From b229930aa1be3075cf260d52ee7259b53e23929c Mon Sep 17 00:00:00 2001
From: Max Goodman <c@chromakode.com>
Date: Mon, 6 Jul 2020 13:59:15 -0700
Subject: [PATCH] Add files missed in code move

---
 src/geometry.js      | 80 ++++++++++++++++++++++++++++++++++++++
 src/geometry.test.js | 91 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 171 insertions(+)
 create mode 100644 src/geometry.js
 create mode 100644 src/geometry.test.js

diff --git a/src/geometry.js b/src/geometry.js
new file mode 100644
index 0000000..615cc45
--- /dev/null
+++ b/src/geometry.js
@@ -0,0 +1,80 @@
+import isEqual from 'lodash/isEqual'
+
+export function boxesFromViewContentMap(width, height, viewContentMap) {
+  const boxes = []
+  const visited = new Set()
+
+  function isPosContent(x, y, content) {
+    const checkIdx = width * y + x
+    return (
+      !visited.has(checkIdx) && isEqual(viewContentMap.get(checkIdx), content)
+    )
+  }
+
+  function findLargestBox(x, y) {
+    const idx = width * y + x
+    const spaces = [idx]
+    const content = viewContentMap.get(idx)
+
+    let maxY
+    for (maxY = y + 1; maxY < height; maxY++) {
+      if (!isPosContent(x, maxY, content)) {
+        break
+      }
+      spaces.push(width * maxY + x)
+    }
+
+    let cx = x
+    let cy = y
+    scan: for (cx = x + 1; cx < width; cx++) {
+      for (cy = y; cy < maxY; cy++) {
+        if (!isPosContent(cx, cy, content)) {
+          break scan
+        }
+      }
+      for (let cy = y; cy < maxY; cy++) {
+        spaces.push(width * cy + cx)
+      }
+    }
+    const w = cx - x
+    const h = maxY - y
+    spaces.sort()
+    return { content, x, y, w, h, spaces }
+  }
+
+  for (let y = 0; y < width; y++) {
+    for (let x = 0; x < height; x++) {
+      const idx = width * y + x
+      if (visited.has(idx) || viewContentMap.get(idx) === undefined) {
+        continue
+      }
+
+      const box = findLargestBox(x, y)
+      boxes.push(box)
+      for (const boxIdx of box.spaces) {
+        visited.add(boxIdx)
+      }
+    }
+  }
+
+  return boxes
+}
+
+export function idxToCoords(gridCount, idx) {
+  const x = idx % gridCount
+  const y = Math.floor(idx / gridCount)
+  return { x, y }
+}
+
+export function idxInBox(gridCount, start, end, idx) {
+  let { x: startX, y: startY } = idxToCoords(gridCount, start)
+  let { x: endX, y: endY } = idxToCoords(gridCount, end)
+  const { x, y } = idxToCoords(gridCount, idx)
+  const lowX = Math.min(startX, endX)
+  const highX = Math.max(startX, endX)
+  const lowY = Math.min(startY, endY)
+  const highY = Math.max(startY, endY)
+  const xInBox = x >= lowX && x <= highX
+  const yInBox = y >= lowY && y <= highY
+  return xInBox && yInBox
+}
diff --git a/src/geometry.test.js b/src/geometry.test.js
new file mode 100644
index 0000000..360651b
--- /dev/null
+++ b/src/geometry.test.js
@@ -0,0 +1,91 @@
+import { boxesFromViewContentMap } from './geometry'
+
+function example([text]) {
+  return text
+    .replace(/\s/g, '')
+    .split('')
+    .map((c) => (c === '.' ? undefined : { url: c }))
+}
+
+const box1 = example`
+  ab
+  ab
+`
+
+const box2 = example`
+  aa
+  bb
+`
+
+const box3 = example`
+  aac
+  aaa
+  dae
+`
+
+const box4 = example`
+  ...
+  .aa
+  .aa
+`
+
+const box5 = example`
+  ..a
+  ..a
+  .aa
+`
+
+describe.each([
+  [
+    2,
+    2,
+    box1,
+    [
+      { content: { url: 'a' }, x: 0, y: 0, w: 1, h: 2, spaces: [0, 2] },
+      { content: { url: 'b' }, x: 1, y: 0, w: 1, h: 2, spaces: [1, 3] },
+    ],
+  ],
+  [
+    2,
+    2,
+    box2,
+    [
+      { content: { url: 'a' }, x: 0, y: 0, w: 2, h: 1, spaces: [0, 1] },
+      { content: { url: 'b' }, x: 0, y: 1, w: 2, h: 1, spaces: [2, 3] },
+    ],
+  ],
+  [
+    3,
+    3,
+    box3,
+    [
+      { content: { url: 'a' }, x: 0, y: 0, w: 2, h: 2, spaces: [0, 1, 3, 4] },
+      { content: { url: 'c' }, x: 2, y: 0, w: 1, h: 1, spaces: [2] },
+      { content: { url: 'a' }, x: 2, y: 1, w: 1, h: 1, spaces: [5] },
+      { content: { url: 'd' }, x: 0, y: 2, w: 1, h: 1, spaces: [6] },
+      { content: { url: 'a' }, x: 1, y: 2, w: 1, h: 1, spaces: [7] },
+      { content: { url: 'e' }, x: 2, y: 2, w: 1, h: 1, spaces: [8] },
+    ],
+  ],
+  [
+    3,
+    3,
+    box4,
+    [{ content: { url: 'a' }, x: 1, y: 1, w: 2, h: 2, spaces: [4, 5, 7, 8] }],
+  ],
+  [
+    3,
+    3,
+    box5,
+    [
+      { content: { url: 'a' }, x: 2, y: 0, w: 1, h: 3, spaces: [2, 5, 8] },
+      { content: { url: 'a' }, x: 1, y: 2, w: 1, h: 1, spaces: [7] },
+    ],
+  ],
+])('boxesFromViewContentMap(%i, %i, %j)', (width, height, data, expected) => {
+  test(`returns expected ${expected.length} boxes`, () => {
+    const stateURLMap = new Map(data.map((v, idx) => [idx, v]))
+    const result = boxesFromViewContentMap(width, height, stateURLMap)
+    expect(result).toStrictEqual(expected)
+  })
+})