2 Pict Objects🔗ℹ

> rectangle() is_a Pict

#true

> rectangle() is_a StaticPict

#true

> animate(fun (n): rectangle()) is_a StaticPict

#false

> beside(stack(~sep: 5, text("Hello"), nothing, nothing, text("World")),          stack(~sep: 5, text("Hello"), text("World")))

> def p = stack(text("Hello"), text("Pict"), text("World"))

> explain_bbox(p)

> p.width

46.0

> p.height

57.0

> p.ascent

15.0

> p.descent

4.0

> explain_bbox(p.pad(-5)).pad(8)

> explain_bbox(text("Hello"))

> explain_bbox(text("Hello").pad(5))

> explain_bbox(text("Hello").pad(~left: 5, ~right: 10))

> explain_bbox(beside(~vert: #'topline,                       text("Hello").drop_topline(-3),                       text("World")))

> explain_bbox(text("Hello").translate(5, -5))

> def p = text("Hello").colorize("firebrick")

> p

> p.scale(2)

> def p = text("Hello").colorize("firebrick")

> p.rotate(math.pi/4)

> def p = text("Hello").colorize("firebrick")

> p.shear(0.5, 0)

> p.shear(0, 0.5)

> def p = text("Hello").colorize("firebrick")

> p

> p.alpha(0.5)

> p.alpha(0.25)

> def p = text("Hello").colorize("firebrick")

> p.hflip()

> p.vflip()

> def p = text("Hello").colorize("firebrick").pad(-5).scale(2)

> rectangle(~around: p).pad(10)

> rectangle(~around: p.clip()).pad(10)

> def h = text("Hello").colorize("firebrick")

> def w = text("World").colorize("firebrick")

> h.children

[]

> stack(h, w)

> stack(h, w).children

[, ]

> Find.top_left(w).in(stack(h, w))

0.0

19.0

If rebuild_prompt is true, then the result pict also has no replaceable dependencies.

See also Pict Findable and Replaceable Identity and Pict.blank.

> def h = text("Hello")

> def w = text("World")

> def p = stack(h, w)

> Find.top_left(w).in(p)

0.0

19.0

> def q = p.launder()

> Find.top_left(w).in(q)

Find.in: cannot find pict

pict: Pict("World", 56111980)

in pict: Pict("stack", "Hello", "World", 56111982)

The do_ghost argument is intended to help avoid if wrappers, enabling pict.ghost(test) instead of if test | pict.ghost() | pict, where the former works even without having to bind an intermediate variable if pict is replaced with a more complex expression.

See also Pict.blank.

> def p = text("Hello")

> rectangle(~around: p)

> rectangle(~around: p.ghost())

> rectangle(~around: p.ghost(#false))

> def h = text("Hello")

> def p = beside(circle(~size: 20, ~fill: "lightgreen"),                  stack(h, text("World")),                  square(~size: 20, ~fill: "lightblue"))

> explain_bbox(p).pad(20)

> explain_bbox(p.refocus(h)).pad(20)

For most pict constructions, the paragraph-end bounding box will be the same as the pict’s overall bounding box with a zero offset.

Whenever multiple picts are combined using stack or beside, the paragraph-end bounding box of the last pict provided to stack or beside is used for the result pict’s paragraph-end bounds. A beside combination in #'paragraph attach mode will then append relative to that last pict in the composition, instead of to the composition as a whole.

Unlike epoch-specific metadata added with Pict.epoch_set_metadata, metadata added by Pict.set_metadata is not propagated to new picts that are derived from the returned pict. The Pict.children property of a pict can be used to search the metadata of its component picts.

An identity has a description that is used by to_string for a pict, which can be helpful for debugging. A pict’s description is normally synthesized automatically, but it can be configured through Pict.set_description. A description provided to Pict.set_description is most useful as a string, another pict’s identity, a list of such values, or #false to suppress a debugging description.

The Pict.description method is a shorthand for getting the description of pict’s identity.

> def bm = draw.Bitmap([20, 20], ~backing_scale: 2)

> def p = circle(~size: 20, ~fill: "lightgreen")

> p.draw(bm.make_dc())

> bm.write("circle.png", ~kind: #'png)

The StaticPict.draw_handle property returns a Racket pict suitable for drawing directly or embedding in a Racket pict construction. It configures the drawing context with more modern defaults, including drawing in #'smoothed mode.