From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Fri, 19 Apr 2024 02:47:55 +0200
Subject: Adding upstream version 124.0.1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../css/css-text/support/get-char-advances.js      | 70 ++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 testing/web-platform/tests/css/css-text/support/get-char-advances.js

(limited to 'testing/web-platform/tests/css/css-text/support/get-char-advances.js')

diff --git a/testing/web-platform/tests/css/css-text/support/get-char-advances.js b/testing/web-platform/tests/css/css-text/support/get-char-advances.js
new file mode 100644
index 0000000000..0fd7332c4e
--- /dev/null
+++ b/testing/web-platform/tests/css/css-text/support/get-char-advances.js
@@ -0,0 +1,70 @@
+'use strict';
+
+/**
+ * Returns an array of advances for all characters in the descendants
+ * of the specified element.
+ *
+ * Technically speaking, advances and glyph bounding boxes are different things,
+ * and advances are not exposed. This function computes approximate values from
+ * bounding boxes.
+ */
+function getCharAdvances(element) {
+  const style = getComputedStyle(element);
+  const is_vertical = style.writingMode.startsWith('vertical');
+  const range = document.createRange();
+  const all_bounds = []
+
+  function walk(element) {
+    for (const node of element.childNodes) {
+      const nodeType = node.nodeType;
+      if (nodeType === Node.TEXT_NODE) {
+        const text = node.nodeValue;
+        for (let i = 0; i < text.length; ++i) {
+          range.setStart(node, i);
+          range.setEnd(node, i + 1);
+          let bounds = range.getBoundingClientRect();
+          // Transpose if it's in vertical flow. Guarantee that top < bottom
+          // and left < right are always true.
+          if (is_vertical) {
+            bounds = {
+              left: bounds.top,
+              top: bounds.left,
+              right: bounds.bottom,
+              bottom: bounds.right
+            };
+          }
+          all_bounds.push(bounds);
+        }
+      } else if (nodeType === Node.ELEMENT_NODE) {
+        walk(node);
+      }
+    }
+  }
+  walk(element);
+  all_bounds.sort(function(bound_a, bound_b) {
+    if (bound_a.bottom <= bound_b.top) {
+      return -1;
+    }
+    if (bound_b.bottom <= bound_a.top) {
+      return 1;
+    }
+    return bound_a.left - bound_b.left;
+  });
+  let origin = undefined;
+  let blockEnd = -1;
+  const advances = [];
+  for (let bounds of all_bounds) {
+    // Check if this is on the same line.
+    if (bounds.top >= blockEnd) {
+      origin = undefined;
+      blockEnd = bounds.bottom;
+    }
+    // For the first character, the left bound is closest to the origin.
+    if (origin === undefined)
+      origin = bounds.left;
+    // The right bound is a good approximation of the next origin.
+    advances.push(bounds.right - origin);
+    origin = bounds.right;
+  }
+  return advances;
+}
-- 
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