[Blindmath] Determining shape coordinates when using SVGDraw01

[Ben Humphreys]

In a CAD program such as AutoCAD, there are two features that make 
drawing these kinds of things much easier:

1.  One line segment or edge of an existing shape can "snap" to 
another.  This is typically done by moving the mouse "close" to the 
edge of a segment or shape and the "snap-to" is indicated visually 
with a small pink rectangle if memory serves.

2.  In addition to drawing using pairs of x-y coordinates, polor 
coordinates can be used as well.  So instead of saying something like:

Line from 0, 0 to 3, 4 you could say:
Line from 0, 0  , length 5 at a 60 degree angle

In such a system, the actual exact coordinates take a back seat yet 
the length of lines and angles is very precise.  In order to 
replicate the "snap-to" functionality present in a CAD program, SVG 
Draw would need to allow naming of objects (which I think it already 
does) and then the ability to specify a "point" on that object, such 
as top, left, right, bottom, midpoint, intersection, etc

In this way, you could assemble objects using lines that connect to 
the ends of other lines or edges or midpoints of other objects 
without regard to their coordinates.

I suspect implementing some of this would represent a fair bit of 
work, since we're talking features typically found in a CAD 
program.  But the level of flexability would be improved marketdly I believe.

Ben

At 08:45 AM 12/22/2011, you wrote:
>Hi all,
>
>I am trying to draw things like tables, chairs etc using SVGDraw01. One
>problem I have is that if I try to draw something like a rhombus, I need to
>get the coordinates myself. My civil engineer dad draws the shape on paper
>and then gets the coordinates. However, in a program, I suspect I will have
>to use a different approach since I cannot draw the shape and then derive
>the coordinates. What approach should this be? Do I need to use equations of
>shapes or is this a simpler problem?
>
>Pranav
>
>
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