fix a bug where copybit only renders in the first buffer when used with s/w GL
diff --git a/opengl/libagl/copybit.h b/opengl/libagl/copybit.h
index 1888aee..401b68c 100644
--- a/opengl/libagl/copybit.h
+++ b/opengl/libagl/copybit.h
@@ -32,9 +32,9 @@
         GLsizei count);
 
 inline bool copybitQuickCheckContext(ogles_context_t* c) {
-        return  c->copybits.drawSurfaceFd >= 0
+        return  c->copybits.drawSurfaceBuffer != 0
             && c->rasterizer.state.enabled_tmu == 1
-            && c->textures.tmu[0].texture->copybits_fd >= 0;
+            && c->textures.tmu[0].texture->try_copybit;
 }
 
 /*