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2.5 Bounding-Box Adjusters

(inset pict amt)  pict?
  pict : pict?
  amt : real?
(inset pict h-amt v-amt)  pict?
  pict : pict?
  h-amt : real?
  v-amt : real?
(inset pict l-amt t-amt r-amt b-amt)  pict?
  pict : pict?
  l-amt : real?
  t-amt : real?
  r-amt : real?
  b-amt : real?
Extends pict’s bounding box by adding the given amounts to the corresponding sides; ascent and descent are extended, too.

(clip-descent pict)  pict?
  pict : pict?
Truncates pict’s bounding box by removing the descent part.

(lift-above-baseline pict amt)  pict?
  pict : pict?
  amt : real?
Lifts pict relative to its baseline, extending the bounding-box height if necessary.

(drop-below-ascent pict amt)  pict?
  pict : pict?
  amt : real?
Drops pict relative to its ascent line, extending the bounding-box height if necessary.

(baseless pict)  pict?
  pict : pict?
Makes the descent 0 and the ascent the same as the height.

(refocus pict sub-pict)  pict?
  pict : pict?
  sub-pict : pict?
Assuming that sub-pict can be found within pict, shifts the overall bounding box to that of sub-pict (but preserving all the drawing of pict). The last element, as reported by pict-last is also set to (or (pict-last sub-pict) sub-pict).

(panorama pict)  pict?
  pict : pict?
Shifts the given pict’s bounding box to enclose the bounding boxes of all sub-picts (even laundered picts).

(use-last pict sub-pict)  pict?
  pict : pict?
  sub-pict : pict-path?
Returns a pict like pict, but with the last element (as reported by pict-last) set to sub-pict. The sub-pict must exist as a sub-pict (or path of sub-picts) within pict.

(use-last* pict sub-pict)  pict?
  pict : pict?
  sub-pict : pict-path?
Propagates the last element of sub-pict to pict.

That is, use-last* is like use-last, but the last element of sub-pict is used as the new last element for pict, instead of sub-pict itself – unless (pict-last sub-pict) is #f, in which case sub-pict is used as the last element of pict.