rtsi.com/2014.01.www.rtsi.com.tar/www.rtsi.com/OS9/OSK/APPS/lout2.lzh/LOUT2/DOC/TR.FIG/s8

Text File | 1994-01-25 | 12KB | 485 lines

@Section
   @Title { A Concise Reference for Fig }
@Begin
@PP
The options to the @Code "@Fig" symbol, and their
default values, are as follows.  The complete range of options is shown
at right:
@ID @Tab
  hmargin { 1s }
  vmargin { 0.5vx }
  @Fmth { @Col @Code A ! @Col @Code " " ! @Col @Code B ! @Col @Code " " !
      @Col 1.0c @Wide ! @Col C }
  @Fmta { @Col @Code A ! @Col @Code "{" ! @Col @Code B ! @Col @Code "}" !
      @Col 1.0c @Wide ! @Col C }
{
@Rowh
  A { "@Fig" }
@Rowa
  A { "   maxlabels" }
  B { 200 }
  C { any whole number }
@Rowa
  A { "   linestyle" }
  B { solid }
  C { @Code "solid dashed cdashed dotted noline" }
@Rowa
  A { "   linewidth" }
  B { 0.5 pt }
  C { any Fig length (see below) }
@Rowa
  A { "   linecap"   }
  B { round  }
  C { @Code "butt round project" }
@Rowa
  A { "   dashlength"}
  B { 0.15 cm }
  C { any Fig length }
@Rowa
  A { "   paint"     }
  B { nopaint }
  C { @Code "nopaint white light grey gray dark black" }
@Rowa
  A { "   margin"    }
  B { 0.4c }
  C { any Lout length }
@Rowa
  A { "   arrow"     }
  B { noarrow }
  C { @Code "noarrow forward back both" }
@Rowa
  A { "   headstyle" }
  B { open }
  C { @Code "open halfopen closed" }
@Rowa
  A { "   headwidth" }
  B { 0.05 cm }
  C { any Fig length }
@Rowa
  A { "   headlength"}
  B { 0.15 cm }
  C { any Fig length }
}
The @Code "linecap" option determines the shape of the ends of lines:
@Code "round" puts a round cap on them, which is the most useful in
Fig;  @Code "butt" is a square end; and @Code "project" is a square end
projecting half a line width past the end of the line; it is useful for
getting sharp corners on rectangles and square dots in dotted lines.
@FootNote {
The line joining options of PostScript are not reflected in Fig options
because Fig strokes paths segment by segment, not all at once, and so
there are no line joins in the PostScript sense.  This was done to
improve the appearance of dashed and dotted lines.
}
@PP
The following standard shapes take the same options as {@Code "@Fig"},
except that they do not have @Code "maxlabels" or the last four
(arrow-drawing) options,
and occasionally they have other options.  In most cases the default
values of these options are taken from the enclosing {@Code "@Fig"}.
Where there are extra options, or where a different default value is
used, the option and its default value are shown.  The list also shows
the shape's labels, and how it is superimposed on its right parameter
(shown as a grey rectangle).  A larger margin will enlarge the right
parameter and hence the shape as well.  Squares, polygons and circles
have a diameter equal to the larger of @Code xsize and {@Code ysize}.
@LP
@ID {
5c @Wide @Code "@Box"
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Box margin { 0c }
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@LP
@ID {
5c @Wide @Code "@Square"
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Square margin { 0c }
{ 2c @Wide 1c @High }
// @ShowLabels
}
}
@LP

@ID {
5c @Wide @Code "@Diamond"
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Diamond margin { 0c }
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@LP
@ID {
5c @Wide @Code {
"@Polygon"
"   sides { 3 }"
"   angle { 180/sides }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Polygon margin { 0c }
{ 2c @Wide 1c @High }
|| @ShowLabels ||0.5c ... ||0.5c
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Polygon sides { 12 } margin { 0c }
{ 2c @Wide 1c @High }
||1c ...
// @ShowLabels
}
}

@ID {
5c @Wide @Code "@Ellipse"
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Ellipse margin { 0c }
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@LP
@ID {
5c @Wide @Code "@Circle"
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Circle margin { 0c }
{ 2c @Wide 1c @High }
// @ShowLabels
}
}
@LP

The following standard shapes have the same options as
{@Code "@Fig"}, including the four arrow-drawing options,
and occasionally they have others.  In each case the only difference
between the line and arrow symbols is the default value of
{@Code "arrow"}, which lines take from {@Code "@Fig"} and arrows set
to {@Code "forward"}.  The first four draw a line along the mark of the
right parameter, which is not necessarily the same as its left or top
edge.
@LP
@ID {
5c @Wide @Code {
"@HLine"
"   margin { 0c }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@HLine
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@ID {
5c @Wide @Code {
"@HArrow"
"   margin { 0c }"
"   arrow { forward }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@HArrow
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@ID {
5c @Wide @Code {
"@VLine"
"   margin { 0c }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@VLine
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@ID {
5c @Wide @Code {
"@VArrow"
"   margin { 0c }"
"   arrow { forward }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@VArrow
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@ID {
5c @Wide @Code {
"@Line"
"   from { 0 ysize }"
"   to { xsize 0 }"
"   margin { 0c }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Line
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@ID {
5c @Wide @Code {
"@Arrow"
"   from { 0 ysize }"
"   to { xsize 0 }"
"   margin { 0c }"
"   arrow { forward }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Arrow
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

@ID {
5c @Wide @Code {
"@Arc"
"   from { 0 ysize }"
"   to { xsize 0 }"
"   ctr { 0 0 }"
"   direction { clockwise }"
"   margin { 0c }"
}
||7ct
@Fig {
@Figure shape { 0 0 xsize 0 xsize ysize 0 ysize 0 0 } paint { grey }
linestyle { noline }  margin { 0c }
@Arc
{ 2c @Wide 1c @High }
// @ShowLabels
}
}

More generally, the @Code "@Figure" symbol takes all the options of
@Code "@Fig" except {@Code "maxlabels"}, together with a @Code shape
option containing a sequence of points, and it connects each pair of
points by a line or curve as specified by the following:
@ID @Tab
   vmargin { 0.5vx }
   @Fmta { @Col A ! @Col B }
{
@Rowa
  A { @I { point  point } }
  B { Straight line }
@Rowa
  A { @I { point } @Code "[" &0.5s @Code "]" @I { point } }
  B { Draw nothing }
@Rowa
  A { @I { point } @Code "[" @I point @Code "]" @I { point } }
  B { Anticlockwise circular or elliptical arc }
@Rowa
  A { @I { point } @Code "[" @I point @Code "clockwise ]" @I { point } }
  B { Clockwise circular or elliptical arc }
@Rowa
  A { @I { point } @Code "[" @I {point point} @Code "]" @I { point } }
  B { Bezier curve with two control points }
}
@LP
The remaining symbols do not draw shapes.  They are
@ID lines @Break {
@I colour  @Code "@Colour"  @I object
@I colour  @Code "@Color"  @I object
}
Print @I object in {@I colour}, which may be {@Code "white"},
{@Code "grey"}, {@Code "gray"}, {@Code "black"}, {@Code "red"},
{@Code "green"}, or {@Code "blue"} at least.
@ID lines @Break {
@Code "{" @I {number number number} @Code "} @RGBColour"  @I object
@Code "{" @I {number number number} @Code "} @RGBColor"  @I object
@Code "{" @I {number number number} @Code "} @HSBColour"  @I object
@Code "{" @I {number number number} @Code "} @HSBColor"  @I object
}
Print @I object in the colour defined by the three numbers, using the
red-green-blue or hue-saturation-brightness colour models.
@ID {
@I point  @Code "@Label"  @I label
}
Within a shape, makes @I label stand for the point on the page denoted
by {@I point}, which is not made part of the shape.  The label applies
from here onwards until some other point is given this label, a
relabelling occurs, or the figure ends.
@ID {
@I label  @Code "::"  @I object
}
Relabel every labelled point in the right parameter (which may be an
arbitrary Lout object), by adding {@I label}{@Code "@"} to the front of
each label.
@ID {
@Code "@Frame"  @I object
}
Equivalent to @Code "@Figure shape {xsize 0 @Label X 0 ysize @Label Y}"
@I object & .
@ID {
@I point  @Code "@BaseOf"  @I object
}
Translate @I object so that its bottom left-hand corner appears at
{@I point}.  Lout thinks that the result is an empty object.
@ID {
@I point  @Code "@MarkOf"  @I object
}
Translate @I object so that the point where its marks cross appears at
{@I point}.  Lout thinks that the result is an empty object.
@ID {
@Code "@ShowLabels"
}
Display all the labels of the figure created up to this point.
@PP
The following lists define all the ways to specify lengths, angles and
points.
@FootNote {
A length is represented in PostScript by a single number on the operand
stack; so is an angle.  A point is represented by two numbers on the
stack.  Those familiar with PostScript and willing to sacrifice portability
and increase their risk of error can therefore write, for example,
@OneCol {@I length @Code "sqrt"} within a shape, to obtain a length which
is the square root of another length, or @OneCol { @I point @Code "exch" }
to obtain the reflection of a point about the main diagonal, and so on.
}
Brief explanations appear to the right, with the symbols' precedences in
parentheses where appropriate.
@DP
@Tab
  vmargin { 0.5vx }
  @Fmth { @Col { &@DispIndent     A } ! @Col   }
  @Fmta { @Col { &@DispIndent &2s A } ! @Col B }
{
@Rowh A { @I length } vmargin { 0.2vx }
@Rowh
@Rowa
  A { 0 }
  B { zero }
@Rowa
  A { @Code xmark }
  B { distance to column mark }
@Rowa
  A { @Code ymark }
  B { distance to row mark }
@Rowa
  A { @Code xsize }
  B { distance to right boundary }
@Rowa
  A { @Code ysize }
  B { distance to top boundary }
@Rowa
  A { @I number @Code in }
  B { @I number inches (39) }
@Rowa
  A { @I number @Code cm }
  B { @I number centimetres (39) }
@Rowa
  A { @I number @Code pt }
  B { @I number points (39) }
@Rowa
  A { @I number @Code em }
  B { @I number ems (39) }
@Rowa
  A { @I number @Code sp }
  B { 1 sp is the current width of a space (39) }
@Rowa
  A { @I number @Code vs }
  B { 1 vs is the current inter-line space (39) }
@Rowa
  A { @I number @Code ft }
  B { 1 ft is the size of the current font (39) }
@Rowa
  A { @I point @Code "@Distance" @I point }
  B { distance between two points (35) }
@Rowa
  A { @I point @Code "@XDistance" @I point }
  B { horizontal distance between two points (35) }
@Rowa
  A { @I point @Code "@YDistance" @I point }
  B { vertical distance between two points (35) }
@Rowh
@Rowh
@Rowh A { @I angle } vmargin { 0.2vx }
@Rowh
@Rowa
  A { @I number @Code dg }
  B { @I number degrees (39) }
@Rowa
  A { @I number }
  B { @I number degrees (@Code dg is optional) }
@Rowa
  A { @I point @Code "@Angle" @I point }
  B { angle from first point to second (35) }
@Rowh
@Rowh
@Rowh A { @I point } vmargin { 0.2vx }
@Rowh
@Rowa
  A { @I {length  length} }
  B { @I x and @I y distance from origin (5) }
@Rowa
  A { @I length  @Code "<<"  @I angle }
  B { distance and angle from origin (38) }
@Rowa
  A { @I point  @Code "++"  @I point }
  B { vector sum of two points (36) }
@Rowa
  A { @I point  @Code "--"  @I point }
  B { vector difference of two points (36) }
@Rowa
  A { @I point  @Code "@Max"  @I point }
  B { vector maximum of two points (36) }
@Rowa
  A { @I point  @Code "@Min"  @I point }
  B { vector minimum of two points (36) }
@Rowa
  A { @I point  @Code "**"  @I number }
  B { multiplication of point by number (37) }
@Rowa
  A { @I label }
  B {  a previously defined label }
@Rowa
  A { @Code "@Prev"     }
  B {  the previous point in a shape }
}
@End @Section