#pdflite/geometry

flowchart LR
  Units[PdfUnit] --> Paper[PaperSize]
  Paper --> PageBox[page MediaBox]
  Point[Point2] --> Matrix[TransformMatrix]
  Ops[TransformOp list] --> Matrix
  Matrix --> PointOut[transformed point]

#Checked Examples

///|
test "paper sizes and units are explicit" {
  if paper_a4.unit() != Millimetre {
    fail("A4 is stored in millimetres")
  }
  if unit_points(1.0, Inch) != 72.0 {
    fail("one inch is 72 PDF points")
  }
  let landscape = paper_a4.landscape()
  if landscape.width() != 297.0 || landscape.height() != 210.0 {
    fail("landscape swaps paper width and height")
  }
}

///|
test "transforms apply to points and render as PDF matrices" {
  let moved = transform_translate(5.0, -10.0).apply(point2(10.0, 20.0))
  if moved.x != 15.0 || moved.y != 10.0 {
    fail("translation should move the point")
  }
  inspect(
    transform_string_of_matrix(transform_translate(5.0, -10.0)),
    content="1, 0, 0, 1, 5, -10",
  )
}

#Package Notes

• PaperSize keeps both dimensions and their original unit.
• TransformMatrix uses the PDF six-number affine matrix layout.
• TransformOp preserves CamlPDF-style transform-list ordering for callers that build or inspect transformation pipelines.

#Pedantic Boundaries

• This package owns unit conversion and affine transform math only. It does not inspect page dictionaries, content streams, or resources.
• Units are explicit: PaperSize stores its source unit, while page code converts to PDF points when constructing /MediaBox.
• Transform matrices follow PDF's six-number convention (a b c d e f). Composition order must be tested with points, not only by comparing matrix fields.
• Singular matrices raise the shared PdfError::MatrixNotInvertable through the core dependency.

#Verification Notes

• README examples are blackbox tests for public geometry APIs.
• Use exact assertions for simple unit conversions and tolerance-based tests for rotations or decompositions.
• Run moon test geometry/README.mbt.md after editing this file.
• Run moon info before review; this README should not change geometry/pkg.generated.mbti.