Add PcloudAmbienceStencil, LG1PcloudAmbienceStencil

These two classes represent our first foray into stencil
construction. One of them standardizes PcloudAmbience stencils
across all stimbuffs, and the other specifies the internal
memory constraints and requirements for a LivoxGen1 device's
stencils.

include/user/pcloudAmbienceStencil.h

@@ -0,0 +1,38 @@
+#ifndef _PCLOUD_AMBIENCE_STENCIL_H
+#define _PCLOUD_AMBIENCE_STENCIL_H
+
+#include <cstdint>
+#include <cstddef>
+#include <user/stencil.h>
+
+namespace smo {
+namespace stim_buff {
+
+/**
+ * PcloudAmbienceStencil represents stencils for point cloud ambience data.
+ * This is a base class for device-specific implementations.
+ */
+class PcloudAmbienceStencil
+:	public smo::cologex::Stencil
+{
+public:
+	typedef uint32_t PcloudAmbienceStimulusValue;
+
+	/**
+	 * RangeDescriptor describes a contiguous range of body spots for
+	 * point cloud ambience stencils.
+	 */
+	struct RangeDescriptor : public Stencil::RangeDescriptor
+	{
+		uint32_t bodySpot;
+		size_t nContiguousSpots;
+	};
+
+	PcloudAmbienceStencil() = default;
+	virtual ~PcloudAmbienceStencil() = default;
+};
+
+} // namespace stim_buff
+} // namespace smo
+
+#endif // _PCLOUD_AMBIENCE_STENCIL_H