depending on which is available.
diff --git a/progs/xdemos/wincopy.c b/progs/xdemos/wincopy.c
index e3516e1..04fa98a 100644
--- a/progs/xdemos/wincopy.c
+++ b/progs/xdemos/wincopy.c
@@ -55,7 +55,7 @@
static GLboolean DrawFront = GL_FALSE;
-
+PFNGLXMAKECURRENTREADSGIPROC make_context_current = NULL;
static Window
CreateWindow(Display *dpy, int scrnum, XVisualInfo *visinfo,
@@ -100,7 +100,7 @@
Redraw(void)
{
/* make the first window the current one */
- if (!glXMakeContextCurrent(Dpy, Win[0], Win[0], Context)) {
+ if (! (*make_context_current)(Dpy, Win[0], Win[0], Context)) {
printf("glXMakeContextCurrent failed in Redraw()\n");
return;
}
@@ -145,7 +145,7 @@
/* copy image from window 0 to window 1 */
- if (!glXMakeContextCurrent(Dpy, Win[1], Win[0], Context)) {
+ if (!(*make_context_current)(Dpy, Win[1], Win[0], Context)) {
printf("glXMakeContextCurrent failed in Redraw()\n");
return;
}
@@ -259,8 +259,26 @@
ScrNum = DefaultScreen(Dpy);
glXQueryVersion(Dpy, &major, &minor);
- if (major * 100 + minor < 103) {
- fprintf(stderr, "Sorry, this program requires GLX 1.3\n");
+
+ if (major * 100 + minor >= 103) {
+ make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
+ glXGetProcAddressARB( (GLubyte *) "glXMakeContextCurrent" );
+ }
+ else {
+ const char * const glxExtensions = glXQueryExtensionsString(Dpy, ScrNum);
+ const char * ext = strstr( glxExtensions, "GLX_SGI_make_current_read" );
+ const size_t len = strlen( "GLX_SGI_make_current_read" );
+
+ if ( (ext != NULL)
+ && ((ext[len] == ' ') || (ext[len] == '\0')) ) {
+ make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
+ glXGetProcAddressARB( (GLubyte *) "glXMakeCurrentReadSGI" );
+ }
+ }
+
+ if (make_context_current == NULL) {
+ fprintf(stderr, "Sorry, this program requires either GLX 1.3 "
+ "or GLX_SGI_make_current_read.\n");
exit(1);
}