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Fix line width calculation for expressions with superscripts/subscripts

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The typesetter was incorrectly measuring line width when expressions contained
  superscripts or subscripts (e.g., b²). After rendering a superscript, the line
  is split into multiple display segments, but the width checking code was only
  measuring the current segment, not the total visual line width.

  Key changes:
  - Use currentPosition.x to track actual horizontal position across all segments
  - Calculate visualLineWidth = currentPosition.x + currentSegmentWidth
  - Pass remainingWidth (maxWidth - currentPosition.x) to findBestBreakPoint
  - Apply fix to both interatom breaking and inline text breaking

  This fixes truncation issues where content like "Δ=b²-4ac avec a=1..." was
  being clipped instead of wrapped to a new line.

  Before: Each segment checked in isolation → segments appeared to fit individually
          but total visual width exceeded maxWidth → content truncated/clipped

  After:  Total visual width tracked correctly → line breaking triggered when
          actual visual width exceeds maxWidth → content wraps properly
This commit is contained in:
Nicolas Guillot
2025-11-17 17:51:30 +01:00
parent 43c69240bd
commit 3aa6c6c98b
3 changed files with 57 additions and 23 deletions
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15
Sources/SwiftMath/MathRender/MTMathUILabel.swift
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@@ -278,24 +278,9 @@ public class MTMathUILabel : MTView {
let effectiveWidth = _preferredMaxLayoutWidth > 0 ? _preferredMaxLayoutWidth : bounds.size.width
let availableWidth = effectiveWidth - contentInsets.left - contentInsets.right
print("🔧 MTMathUILabel _layoutSubviews:")
print(" preferredMaxLayoutWidth: \(_preferredMaxLayoutWidth)")
print(" bounds.size.width: \(bounds.size.width)")
print(" effectiveWidth: \(effectiveWidth)")
print(" availableWidth: \(availableWidth)")
print(" LaTeX: \(_latex.prefix(60))...")
// print("Pre list = \(_mathList!)")
_displayList = MTTypesetter.createLineForMathList(_mathList, font: self.font, style: currentStyle, maxWidth: availableWidth)
_displayList!.textColor = textColor
print(" Display subDisplays count: \(_displayList!.subDisplays.count)")
for (index, subDisplay) in _displayList!.subDisplays.enumerated() {
print(" Display \(index): type=\(type(of: subDisplay)), x=\(subDisplay.position.x), width=\(subDisplay.width)")
if let lineDisplay = subDisplay as? MTCTLineDisplay {
print(" Content: '\(lineDisplay.attributedString?.string ?? "")'")
}
}
// print("Post list = \(_mathList!)")
var textX = CGFloat(0)
switch self.textAlignment {