On this page:
scale
rotate
ghost
linewidth
linestyle
colorize
cellophane
clip
inset/ clip
scale/ improve-new-text
black-and-white

2.4 Pict Drawing Adjusters

procedure

(scale pict factor)  pict?

  pict : pict?
  factor : real?
(scale pict w-factor h-factor)  pict?
  pict : pict?
  w-factor : real?
  h-factor : real?
Scales a pict drawing, as well as its bounding box. The drawing is scaled by adjusting the destination dc<%>’s scale while drawing the original pict.

procedure

(rotate pict theta)  pict?

  pict : pict?
  theta : real?
Rotates a pict’s drawing by theta radians counter-clockwise.

The bounding box of the resulting pict is the box encloses the rotated corners of pict (which inflates the area of the bounding box, unless theta is a multiple of half of pi). The ascent and descent lines of the result’s bounding box are the horizontal lines that bisect the rotated original lines; if the ascent line drops below the descent line, the two lines are flipped.

procedure

(ghost pict)  pict?

  pict : pict?
Creats a container picture that doesn’t draw the child picture, but uses the child’s size.

procedure

(linewidth w pict)  pict?

  w : (or/c real? #f)
  pict : pict?
Selects a specific pen width for drawing, which applies to pen drawing for pict that does not already use a specific pen width. A #f value for w makes the pen transparent (in contrast to a zero value, which means “as thin as possible for the target device”).

procedure

(linestyle style pict)  pict?

  style : 
(one-of/c 'transparent 'solid 'xor 'hilite
          'dot 'long-dash 'short-dash 'dot-dash
          'xor-dot 'xor-long-dash 'xor-short-dash
          'xor-dot-dash)
  pict : pict?
Selects a specific pen style for drawing, which applies to pen drawing for pict that does not already use a specific pen style.

procedure

(colorize pict color)  pict?

  pict : pict?
  color : 
(or/c string?
      (is-a?/c color%)
      (list (integer-in 0 255)
            (integer-in 0 255)
            (integer-in 0 255)))
Selects a specific color drawing, which applies to drawing in pict that does not already use a specific color. The black-and-white parameter causes all non-white colors to be converted to black.

procedure

(cellophane pict opacity)  pict?

  pict : pict?
  opacity : (real-in 0 1)
Makes the given pict semi-transparent, where an opacity of 0 is fully transparent, and an opacity of 1 is fully opaque. See set-alpha for information about the contexts and cases when semi-transparent drawing works.

procedure

(clip pict)  pict

  pict : pict?
Clips a pict’s drawing to its bounding box.

procedure

(inset/clip pict amt)  pict?

  pict : pict?
  amt : real?
(inset/clip pict h-amt v-amt)  pict?
  pict : pict?
  h-amt : real?
  v-amt : real?
(inset/clip pict l-amt t-amt r-amt b-amt)  pict?
  pict : pict?
  l-amt : real?
  t-amt : real?
  r-amt : real?
  b-amt : real?
Insets and clips the pict’s drawing to its bounding box. Usually, the inset amounts are negative.

syntax

(scale/improve-new-text pict-expr scale-expr)

(scale/improve-new-text pict-expr x-scale-expr y-scale-expr)
Like the scale procedure, but also sets current-expected-text-scale while evaluating pict-expr.

parameter

(black-and-white)  boolean?

(black-and-white on?)  void?
  on? : any/c
A parameter that determines whether colorize uses color or black-and-white colors.