conic-toan:0.3.4

[Thutran1891]

Update of conic-toan from 0.3.3 to 0.3.4. No breaking API changes; the minimum compiler version stays at 0.13.0. All existing figures and layouts are unchanged — every new parameter defaults to the previous behaviour.

New

• New circle helpers.
  • giao-duong-thang-duong-tron((A, B), (O, r)) returns the intersection of a line and a circle as an array ordered along A -> B: () when they miss, (P,) when tangent, (P1, P2) when secant. It works by projecting O onto the line, so it is exact rather than sampled.
  • tiep-tuyen-tai-diem(ctx, O, r, M) draws the tangent through M perpendicular to the radius OM (the direction is taken from the actual OM, so M need not sit precisely on the circle). dai is the half-length of the segment (auto = 1.4·r, in math coordinates).
  • dung-diem(A, B, goc, r) returns the point M such that ray AM is ray AB rotated about A by the signed angle goc (degrees, positive counter-clockwise) with AM = r.
  • nhan-goc(ctx, ..items) labels several points at once, choosing each label's side by a signed angle instead of a named direction. Each item is a tuple (P, text, angle), optionally extended with a radius and/or colour in either order.
• dut: for duong-tron-ngoai-tiep and duong-tron-noi-tiep — draws the circle with a dashed stroke. Defaults to false, so existing figures are unchanged.
• an / hien-khoang — exit animations for slides. The mirror image of lo: #an(n)[…] shows content from the start and hides it from step n onward (collapsing the following material by default, giu-cho: true to keep its space). #hien-khoang(tu, den)[…] shows content only during steps [tu, den). Pairing #an(n)[old] #lo(n)[new] replaces an element in place on the same step. In the printed (non-beamer) profile everything is shown, as with lo/chi.
• fig-pos: "center" — a figure centred between the prompt and the options. The four existing placements are "right"/"left" (figure in a side column with text wrapping), "top" (above the whole prompt) and "bottom" (below all four options). None of these suit a wide figure such as a variation table, a statistical chart or a large graph. "center" puts the figure on its own centred line, between the prompt and the options / sub-questions. Available for #tn, #ds, #tln (fig-pos:), for figures attached to a solution (fig-giai-pos:) and for #voi-hinh(..., vi-tri: "center"). An invalid fig-pos now raises an error listing the valid values instead of silently falling back to "right".
• fig-pos: / fig-width: on all eight question types. #vd, #tl, #hd, #lt, #vdtt (and #cau-tl/#cau-hd/#cau-lt/#cau-vdtt) previously accepted only fig-giai-pos: for a figure attached to the solution; a figure on the prompt was always forced into the right column, with no parameter to change it, even though the manual described it as "every question type". These five now take the same fig: / fig-pos: / fig-width: as #tn/#ds/#tln. Omitting them keeps the default "right", so existing questions keep their layout.
• SGK activity blocks: kham-pha / trai-nghiem / thao-luan. The "Khám phá."/"Trải nghiệm."/"Thảo luận." activities of the Vietnamese textbooks are one-off, not numbered — unlike hd/lt/vdtt — so they carry no counter. Each has its own colour, plus an inline builder (cau-kham-pha / cau-trai-nghiem / cau-thao-luan) for use as a step inside a #slide (the top-level form creates its own slide and so cannot be nested).

Changed

• bpt labels rotate along the line. bpt(...) gains nghieng-ten: true (the default), which rotates the label to follow the line and hugs it along the normal; huong-ten then only selects the side with "above"/"below", and cach-ten: 3pt tunes the gap. nghieng-ten: false restores the previous horizontal label, which still accepts any direction. Each bpt also takes its own goc-gach: / buoc-gach: instead of sharing the values from mien-nghiem.

• dat-lai-cau split per category. dat-lai-cau() now resets only the "Câu" counters (tn/ds/tln/tl); the new dat-lai-cau-vd / -hd / -lt / -vdtt each reset a single counter, and dat-lai-cau-tat-ca() keeps the old behaviour of resetting all five groups. Exam files calling #dat-lai-cau() are unaffected, as they only use the "Câu" counters.

• so-do-cay probability labels sit below descending branches. An edge's probability label was always placed above the line; on a branch going down to a lower child this pushed the label into the fork. Labels on descending branches now go below their edge (ascending and level branches are unchanged), mirroring the top branches for a cleaner tree.

Fixed

• Implicit ctx no longer panics inside measure. Drawing helpers may be called without an explicit ctx — the _voi-ctx wrapper picks up the current #hinh frame from a state stack. But content built inside measure(...) is never laid out, so that state reads back empty and the wrapper used to panic. This aborted the whole compile in the beamer profile (its automatic slide-breaking measures a trial slide) and in cot: auto for multiple-choice options containing a figure. An empty stack inside a measure is now skipped silently — the measured size is unchanged, since #hinh is a fixed-size box whose strokes are all placed — while a helper genuinely called outside any #hinh leaves a small red marker instead of aborting. Printed output is unchanged.