Bug fix (#172): Check the variable is nil correctly

1 files changed, 1 insertions, 1 deletions

diff --git a/gl.go b/gl.go
index f83a4d3..1763b05 100644
--- a/gl.go
+++ b/gl.go
@@ -54,7 +54,7 @@ func freeString(ptr *C.GLchar) { C.free(unsafe.Pointer(ptr)) }
 
 func ptr(v interface{}) unsafe.Pointer {
 
-	if v == nil {
+	if v == nil || reflect.ValueOf(v).IsNil() {
 		return unsafe.Pointer(nil)
 	}