1 files changed, 82 insertions, 0 deletions
diff --git a/packages/math/range.ts b/packages/math/range.ts
new file mode 100644
index 0000000..d90530c
--- /dev/null
+++ b/packages/math/range.ts
@@ -0,0 +1,82 @@
+import { toBrandedType } from "@excalidraw/excalidraw/utils";
+import type { InclusiveRange } from "./types";
+
+/**
+ * Create an inclusive range from the two numbers provided.
+ *
+ * @param start Start of the range
+ * @param end End of the range
+ * @returns
+ */
+export function rangeInclusive(start: number, end: number): InclusiveRange {
+  return toBrandedType<InclusiveRange>([start, end]);
+}
+
+/**
+ * Turn a number pair into an inclusive range.
+ *
+ * @param pair The number pair to convert to an inclusive range
+ * @returns The new inclusive range
+ */
+export function rangeInclusiveFromPair(pair: [start: number, end: number]) {
+  return toBrandedType<InclusiveRange>(pair);
+}
+
+/**
+ * Given two ranges, return if the two ranges overlap with each other e.g.
+ * [1, 3] overlaps with [2, 4] while [1, 3] does not overlap with [4, 5].
+ *
+ * @param param0 One of the ranges to compare
+ * @param param1 The other range to compare against
+ * @returns TRUE if the ranges overlap
+ */
+export const rangesOverlap = (
+  [a0, a1]: InclusiveRange,
+  [b0, b1]: InclusiveRange,
+): boolean => {
+  if (a0 <= b0) {
+    return a1 >= b0;
+  }
+
+  if (a0 >= b0) {
+    return b1 >= a0;
+  }
+
+  return false;
+};
+
+/**
+ * Given two ranges,return ther intersection of the two ranges if any e.g. the
+ * intersection of [1, 3] and [2, 4] is [2, 3].
+ *
+ * @param param0 The first range to compare
+ * @param param1 The second range to compare
+ * @returns The inclusive range intersection or NULL if no intersection
+ */
+export const rangeIntersection = (
+  [a0, a1]: InclusiveRange,
+  [b0, b1]: InclusiveRange,
+): InclusiveRange | null => {
+  const rangeStart = Math.max(a0, b0);
+  const rangeEnd = Math.min(a1, b1);
+
+  if (rangeStart <= rangeEnd) {
+    return toBrandedType<InclusiveRange>([rangeStart, rangeEnd]);
+  }
+
+  return null;
+};
+
+/**
+ * Determine if a value is inside a range.
+ *
+ * @param value The value to check
+ * @param range The range
+ * @returns
+ */
+export const rangeIncludesValue = (
+  value: number,
+  [min, max]: InclusiveRange,
+): boolean => {
+  return value >= min && value <= max;
+};