+ /* In OpenGL the fragment shader can't read gl_ClipDistance[], but
+ * Vulkan allows it, in which case the SPIR-V compiler will declare
+ * VARING_SLOT_CLIP_DIST0 as compact array variable. Pass true as
+ * the last parameter to always operate with a compact array in both
+ * OpenGL and Vulkan so we do't have to care about the API we
+ * are using.
+ */