flowchart
¶This module provides routines for drawing flowcharts. The primary
structure is a block
, which represents a single block on the
flowchart. The following eight functions return a position on the appropriate
edge of the block, given picture transform t
:
pair block.top(transform t=identity()); pair block.left(transform t=identity()); pair block.right(transform t=identity()); pair block.bottom(transform t=identity()); pair block.topleft(transform t=identity()); pair block.topright(transform t=identity()); pair block.bottomleft(transform t=identity()); pair block.bottomright(transform t=identity());
To obtain an arbitrary position along the boundary of the block in user coordinates, use:
pair block.position(real x, transform t=identity());
The center of the block in user coordinates is stored in
block.center
and the block size in PostScript
coordinates
is given by block.size
.
A frame containing the block is returned by
frame block.draw(pen p=currentpen);
The following block generation routines accept a Label, string, or frame for their object argument:
dx
around header and body): ¶block rectangle(object header, object body, pair center=(0,0), pen headerpen=mediumgray, pen bodypen=invisible, pen drawpen=currentpen, real dx=3, real minheaderwidth=minblockwidth, real minheaderheight=minblockwidth, real minbodywidth=minblockheight, real minbodyheight=minblockheight); block rectangle(object body, pair center=(0,0), pen fillpen=invisible, pen drawpen=currentpen, real dx=3, real minwidth=minblockwidth, real minheight=minblockheight);
block parallelogram(object body, pair center=(0,0), pen fillpen=invisible, pen drawpen=currentpen, real dx=3, real slope=2, real minwidth=minblockwidth, real minheight=minblockheight);
block diamond(object body, pair center=(0,0), pen fillpen=invisible, pen drawpen=currentpen, real ds=5, real dw=1, real height=20, real minwidth=minblockwidth, real minheight=minblockheight);
block circle(object body, pair center=(0,0), pen fillpen=invisible, pen drawpen=currentpen, real dr=3, real mindiameter=mincirclediameter);
block roundrectangle(object body, pair center=(0,0), pen fillpen=invisible, pen drawpen=currentpen, real ds=5, real dw=0, real minwidth=minblockwidth, real minheight=minblockheight);
block bevel(object body, pair center=(0,0), pen fillpen=invisible, pen drawpen=currentpen, real dh=5, real dw=5, real minwidth=minblockwidth, real minheight=minblockheight);
To draw paths joining the pairs in point
with right-angled lines,
use the routine:
path path(pair point[] ... flowdir dir[]);
The entries in dir
identify whether successive
segments between the pairs specified by point
should be drawn
in the Horizontal
or Vertical
direction.
Here is a simple flowchart example (see also the example
controlsystem.asy
):
size(0,300); import flowchart; block block1=rectangle(Label("Example",magenta), pack(Label("Start:",heavygreen),"",Label("$A:=0$",blue), "$B:=1$"),(-0.5,3),palegreen,paleblue,red); block block2=diamond(Label("Choice?",blue),(0,2),palegreen,red); block block3=roundrectangle("Do something",(-1,1)); block block4=bevel("Don't do something",(1,1)); block block5=circle("End",(0,0)); draw(block1); draw(block2); draw(block3); draw(block4); draw(block5); add(new void(picture pic, transform t) { blockconnector operator --=blockconnector(pic,t); // draw(pic,block1.right(t)--block2.top(t)); block1--Right--Down--Arrow--block2; block2--Label("Yes",0.5,NW)--Left--Down--Arrow--block3; block2--Right--Label("No",0.5,NE)--Down--Arrow--block4; block4--Down--Left--Arrow--block5; block3--Down--Right--Arrow--block5; });