- HDC hdc = (HDC)context_private;
- struct stw_framebuffer *fb;
-
- fb = stw_framebuffer_from_hdc( hdc );
- if (!fb) {
- /* fb can be NULL if window was destroyed already */
- return;
+ switch (param) {
+ case ST_MANAGER_BROKEN_INVALIDATE:
+ /*
+ * Force framebuffer validation on glViewport.
+ *
+ * Certain applications, like Rhinoceros 4, uses glReadPixels
+ * exclusively (never uses SwapBuffers), so framebuffers never get
+ * resized unless we check on glViewport.
+ */
+ return 1;
+ default:
+ return 0;