Clear depth buffer, but only depth buffer for gears.
diff --git a/gears.c b/gears.c
index db79d4d..9722eef 100644
--- a/gears.c
+++ b/gears.c
@@ -174,6 +174,8 @@
 {
 	GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
 
+	glClear(GL_DEPTH_BUFFER_BIT);
+
 	glPushMatrix();
 
 	glTranslatef(0.0, 0.0, -50);