GEEKING

App/include/util/SpatialRegion.h

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+#pragma once
+
+#include "Util/G3DCore.h"
+#include "Util/Region3int16.h"
+#include "Util/Vector3int32.h"
+
+namespace RBX {
+
+// Utilities for working with sub-sections of global coordinate space called
+// SpacialRegions. The sub-sections are of a fixed, globally defined size and
+// position. The sub-sections are integer aligned and origin aligned (the
+// origin is at the meeting point of 8 regions).
+namespace SpatialRegion {
+
+namespace Constants {
+	// these are const int to allow proper constant folding, inlining, and
+	// to allow other, derived static const int values to also have these
+	// benefits.
+	const int kRegionXDimensionInVoxelsAsBitShift = 5;
+	const int kRegionYDimensionInVoxelsAsBitShift = 4;
+	const int kRegionZDimensionInVoxelsAsBitShift = 5;
+
+	const int kRegionInVoxelsAsBitShift = kRegionXDimensionInVoxelsAsBitShift + kRegionYDimensionInVoxelsAsBitShift + kRegionZDimensionInVoxelsAsBitShift;
+
+	const int kRegionXDimensionInVoxels = 1 << Constants::kRegionXDimensionInVoxelsAsBitShift;
+	const int kRegionYDimensionInVoxels = 1 << Constants::kRegionYDimensionInVoxelsAsBitShift;
+	const int kRegionZDimensionInVoxels = 1 << Constants::kRegionZDimensionInVoxelsAsBitShift;
+
+	const int kMaxXVoxelOffsetInsideRegion = kRegionXDimensionInVoxels - 1;
+	const int kMaxYVoxelOffsetInsideRegion = kRegionYDimensionInVoxels - 1;
+	const int kMaxZVoxelOffsetInsideRegion = kRegionZDimensionInVoxels - 1;
+}
+
+namespace _PrivateConstants {
+	extern const Vector3int16 kRegionDimensionInStudsAsBitShifts;
+}
+
+// Identifier object for regions of space. Has a Vector3int16 representation
+// also. The Vector3int16 representation has constraints:
+// * If two Ids represent the same area of space, then the Vector3int16's are ==
+// * If one Vector3int16's values (x, y, and/or z) is > another, then the
+//   spacial coordinates on those axis(es) are also >.
+// * If two regions are adjacent, then the Vector3int16 values will be
+//   sequential on the axis(es) they are adjacent in.
+// * The Vector3int16 representation is consitent between runs, and between
+//   client/server.
+class Id {
+	Vector3int16 internalValue;
+public:
+	explicit Id(const Vector3int16& internalValue) : internalValue(internalValue) {}
+	Id(int x, int y, int z) : internalValue(Vector3int16(x,y,z)) {}
+
+	const Vector3int16& value() const { return internalValue; }
+
+	Id operator+(const Vector3int16& other) const { return Id(internalValue + other); }
+	bool operator==(const Id& other) const { return internalValue == other.internalValue; }
+	bool operator!=(const Id& other) const { return internalValue != other.internalValue; }
+
+	struct boost_compatible_hash_value {
+		size_t operator()(const Id& key) const {
+			return Vector3int16::boost_compatible_hash_value()(key.internalValue);
+		}
+	};
+};
+
+std::size_t hash_value(const Id& key);
+
+inline Vector3int16 getRegionDimensionsInVoxels() {
+	using namespace Constants;
+	return Vector3int16(
+		kRegionXDimensionInVoxels,
+		kRegionYDimensionInVoxels,
+		kRegionZDimensionInVoxels);
+}
+
+inline Vector3int16 getRegionDimensionInVoxelsAsBitShifts() {
+	using namespace Constants;
+	return Vector3int16(
+		kRegionXDimensionInVoxelsAsBitShift,
+		kRegionYDimensionInVoxelsAsBitShift,
+		kRegionZDimensionInVoxelsAsBitShift);
+}
+
+inline Vector3int16 getMaxVoxelOffsetInsideRegion() {
+	using namespace Constants;
+	return Vector3int16(
+		kMaxXVoxelOffsetInsideRegion,
+		kMaxYVoxelOffsetInsideRegion,
+		kMaxZVoxelOffsetInsideRegion);
+}
+
+inline Id regionContainingVoxel(const Vector3int16& globalVoxelCoordinate) {
+	return Id(globalVoxelCoordinate >> getRegionDimensionInVoxelsAsBitShifts());
+}
+
+inline Vector3int16 voxelCoordinateRelativeToEnclosingRegion(
+		const Vector3int16& globalVoxelCoordinate) {
+	return globalVoxelCoordinate & getMaxVoxelOffsetInsideRegion();
+}
+
+inline Vector3int16 globalVoxelCoordinateFromRegionAndRelativeCoordinate(
+		const Id& id, const Vector3int16& relativeCoordinate) {
+	return (id.value() << getRegionDimensionInVoxelsAsBitShifts()) + relativeCoordinate;
+}
+
+inline Region3int16 inclusiveVoxelExtentsOfRegion(const Id& id) {
+	Vector3int16 min(id.value() << getRegionDimensionInVoxelsAsBitShifts());
+	return Region3int16(min, min + getMaxVoxelOffsetInsideRegion());
+}
+
+inline Vector3int32 smallestCornerOfRegionInGlobalCoordStuds(const Id& id) {
+    return Vector3int32(id.value()) << _PrivateConstants::kRegionDimensionInStudsAsBitShifts;
+}
+
+inline Vector3int32 centerOfRegionInGlobalCoordStuds(const Id& id) {
+	static const Vector3int32 kHalfDimensionInStuds(Vector3int32::one() <<
+		(_PrivateConstants::kRegionDimensionInStudsAsBitShifts - Vector3int16::one()));
+	return smallestCornerOfRegionInGlobalCoordStuds(id) +
+		kHalfDimensionInStuds;
+}
+
+inline Vector3int32 largestCornerOfRegionInGlobalCoordStuds(const Id& id) {
+	return smallestCornerOfRegionInGlobalCoordStuds(Id(id.value() + Vector3int16::one()));
+}
+
+} // SpacialRegion
+
+} // RBX